fix(lints): remove unstable ones

Reviewed-on: #82
Reviewed-by: Stas <business@jexter.tech>

.woodpecker/server-test.yaml

@@ -24,4 +24,4 @@ steps:
       - mise install rust 
       - mise install protoc
       - mise install cargo:cargo-nextest
-      - mise exec cargo:cargo-nextest -- cargo nextest run --no-fail-fast
+      - mise exec cargo:cargo-nextest -- cargo nextest run --no-fail-fast --all-features

AGENTS.md

@@ -100,6 +100,27 @@ diesel migration generate <name> --migration-dir crates/arbiter-server/migration
 diesel migration run --migration-dir crates/arbiter-server/migrations
 ```
 
+### Code Conventions
+
+**`#[must_use]` Attribute:**
+Apply the `#[must_use]` attribute to return types of functions where the return value is critical and should not be accidentally ignored. This is commonly used for:
+
+- Methods that return `bool` indicating success/failure or validation state
+- Any function where ignoring the return value indicates a logic error
+
+Do not apply `#[must_use]` redundantly to items (types or functions) that are already annotated with `#[must_use]`.
+
+Example:
+
+```rust
+#[must_use]
+pub fn verify(&self, nonce: i32, context: &[u8], signature: &Signature) -> bool {
+    // verification logic
+}
+```
+
+This forces callers to either use the return value or explicitly ignore it with `let _ = ...;`, preventing silent failures.
+
 ## User Agent (Flutter + Rinf at `useragent/`)
 
 The Flutter app uses [Rinf](https://rinf.cunarist.org) to call Rust code. The Rust logic lives in `useragent/native/hub/` as a separate crate that uses `arbiter-useragent` for the gRPC client.

ARCHITECTURE.md

@@ -11,6 +11,7 @@ Arbiter distinguishes two kinds of peers:
 
 - **User Agent** — A client application used by the owner to manage the vault (create wallets, approve SDK clients, configure policies).
 - **SDK Client** — A consumer of signing capabilities, typically an automation tool. In the future, this could include a browser-based wallet.
+- **Recovery Operator** — A dormant recovery participant with narrowly scoped authority used only for custody recovery and operator replacement.
 
 ---
 
@@ -42,7 +43,149 @@ There is no bootstrap mechanism for SDK clients. They must be explicitly approve
 
 ---
 
-## 3. Server Identity
+## 3. Multi-Operator Governance
+
+When more than one User Agent is registered, the vault is treated as having multiple operators. In that mode, sensitive actions are governed by voting rather than by a single operator decision.
+
+### 3.1 Voting Rules
+
+Voting is based on the total number of registered operators:
+
+- **1 operator:** no vote is needed; the single operator decides directly.
+- **2 operators:** full consensus is required; both operators must approve.
+- **3 or more operators:** quorum is `floor(N / 2) + 1`.
+
+For a decision to count, the operator's approval or rejection must be signed by that operator's associated key. Unsigned votes, or votes that fail signature verification, are ignored.
+
+Examples:
+
+- **3 operators:** 2 approvals required
+- **4 operators:** 3 approvals required
+
+### 3.2 Actions Requiring a Vote
+
+In multi-operator mode, a successful vote is required for:
+
+- approving new SDK clients
+- granting an SDK client visibility to a wallet
+- approving a one-off transaction
+- approving creation of a persistent grant
+- approving operator replacement
+- approving server updates
+- updating Shamir secret-sharing parameters
+
+### 3.3 Special Rule for Key Rotation
+
+Key rotation always requires full quorum, regardless of the normal voting threshold.
+
+This is stricter than ordinary governance actions because rotating the root key requires every operator to participate in coordinated share refresh/update steps. The root key itself is not redistributed directly, but each operator's share material must be changed consistently.
+
+### 3.4 Root Key Custody
+
+When the vault has multiple operators, the vault root key is protected using Shamir secret sharing.
+
+The vault root key is encrypted in a way that requires reconstruction from user-held shares rather than from a single shared password.
+
+For ordinary operators, the Shamir threshold matches the ordinary governance quorum. For example:
+
+- **2 operators:** `2-of-2`
+- **3 operators:** `2-of-3`
+- **4 operators:** `3-of-4`
+
+In practice, the Shamir share set also includes Recovery Operator shares. This means the effective Shamir parameters are computed over the combined share pool while keeping the same threshold. For example:
+
+- **3 ordinary operators + 2 recovery shares:** `2-of-5`
+
+This ensures that the normal custody threshold follows the ordinary operator quorum, while still allowing dormant recovery shares to exist for break-glass recovery flows.
+
+### 3.5 Recovery Operators
+
+Recovery Operators are a separate peer type from ordinary vault operators.
+
+Their role is intentionally narrow. They can only:
+
+- participate in unsealing the vault
+- vote for operator replacement
+
+Recovery Operators do not participate in routine governance such as approving SDK clients, granting wallet visibility, approving transactions, creating grants, approving server updates, or changing Shamir parameters.
+
+### 3.6 Sleeping and Waking Recovery Operators
+
+By default, Recovery Operators are **sleeping** and do not participate in any active flow.
+
+Any ordinary operator may request that Recovery Operators **wake up**.
+
+Any ordinary operator may also cancel a pending wake-up request.
+
+This creates a dispute window before recovery powers become active. The default wake-up delay is **14 days**.
+
+Recovery Operators are therefore part of the break-glass recovery path rather than the normal operating quorum.
+
+The high-level recovery flow is:
+
+```mermaid
+sequenceDiagram
+    autonumber
+    actor Op as Ordinary Operator
+    participant Server
+    actor Other as Other Operator
+    actor Rec as Recovery Operator
+
+    Op->>Server: Request recovery wake-up
+    Server-->>Op: Wake-up pending
+    Note over Server: Default dispute window: 14 days
+
+    alt Wake-up cancelled during dispute window
+        Other->>Server: Cancel wake-up
+        Server-->>Op: Recovery cancelled
+        Server-->>Rec: Stay sleeping
+    else No cancellation for 14 days
+        Server-->>Rec: Wake up
+        Rec->>Server: Join recovery flow
+        critical Recovery authority
+            Rec->>Server: Participate in unseal
+            Rec->>Server: Vote on operator replacement
+        end
+        Server-->>Op: Recovery mode active
+    end
+```
+
+### 3.7 Committee Formation
+
+There are two ways to form a multi-operator committee:
+
+- convert an existing single-operator vault by adding new operators
+- bootstrap an unbootstrapped vault directly into multi-operator mode
+
+In both cases, committee formation is a coordinated process. Arbiter does not allow multi-operator custody to emerge implicitly from unrelated registrations.
+
+### 3.8 Bootstrapping an Unbootstrapped Vault into Multi-Operator Mode
+
+When an unbootstrapped vault is initialized as a multi-operator vault, the setup proceeds as follows:
+
+1. An operator connects to the unbootstrapped vault using a User Agent and the bootstrap token.
+2. During bootstrap setup, that operator declares:
+   - the total number of ordinary operators
+   - the total number of Recovery Operators
+3. The vault enters **multi-bootstrap mode**.
+4. While in multi-bootstrap mode:
+   - every ordinary operator must connect with a User Agent using the bootstrap token
+   - every Recovery Operator must also connect using the bootstrap token
+   - each participant is registered individually
+   - each participant's share is created and protected with that participant's credentials
+5. The vault is considered fully bootstrapped only after all declared operator and recovery-share registrations have completed successfully.
+
+This means the operator and recovery set is fixed at bootstrap completion time, based on the counts declared when multi-bootstrap mode was entered.
+
+### 3.9 Special Bootstrap Constraint for Two-Operator Vaults
+
+If a vault is declared with exactly **2 ordinary operators**, Arbiter requires at least **1 Recovery Operator** to be configured during bootstrap.
+
+This prevents the worst-case custody failure in which a `2-of-2` operator set becomes permanently unrecoverable after loss of a single operator.
+
+---
+
+## 4. Server Identity
 
 The server proves its identity using TLS with a self-signed certificate. The TLS private key is generated on first run and is long-term; no rotation mechanism exists yet due to the complexity of multi-peer coordination.
 
@@ -55,9 +198,9 @@ Peers verify the server by its **public key fingerprint**:
 
 ---
 
-## 4. Key Management
+## 5. Key Management
 
-### 4.1 Key Hierarchy
+### 5.1 Key Hierarchy
 
 There are three layers of keys:
 
@@ -72,19 +215,19 @@ This layered design enables:
 - **Password rotation** without re-encrypting every wallet key (only the root key is re-encrypted).
 - **Root key rotation** without requiring the user to change their password.
 
-### 4.2 Encryption at Rest
+### 5.2 Encryption at Rest
 
 The database stores everything in encrypted form using symmetric AEAD. The encryption scheme is versioned to support transparent migration — when the vault unseals, Arbiter automatically re-encrypts any entries that are behind the current scheme version. See [IMPLEMENTATION.md](IMPLEMENTATION.md) for the specific scheme and versioning mechanism.
 
 ---
 
-## 5. Vault Lifecycle
+## 6. Vault Lifecycle
 
-### 5.1 Sealed State
+### 6.1 Sealed State
 
 On boot, the root key is encrypted and the server cannot perform any signing operations. This state is called **Sealed**.
 
-### 5.2 Unseal Flow
+### 6.2 Unseal Flow
 
 To transition to the **Unsealed** state, a User Agent must provide the password:
 
@@ -95,7 +238,7 @@ To transition to the **Unsealed** state, a User Agent must provide the password:
    - **Success:** The root key is decrypted and placed into a hardened memory cell. The server transitions to `Unsealed`. Any entries pending encryption scheme migration are re-encrypted.
    - **Failure:** The server returns an error indicating the password is incorrect.
 
-### 5.3 Memory Protection
+### 6.3 Memory Protection
 
 Once unsealed, the root key must be protected in memory against:
 
@@ -107,9 +250,9 @@ See [IMPLEMENTATION.md](IMPLEMENTATION.md) for the current and planned memory pr
 
 ---
 
-## 6. Permission Engine
+## 7. Permission Engine
 
-### 6.1 Fundamental Rules
+### 7.1 Fundamental Rules
 
 - SDK clients have **no access by default**.
 - Access is granted **explicitly** by a User Agent.
@@ -119,11 +262,45 @@ Each blockchain requires its own policy system due to differences in static tran
 
 Arbiter is also responsible for ensuring that **transaction nonces are never reused**.
 
-### 6.2 EVM Policies
+### 7.2 EVM Policies
 
 Every EVM grant is scoped to a specific **wallet** and **chain ID**.
 
-#### 6.2.1 Transaction Sub-Grants
+#### 7.2.0 Transaction Signing Sequence
+
+The high-level interaction order is:
+
+```mermaid
+sequenceDiagram
+    autonumber
+    actor SDK as SDK Client
+    participant Server
+    participant UA as User Agent
+
+    SDK->>Server: SignTransactionRequest
+    Server->>Server: Resolve wallet and wallet visibility
+    alt Visibility approval required
+        Server->>UA: Ask for wallet visibility approval
+        UA-->>Server: Vote result
+    end
+    Server->>Server: Evaluate transaction
+    Server->>Server: Load grant and limits context
+    alt Grant approval required
+        Server->>UA: Ask for execution / grant approval
+        UA-->>Server: Vote result
+        opt Create persistent grant
+            Server->>Server: Create and store grant
+        end
+        Server->>Server: Retry evaluation
+    end
+    critical Final authorization path
+        Server->>Server: Check limits and record execution
+        Server-->>Server: Signature or evaluation error
+    end
+    Server-->>SDK: Signature or error
+```
+
+#### 7.2.1 Transaction Sub-Grants
 
 Arbiter maintains an ever-expanding database of known contracts and their ABIs. Based on contract knowledge, transaction requests fall into three categories:
 
@@ -147,7 +324,7 @@ Available restrictions:
 
 These transactions have no `calldata` and therefore cannot interact with contracts. They can be subject to the same volume and rate restrictions as above.
 
-#### 6.2.2 Global Limits
+#### 7.2.2 Global Limits
 
 In addition to sub-grant-specific restrictions, the following limits can be applied across all grant types:
 

CLAUDE.md

@@ -100,6 +100,27 @@ diesel migration generate <name> --migration-dir crates/arbiter-server/migration
 diesel migration run --migration-dir crates/arbiter-server/migrations
 ```
 
+### Code Conventions
+
+**`#[must_use]` Attribute:**
+Apply the `#[must_use]` attribute to return types of functions where the return value is critical and should not be accidentally ignored. This is commonly used for:
+
+- Methods that return `bool` indicating success/failure or validation state
+- Any function where ignoring the return value indicates a logic error
+
+Do not apply `#[must_use]` redundantly to items (types or functions) that are already annotated with `#[must_use]`.
+
+Example:
+
+```rust
+#[must_use]
+pub fn verify(&self, nonce: i32, context: &[u8], signature: &Signature) -> bool {
+    // verification logic
+}
+```
+
+This forces callers to either use the return value or explicitly ignore it with `let _ = ...;`, preventing silent failures.
+
 ## User Agent (Flutter + Rinf at `useragent/`)
 
 The Flutter app uses [Rinf](https://rinf.cunarist.org) to call Rust code. The Rust logic lives in `useragent/native/hub/` as a separate crate that uses `arbiter-useragent` for the gRPC client.

IMPLEMENTATION.md

@@ -67,18 +67,14 @@ The `program_client.nonce` column stores the **next usable nonce** — i.e. it i
 ## Cryptography
 
 ### Authentication
-- **Client protocol:** ed25519
+- **Client protocol:** ML-DSA
 
 ### User-Agent Authentication
 
 User-agent authentication supports multiple signature schemes because platform-provided "hardware-bound" keys do not expose a uniform algorithm across operating systems and hardware.
 
-- **Supported schemes:** RSA, Ed25519, ECDSA (secp256k1)
-- **Why:** the user agent authenticates with keys backed by platform facilities, and those facilities differ by platform
-- **Apple Silicon Secure Enclave / Secure Element:** ECDSA-only in practice
-- **Windows Hello / TPM 2.0:** currently RSA-backed in our integration
-
-This is why the user-agent auth protocol carries an explicit `KeyType`, while the SDK client protocol remains fixed to ed25519.
+- **Supported schemes:** ML-DSA
+- **Why:** Secure Enclave (MacOS) support them natively, on other platforms we could emulate while they roll-out
 
 ### Encryption at Rest
 - **Scheme:** Symmetric AEAD — currently **XChaCha20-Poly1305**
@@ -128,6 +124,52 @@ The central abstraction is the `Policy` trait. Each implementation handles one s
 4. **Evaluate** — `Policy::evaluate` checks the decoded meaning against the grant's policy-specific constraints and returns any violations.
 5. **Record** — If `RunKind::Execution` and there are no violations, the engine writes to `evm_transaction_log` and calls `Policy::record_transaction` for any policy-specific logging (e.g., token transfer volume).
 
+The detailed branch structure is shown below:
+
+```mermaid
+flowchart TD
+    A[SDK Client sends sign transaction request] --> B[Server resolves wallet]
+    B --> C{Wallet exists?}
+
+    C -- No --> Z1[Return wallet not found error]
+    C -- Yes --> D[Check SDK client wallet visibility]
+
+    D --> E{Wallet visible to SDK client?}
+    E -- No --> F[Start wallet visibility voting flow]
+    F --> G{Vote approved?}
+    G -- No --> Z2[Return wallet access denied error]
+    G -- Yes --> H[Persist wallet visibility]
+    E -- Yes --> I[Classify transaction meaning]
+    H --> I
+
+    I --> J{Meaning supported?}
+    J -- No --> Z3[Return unsupported transaction error]
+    J -- Yes --> K[Find matching grant]
+
+    K --> L{Grant exists?}
+    L -- Yes --> M[Check grant limits]
+    L -- No --> N[Start execution or grant voting flow]
+
+    N --> O{User-agent decision}
+    O -- Reject --> Z4[Return no matching grant error]
+    O -- Allow once --> M
+    O -- Create grant --> P[Create grant with user-selected limits]
+    P --> Q[Persist grant]
+    Q --> M
+
+    M --> R{Limits exceeded?}
+    R -- Yes --> Z5[Return evaluation error]
+    R -- No --> S[Record transaction in logs]
+    S --> T[Produce signature]
+    T --> U[Return signature to SDK client]
+
+    note1[Limit checks include volume, count, and gas constraints.]
+    note2[Grant lookup depends on classified meaning, such as ether transfer or token transfer.]
+
+    K -. uses .-> note2
+    M -. checks .-> note1
+```
+
 ### Policy Trait
 
 | Method | Purpose |

docs/superpowers/plans/2026-03-28-grant-grid-view.md

@@ -0,0 +1,821 @@
+# Grant Grid View Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Add an "EVM Grants" dashboard tab that displays all grants as enriched cards (type, chain, wallet address, client name) with per-card revoke support.
+
+**Architecture:** A new `walletAccessListProvider` fetches wallet accesses with their DB row IDs. The screen (`grants.dart`) watches only `evmGrantsProvider` for top-level state. Each `GrantCard` widget (its own file) watches enrichment providers (`walletAccessListProvider`, `evmProvider`, `sdkClientsProvider`) and the revoke mutation directly — keeping rebuilds scoped to the card. The screen is registered as a dashboard tab in `AdaptiveScaffold`.
+
+**Tech Stack:** Flutter, Riverpod (`riverpod_annotation` + `build_runner` codegen), `sizer` (adaptive sizing), `auto_route`, Protocol Buffers (Dart), `Palette` design tokens.
+
+---
+
+## File Map
+
+| File | Action | Responsibility |
+|---|---|---|
+| `useragent/lib/theme/palette.dart` | Modify | Add `Palette.token` (indigo accent for token-transfer cards) |
+| `useragent/lib/features/connection/evm/wallet_access.dart` | Modify | Add `listAllWalletAccesses()` function |
+| `useragent/lib/providers/sdk_clients/wallet_access_list.dart` | Create | `WalletAccessListProvider` — fetches full wallet access list with IDs |
+| `useragent/lib/screens/dashboard/evm/grants/widgets/grant_card.dart` | Create | `GrantCard` widget — watches enrichment providers + revoke mutation; one card per grant |
+| `useragent/lib/screens/dashboard/evm/grants/grants.dart` | Create | `EvmGrantsScreen` — watches `evmGrantsProvider`; handles loading/error/empty/data states; renders `GrantCard` list |
+| `useragent/lib/router.dart` | Modify | Register `EvmGrantsRoute` in dashboard children |
+| `useragent/lib/screens/dashboard.dart` | Modify | Add Grants entry to `routes` list and `NavigationDestination` list |
+
+---
+
+## Task 1: Add `Palette.token`
+
+**Files:**
+- Modify: `useragent/lib/theme/palette.dart`
+
+- [ ] **Step 1: Add the color**
+
+Replace the contents of `useragent/lib/theme/palette.dart` with:
+
+```dart
+import 'package:flutter/material.dart';
+
+class Palette {
+  static const ink = Color(0xFF15263C);
+  static const coral = Color(0xFFE26254);
+  static const cream = Color(0xFFFFFAF4);
+  static const line = Color(0x1A15263C);
+  static const token = Color(0xFF5C6BC0);
+}
+```
+
+- [ ] **Step 2: Verify**
+
+```sh
+cd useragent && flutter analyze lib/theme/palette.dart
+```
+
+Expected: no issues.
+
+- [ ] **Step 3: Commit**
+
+```sh
+jj describe -m "feat(theme): add Palette.token for token-transfer grant cards"
+jj new
+```
+
+---
+
+## Task 2: Add `listAllWalletAccesses` feature function
+
+**Files:**
+- Modify: `useragent/lib/features/connection/evm/wallet_access.dart`
+
+`readClientWalletAccess` (existing) filters the list to one client's wallet IDs and returns `Set<int>`. This new function returns the complete unfiltered list with row IDs so the grant cards can resolve wallet_access_id → wallet + client.
+
+- [ ] **Step 1: Append function**
+
+Add at the bottom of `useragent/lib/features/connection/evm/wallet_access.dart`:
+
+```dart
+Future<List<SdkClientWalletAccess>> listAllWalletAccesses(
+  Connection connection,
+) async {
+  final response = await connection.ask(
+    UserAgentRequest(listWalletAccess: Empty()),
+  );
+  if (!response.hasListWalletAccessResponse()) {
+    throw Exception(
+      'Expected list wallet access response, got ${response.whichPayload()}',
+    );
+  }
+  return response.listWalletAccessResponse.accesses.toList(growable: false);
+}
+```
+
+Each returned `SdkClientWalletAccess` has:
+- `.id` — the `evm_wallet_access` row ID (same value as `wallet_access_id` in a `GrantEntry`)
+- `.access.walletId` — the EVM wallet DB ID
+- `.access.sdkClientId` — the SDK client DB ID
+
+- [ ] **Step 2: Verify**
+
+```sh
+cd useragent && flutter analyze lib/features/connection/evm/wallet_access.dart
+```
+
+Expected: no issues.
+
+- [ ] **Step 3: Commit**
+
+```sh
+jj describe -m "feat(evm): add listAllWalletAccesses feature function"
+jj new
+```
+
+---
+
+## Task 3: Create `WalletAccessListProvider`
+
+**Files:**
+- Create: `useragent/lib/providers/sdk_clients/wallet_access_list.dart`
+- Generated: `useragent/lib/providers/sdk_clients/wallet_access_list.g.dart`
+
+Mirrors the structure of `EvmGrants` in `providers/evm/evm_grants.dart` — class-based `@riverpod` with a `refresh()` method.
+
+- [ ] **Step 1: Write the provider**
+
+Create `useragent/lib/providers/sdk_clients/wallet_access_list.dart`:
+
+```dart
+import 'package:arbiter/features/connection/evm/wallet_access.dart';
+import 'package:arbiter/proto/user_agent.pb.dart';
+import 'package:arbiter/providers/connection/connection_manager.dart';
+import 'package:mtcore/markettakers.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+part 'wallet_access_list.g.dart';
+
+@riverpod
+class WalletAccessList extends _$WalletAccessList {
+  @override
+  Future<List<SdkClientWalletAccess>?> build() async {
+    final connection = await ref.watch(connectionManagerProvider.future);
+    if (connection == null) {
+      return null;
+    }
+
+    try {
+      return await listAllWalletAccesses(connection);
+    } catch (e, st) {
+      talker.handle(e, st);
+      rethrow;
+    }
+  }
+
+  Future<void> refresh() async {
+    final connection = await ref.read(connectionManagerProvider.future);
+    if (connection == null) {
+      state = const AsyncData(null);
+      return;
+    }
+
+    state = const AsyncLoading();
+    state = await AsyncValue.guard(() => listAllWalletAccesses(connection));
+  }
+}
+```
+
+- [ ] **Step 2: Run code generation**
+
+```sh
+cd useragent && dart run build_runner build --delete-conflicting-outputs
+```
+
+Expected: `useragent/lib/providers/sdk_clients/wallet_access_list.g.dart` created. No errors.
+
+- [ ] **Step 3: Verify**
+
+```sh
+cd useragent && flutter analyze lib/providers/sdk_clients/
+```
+
+Expected: no issues.
+
+- [ ] **Step 4: Commit**
+
+```sh
+jj describe -m "feat(providers): add WalletAccessListProvider"
+jj new
+```
+
+---
+
+## Task 4: Create `GrantCard` widget
+
+**Files:**
+- Create: `useragent/lib/screens/dashboard/evm/grants/widgets/grant_card.dart`
+
+This widget owns all per-card logic: enrichment lookups, revoke action, and rebuild scope. The screen only passes it a `GrantEntry` — the card fetches everything else itself.
+
+**Key types:**
+- `GrantEntry` (from `proto/evm.pb.dart`): `.id`, `.shared.walletAccessId`, `.shared.chainId`, `.specific.whichGrant()`
+- `SpecificGrant_Grant.etherTransfer` / `.tokenTransfer` — enum values for the oneof
+- `SdkClientWalletAccess` (from `proto/user_agent.pb.dart`): `.id`, `.access.walletId`, `.access.sdkClientId`
+- `WalletEntry` (from `proto/evm.pb.dart`): `.id`, `.address` (List<int>)
+- `SdkClientEntry` (from `proto/user_agent.pb.dart`): `.id`, `.info.name`
+- `revokeEvmGrantMutation` — `Mutation<void>` (global; all revoke buttons disable together while any revoke is in flight)
+- `executeRevokeEvmGrant(ref, grantId: int)` — `Future<void>`
+
+- [ ] **Step 1: Write the widget**
+
+Create `useragent/lib/screens/dashboard/evm/grants/widgets/grant_card.dart`:
+
+```dart
+import 'package:arbiter/proto/evm.pb.dart';
+import 'package:arbiter/proto/user_agent.pb.dart';
+import 'package:arbiter/providers/evm/evm.dart';
+import 'package:arbiter/providers/evm/evm_grants.dart';
+import 'package:arbiter/providers/sdk_clients/list.dart';
+import 'package:arbiter/providers/sdk_clients/wallet_access_list.dart';
+import 'package:arbiter/theme/palette.dart';
+import 'package:flutter/material.dart';
+import 'package:hooks_riverpod/experimental/mutation.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:sizer/sizer.dart';
+
+String _shortAddress(List<int> bytes) {
+  final hex = bytes.map((b) => b.toRadixString(16).padLeft(2, '0')).join();
+  return '0x${hex.substring(0, 6)}...${hex.substring(hex.length - 4)}';
+}
+
+String _formatError(Object error) {
+  final message = error.toString();
+  if (message.startsWith('Exception: ')) {
+    return message.substring('Exception: '.length);
+  }
+  return message;
+}
+
+class GrantCard extends ConsumerWidget {
+  const GrantCard({super.key, required this.grant});
+
+  final GrantEntry grant;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    // Enrichment lookups — each watch scopes rebuilds to this card only
+    final walletAccesses =
+        ref.watch(walletAccessListProvider).asData?.value ?? const [];
+    final wallets = ref.watch(evmProvider).asData?.value ?? const [];
+    final clients = ref.watch(sdkClientsProvider).asData?.value ?? const [];
+    final revoking = ref.watch(revokeEvmGrantMutation) is MutationPending;
+
+    final isEther =
+        grant.specific.whichGrant() == SpecificGrant_Grant.etherTransfer;
+    final accent = isEther ? Palette.coral : Palette.token;
+    final typeLabel = isEther ? 'Ether' : 'Token';
+    final theme = Theme.of(context);
+    final muted = Palette.ink.withValues(alpha: 0.62);
+
+    // Resolve wallet_access_id → wallet address + client name
+    final accessById = <int, SdkClientWalletAccess>{
+      for (final a in walletAccesses) a.id: a,
+    };
+    final walletById = <int, WalletEntry>{
+      for (final w in wallets) w.id: w,
+    };
+    final clientNameById = <int, String>{
+      for (final c in clients) c.id: c.info.name,
+    };
+
+    final accessId = grant.shared.walletAccessId;
+    final access = accessById[accessId];
+    final wallet = access != null ? walletById[access.access.walletId] : null;
+
+    final walletLabel = wallet != null
+        ? _shortAddress(wallet.address)
+        : 'Access #$accessId';
+
+    final clientLabel = () {
+      if (access == null) return '';
+      final name = clientNameById[access.access.sdkClientId] ?? '';
+      return name.isEmpty ? 'Client #${access.access.sdkClientId}' : name;
+    }();
+
+    void showError(String message) {
+      if (!context.mounted) return;
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(content: Text(message), behavior: SnackBarBehavior.floating),
+      );
+    }
+
+    Future<void> revoke() async {
+      try {
+        await executeRevokeEvmGrant(ref, grantId: grant.id);
+      } catch (e) {
+        showError(_formatError(e));
+      }
+    }
+
+    return Container(
+      decoration: BoxDecoration(
+        borderRadius: BorderRadius.circular(24),
+        color: Palette.cream.withValues(alpha: 0.92),
+        border: Border.all(color: Palette.line),
+      ),
+      child: IntrinsicHeight(
+        child: Row(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            // Accent strip
+            Container(
+              width: 0.8.w,
+              decoration: BoxDecoration(
+                color: accent,
+                borderRadius: const BorderRadius.horizontal(
+                  left: Radius.circular(24),
+                ),
+              ),
+            ),
+            // Card body
+            Expanded(
+              child: Padding(
+                padding: EdgeInsets.symmetric(
+                  horizontal: 1.6.w,
+                  vertical: 1.4.h,
+                ),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    // Row 1: type badge · chain · spacer · revoke button
+                    Row(
+                      children: [
+                        Container(
+                          padding: EdgeInsets.symmetric(
+                            horizontal: 1.w,
+                            vertical: 0.4.h,
+                          ),
+                          decoration: BoxDecoration(
+                            color: accent.withValues(alpha: 0.15),
+                            borderRadius: BorderRadius.circular(8),
+                          ),
+                          child: Text(
+                            typeLabel,
+                            style: theme.textTheme.labelSmall?.copyWith(
+                              color: accent,
+                              fontWeight: FontWeight.w800,
+                            ),
+                          ),
+                        ),
+                        SizedBox(width: 1.w),
+                        Container(
+                          padding: EdgeInsets.symmetric(
+                            horizontal: 1.w,
+                            vertical: 0.4.h,
+                          ),
+                          decoration: BoxDecoration(
+                            color: Palette.ink.withValues(alpha: 0.06),
+                            borderRadius: BorderRadius.circular(8),
+                          ),
+                          child: Text(
+                            'Chain ${grant.shared.chainId}',
+                            style: theme.textTheme.labelSmall?.copyWith(
+                              color: muted,
+                              fontWeight: FontWeight.w700,
+                            ),
+                          ),
+                        ),
+                        const Spacer(),
+                        if (revoking)
+                          SizedBox(
+                            width: 1.8.h,
+                            height: 1.8.h,
+                            child: CircularProgressIndicator(
+                              strokeWidth: 2,
+                              color: Palette.coral,
+                            ),
+                          )
+                        else
+                          OutlinedButton.icon(
+                            onPressed: revoke,
+                            style: OutlinedButton.styleFrom(
+                              foregroundColor: Palette.coral,
+                              side: BorderSide(
+                                color: Palette.coral.withValues(alpha: 0.4),
+                              ),
+                              padding: EdgeInsets.symmetric(
+                                horizontal: 1.w,
+                                vertical: 0.6.h,
+                              ),
+                              shape: RoundedRectangleBorder(
+                                borderRadius: BorderRadius.circular(10),
+                              ),
+                            ),
+                            icon: const Icon(Icons.block_rounded, size: 16),
+                            label: const Text('Revoke'),
+                          ),
+                      ],
+                    ),
+                    SizedBox(height: 0.8.h),
+                    // Row 2: wallet address · client name
+                    Row(
+                      children: [
+                        Text(
+                          walletLabel,
+                          style: theme.textTheme.bodySmall?.copyWith(
+                            color: Palette.ink,
+                            fontFamily: 'monospace',
+                          ),
+                        ),
+                        Padding(
+                          padding: EdgeInsets.symmetric(horizontal: 0.8.w),
+                          child: Text(
+                            '·',
+                            style: theme.textTheme.bodySmall
+                                ?.copyWith(color: muted),
+                          ),
+                        ),
+                        Expanded(
+                          child: Text(
+                            clientLabel,
+                            maxLines: 1,
+                            overflow: TextOverflow.ellipsis,
+                            style: theme.textTheme.bodySmall
+                                ?.copyWith(color: muted),
+                          ),
+                        ),
+                      ],
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+```
+
+- [ ] **Step 2: Verify**
+
+```sh
+cd useragent && flutter analyze lib/screens/dashboard/evm/grants/widgets/grant_card.dart
+```
+
+Expected: no issues.
+
+- [ ] **Step 3: Commit**
+
+```sh
+jj describe -m "feat(grants): add GrantCard widget with self-contained enrichment"
+jj new
+```
+
+---
+
+## Task 5: Create `EvmGrantsScreen`
+
+**Files:**
+- Create: `useragent/lib/screens/dashboard/evm/grants/grants.dart`
+
+The screen watches only `evmGrantsProvider` for top-level state (loading / error / no connection / empty / data). When there is data it renders a list of `GrantCard` widgets — each card manages its own enrichment subscriptions.
+
+- [ ] **Step 1: Write the screen**
+
+Create `useragent/lib/screens/dashboard/evm/grants/grants.dart`:
+
+```dart
+import 'package:arbiter/proto/evm.pb.dart';
+import 'package:arbiter/providers/evm/evm_grants.dart';
+import 'package:arbiter/providers/sdk_clients/wallet_access_list.dart';
+import 'package:arbiter/router.gr.dart';
+import 'package:arbiter/screens/dashboard/evm/grants/widgets/grant_card.dart';
+import 'package:arbiter/theme/palette.dart';
+import 'package:arbiter/widgets/page_header.dart';
+import 'package:auto_route/auto_route.dart';
+import 'package:flutter/material.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:sizer/sizer.dart';
+
+String _formatError(Object error) {
+  final message = error.toString();
+  if (message.startsWith('Exception: ')) {
+    return message.substring('Exception: '.length);
+  }
+  return message;
+}
+
+// ─── State panel ──────────────────────────────────────────────────────────────
+
+class _StatePanel extends StatelessWidget {
+  const _StatePanel({
+    required this.icon,
+    required this.title,
+    required this.body,
+    this.actionLabel,
+    this.onAction,
+    this.busy = false,
+  });
+
+  final IconData icon;
+  final String title;
+  final String body;
+  final String? actionLabel;
+  final Future<void> Function()? onAction;
+  final bool busy;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Container(
+      decoration: BoxDecoration(
+        borderRadius: BorderRadius.circular(24),
+        color: Palette.cream.withValues(alpha: 0.92),
+        border: Border.all(color: Palette.line),
+      ),
+      child: Padding(
+        padding: EdgeInsets.all(2.8.h),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            if (busy)
+              SizedBox(
+                width: 2.8.h,
+                height: 2.8.h,
+                child: const CircularProgressIndicator(strokeWidth: 2.5),
+              )
+            else
+              Icon(icon, size: 34, color: Palette.coral),
+            SizedBox(height: 1.8.h),
+            Text(
+              title,
+              style: theme.textTheme.headlineSmall?.copyWith(
+                color: Palette.ink,
+                fontWeight: FontWeight.w800,
+              ),
+            ),
+            SizedBox(height: 1.h),
+            Text(
+              body,
+              style: theme.textTheme.bodyLarge?.copyWith(
+                color: Palette.ink.withValues(alpha: 0.72),
+                height: 1.5,
+              ),
+            ),
+            if (actionLabel != null && onAction != null) ...[
+              SizedBox(height: 2.h),
+              OutlinedButton.icon(
+                onPressed: () => onAction!(),
+                icon: const Icon(Icons.refresh),
+                label: Text(actionLabel!),
+              ),
+            ],
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+// ─── Grant list ───────────────────────────────────────────────────────────────
+
+class _GrantList extends StatelessWidget {
+  const _GrantList({required this.grants});
+
+  final List<GrantEntry> grants;
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      children: [
+        for (var i = 0; i < grants.length; i++)
+          Padding(
+            padding: EdgeInsets.only(
+              bottom: i == grants.length - 1 ? 0 : 1.8.h,
+            ),
+            child: GrantCard(grant: grants[i]),
+          ),
+      ],
+    );
+  }
+}
+
+// ─── Screen ───────────────────────────────────────────────────────────────────
+
+@RoutePage()
+class EvmGrantsScreen extends ConsumerWidget {
+  const EvmGrantsScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    // Screen watches only the grant list for top-level state decisions
+    final grantsAsync = ref.watch(evmGrantsProvider);
+
+    Future<void> refresh() async {
+      await Future.wait([
+        ref.read(evmGrantsProvider.notifier).refresh(),
+        ref.read(walletAccessListProvider.notifier).refresh(),
+      ]);
+    }
+
+    void showMessage(String message) {
+      if (!context.mounted) return;
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(content: Text(message), behavior: SnackBarBehavior.floating),
+      );
+    }
+
+    Future<void> safeRefresh() async {
+      try {
+        await refresh();
+      } catch (e) {
+        showMessage(_formatError(e));
+      }
+    }
+
+    final grantsState = grantsAsync.asData?.value;
+    final grants = grantsState?.grants;
+
+    final content = switch (grantsAsync) {
+      AsyncLoading() when grantsState == null => const _StatePanel(
+        icon: Icons.hourglass_top,
+        title: 'Loading grants',
+        body: 'Pulling grant registry from Arbiter.',
+        busy: true,
+      ),
+      AsyncError(:final error) => _StatePanel(
+        icon: Icons.sync_problem,
+        title: 'Grant registry unavailable',
+        body: _formatError(error),
+        actionLabel: 'Retry',
+        onAction: safeRefresh,
+      ),
+      AsyncData(:final value) when value == null => _StatePanel(
+        icon: Icons.portable_wifi_off,
+        title: 'No active server connection',
+        body: 'Reconnect to Arbiter to list EVM grants.',
+        actionLabel: 'Refresh',
+        onAction: safeRefresh,
+      ),
+      _ when grants != null && grants.isEmpty => _StatePanel(
+        icon: Icons.policy_outlined,
+        title: 'No grants yet',
+        body: 'Create a grant to allow SDK clients to sign transactions.',
+        actionLabel: 'Create grant',
+        onAction: () => context.router.push(const CreateEvmGrantRoute()),
+      ),
+      _ => _GrantList(grants: grants ?? const []),
+    };
+
+    return Scaffold(
+      body: SafeArea(
+        child: RefreshIndicator.adaptive(
+          color: Palette.ink,
+          backgroundColor: Colors.white,
+          onRefresh: safeRefresh,
+          child: ListView(
+            physics: const BouncingScrollPhysics(
+              parent: AlwaysScrollableScrollPhysics(),
+            ),
+            padding: EdgeInsets.fromLTRB(2.4.w, 2.4.h, 2.4.w, 3.2.h),
+            children: [
+              PageHeader(
+                title: 'EVM Grants',
+                isBusy: grantsAsync.isLoading,
+                actions: [
+                  FilledButton.icon(
+                    onPressed: () =>
+                        context.router.push(const CreateEvmGrantRoute()),
+                    icon: const Icon(Icons.add_rounded),
+                    label: const Text('Create grant'),
+                  ),
+                  SizedBox(width: 1.w),
+                  OutlinedButton.icon(
+                    onPressed: safeRefresh,
+                    style: OutlinedButton.styleFrom(
+                      foregroundColor: Palette.ink,
+                      side: BorderSide(color: Palette.line),
+                      padding: EdgeInsets.symmetric(
+                        horizontal: 1.4.w,
+                        vertical: 1.2.h,
+                      ),
+                      shape: RoundedRectangleBorder(
+                        borderRadius: BorderRadius.circular(14),
+                      ),
+                    ),
+                    icon: const Icon(Icons.refresh, size: 18),
+                    label: const Text('Refresh'),
+                  ),
+                ],
+              ),
+              SizedBox(height: 1.8.h),
+              content,
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
+```
+
+- [ ] **Step 2: Verify**
+
+```sh
+cd useragent && flutter analyze lib/screens/dashboard/evm/grants/
+```
+
+Expected: no issues.
+
+- [ ] **Step 3: Commit**
+
+```sh
+jj describe -m "feat(grants): add EvmGrantsScreen"
+jj new
+```
+
+---
+
+## Task 6: Wire router and dashboard tab
+
+**Files:**
+- Modify: `useragent/lib/router.dart`
+- Modify: `useragent/lib/screens/dashboard.dart`
+- Regenerated: `useragent/lib/router.gr.dart`
+
+- [ ] **Step 1: Add route to `router.dart`**
+
+Replace the contents of `useragent/lib/router.dart` with:
+
+```dart
+import 'package:auto_route/auto_route.dart';
+
+import 'router.gr.dart';
+
+@AutoRouterConfig(generateForDir: ['lib/screens'])
+class Router extends RootStackRouter {
+  @override
+  List<AutoRoute> get routes => [
+    AutoRoute(page: Bootstrap.page, path: '/bootstrap', initial: true),
+    AutoRoute(page: ServerInfoSetupRoute.page, path: '/server-info'),
+    AutoRoute(page: ServerConnectionRoute.page, path: '/server-connection'),
+    AutoRoute(page: VaultSetupRoute.page, path: '/vault'),
+    AutoRoute(page: ClientDetailsRoute.page, path: '/clients/:clientId'),
+    AutoRoute(page: CreateEvmGrantRoute.page, path: '/evm-grants/create'),
+
+    AutoRoute(
+      page: DashboardRouter.page,
+      path: '/dashboard',
+      children: [
+        AutoRoute(page: EvmRoute.page, path: 'evm'),
+        AutoRoute(page: ClientsRoute.page, path: 'clients'),
+        AutoRoute(page: EvmGrantsRoute.page, path: 'grants'),
+        AutoRoute(page: AboutRoute.page, path: 'about'),
+      ],
+    ),
+  ];
+}
+```
+
+- [ ] **Step 2: Update `dashboard.dart`**
+
+In `useragent/lib/screens/dashboard.dart`, replace the `routes` constant:
+
+```dart
+final routes = [
+  const EvmRoute(),
+  const ClientsRoute(),
+  const EvmGrantsRoute(),
+  const AboutRoute(),
+];
+```
+
+And replace the `destinations` list inside `AdaptiveScaffold`:
+
+```dart
+destinations: const [
+  NavigationDestination(
+    icon: Icon(Icons.account_balance_wallet_outlined),
+    selectedIcon: Icon(Icons.account_balance_wallet),
+    label: 'Wallets',
+  ),
+  NavigationDestination(
+    icon: Icon(Icons.devices_other_outlined),
+    selectedIcon: Icon(Icons.devices_other),
+    label: 'Clients',
+  ),
+  NavigationDestination(
+    icon: Icon(Icons.policy_outlined),
+    selectedIcon: Icon(Icons.policy),
+    label: 'Grants',
+  ),
+  NavigationDestination(
+    icon: Icon(Icons.info_outline),
+    selectedIcon: Icon(Icons.info),
+    label: 'About',
+  ),
+],
+```
+
+- [ ] **Step 3: Regenerate router**
+
+```sh
+cd useragent && dart run build_runner build --delete-conflicting-outputs
+```
+
+Expected: `lib/router.gr.dart` updated, `EvmGrantsRoute` now available, no errors.
+
+- [ ] **Step 4: Full project verify**
+
+```sh
+cd useragent && flutter analyze
+```
+
+Expected: no issues.
+
+- [ ] **Step 5: Commit**
+
+```sh
+jj describe -m "feat(nav): add Grants dashboard tab"
+jj new
+```

docs/superpowers/specs/2026-03-28-grant-grid-view-design.md

@@ -0,0 +1,170 @@
+# Grant Grid View — Design Spec
+
+**Date:** 2026-03-28
+
+## Overview
+
+Add a "Grants" dashboard tab to the Flutter user-agent app that displays all EVM grants as a card-based grid. Each card shows a compact summary (type, chain, wallet address, client name) with a revoke action. The tab integrates into the existing `AdaptiveScaffold` navigation alongside Wallets, Clients, and About.
+
+## Scope
+
+- New `walletAccessListProvider` for fetching wallet access entries with their DB row IDs
+- New `EvmGrantsScreen` as a dashboard tab
+- Grant card widget with enriched display (type, chain, wallet, client)
+- Revoke action wired to existing `executeRevokeEvmGrant` mutation
+- Dashboard tab bar and router updated
+- New token-transfer accent color added to `Palette`
+
+**Out of scope:** Fixing grant creation (separate task).
+
+---
+
+## Data Layer
+
+### `walletAccessListProvider`
+
+**File:** `useragent/lib/providers/sdk_clients/wallet_access_list.dart`
+
+- `@riverpod` class, watches `connectionManagerProvider.future`
+- Returns `List<SdkClientWalletAccess>?` (null when not connected)
+- Each entry: `.id` (wallet_access_id), `.access.walletId`, `.access.sdkClientId`
+- Exposes a `refresh()` method following the same pattern as `EvmGrants.refresh()`
+
+### Enrichment at render time (Approach A)
+
+The `EvmGrantsScreen` watches four providers:
+1. `evmGrantsProvider` — the grant list
+2. `walletAccessListProvider` — to resolve wallet_access_id → (wallet_id, sdk_client_id)
+3. `evmProvider` — to resolve wallet_id → wallet address
+4. `sdkClientsProvider` — to resolve sdk_client_id → client name
+
+All lookups are in-memory Maps built inside the build method; no extra model class needed.
+
+Fallbacks:
+- Wallet address not found → `"Access #N"` where N is the wallet_access_id
+- Client name not found → `"Client #N"` where N is the sdk_client_id
+
+---
+
+## Route Structure
+
+```
+/dashboard
+  /evm          ← existing (Wallets tab)
+  /clients      ← existing (Clients tab)
+  /grants       ← NEW (Grants tab)
+  /about        ← existing
+
+/evm-grants/create  ← existing push route (unchanged)
+```
+
+### Changes to `router.dart`
+
+Add inside dashboard children:
+```dart
+AutoRoute(page: EvmGrantsRoute.page, path: 'grants'),
+```
+
+### Changes to `dashboard.dart`
+
+Add to `routes` list:
+```dart
+const EvmGrantsRoute()
+```
+
+Add `NavigationDestination`:
+```dart
+NavigationDestination(
+  icon: Icon(Icons.policy_outlined),
+  selectedIcon: Icon(Icons.policy),
+  label: 'Grants',
+),
+```
+
+---
+
+## Screen: `EvmGrantsScreen`
+
+**File:** `useragent/lib/screens/dashboard/evm/grants/grants.dart`
+
+```
+Scaffold
+└─ SafeArea
+   └─ RefreshIndicator.adaptive (refreshes evmGrantsProvider + walletAccessListProvider)
+      └─ ListView (BouncingScrollPhysics + AlwaysScrollableScrollPhysics)
+         ├─ PageHeader
+         │    title: 'EVM Grants'
+         │    isBusy: evmGrantsProvider.isLoading
+         │    actions: [CreateGrantButton, RefreshButton]
+         ├─ SizedBox(height: 1.8.h)
+         └─ <content>
+```
+
+### State handling
+
+Matches the pattern from `EvmScreen` and `ClientsScreen`:
+
+| State | Display |
+|---|---|
+| Loading (no data yet) | `_StatePanel` with spinner, "Loading grants" |
+| Error | `_StatePanel` with coral icon, error message, Retry button |
+| No connection | `_StatePanel`, "No active server connection" |
+| Empty list | `_StatePanel`, "No grants yet", with Create Grant shortcut |
+| Data | Column of `_GrantCard` widgets |
+
+### Header actions
+
+**CreateGrantButton:** `FilledButton.icon` with `Icons.add_rounded`, pushes `CreateEvmGrantRoute()` via `context.router.push(...)`.
+
+**RefreshButton:** `OutlinedButton.icon` with `Icons.refresh`, calls `ref.read(evmGrantsProvider.notifier).refresh()`.
+
+---
+
+## Grant Card: `_GrantCard`
+
+**Layout:**
+
+```
+Container (rounded 24, Palette.cream bg, Palette.line border)
+└─ IntrinsicHeight > Row
+   ├─ Accent strip (0.8.w wide, full height, rounded left)
+   └─ Padding > Column
+        ├─ Row 1: TypeBadge + ChainChip + Spacer + RevokeButton
+        └─ Row 2: WalletText + "·" + ClientText
+```
+
+**Accent color by grant type:**
+- Ether transfer → `Palette.coral`
+- Token transfer → `Palette.token` (new entry in `Palette` — indigo, e.g. `Color(0xFF5C6BC0)`)
+
+**TypeBadge:** Small pill container with accent color background at 15% opacity, accent-colored text. Label: `'Ether'` or `'Token'`.
+
+**ChainChip:** Small container: `'Chain ${grant.shared.chainId}'`, muted ink color.
+
+**WalletText:** Short hex address (`0xabc...def`) from wallet lookup, `bodySmall`, monospace font family.
+
+**ClientText:** Client name from `sdkClientsProvider` lookup, or fallback string. `bodySmall`, muted ink.
+
+**RevokeButton:**
+- `OutlinedButton` with `Icons.block_rounded` icon, label `'Revoke'`
+- `foregroundColor: Palette.coral`, `side: BorderSide(color: Palette.coral.withValues(alpha: 0.4))`
+- Disabled (replaced with `CircularProgressIndicator`) while `revokeEvmGrantMutation` is pending — note: this is a single global mutation, so all revoke buttons disable while any revoke is in flight
+- On press: calls `executeRevokeEvmGrant(ref, grantId: grant.id)`; shows `SnackBar` on error
+
+---
+
+## Adaptive Sizing
+
+All sizing uses `sizer` units (`1.h`, `1.w`, etc.). No hardcoded pixel values.
+
+---
+
+## Files to Create / Modify
+
+| File | Action |
+|---|---|
+| `lib/theme/palette.dart` | Modify — add `Palette.token` color |
+| `lib/providers/sdk_clients/wallet_access_list.dart` | Create |
+| `lib/screens/dashboard/evm/grants/grants.dart` | Create |
+| `lib/router.dart` | Modify — add grants route to dashboard children |
+| `lib/screens/dashboard.dart` | Modify — add tab to routes list and NavigationDestinations |

mise.lock

@@ -48,6 +48,10 @@ backend = "cargo:cargo-features-manager"
 version = "1.46.3"
 backend = "cargo:cargo-insta"
 
+[[tools."cargo:cargo-mutants"]]
+version = "27.0.0"
+backend = "cargo:cargo-mutants"
+
 [[tools."cargo:cargo-nextest"]]
 version = "0.9.126"
 backend = "cargo:cargo-nextest"
@@ -111,30 +115,37 @@ backend = "core:python"
 [tools.python."platforms.linux-arm64"]
 checksum = "sha256:53700338695e402a1a1fe22be4a41fbdacc70e22bb308a48eca8ed67cb7992be"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-aarch64-unknown-linux-gnu-install_only_stripped.tar.gz"
+provenance = "github-attestations"
 
 [tools.python."platforms.linux-arm64-musl"]
 checksum = "sha256:53700338695e402a1a1fe22be4a41fbdacc70e22bb308a48eca8ed67cb7992be"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-aarch64-unknown-linux-gnu-install_only_stripped.tar.gz"
+provenance = "github-attestations"
 
 [tools.python."platforms.linux-x64"]
 checksum = "sha256:d7a9f970914bb4c88756fe3bdcc186d4feb90e9500e54f1db47dae4dc9687e39"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz"
+provenance = "github-attestations"
 
 [tools.python."platforms.linux-x64-musl"]
 checksum = "sha256:d7a9f970914bb4c88756fe3bdcc186d4feb90e9500e54f1db47dae4dc9687e39"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz"
+provenance = "github-attestations"
 
 [tools.python."platforms.macos-arm64"]
 checksum = "sha256:c43aecde4a663aebff99b9b83da0efec506479f1c3f98331442f33d2c43501f9"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-aarch64-apple-darwin-install_only_stripped.tar.gz"
+provenance = "github-attestations"
 
 [tools.python."platforms.macos-x64"]
 checksum = "sha256:9ab41dbc2f100a2a45d1833b9c11165f51051c558b5213eda9a9731d5948a0c0"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-x86_64-apple-darwin-install_only_stripped.tar.gz"
+provenance = "github-attestations"
 
 [tools.python."platforms.windows-x64"]
 checksum = "sha256:bbe19034b35b0267176a7442575ae7dc6343480fd4d35598cb7700173d431e09"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-x86_64-pc-windows-msvc-install_only_stripped.tar.gz"
+provenance = "github-attestations"
 
 [[tools.rust]]
 version = "1.93.0"

mise.toml

@@ -12,6 +12,7 @@ protoc = "29.6"
 python = "3.14.3"
 ast-grep = "0.42.0"
 "cargo:cargo-edit" = "0.13.9"
+"cargo:cargo-mutants" = "27.0.0"
 
 [tasks.codegen]
 sources = ['protobufs/*.proto', 'protobufs/**/*.proto']

protobufs/shared/evm.proto

@@ -36,6 +36,10 @@ message GasLimitExceededViolation {
 }
 
 message EvalViolation {
+  message ChainIdMismatch {
+    uint64 expected = 1;
+    uint64 actual = 2;
+  }
   oneof kind {
     bytes invalid_target = 1; // 20-byte Ethereum address
     GasLimitExceededViolation gas_limit_exceeded = 2;
@@ -43,6 +47,8 @@ message EvalViolation {
     google.protobuf.Empty volumetric_limit_exceeded = 4;
     google.protobuf.Empty invalid_time = 5;
     google.protobuf.Empty invalid_transaction_type = 6;
+
+    ChainIdMismatch chain_id_mismatch = 7;
   }
 }
 

server/.cargo/mutants.toml

@@ -0,0 +1 @@
+test_tool = "nextest"

server/.gitignore

@@ -0,0 +1,2 @@
+mutants.out/
+mutants.out.old/

server/Cargo.toml

@@ -4,42 +4,169 @@ members = [
 ]
 resolver = "3"
 
-[workspace.lints.clippy]
-disallowed-methods = "deny"
-
 
 [workspace.dependencies]
-tonic = { version = "0.14.5", features = [
-    "deflate",
-    "gzip",
-    "tls-connect-info",
-    "zstd",
-] }
-tracing = "0.1.44"
-tokio = { version = "1.50.0", features = ["full"] }
-ed25519-dalek = { version = "3.0.0-pre.6", features = ["rand_core"] }
-chrono = { version = "0.4.44", features = ["serde"] }
-rand = "0.10.0"
-rustls = { version = "0.23.37", features = ["aws-lc-rs"] }
-smlang = "0.8.0"
-miette = { version = "7.6.0", features = ["fancy", "serde"] }
-thiserror = "2.0.18"
-async-trait = "0.1.89"
-futures = "0.3.32"
-tokio-stream = { version = "0.1.18", features = ["full"] }
-kameo = "0.19.2"
-prost-types = { version = "0.14.3", features = ["chrono"] }
-x25519-dalek = { version = "2.0.1", features = ["getrandom"] }
-rstest = "0.26.1"
-rustls-pki-types = "1.14.0"
 alloy = "1.7.3"
-rcgen = { version = "0.14.7", features = [
-    "aws_lc_rs",
-    "pem",
-    "x509-parser",
-    "zeroize",
-], default-features = false }
+async-trait = "0.1.89"
+base64 = "0.22.1"
+chrono = { version = "0.4.44", features = ["serde"] }
+ed25519-dalek = { version = "3.0.0-pre.6", features = ["rand_core"] }
+futures = "0.3.32"
+hmac = "0.12.1"
 k256 = { version = "0.13.4", features = ["ecdsa", "pkcs8"] }
+kameo = { version = "0.20.0", git = "https://github.com/tqwewe/kameo" } # hold this until new patch version is released
+miette = { version = "7.6.0", features = ["fancy", "serde"] }
+ml-dsa = { version = "0.1.0-rc.8", features = ["zeroize"] }
+mutants = "0.0.4"
+prost = "0.14.3"
+prost-types = { version = "0.14.3", features = ["chrono"] }
+rand = "0.10.0"
+rcgen = { version = "0.14.7", features = [ "aws_lc_rs",  "pem", "x509-parser", "zeroize" ], default-features = false }
 rsa = { version = "0.9", features = ["sha2"] }
+rstest = "0.26.1"
+rustls = { version = "0.23.37", features = ["aws-lc-rs", "logging", "prefer-post-quantum", "std"], default-features = false }
+rustls-pki-types = "1.14.0"
 sha2 = "0.10"
+smlang = "0.8.0"
 spki = "0.7"
+thiserror = "2.0.18"
+tokio = { version = "1.50.0", features = ["full"] }
+tokio-stream = { version = "0.1.18", features = ["full"] }
+tonic = { version = "0.14.5", features = [ "deflate", "gzip", "tls-connect-info", "zstd" ] }
+tracing = "0.1.44"
+x25519-dalek = { version = "2.0.1", features = ["getrandom"] }
+
+[workspace.lints.rust]
+missing_unsafe_on_extern = "deny"
+unsafe_attr_outside_unsafe = "deny"
+unsafe_op_in_unsafe_fn = "deny"
+unstable_features = "deny"
+
+deprecated_safe_2024 = "warn"
+ffi_unwind_calls = "warn"
+linker_messages = "warn"
+
+elided_lifetimes_in_paths = "warn"
+explicit_outlives_requirements = "warn"
+impl-trait-overcaptures = "warn"
+impl-trait-redundant-captures = "warn"
+redundant_lifetimes = "warn"
+single_use_lifetimes = "warn"
+unused_lifetimes = "warn"
+
+macro_use_extern_crate = "warn"
+redundant_imports = "warn"
+unused_import_braces = "warn"
+unused_macro_rules = "warn"
+unused_qualifications = "warn"
+
+unit_bindings = "warn"
+
+# missing_docs = "warn" # ENABLE BY THE FIRST MAJOR VERSION!!
+unnameable_types = "warn"
+variant_size_differences = "warn"
+
+[workspace.lints.clippy]
+derive_partial_eq_without_eq = "allow" 
+future_not_send = "allow"
+inconsistent_struct_constructor = "allow"
+inline_always = "allow"
+missing_errors_doc = "allow"
+missing_fields_in_debug = "allow"
+missing_panics_doc = "allow"
+must_use_candidate = "allow"
+needless_pass_by_ref_mut = "allow"
+pub_underscore_fields = "allow"
+redundant_pub_crate = "allow" 
+uninhabited_references = "allow" # safe with unsafe_code = "forbid" and standard uninhabited pattern (match *self {})
+
+# restriction lints
+alloc_instead_of_core = "warn"
+allow_attributes_without_reason = "warn"
+as_conversions = "warn"
+assertions_on_result_states = "warn"
+cfg_not_test = "warn"
+clone_on_ref_ptr = "warn"
+cognitive_complexity = "warn"
+create_dir = "warn"
+dbg_macro = "warn"
+decimal_literal_representation = "warn"
+default_union_representation = "warn"
+deref_by_slicing = "warn"
+disallowed_script_idents = "warn"
+doc_include_without_cfg = "warn"
+empty_drop = "warn"
+empty_enum_variants_with_brackets = "warn"
+empty_structs_with_brackets = "warn"
+error_impl_error = "warn"
+exit = "warn"
+filetype_is_file = "warn"
+float_arithmetic = "warn"
+float_cmp_const = "warn"
+fn_to_numeric_cast_any = "warn"
+get_unwrap = "warn"
+if_then_some_else_none = "warn"
+indexing_slicing = "warn"
+infinite_loop = "warn"
+inline_asm_x86_att_syntax = "warn"
+inline_asm_x86_intel_syntax = "warn"
+integer_division = "warn"
+large_include_file = "warn"
+lossy_float_literal = "warn"
+map_with_unused_argument_over_ranges = "warn"
+mem_forget = "warn"
+missing_assert_message = "warn"
+mixed_read_write_in_expression = "warn"
+modulo_arithmetic = "warn"
+multiple_unsafe_ops_per_block = "warn"
+mutex_atomic = "warn"
+mutex_integer = "warn"
+needless_raw_strings = "warn"
+non_ascii_literal = "warn"
+non_zero_suggestions = "warn"
+pathbuf_init_then_push = "warn"
+pointer_format = "warn"
+precedence_bits = "warn"
+pub_without_shorthand = "warn"
+rc_buffer = "warn"
+rc_mutex = "warn"
+redundant_test_prefix = "warn"
+redundant_type_annotations = "warn"
+ref_patterns = "warn"
+renamed_function_params = "warn"
+rest_pat_in_fully_bound_structs = "warn"
+return_and_then = "warn"
+semicolon_inside_block = "warn"
+str_to_string = "warn"
+string_add = "warn"
+string_lit_chars_any = "warn"
+string_slice = "warn"
+suspicious_xor_used_as_pow = "warn"
+try_err = "warn"
+undocumented_unsafe_blocks = "warn"
+uninlined_format_args = "warn"
+unnecessary_safety_comment = "warn"
+unnecessary_safety_doc = "warn"
+unnecessary_self_imports = "warn"
+unneeded_field_pattern = "warn"
+unused_result_ok = "warn"
+verbose_file_reads = "warn"
+
+# cargo lints
+negative_feature_names = "warn"
+redundant_feature_names = "warn"
+wildcard_dependencies = "warn"
+
+# ENABLE BY THE FIRST MAJOR VERSION!!
+# todo = "warn"
+# unimplemented = "warn"
+# panic = "warn"
+# panic_in_result_fn = "warn"
+# 
+# cargo_common_metadata = "warn"
+# multiple_crate_versions = "warn" # a controversial option since it's really difficult to maintain
+
+disallowed_methods = "deny"
+
+nursery = { level = "warn", priority = -1 }
+pedantic = { level = "warn", priority = -1 }

server/clippy.toml

@@ -7,3 +7,22 @@ disallowed-methods = [
     { path = "rsa::traits::Decryptor::decrypt", reason = "RSA decryption is forbidden (RUSTSEC-2023-0071 Marvin Attack). This blocks decrypt() on rsa::{pkcs1v15,oaep}::DecryptingKey." },
     { path = "rsa::traits::RandomizedDecryptor::decrypt_with_rng", reason = "RSA decryption is forbidden (RUSTSEC-2023-0071 Marvin Attack). This blocks decrypt_with_rng() on rsa::{pkcs1v15,oaep}::DecryptingKey." },
 ]
+
+allow-indexing-slicing-in-tests = true
+allow-panic-in-tests = true
+check-inconsistent-struct-field-initializers = true
+suppress-restriction-lint-in-const = true
+allow-renamed-params-for = [
+    "core::convert::From",
+    "core::convert::TryFrom",
+    "core::str::FromStr",
+    "kameo::actor::Actor",
+]
+
+module-items-ordered-within-groupings = ["UPPER_SNAKE_CASE"]
+source-item-ordering = ["enum"]
+trait-assoc-item-kinds-order = [
+    "const",
+    "type",
+    "fn",
+] # community tested standard

server/crates/arbiter-client/Cargo.toml

@@ -13,12 +13,12 @@ evm = ["dep:alloy"]
 
 [dependencies]
 arbiter-proto.path = "../arbiter-proto"
+arbiter-crypto.path = "../arbiter-crypto"
 alloy = { workspace = true, optional = true }
 tonic.workspace = true
 tonic.features = ["tls-aws-lc"]
 tokio.workspace = true
 tokio-stream.workspace = true
-ed25519-dalek.workspace = true
 thiserror.workspace = true
 http = "1.4.0"
 rustls-webpki = { version = "0.103.10", features = ["aws-lc-rs"] }

server/crates/arbiter-client/src/auth.rs

@@ -1,5 +1,6 @@
+use arbiter_crypto::authn::{CLIENT_CONTEXT, SigningKey, format_challenge};
 use arbiter_proto::{
-    ClientMetadata, format_challenge,
+    ClientMetadata,
     proto::{
         client::{
             ClientRequest,
@@ -14,7 +15,6 @@ use arbiter_proto::{
         shared::ClientInfo as ProtoClientInfo,
     },
 };
-use ed25519_dalek::Signer as _;
 
 use crate::{
     storage::StorageError,
@@ -23,20 +23,20 @@ use crate::{
 
 #[derive(Debug, thiserror::Error)]
 pub enum AuthError {
-    #[error("Auth challenge was not returned by server")]
-    MissingAuthChallenge,
-
     #[error("Client approval denied by User Agent")]
     ApprovalDenied,
 
+    #[error("Auth challenge was not returned by server")]
+    MissingAuthChallenge,
+
     #[error("No User Agents online to approve client")]
     NoUserAgentsOnline,
 
-    #[error("Unexpected auth response payload")]
-    UnexpectedAuthResponse,
-
     #[error("Signing key storage error")]
     Storage(#[from] StorageError),
+
+    #[error("Unexpected auth response payload")]
+    UnexpectedAuthResponse,
 }
 
 fn map_auth_result(code: i32) -> AuthError {
@@ -54,14 +54,14 @@ fn map_auth_result(code: i32) -> AuthError {
 async fn send_auth_challenge_request(
     transport: &mut ClientTransport,
     metadata: ClientMetadata,
-    key: &ed25519_dalek::SigningKey,
-) -> std::result::Result<(), AuthError> {
+    key: &SigningKey,
+) -> Result<(), AuthError> {
     transport
         .send(ClientRequest {
             request_id: next_request_id(),
             payload: Some(ClientRequestPayload::Auth(proto_auth::Request {
                 payload: Some(AuthRequestPayload::ChallengeRequest(AuthChallengeRequest {
-                    pubkey: key.verifying_key().to_bytes().to_vec(),
+                    pubkey: key.public_key().to_bytes(),
                     client_info: Some(ProtoClientInfo {
                         name: metadata.name,
                         description: metadata.description,
@@ -76,7 +76,7 @@ async fn send_auth_challenge_request(
 
 async fn receive_auth_challenge(
     transport: &mut ClientTransport,
-) -> std::result::Result<AuthChallenge, AuthError> {
+) -> Result<AuthChallenge, AuthError> {
     let response = transport
         .recv()
         .await
@@ -95,11 +95,14 @@ async fn receive_auth_challenge(
 
 async fn send_auth_challenge_solution(
     transport: &mut ClientTransport,
-    key: &ed25519_dalek::SigningKey,
+    key: &SigningKey,
     challenge: AuthChallenge,
-) -> std::result::Result<(), AuthError> {
+) -> Result<(), AuthError> {
     let challenge_payload = format_challenge(challenge.nonce, &challenge.pubkey);
-    let signature = key.sign(&challenge_payload).to_bytes().to_vec();
+    let signature = key
+        .sign_message(&challenge_payload, CLIENT_CONTEXT)
+        .map_err(|_| AuthError::UnexpectedAuthResponse)?
+        .to_bytes();
 
     transport
         .send(ClientRequest {
@@ -114,17 +117,13 @@ async fn send_auth_challenge_solution(
         .map_err(|_| AuthError::UnexpectedAuthResponse)
 }
 
-async fn receive_auth_confirmation(
-    transport: &mut ClientTransport,
-) -> std::result::Result<(), AuthError> {
+async fn receive_auth_confirmation(transport: &mut ClientTransport) -> Result<(), AuthError> {
     let response = transport
         .recv()
         .await
         .map_err(|_| AuthError::UnexpectedAuthResponse)?;
 
-    let payload = response
-        .payload
-        .ok_or(AuthError::UnexpectedAuthResponse)?;
+    let payload = response.payload.ok_or(AuthError::UnexpectedAuthResponse)?;
     match payload {
         ClientResponsePayload::Auth(response) => match response.payload {
             Some(AuthResponsePayload::Result(result))
@@ -139,11 +138,11 @@ async fn receive_auth_confirmation(
     }
 }
 
-pub(crate) async fn authenticate(
+pub async fn authenticate(
     transport: &mut ClientTransport,
     metadata: ClientMetadata,
-    key: &ed25519_dalek::SigningKey,
-) -> std::result::Result<(), AuthError> {
+    key: &SigningKey,
+) -> Result<(), AuthError> {
     send_auth_challenge_request(transport, metadata, key).await?;
     let challenge = receive_auth_challenge(transport).await?;
     send_auth_challenge_solution(transport, key, challenge).await?;

server/crates/arbiter-client/src/bin/test_connect.rs

@@ -1,4 +1,3 @@
-
 use std::io::{self, Write};
 
 use arbiter_client::ArbiterClient;
@@ -22,8 +21,6 @@ async fn main() {
         return;
     }
 
-   
-
     let url = match ArbiterUrl::try_from(input) {
         Ok(url) => url,
         Err(err) => {
@@ -32,16 +29,16 @@ async fn main() {
         }
     };
 
-     println!("{:#?}", url);
+    println!("{url:#?}");
 
     let metadata = ClientMetadata {
-        name: "arbiter-client test_connect".to_string(),
-        description: Some("Manual connection smoke test".to_string()),
-        version: Some(env!("CARGO_PKG_VERSION").to_string()),
+        name: "arbiter-client test_connect".to_owned(),
+        description: Some("Manual connection smoke test".to_owned()),
+        version: Some(env!("CARGO_PKG_VERSION").to_owned()),
     };
 
     match ArbiterClient::connect(url, metadata).await {
         Ok(_) => println!("Connected and authenticated successfully."),
-        Err(err) => eprintln!("Failed to connect: {:#?}", err),
+        Err(err) => eprintln!("Failed to connect: {err:#?}"),
     }
 }

server/crates/arbiter-client/src/client.rs

@@ -1,45 +1,56 @@
-use arbiter_proto::{ClientMetadata, proto::arbiter_service_client::ArbiterServiceClient, url::ArbiterUrl};
+use arbiter_crypto::authn::SigningKey;
+use arbiter_proto::{
+    ClientMetadata, proto::arbiter_service_client::ArbiterServiceClient, url::ArbiterUrl,
+};
 use std::sync::Arc;
 use tokio::sync::{Mutex, mpsc};
 use tokio_stream::wrappers::ReceiverStream;
 use tonic::transport::ClientTlsConfig;
 
 use crate::{
-    StorageError, auth::{AuthError, authenticate}, storage::{FileSigningKeyStorage, SigningKeyStorage}, transport::{BUFFER_LENGTH, ClientTransport}
+    StorageError,
+    auth::{AuthError, authenticate},
+    storage::{FileSigningKeyStorage, SigningKeyStorage},
+    transport::{BUFFER_LENGTH, ClientTransport},
 };
 
 #[cfg(feature = "evm")]
 use crate::wallets::evm::ArbiterEvmWallet;
 
 #[derive(Debug, thiserror::Error)]
-pub enum Error {
-    #[error("gRPC error")]
-    Grpc(#[from] tonic::Status),
+pub enum ArbiterClientError {
+    #[error("Authentication error")]
+    Authentication(#[from] AuthError),
 
     #[error("Could not establish connection")]
     Connection(#[from] tonic::transport::Error),
 
-    #[error("Invalid server URI")]
-    InvalidUri(#[from] http::uri::InvalidUri),
+    #[error("gRPC error")]
+    Grpc(#[from] tonic::Status),
 
     #[error("Invalid CA certificate")]
     InvalidCaCert(#[from] webpki::Error),
 
-    #[error("Authentication error")]
-    Authentication(#[from] AuthError),
+    #[error("Invalid server URI")]
+    InvalidUri(#[from] http::uri::InvalidUri),
 
     #[error("Storage error")]
     Storage(#[from] StorageError),
-    
 }
 
 pub struct ArbiterClient {
-    #[allow(dead_code)]
+    #[expect(
+        dead_code,
+        reason = "transport will be used in future methods for sending requests and receiving responses"
+    )]
     transport: Arc<Mutex<ClientTransport>>,
 }
 
 impl ArbiterClient {
-    pub async fn connect(url: ArbiterUrl, metadata: ClientMetadata) -> Result<Self, Error> {
+    pub async fn connect(
+        url: ArbiterUrl,
+        metadata: ClientMetadata,
+    ) -> Result<Self, ArbiterClientError> {
         let storage = FileSigningKeyStorage::from_default_location()?;
         Self::connect_with_storage(url, metadata, &storage).await
     }
@@ -48,7 +59,7 @@ impl ArbiterClient {
         url: ArbiterUrl,
         metadata: ClientMetadata,
         storage: &S,
-    ) -> Result<Self, Error> {
+    ) -> Result<Self, ArbiterClientError> {
         let key = storage.load_or_create()?;
         Self::connect_with_key(url, metadata, key).await
     }
@@ -56,15 +67,16 @@ impl ArbiterClient {
     pub async fn connect_with_key(
         url: ArbiterUrl,
         metadata: ClientMetadata,
-        key: ed25519_dalek::SigningKey,
-    ) -> Result<Self, Error> {
+        key: SigningKey,
+    ) -> Result<Self, ArbiterClientError> {
         let anchor = webpki::anchor_from_trusted_cert(&url.ca_cert)?.to_owned();
         let tls = ClientTlsConfig::new().trust_anchor(anchor);
 
-        let channel = tonic::transport::Channel::from_shared(format!("https://{}:{}", url.host, url.port))?
-            .tls_config(tls)?
-            .connect()
-            .await?;
+        let channel =
+            tonic::transport::Channel::from_shared(format!("https://{}:{}", url.host, url.port))?
+                .tls_config(tls)?
+                .connect()
+                .await?;
 
         let mut client = ArbiterServiceClient::new(channel);
         let (tx, rx) = mpsc::channel(BUFFER_LENGTH);
@@ -83,7 +95,8 @@ impl ArbiterClient {
     }
 
     #[cfg(feature = "evm")]
-    pub async fn evm_wallets(&self) -> Result<Vec<ArbiterEvmWallet>, Error> {
+    #[expect(clippy::unused_async, reason = "false positive")]
+    pub async fn evm_wallets(&self) -> Result<Vec<ArbiterEvmWallet>, ArbiterClientError> {
         todo!("fetch EVM wallet list from server")
     }
 }

server/crates/arbiter-client/src/lib.rs

@@ -5,8 +5,8 @@ mod transport;
 pub mod wallets;
 
 pub use auth::AuthError;
-pub use client::{ArbiterClient, Error};
+pub use client::{ArbiterClient, ArbiterClientError};
 pub use storage::{FileSigningKeyStorage, SigningKeyStorage, StorageError};
 
 #[cfg(feature = "evm")]
-pub use wallets::evm::ArbiterEvmWallet;
+pub use wallets::evm::{ArbiterEvmSignTransactionError, ArbiterEvmWallet};

server/crates/arbiter-client/src/storage.rs

@@ -1,17 +1,18 @@
+use arbiter_crypto::authn::SigningKey;
 use arbiter_proto::home_path;
 use std::path::{Path, PathBuf};
 
 #[derive(Debug, thiserror::Error)]
 pub enum StorageError {
-    #[error("I/O error")]
-    Io(#[from] std::io::Error),
-
     #[error("Invalid signing key length in storage: expected {expected} bytes, got {actual} bytes")]
     InvalidKeyLength { expected: usize, actual: usize },
+
+    #[error("I/O error")]
+    Io(#[from] std::io::Error),
 }
 
 pub trait SigningKeyStorage {
-    fn load_or_create(&self) -> std::result::Result<ed25519_dalek::SigningKey, StorageError>;
+    fn load_or_create(&self) -> Result<SigningKey, StorageError>;
 }
 
 #[derive(Debug, Clone)]
@@ -20,17 +21,17 @@ pub struct FileSigningKeyStorage {
 }
 
 impl FileSigningKeyStorage {
-    pub const DEFAULT_FILE_NAME: &str = "sdk_client_ed25519.key";
+    pub const DEFAULT_FILE_NAME: &str = "sdk_client_ml_dsa.key";
 
     pub fn new(path: impl Into<PathBuf>) -> Self {
         Self { path: path.into() }
     }
 
-    pub fn from_default_location() -> std::result::Result<Self, StorageError> {
+    pub fn from_default_location() -> Result<Self, StorageError> {
         Ok(Self::new(home_path()?.join(Self::DEFAULT_FILE_NAME)))
     }
 
-    fn read_key(path: &Path) -> std::result::Result<ed25519_dalek::SigningKey, StorageError> {
+    fn read_key(path: &Path) -> Result<SigningKey, StorageError> {
         let bytes = std::fs::read(path)?;
         let raw: [u8; 32] =
             bytes
@@ -39,12 +40,12 @@ impl FileSigningKeyStorage {
                     expected: 32,
                     actual: v.len(),
                 })?;
-        Ok(ed25519_dalek::SigningKey::from_bytes(&raw))
+        Ok(SigningKey::from_seed(raw))
     }
 }
 
 impl SigningKeyStorage for FileSigningKeyStorage {
-    fn load_or_create(&self) -> std::result::Result<ed25519_dalek::SigningKey, StorageError> {
+    fn load_or_create(&self) -> Result<SigningKey, StorageError> {
         if let Some(parent) = self.path.parent() {
             std::fs::create_dir_all(parent)?;
         }
@@ -53,8 +54,8 @@ impl SigningKeyStorage for FileSigningKeyStorage {
             return Self::read_key(&self.path);
         }
 
-        let key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
-        let raw_key = key.to_bytes();
+        let key = SigningKey::generate();
+        let raw_key = key.to_seed();
 
         // Use create_new to prevent accidental overwrite if another process creates the key first.
         match std::fs::OpenOptions::new()
@@ -103,7 +104,7 @@ mod tests {
             .load_or_create()
             .expect("second load_or_create should read same key");
 
-        assert_eq!(key_a.to_bytes(), key_b.to_bytes());
+        assert_eq!(key_a.to_seed(), key_b.to_seed());
         assert!(path.exists());
 
         std::fs::remove_file(path).expect("temp key file should be removable");
@@ -124,7 +125,7 @@ mod tests {
                 assert_eq!(expected, 32);
                 assert_eq!(actual, 31);
             }
-            other => panic!("unexpected error: {other:?}"),
+            other @ StorageError::Io(_) => panic!("unexpected error: {other:?}"),
         }
 
         std::fs::remove_file(path).expect("temp key file should be removable");

server/crates/arbiter-client/src/transport.rs

@@ -2,15 +2,15 @@ use arbiter_proto::proto::client::{ClientRequest, ClientResponse};
 use std::sync::atomic::{AtomicI32, Ordering};
 use tokio::sync::mpsc;
 
-pub(crate) const BUFFER_LENGTH: usize = 16;
+pub const BUFFER_LENGTH: usize = 16;
 static NEXT_REQUEST_ID: AtomicI32 = AtomicI32::new(1);
 
-pub(crate) fn next_request_id() -> i32 {
+pub fn next_request_id() -> i32 {
     NEXT_REQUEST_ID.fetch_add(1, Ordering::Relaxed)
 }
 
 #[derive(Debug, thiserror::Error)]
-pub(crate) enum ClientSignError {
+pub enum ClientSignError {
     #[error("Transport channel closed")]
     ChannelClosed,
 
@@ -18,7 +18,7 @@ pub(crate) enum ClientSignError {
     ConnectionClosed,
 }
 
-pub(crate) struct ClientTransport {
+pub struct ClientTransport {
     pub(crate) sender: mpsc::Sender<ClientRequest>,
     pub(crate) receiver: tonic::Streaming<ClientResponse>,
 }
@@ -27,18 +27,17 @@ impl ClientTransport {
     pub(crate) async fn send(
         &mut self,
         request: ClientRequest,
-    ) -> std::result::Result<(), ClientSignError> {
+    ) -> Result<(), ClientSignError> {
         self.sender
             .send(request)
             .await
             .map_err(|_| ClientSignError::ChannelClosed)
     }
 
-    pub(crate) async fn recv(&mut self) -> std::result::Result<ClientResponse, ClientSignError> {
+    pub(crate) async fn recv(&mut self) -> Result<ClientResponse, ClientSignError> {
         match self.receiver.message().await {
             Ok(Some(resp)) => Ok(resp),
-            Ok(None) => Err(ClientSignError::ConnectionClosed),
-            Err(_) => Err(ClientSignError::ConnectionClosed),
+            Ok(None) | Err(_) => Err(ClientSignError::ConnectionClosed),
         }
     }
 }

server/crates/arbiter-client/src/wallets/evm.rs

@@ -10,14 +10,48 @@ use tokio::sync::Mutex;
 
 use arbiter_proto::proto::{
     client::{
-        ClientRequest, client_request::Payload as ClientRequestPayload,
+        ClientRequest,
+        client_request::Payload as ClientRequestPayload,
         client_response::Payload as ClientResponsePayload,
+        evm::{
+            self as proto_evm, request::Payload as EvmRequestPayload,
+            response::Payload as EvmResponsePayload,
+        },
     },
-    evm::evm_sign_transaction_response::Result as EvmSignTransactionResult,
+    evm::{
+        EvmSignTransactionRequest,
+        evm_sign_transaction_response::Result as EvmSignTransactionResult,
+    },
+    shared::evm::TransactionEvalError,
 };
 
 use crate::transport::{ClientTransport, next_request_id};
 
+/// A typed error payload returned by [`ArbiterEvmWallet`] transaction signing.
+///
+/// This is wrapped into `alloy::signers::Error::Other`, so consumers can downcast by [`TryFrom`] and
+/// interpret the concrete policy evaluation failure instead of parsing strings.
+#[derive(Debug, thiserror::Error)]
+#[non_exhaustive]
+pub enum ArbiterEvmSignTransactionError {
+    #[error("transaction rejected by policy: {0:?}")]
+    PolicyEval(TransactionEvalError),
+}
+
+impl<'a> TryFrom<&'a Error> for &'a ArbiterEvmSignTransactionError {
+    type Error = ();
+
+    fn try_from(value: &'a Error) -> Result<Self, Self::Error> {
+        if let Error::Other(inner) = value
+            && let Some(eval_error) = inner.downcast_ref()
+        {
+            Ok(eval_error)
+        } else {
+            Err(())
+        }
+    }
+}
+
 pub struct ArbiterEvmWallet {
     transport: Arc<Mutex<ClientTransport>>,
     address: Address,
@@ -25,7 +59,11 @@ pub struct ArbiterEvmWallet {
 }
 
 impl ArbiterEvmWallet {
-    pub(crate) fn new(transport: Arc<Mutex<ClientTransport>>, address: Address) -> Self {
+    #[expect(
+        dead_code,
+        reason = "new will be used in future methods for creating wallets with different parameters"
+    )]
+    pub(crate) const fn new(transport: Arc<Mutex<ClientTransport>>, address: Address) -> Self {
         Self {
             transport,
             address,
@@ -33,11 +71,12 @@ impl ArbiterEvmWallet {
         }
     }
 
-    pub fn address(&self) -> Address {
+    pub const fn address(&self) -> Address {
         self.address
     }
 
-    pub fn with_chain_id(mut self, chain_id: ChainId) -> Self {
+    #[must_use]
+    pub const fn with_chain_id(mut self, chain_id: ChainId) -> Self {
         self.chain_id = Some(chain_id);
         self
     }
@@ -96,12 +135,14 @@ impl TxSigner<Signature> for ArbiterEvmWallet {
         transport
             .send(ClientRequest {
                 request_id,
-                payload: Some(ClientRequestPayload::EvmSignTransaction(
-                    arbiter_proto::proto::evm::EvmSignTransactionRequest {
-                        wallet_address: self.address.to_vec(),
-                        rlp_transaction,
-                    },
-                )),
+                payload: Some(ClientRequestPayload::Evm(proto_evm::Request {
+                    payload: Some(EvmRequestPayload::SignTransaction(
+                        EvmSignTransactionRequest {
+                            wallet_address: self.address.to_vec(),
+                            rlp_transaction,
+                        },
+                    )),
+                })),
             })
             .await
             .map_err(|_| Error::other("failed to send evm sign transaction request"))?;
@@ -110,6 +151,7 @@ impl TxSigner<Signature> for ArbiterEvmWallet {
             .recv()
             .await
             .map_err(|_| Error::other("failed to receive evm sign transaction response"))?;
+        drop(transport);
 
         if response.request_id != Some(request_id) {
             return Err(Error::other(
@@ -121,12 +163,21 @@ impl TxSigner<Signature> for ArbiterEvmWallet {
             .payload
             .ok_or_else(|| Error::other("missing evm sign transaction response payload"))?;
 
-        let ClientResponsePayload::EvmSignTransaction(response) = payload else {
+        let ClientResponsePayload::Evm(proto_evm::Response {
+            payload: Some(payload),
+        }) = payload
+        else {
             return Err(Error::other(
                 "unexpected response payload for evm sign transaction request",
             ));
         };
 
+        let EvmResponsePayload::SignTransaction(response) = payload else {
+            return Err(Error::other(
+                "unexpected evm response payload for sign transaction request",
+            ));
+        };
+
         let result = response
             .result
             .ok_or_else(|| Error::other("missing evm sign transaction result"))?;
@@ -136,9 +187,9 @@ impl TxSigner<Signature> for ArbiterEvmWallet {
                 Signature::try_from(signature.as_slice())
                     .map_err(|_| Error::other("invalid signature returned by server"))
             }
-            EvmSignTransactionResult::EvalError(eval_error) => Err(Error::other(format!(
-                "transaction rejected by policy: {eval_error:?}"
-            ))),
+            EvmSignTransactionResult::EvalError(eval_error) => Err(Error::other(
+                ArbiterEvmSignTransactionError::PolicyEval(eval_error),
+            )),
             EvmSignTransactionResult::Error(code) => Err(Error::other(format!(
                 "server failed to sign transaction with error code {code}"
             ))),

server/crates/arbiter-crypto/.gitignore

@@ -0,0 +1 @@
+/target

server/crates/arbiter-crypto/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "arbiter-crypto"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+ml-dsa = {workspace = true, optional = true }
+rand = {workspace = true, optional = true}
+base64 = {workspace = true, optional = true }
+memsafe = {version = "0.4.0", optional = true}
+hmac.workspace = true
+alloy.workspace = true
+chrono.workspace = true
+
+[lints]
+workspace = true
+
+[features]
+default = ["authn", "safecell"]
+authn = ["dep:ml-dsa", "dep:rand", "dep:base64"]
+safecell = ["dep:memsafe"]

server/crates/arbiter-crypto/src/authn/mod.rs

@@ -0,0 +1,2 @@
+pub mod v1;
+pub use v1::*;

server/crates/arbiter-crypto/src/authn/v1.rs

@@ -0,0 +1,194 @@
+use base64::{Engine as _, prelude::BASE64_STANDARD};
+use hmac::digest::Digest;
+use ml_dsa::{
+    EncodedVerifyingKey, Error, KeyGen, MlDsa87, Seed, Signature as MlDsaSignature,
+    SigningKey as MlDsaSigningKey, VerifyingKey as MlDsaVerifyingKey, signature::Keypair as _,
+};
+
+pub static CLIENT_CONTEXT: &[u8] = b"arbiter_client";
+pub static USERAGENT_CONTEXT: &[u8] = b"arbiter_user_agent";
+
+pub fn format_challenge(nonce: i32, pubkey: &[u8]) -> Vec<u8> {
+    let concat_form = format!("{}:{}", nonce, BASE64_STANDARD.encode(pubkey));
+    concat_form.into_bytes()
+}
+
+pub type KeyParams = MlDsa87;
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct PublicKey(Box<MlDsaVerifyingKey<KeyParams>>);
+
+impl crate::hashing::Hashable for PublicKey {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.to_bytes());
+    }
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct Signature(Box<MlDsaSignature<KeyParams>>);
+
+#[derive(Debug)]
+pub struct SigningKey(Box<MlDsaSigningKey<KeyParams>>);
+
+impl PublicKey {
+    pub fn to_bytes(&self) -> Vec<u8> {
+        self.0.encode().0.to_vec()
+    }
+
+    #[must_use]
+    pub fn verify(&self, nonce: i32, context: &[u8], signature: &Signature) -> bool {
+        self.0.verify_with_context(
+            &format_challenge(nonce, &self.to_bytes()),
+            context,
+            &signature.0,
+        )
+    }
+}
+
+impl Signature {
+    pub fn to_bytes(&self) -> Vec<u8> {
+        self.0.encode().0.to_vec()
+    }
+}
+
+impl SigningKey {
+    pub fn generate() -> Self {
+        Self(Box::new(KeyParams::key_gen(&mut rand::rng())))
+    }
+
+    pub fn from_seed(seed: [u8; 32]) -> Self {
+        Self(Box::new(KeyParams::from_seed(&Seed::from(seed))))
+    }
+
+    pub fn to_seed(&self) -> [u8; 32] {
+        self.0.to_seed().into()
+    }
+
+    pub fn public_key(&self) -> PublicKey {
+        self.0.verifying_key().into()
+    }
+
+    pub fn sign_message(&self, message: &[u8], context: &[u8]) -> Result<Signature, Error> {
+        self.0
+            .signing_key()
+            .sign_deterministic(message, context)
+            .map(Into::into)
+    }
+
+    pub fn sign_challenge(&self, nonce: i32, context: &[u8]) -> Result<Signature, Error> {
+        self.sign_message(
+            &format_challenge(nonce, &self.public_key().to_bytes()),
+            context,
+        )
+    }
+}
+
+impl From<MlDsaVerifyingKey<KeyParams>> for PublicKey {
+    fn from(value: MlDsaVerifyingKey<KeyParams>) -> Self {
+        Self(Box::new(value))
+    }
+}
+
+impl From<MlDsaSignature<KeyParams>> for Signature {
+    fn from(value: MlDsaSignature<KeyParams>) -> Self {
+        Self(Box::new(value))
+    }
+}
+
+impl From<MlDsaSigningKey<KeyParams>> for SigningKey {
+    fn from(value: MlDsaSigningKey<KeyParams>) -> Self {
+        Self(Box::new(value))
+    }
+}
+
+impl TryFrom<Vec<u8>> for PublicKey {
+    type Error = ();
+
+    fn try_from(value: Vec<u8>) -> Result<Self, Self::Error> {
+        Self::try_from(value.as_slice())
+    }
+}
+
+impl TryFrom<&'_ [u8]> for PublicKey {
+    type Error = ();
+
+    fn try_from(value: &[u8]) -> Result<Self, Self::Error> {
+        let encoded = EncodedVerifyingKey::<KeyParams>::try_from(value).map_err(|_| ())?;
+        Ok(Self(Box::new(MlDsaVerifyingKey::decode(&encoded))))
+    }
+}
+
+impl TryFrom<Vec<u8>> for Signature {
+    type Error = ();
+
+    fn try_from(value: Vec<u8>) -> Result<Self, Self::Error> {
+        Self::try_from(value.as_slice())
+    }
+}
+
+impl TryFrom<&'_ [u8]> for Signature {
+    type Error = ();
+
+    fn try_from(value: &[u8]) -> Result<Self, Self::Error> {
+        MlDsaSignature::try_from(value)
+            .map(|sig| Self(Box::new(sig)))
+            .map_err(|_| ())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use ml_dsa::{KeyGen, MlDsa87, signature::Keypair as _};
+
+    use super::{CLIENT_CONTEXT, PublicKey, Signature, SigningKey, USERAGENT_CONTEXT};
+
+    #[test]
+    fn public_key_round_trip_decodes() {
+        let key = MlDsa87::key_gen(&mut rand::rng());
+        let encoded = PublicKey::from(key.verifying_key()).to_bytes();
+
+        let decoded = PublicKey::try_from(encoded.as_slice()).expect("public key should decode");
+
+        assert_eq!(decoded, PublicKey::from(key.verifying_key()));
+    }
+
+    #[test]
+    fn signature_round_trip_decodes() {
+        let key = SigningKey::generate();
+        let signature = key
+            .sign_message(b"challenge", CLIENT_CONTEXT)
+            .expect("signature should be created");
+
+        let decoded =
+            Signature::try_from(signature.to_bytes().as_slice()).expect("signature should decode");
+
+        assert_eq!(decoded, signature);
+    }
+
+    #[test]
+    fn challenge_verification_uses_context_and_canonical_key_bytes() {
+        let key = SigningKey::generate();
+        let public_key = key.public_key();
+        let nonce = 17;
+        let signature = key
+            .sign_challenge(nonce, CLIENT_CONTEXT)
+            .expect("signature should be created");
+
+        assert!(public_key.verify(nonce, CLIENT_CONTEXT, &signature));
+        assert!(!public_key.verify(nonce, USERAGENT_CONTEXT, &signature));
+    }
+
+    #[test]
+    fn signing_key_round_trip_seed_preserves_public_key_and_signing() {
+        let original = SigningKey::generate();
+        let restored = SigningKey::from_seed(original.to_seed());
+
+        assert_eq!(restored.public_key(), original.public_key());
+
+        let signature = restored
+            .sign_challenge(9, CLIENT_CONTEXT)
+            .expect("signature should be created");
+
+        assert!(restored.public_key().verify(9, CLIENT_CONTEXT, &signature));
+    }
+}

server/crates/arbiter-crypto/src/hashing.rs

@@ -0,0 +1,111 @@
+pub use hmac::digest::Digest;
+use std::collections::HashSet;
+
+/// Deterministically hash a value by feeding its fields into the hasher in a consistent order.
+#[diagnostic::on_unimplemented(
+    note = "for local types consider adding `#[derive(arbiter_macros::Hashable)]` to your `{Self}` type",
+    note = "for types from other crates check whether the crate offers a `Hashable` implementation"
+)]
+pub trait Hashable {
+    fn hash<H: Digest>(&self, hasher: &mut H);
+}
+
+macro_rules! impl_numeric {
+    ($($t:ty),*) => {
+        $(
+            impl Hashable for $t {
+                fn hash<H: Digest>(&self, hasher: &mut H) {
+                    hasher.update(&self.to_be_bytes());
+                }
+            }
+        )*
+    };
+}
+
+impl_numeric!(u8, u16, u32, u64, i8, i16, i32, i64);
+
+impl Hashable for &[u8] {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self);
+    }
+}
+
+impl Hashable for String {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.as_bytes());
+    }
+}
+
+impl<T: Hashable + PartialOrd> Hashable for Vec<T> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        let ref_sorted = {
+            let mut sorted = self.iter().collect::<Vec<_>>();
+            sorted.sort_by(|a, b| a.partial_cmp(b).unwrap());
+            sorted
+        };
+        for item in ref_sorted {
+            item.hash(hasher);
+        }
+    }
+}
+
+impl<T: Hashable + PartialOrd, S: std::hash::BuildHasher> Hashable for HashSet<T, S> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        let ref_sorted = {
+            let mut sorted = self.iter().collect::<Vec<_>>();
+            sorted.sort_by(|a, b| a.partial_cmp(b).unwrap());
+            sorted
+        };
+        for item in ref_sorted {
+            item.hash(hasher);
+        }
+    }
+}
+
+impl<T: Hashable> Hashable for Option<T> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        match self {
+            Some(value) => {
+                hasher.update([1]);
+                value.hash(hasher);
+            }
+            None => hasher.update([0]),
+        }
+    }
+}
+
+impl<T: Hashable> Hashable for Box<T> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        self.as_ref().hash(hasher);
+    }
+}
+
+impl<T: Hashable> Hashable for &T {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        (*self).hash(hasher);
+    }
+}
+
+impl Hashable for alloy::primitives::Address {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.as_slice());
+    }
+}
+
+impl Hashable for alloy::primitives::U256 {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.to_be_bytes::<32>());
+    }
+}
+
+impl Hashable for chrono::Duration {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.num_seconds().to_be_bytes());
+    }
+}
+
+impl Hashable for chrono::DateTime<chrono::Utc> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.timestamp_millis().to_be_bytes());
+    }
+}

server/crates/arbiter-crypto/src/lib.rs

@@ -0,0 +1,5 @@
+#[cfg(feature = "authn")]
+pub mod authn;
+pub mod hashing;
+#[cfg(feature = "safecell")]
+pub mod safecell;

server/crates/arbiter-crypto/src/safecell.rs

@@ -29,7 +29,7 @@ pub trait SafeCellHandle<T> {
         let mut cell = Self::new(T::default());
         {
             let mut handle = cell.write();
-            f(handle.deref_mut());
+            f(&mut *handle);
         }
         cell
     }
@@ -105,6 +105,11 @@ impl<T> SafeCellHandle<T> for MemSafeCell<T> {
 
 fn abort_memory_breach(action: &str, err: &memsafe::error::MemoryError) -> ! {
     eprintln!("fatal {action}: {err}");
+    // SAFETY: Intentionally cause a segmentation fault to prevent further execution in a compromised state.
+    unsafe {
+        let unsafe_pointer = std::ptr::null_mut::<u8>();
+        std::ptr::write_volatile(unsafe_pointer, 0);
+    }
     std::process::abort();
 }
 

server/crates/arbiter-macros/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "arbiter-macros"
+version = "0.1.0"
+edition = "2024"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1.0"
+quote = "1.0"
+syn = { version = "2.0", features = ["derive", "fold", "full", "visit-mut"] }
+
+[dev-dependencies]
+arbiter-crypto = { path = "../arbiter-crypto" }
+
+[lints]
+workspace = true

server/crates/arbiter-macros/src/hashable.rs

@@ -0,0 +1,133 @@
+use proc_macro2::{Span, TokenStream, TokenTree};
+use quote::quote;
+use syn::parse_quote;
+use syn::spanned::Spanned;
+use syn::{DataStruct, DeriveInput, Fields, Generics, Index};
+
+use crate::utils::{HASHABLE_TRAIT_PATH, HMAC_DIGEST_PATH};
+
+pub(crate) fn derive(input: &DeriveInput) -> TokenStream {
+    match &input.data {
+        syn::Data::Struct(struct_data) => hashable_struct(input, struct_data),
+        syn::Data::Enum(_) => {
+            syn::Error::new_spanned(input, "Hashable can currently be derived only for structs")
+                .to_compile_error()
+        }
+        syn::Data::Union(_) => {
+            syn::Error::new_spanned(input, "Hashable cannot be derived for unions")
+                .to_compile_error()
+        }
+    }
+}
+
+fn hashable_struct(input: &DeriveInput, struct_data: &DataStruct) -> TokenStream {
+    let ident = &input.ident;
+    let hashable_trait = HASHABLE_TRAIT_PATH.to_path();
+    let hmac_digest = HMAC_DIGEST_PATH.to_path();
+    let generics = add_hashable_bounds(input.generics.clone(), &hashable_trait);
+    let field_accesses = collect_field_accesses(struct_data);
+    let hash_calls = build_hash_calls(&field_accesses, &hashable_trait);
+
+    let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
+
+    quote! {
+        #[automatically_derived]
+        impl #impl_generics #hashable_trait for #ident #ty_generics #where_clause {
+            fn hash<H: #hmac_digest>(&self, hasher: &mut H) {
+                #(#hash_calls)*
+            }
+        }
+    }
+}
+
+fn add_hashable_bounds(mut generics: Generics, hashable_trait: &syn::Path) -> Generics {
+    for type_param in generics.type_params_mut() {
+        type_param.bounds.push(parse_quote!(#hashable_trait));
+    }
+
+    generics
+}
+
+struct FieldAccess {
+    access: TokenStream,
+    span: Span,
+}
+
+fn collect_field_accesses(struct_data: &DataStruct) -> Vec<FieldAccess> {
+    match &struct_data.fields {
+        Fields::Named(fields) => {
+            // Keep deterministic alphabetical order for named fields.
+            // Do not remove this sort, because it keeps hash output stable regardless of source order.
+            let mut named_fields = fields
+                .named
+                .iter()
+                .map(|field| {
+                    let name = field
+                        .ident
+                        .as_ref()
+                        .expect("Fields::Named(fields) must have names")
+                        .clone();
+                    (name.to_string(), name)
+                })
+                .collect::<Vec<_>>();
+
+            named_fields.sort_by(|a, b| a.0.cmp(&b.0));
+
+            named_fields
+                .into_iter()
+                .map(|(_, name)| FieldAccess {
+                    access: quote! { #name },
+                    span: name.span(),
+                })
+                .collect()
+        }
+        Fields::Unnamed(fields) => fields
+            .unnamed
+            .iter()
+            .enumerate()
+            .map(|(i, field)| FieldAccess {
+                access: {
+                    let index = Index::from(i);
+                    quote! { #index }
+                },
+                span: field.ty.span(),
+            })
+            .collect(),
+        Fields::Unit => Vec::new(),
+    }
+}
+
+fn build_hash_calls(
+    field_accesses: &[FieldAccess],
+    hashable_trait: &syn::Path,
+) -> Vec<TokenStream> {
+    field_accesses
+        .iter()
+        .map(|field| {
+            let access = &field.access;
+            let call = quote! {
+                #hashable_trait::hash(&self.#access, hasher);
+            };
+
+            respan(call, field.span)
+        })
+        .collect()
+}
+
+/// Recursively set span on all tokens, including interpolated ones.
+fn respan(tokens: TokenStream, span: Span) -> TokenStream {
+    tokens
+        .into_iter()
+        .map(|tt| match tt {
+            TokenTree::Group(g) => {
+                let mut new = proc_macro2::Group::new(g.delimiter(), respan(g.stream(), span));
+                new.set_span(span);
+                TokenTree::Group(new)
+            }
+            mut other => {
+                other.set_span(span);
+                other
+            }
+        })
+        .collect()
+}

server/crates/arbiter-macros/src/lib.rs

@@ -0,0 +1,10 @@
+use syn::{DeriveInput, parse_macro_input};
+
+mod hashable;
+mod utils;
+
+#[proc_macro_derive(Hashable)]
+pub fn derive_hashable(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    let input = parse_macro_input!(input as DeriveInput);
+    hashable::derive(&input).into()
+}

server/crates/arbiter-macros/src/utils.rs

@@ -0,0 +1,24 @@
+pub(crate) struct ToPath(pub &'static str);
+
+impl ToPath {
+    pub(crate) fn to_path(&self) -> syn::Path {
+        syn::parse_str(self.0).expect("Invalid path")
+    }
+}
+
+macro_rules! ensure_path {
+    ($path:path as $name:ident) => {
+        const _: () = {
+            #[cfg(test)]
+            #[expect(
+                unused_imports,
+                reason = "Ensures the path is valid and will cause a compile error if not"
+            )]
+            use $path as _;
+        };
+        pub(crate) const $name: ToPath = ToPath(stringify!($path));
+    };
+}
+
+ensure_path!(::arbiter_crypto::hashing::Hashable as HASHABLE_TRAIT_PATH);
+ensure_path!(::arbiter_crypto::hashing::Digest as HMAC_DIGEST_PATH);

server/crates/arbiter-proto/Cargo.toml

@@ -11,13 +11,13 @@ tokio.workspace = true
 futures.workspace = true
 hex = "0.4.3"
 tonic-prost = "0.14.5"
-prost = "0.14.3"
+prost.workspace = true
 kameo.workspace = true
 url = "2.5.8"
 miette.workspace = true
 thiserror.workspace = true
 rustls-pki-types.workspace = true
-base64 = "0.22.1"
+base64.workspace = true
 prost-types.workspace = true
 tracing.workspace = true
 async-trait.workspace = true

server/crates/arbiter-proto/src/lib.rs

@@ -1,8 +1,6 @@
 pub mod transport;
 pub mod url;
 
-use base64::{Engine, prelude::BASE64_STANDARD};
-
 pub mod proto {
     tonic::include_proto!("arbiter");
 
@@ -84,8 +82,3 @@ pub fn home_path() -> Result<std::path::PathBuf, std::io::Error> {
 
     Ok(arbiter_home)
 }
-
-pub fn format_challenge(nonce: i32, pubkey: &[u8]) -> Vec<u8> {
-    let concat_form = format!("{}:{}", nonce, BASE64_STANDARD.encode(pubkey));
-    concat_form.into_bytes()
-}

server/crates/arbiter-proto/src/url.rs

@@ -7,7 +7,6 @@ const ARBITER_URL_SCHEME: &str = "arbiter";
 const CERT_QUERY_KEY: &str = "cert";
 const BOOTSTRAP_TOKEN_QUERY_KEY: &str = "bootstrap_token";
 
-
 #[derive(Debug, Clone)]
 pub struct ArbiterUrl {
     pub host: String,
@@ -106,7 +105,7 @@ mod tests {
 
     #[rstest]
 
-    fn test_parsing_correctness(
+    fn parsing_correctness(
         #[values("127.0.0.1", "localhost", "192.168.1.1", "some.domain.com")] host: &str,
 
         #[values(None, Some("token123".to_string()))] bootstrap_token: Option<String>,

server/crates/arbiter-server/Cargo.toml

@@ -16,8 +16,9 @@ diesel-async = { version = "0.8.0", features = [
     "sqlite",
     "tokio",
 ] }
-ed25519-dalek.workspace = true
 arbiter-proto.path = "../arbiter-proto"
+arbiter-crypto.path = "../arbiter-crypto"
+arbiter-macros.path = "../arbiter-macros"
 tracing.workspace = true
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 tonic.workspace = true
@@ -25,7 +26,6 @@ tonic.features = ["tls-aws-lc"]
 tokio.workspace = true
 rustls.workspace = true
 smlang.workspace = true
-miette.workspace = true
 thiserror.workspace = true
 fatality = "0.1.1"
 diesel_migrations = { version = "2.3.1", features = ["sqlite"] }
@@ -37,23 +37,31 @@ dashmap = "6.1.0"
 rand.workspace = true
 rcgen.workspace = true
 chrono.workspace = true
-memsafe = "0.4.0"
 zeroize = { version = "1.8.2", features = ["std", "simd"] }
 kameo.workspace = true
-x25519-dalek.workspace = true
 chacha20poly1305 = { version = "0.10.1", features = ["std"] }
 argon2 = { version = "0.5.3", features = ["zeroize"] }
 restructed = "0.2.2"
 strum = { version = "0.28.0", features = ["derive"] }
 pem = "3.0.6"
-k256.workspace = true
-rsa.workspace = true
 sha2.workspace = true
+hmac.workspace = true
 spki.workspace = true
 alloy.workspace = true
 prost-types.workspace = true
+prost.workspace = true
 arbiter-tokens-registry.path = "../arbiter-tokens-registry"
+anyhow = "1.0.102"
+serde_with = "3.18.0"
+mutants.workspace = true
+subtle = "2.6.1"
+ml-dsa.workspace = true
+ed25519-dalek.workspace = true
+x25519-dalek.workspace = true
+k256.workspace = true
 
 [dev-dependencies]
 insta = "1.46.3"
+proptest = "1.11.0"
+rstest.workspace = true
 test-log = { version = "0.2", default-features = false, features = ["trace"] }

server/crates/arbiter-server/migrations/2026-02-14-171124-0000_init/up.sql

@@ -47,7 +47,7 @@ create table if not exists useragent_client (
     id integer not null primary key,
     nonce integer not null default(1), -- used for auth challenge
     public_key blob not null,
-    key_type integer not null default(1), -- 1=Ed25519, 2=ECDSA(secp256k1)
+    key_type integer not null default(1),
     created_at integer not null default(unixepoch ('now')),
     updated_at integer not null default(unixepoch ('now'))
 ) STRICT;
@@ -191,3 +191,19 @@ create table if not exists evm_ether_transfer_grant_target (
 ) STRICT;
 
 create unique index if not exists uniq_ether_transfer_target on evm_ether_transfer_grant_target (grant_id, address);
+
+-- ===============================
+-- Integrity Envelopes
+-- ===============================
+create table if not exists integrity_envelope (
+    id integer not null primary key,
+    entity_kind text not null,
+    entity_id blob not null,
+    payload_version integer not null,
+    key_version integer not null,
+    mac blob not null, -- 20-byte recipient address
+    signed_at integer not null default(unixepoch ('now')),
+    created_at integer not null default(unixepoch ('now'))
+) STRICT;
+
+create unique index if not exists uniq_integrity_envelope_entity on integrity_envelope (entity_kind, entity_id);

server/crates/arbiter-server/src/actors/bootstrap.rs

@@ -2,8 +2,9 @@ use arbiter_proto::{BOOTSTRAP_PATH, home_path};
 use diesel::QueryDsl;
 use diesel_async::RunQueryDsl;
 use kameo::{Actor, messages};
-use miette::Diagnostic;
+
 use rand::{RngExt, distr::Alphanumeric, make_rng, rngs::StdRng};
+use subtle::ConstantTimeEq as _;
 use thiserror::Error;
 
 use crate::db::{self, DatabasePool, schema};
@@ -12,8 +13,8 @@ const TOKEN_LENGTH: usize = 64;
 pub async fn generate_token() -> Result<String, std::io::Error> {
     let rng: StdRng = make_rng();
 
-    let token: String = rng.sample_iter(Alphanumeric).take(TOKEN_LENGTH).fold(
-        Default::default(),
+    let token = rng.sample_iter(Alphanumeric).take(TOKEN_LENGTH).fold(
+        String::default(),
         |mut accum, char| {
             accum += char.to_string().as_str();
             accum
@@ -25,19 +26,16 @@ pub async fn generate_token() -> Result<String, std::io::Error> {
     Ok(token)
 }
 
-#[derive(Error, Debug, Diagnostic)]
-pub enum Error {
+#[derive(Error, Debug)]
+pub enum BootstrappError {
     #[error("Database error: {0}")]
-    #[diagnostic(code(arbiter_server::bootstrap::database))]
     Database(#[from] db::PoolError),
 
-    #[error("Database query error: {0}")]
-    #[diagnostic(code(arbiter_server::bootstrap::database_query))]
-    Query(#[from] diesel::result::Error),
-
     #[error("I/O error: {0}")]
-    #[diagnostic(code(arbiter_server::bootstrap::io))]
     Io(#[from] std::io::Error),
+
+    #[error("Database query error: {0}")]
+    Query(#[from] diesel::result::Error),
 }
 
 #[derive(Actor)]
@@ -46,15 +44,15 @@ pub struct Bootstrapper {
 }
 
 impl Bootstrapper {
-    pub async fn new(db: &DatabasePool) -> Result<Self, Error> {
-        let mut conn = db.get().await?;
+    pub async fn new(db: &DatabasePool) -> Result<Self, BootstrappError> {
+        let row_count: i64 = {
+            let mut conn = db.get().await?;
 
-        let row_count: i64 = schema::useragent_client::table
-            .count()
-            .get_result(&mut conn)
-            .await?;
-
-        drop(conn);
+            schema::useragent_client::table
+                .count()
+                .get_result(&mut conn)
+                .await?
+        };
 
         let token = if row_count == 0 {
             let token = generate_token().await?;
@@ -71,10 +69,13 @@ impl Bootstrapper {
 impl Bootstrapper {
     #[message]
     pub fn is_correct_token(&self, token: String) -> bool {
-        match &self.token {
-            Some(expected) => *expected == token,
-            None => false,
-        }
+        self.token.as_ref().is_some_and(|expected| {
+            let expected_bytes = expected.as_bytes();
+            let token_bytes = token.as_bytes();
+
+            let choice = expected_bytes.ct_eq(token_bytes);
+            bool::from(choice)
+        })
     }
 
     #[message]

server/crates/arbiter-server/src/actors/client/auth.rs

@@ -1,5 +1,7 @@
+use arbiter_crypto::authn::{self, CLIENT_CONTEXT};
 use arbiter_proto::{
-    ClientMetadata, format_challenge,
+    ClientMetadata,
+    proto::client::auth::{AuthChallenge as ProtoAuthChallenge, AuthResult as ProtoAuthResult},
     transport::{Bi, expect_message},
 };
 use chrono::Utc;
@@ -8,15 +10,16 @@ use diesel::{
     dsl::insert_into, update,
 };
 use diesel_async::RunQueryDsl as _;
-use ed25519_dalek::{Signature, VerifyingKey};
-use kameo::error::SendError;
+use kameo::{actor::ActorRef, error::SendError};
 use tracing::error;
 
 use crate::{
     actors::{
-        client::{ClientConnection, ClientProfile},
+        client::{ClientConnection, ClientCredentials, ClientProfile},
         flow_coordinator::{self, RequestClientApproval},
+        keyholder::KeyHolder,
     },
+    crypto::integrity::{self, AttestationStatus},
     db::{
         self,
         models::{ProgramClientMetadata, SqliteTimestamp},
@@ -25,25 +28,60 @@ use crate::{
 };
 
 #[derive(thiserror::Error, Debug, Clone, PartialEq, Eq)]
-pub enum Error {
-    #[error("Database pool unavailable")]
-    DatabasePoolUnavailable,
-    #[error("Database operation failed")]
-    DatabaseOperationFailed,
-    #[error("Invalid challenge solution")]
-    InvalidChallengeSolution,
+pub enum ClientAuthError {
     #[error("Client approval request failed")]
     ApproveError(#[from] ApproveError),
+
+    #[error("Database operation failed")]
+    DatabaseOperationFailed,
+
+    #[error("Database pool unavailable")]
+    DatabasePoolUnavailable,
+
+    #[error("Integrity check failed")]
+    IntegrityCheckFailed,
+
+    #[error("Invalid challenge solution")]
+    InvalidChallengeSolution,
+
     #[error("Transport error")]
     Transport,
 }
 
+impl From<diesel::result::Error> for ClientAuthError {
+    fn from(e: diesel::result::Error) -> Self {
+        error!(?e, "Database error");
+        Self::DatabaseOperationFailed
+    }
+}
+
+impl From<ClientAuthError> for arbiter_proto::proto::client::auth::AuthResult {
+    fn from(value: ClientAuthError) -> Self {
+        match value {
+            ClientAuthError::ApproveError(e) => match e {
+                ApproveError::Denied => Self::ApprovalDenied,
+                ApproveError::Internal => Self::Internal,
+                ApproveError::Upstream(flow_coordinator::ApprovalError::NoUserAgentsConnected) => {
+                    Self::NoUserAgentsOnline
+                } // ApproveError::Upstream(_) => Self::Internal,
+            },
+            ClientAuthError::DatabaseOperationFailed
+            | ClientAuthError::DatabasePoolUnavailable
+            | ClientAuthError::IntegrityCheckFailed
+            | ClientAuthError::Transport => Self::Internal,
+            ClientAuthError::InvalidChallengeSolution => Self::InvalidSignature,
+        }
+    }
+}
+
 #[derive(thiserror::Error, Debug, Clone, PartialEq, Eq)]
 pub enum ApproveError {
-    #[error("Internal error")]
-    Internal,
     #[error("Client connection denied by user agents")]
     Denied,
+
+    #[error("Internal error")]
+    Internal,
+
     #[error("Upstream error: {0}")]
     Upstream(flow_coordinator::ApprovalError),
 }
@@ -51,73 +89,147 @@ pub enum ApproveError {
 #[derive(Debug, Clone)]
 pub enum Inbound {
     AuthChallengeRequest {
-        pubkey: VerifyingKey,
+        pubkey: authn::PublicKey,
         metadata: ClientMetadata,
     },
     AuthChallengeSolution {
-        signature: Signature,
+        signature: authn::Signature,
     },
 }
 
 #[derive(Debug, Clone)]
 pub enum Outbound {
-    AuthChallenge { pubkey: VerifyingKey, nonce: i32 },
+    AuthChallenge {
+        pubkey: authn::PublicKey,
+        nonce: i32,
+    },
     AuthSuccess,
 }
 
-pub struct ClientInfo {
-    pub id: i32,
-    pub current_nonce: i32,
+impl From<Outbound> for arbiter_proto::proto::client::auth::response::Payload {
+    fn from(value: Outbound) -> Self {
+        match value {
+            Outbound::AuthChallenge { pubkey, nonce } => Self::Challenge(ProtoAuthChallenge {
+                pubkey: pubkey.to_bytes(),
+                nonce,
+            }),
+            Outbound::AuthSuccess => Self::Result(ProtoAuthResult::Success.into()),
+        }
+    }
 }
 
-/// Atomically reads and increments the nonce for a known client.
+/// Returns the current nonce and client ID for a registered client.
 /// Returns `None` if the pubkey is not registered.
-async fn get_client_and_nonce(
+async fn get_current_nonce_and_id(
     db: &db::DatabasePool,
-    pubkey: &VerifyingKey,
-) -> Result<Option<ClientInfo>, Error> {
-    let pubkey_bytes = pubkey.as_bytes().to_vec();
+    pubkey: &authn::PublicKey,
+) -> Result<Option<(i32, i32)>, ClientAuthError> {
+    let pubkey_bytes = pubkey.to_bytes();
+    let mut conn = db.get().await.map_err(|e| {
+        error!(error = ?e, "Database pool error");
+        ClientAuthError::DatabasePoolUnavailable
+    })?;
+    program_client::table
+        .filter(program_client::public_key.eq(&pubkey_bytes))
+        .select((program_client::id, program_client::nonce))
+        .first::<(i32, i32)>(&mut conn)
+        .await
+        .optional()
+        .map_err(|e| {
+            error!(error = ?e, "Database error");
+            ClientAuthError::DatabaseOperationFailed
+        })
+}
+
+async fn verify_integrity(
+    db: &db::DatabasePool,
+    keyholder: &ActorRef<KeyHolder>,
+    pubkey: &authn::PublicKey,
+) -> Result<(), ClientAuthError> {
+    let mut db_conn = db.get().await.map_err(|e| {
+        error!(error = ?e, "Database pool error");
+        ClientAuthError::DatabasePoolUnavailable
+    })?;
+
+    let (id, nonce) = get_current_nonce_and_id(db, pubkey).await?.ok_or_else(|| {
+        error!("Client not found during integrity verification");
+        ClientAuthError::DatabaseOperationFailed
+    })?;
+
+    let attestation = integrity::verify_entity(
+        &mut db_conn,
+        keyholder,
+        &ClientCredentials {
+            pubkey: pubkey.clone(),
+            nonce,
+        },
+        id,
+    )
+    .await
+    .map_err(|e| {
+        error!(?e, "Integrity verification failed");
+        ClientAuthError::IntegrityCheckFailed
+    })?;
+
+    if attestation != AttestationStatus::Attested {
+        error!("Integrity attestation unavailable for client {id}");
+        return Err(ClientAuthError::IntegrityCheckFailed);
+    }
+
+    Ok(())
+}
+
+/// Atomically increments the nonce and re-signs the integrity envelope.
+/// Returns the new nonce, which is used as the challenge nonce.
+async fn create_nonce(
+    db: &db::DatabasePool,
+    keyholder: &ActorRef<KeyHolder>,
+    pubkey: &authn::PublicKey,
+) -> Result<i32, ClientAuthError> {
+    let pubkey_bytes = pubkey.to_bytes();
+    let pubkey = pubkey.clone();
 
     let mut conn = db.get().await.map_err(|e| {
         error!(error = ?e, "Database pool error");
-        Error::DatabasePoolUnavailable
+        ClientAuthError::DatabasePoolUnavailable
     })?;
 
     conn.exclusive_transaction(|conn| {
+        let keyholder = keyholder.clone();
+        let pubkey = pubkey.clone();
         Box::pin(async move {
-            let Some((client_id, current_nonce)) = program_client::table
+            let (id, new_nonce): (i32, i32) = update(program_client::table)
                 .filter(program_client::public_key.eq(&pubkey_bytes))
-                .select((program_client::id, program_client::nonce))
-                .first::<(i32, i32)>(conn)
-                .await
-                .optional()?
-            else {
-                return Result::<_, diesel::result::Error>::Ok(None);
-            };
-
-            update(program_client::table)
-                .filter(program_client::public_key.eq(&pubkey_bytes))
-                .set(program_client::nonce.eq(current_nonce + 1))
-                .execute(conn)
+                .set(program_client::nonce.eq(program_client::nonce + 1))
+                .returning((program_client::id, program_client::nonce))
+                .get_result(conn)
                 .await?;
 
-            Ok(Some(ClientInfo {
-                id: client_id,
-                current_nonce,
-            }))
+            integrity::sign_entity(
+                conn,
+                &keyholder,
+                &ClientCredentials {
+                    pubkey: pubkey.clone(),
+                    nonce: new_nonce,
+                },
+                id,
+            )
+            .await
+            .map_err(|e| {
+                error!(?e, "Integrity sign failed after nonce update");
+                ClientAuthError::DatabaseOperationFailed
+            })?;
+
+            Ok(new_nonce)
         })
     })
     .await
-    .map_err(|e| {
-        error!(error = ?e, "Database error");
-        Error::DatabaseOperationFailed
-    })
 }
 
 async fn approve_new_client(
     actors: &crate::actors::GlobalActors,
     profile: ClientProfile,
-) -> Result<(), Error> {
+) -> Result<(), ClientAuthError> {
     let result = actors
         .flow_coordinator
         .ask(RequestClientApproval { client: profile })
@@ -125,73 +237,93 @@ async fn approve_new_client(
 
     match result {
         Ok(true) => Ok(()),
-        Ok(false) => Err(Error::ApproveError(ApproveError::Denied)),
+        Ok(false) => Err(ClientAuthError::ApproveError(ApproveError::Denied)),
         Err(SendError::HandlerError(e)) => {
             error!(error = ?e, "Approval upstream error");
-            Err(Error::ApproveError(ApproveError::Upstream(e)))
+            Err(ClientAuthError::ApproveError(ApproveError::Upstream(e)))
         }
         Err(e) => {
             error!(error = ?e, "Approval request to flow coordinator failed");
-            Err(Error::ApproveError(ApproveError::Internal))
+            Err(ClientAuthError::ApproveError(ApproveError::Internal))
         }
     }
 }
 
 async fn insert_client(
     db: &db::DatabasePool,
-    pubkey: &VerifyingKey,
+    keyholder: &ActorRef<KeyHolder>,
+    pubkey: &authn::PublicKey,
     metadata: &ClientMetadata,
-) -> Result<i32, Error> {
-    use crate::db::schema::{client_metadata, program_client};
+) -> Result<i32, ClientAuthError> {
+    use crate::db::schema::client_metadata;
+    let pubkey = pubkey.clone();
+    let metadata = metadata.clone();
+
     let mut conn = db.get().await.map_err(|e| {
         error!(error = ?e, "Database pool error");
-        Error::DatabasePoolUnavailable
+        ClientAuthError::DatabasePoolUnavailable
     })?;
 
-    let metadata_id = insert_into(client_metadata::table)
-        .values((
-            client_metadata::name.eq(&metadata.name),
-            client_metadata::description.eq(&metadata.description),
-            client_metadata::version.eq(&metadata.version),
-        ))
-        .returning(client_metadata::id)
-        .get_result::<i32>(&mut conn)
-        .await
-        .map_err(|e| {
-            error!(error = ?e, "Failed to insert client metadata");
-            Error::DatabaseOperationFailed
-        })?;
+    conn.exclusive_transaction(|conn| {
+        let keyholder = keyholder.clone();
+        let pubkey = pubkey.clone();
+        Box::pin(async move {
+            const NONCE_START: i32 = 1;
 
-    let client_id = insert_into(program_client::table)
-        .values((
-            program_client::public_key.eq(pubkey.as_bytes().to_vec()),
-            program_client::metadata_id.eq(metadata_id),
-            program_client::nonce.eq(1), // pre-incremented; challenge uses 0
-        ))
-        .on_conflict_do_nothing()
-        .returning(program_client::id)
-        .get_result::<i32>(&mut conn)
-        .await
-        .map_err(|e| {
-            error!(error = ?e, "Failed to insert client metadata");
-            Error::DatabaseOperationFailed
-        })?;
+            let metadata_id = insert_into(client_metadata::table)
+                .values((
+                    client_metadata::name.eq(&metadata.name),
+                    client_metadata::description.eq(&metadata.description),
+                    client_metadata::version.eq(&metadata.version),
+                ))
+                .returning(client_metadata::id)
+                .get_result::<i32>(conn)
+                .await?;
 
-    Ok(client_id)
+            let client_id = insert_into(program_client::table)
+                .values((
+                    program_client::public_key.eq(pubkey.to_bytes()),
+                    program_client::metadata_id.eq(metadata_id),
+                    program_client::nonce.eq(NONCE_START),
+                ))
+                .on_conflict_do_nothing()
+                .returning(program_client::id)
+                .get_result::<i32>(conn)
+                .await?;
+
+            integrity::sign_entity(
+                conn,
+                &keyholder,
+                &ClientCredentials {
+                    pubkey: pubkey.clone(),
+                    nonce: NONCE_START,
+                },
+                client_id,
+            )
+            .await
+            .map_err(|e| {
+                error!(error = ?e, "Failed to sign integrity tag for new client key");
+                ClientAuthError::DatabaseOperationFailed
+            })?;
+
+            Ok(client_id)
+        })
+    })
+    .await
 }
 
 async fn sync_client_metadata(
     db: &db::DatabasePool,
     client_id: i32,
     metadata: &ClientMetadata,
-) -> Result<(), Error> {
+) -> Result<(), ClientAuthError> {
     use crate::db::schema::{client_metadata, client_metadata_history};
 
     let now = SqliteTimestamp(Utc::now());
 
     let mut conn = db.get().await.map_err(|e| {
         error!(error = ?e, "Database pool error");
-        Error::DatabasePoolUnavailable
+        ClientAuthError::DatabasePoolUnavailable
     })?;
 
     conn.exclusive_transaction(|conn| {
@@ -247,42 +379,43 @@ async fn sync_client_metadata(
     .await
     .map_err(|e| {
         error!(error = ?e, "Database error");
-        Error::DatabaseOperationFailed
+        ClientAuthError::DatabaseOperationFailed
     })
 }
 
 async fn challenge_client<T>(
     transport: &mut T,
-    pubkey: VerifyingKey,
+    pubkey: authn::PublicKey,
     nonce: i32,
-) -> Result<(), Error>
+) -> Result<(), ClientAuthError>
 where
-    T: Bi<Inbound, Result<Outbound, Error>> + ?Sized,
+    T: Bi<Inbound, Result<Outbound, ClientAuthError>> + ?Sized,
 {
     transport
-        .send(Ok(Outbound::AuthChallenge { pubkey, nonce }))
+        .send(Ok(Outbound::AuthChallenge {
+            pubkey: pubkey.clone(),
+            nonce,
+        }))
         .await
         .map_err(|e| {
             error!(error = ?e, "Failed to send auth challenge");
-            Error::Transport
+            ClientAuthError::Transport
         })?;
 
     let signature = expect_message(transport, |req: Inbound| match req {
         Inbound::AuthChallengeSolution { signature } => Some(signature),
-        _ => None,
+        Inbound::AuthChallengeRequest { .. } => None,
     })
     .await
     .map_err(|e| {
         error!(error = ?e, "Failed to receive challenge solution");
-        Error::Transport
+        ClientAuthError::Transport
     })?;
 
-    let formatted = format_challenge(nonce, pubkey.as_bytes());
-
-    pubkey.verify_strict(&formatted, &signature).map_err(|_| {
+    if !pubkey.verify(nonce, CLIENT_CONTEXT, &signature) {
         error!("Challenge solution verification failed");
-        Error::InvalidChallengeSolution
-    })?;
+        return Err(ClientAuthError::InvalidChallengeSolution);
+    }
 
     Ok(())
 }
@@ -290,43 +423,40 @@ where
 pub async fn authenticate<T>(
     props: &mut ClientConnection,
     transport: &mut T,
-) -> Result<i32, Error>
+) -> Result<i32, ClientAuthError>
 where
-    T: Bi<Inbound, Result<Outbound, Error>> + Send + ?Sized,
+    T: Bi<Inbound, Result<Outbound, ClientAuthError>> + Send + ?Sized,
 {
     let Some(Inbound::AuthChallengeRequest { pubkey, metadata }) = transport.recv().await else {
-        return Err(Error::Transport);
+        return Err(ClientAuthError::Transport);
     };
 
-    let info = match get_client_and_nonce(&props.db, &pubkey).await? {
-        Some(nonce) => nonce,
-        None => {
-            approve_new_client(
-                &props.actors,
-                ClientProfile {
-                    pubkey,
-                    metadata: metadata.clone(),
-                },
-            )
-            .await?;
-            let client_id = insert_client(&props.db, &pubkey, &metadata).await?;
-            ClientInfo {
-                id: client_id,
-                current_nonce: 0,
-            }
-        }
+    let client_id = if let Some((id, _)) = get_current_nonce_and_id(&props.db, &pubkey).await? {
+        verify_integrity(&props.db, &props.actors.key_holder, &pubkey).await?;
+        id
+    } else {
+        approve_new_client(
+            &props.actors,
+            ClientProfile {
+                pubkey: pubkey.clone(),
+                metadata: metadata.clone(),
+            },
+        )
+        .await?;
+        insert_client(&props.db, &props.actors.key_holder, &pubkey, &metadata).await?
     };
 
-    sync_client_metadata(&props.db, info.id, &metadata).await?;
-    challenge_client(transport, pubkey, info.current_nonce).await?;
+    sync_client_metadata(&props.db, client_id, &metadata).await?;
+    let challenge_nonce = create_nonce(&props.db, &props.actors.key_holder, &pubkey).await?;
+    challenge_client(transport, pubkey, challenge_nonce).await?;
 
     transport
         .send(Ok(Outbound::AuthSuccess))
         .await
         .map_err(|e| {
             error!(error = ?e, "Failed to send auth success");
-            Error::Transport
+            ClientAuthError::Transport
         })?;
 
-    Ok(info.id)
+    Ok(client_id)
 }

server/crates/arbiter-server/src/actors/client/mod.rs

@@ -1,29 +1,38 @@
+use arbiter_crypto::authn;
 use arbiter_proto::{ClientMetadata, transport::Bi};
 use kameo::actor::Spawn;
 use tracing::{error, info};
 
 use crate::{
     actors::{GlobalActors, client::session::ClientSession},
+    crypto::integrity::Integrable,
     db,
 };
 
 #[derive(Debug, Clone)]
 pub struct ClientProfile {
-    pub pubkey: ed25519_dalek::VerifyingKey,
+    pub pubkey: authn::PublicKey,
     pub metadata: ClientMetadata,
 }
 
+#[derive(arbiter_macros::Hashable)]
+pub struct ClientCredentials {
+    pub pubkey: authn::PublicKey,
+    pub nonce: i32,
+}
+
+impl Integrable for ClientCredentials {
+    const KIND: &'static str = "client_credentials";
+}
+
 pub struct ClientConnection {
     pub(crate) db: db::DatabasePool,
     pub(crate) actors: GlobalActors,
 }
 
 impl ClientConnection {
-    pub fn new(db: db::DatabasePool, actors: GlobalActors) -> Self {
-        Self {
-            db,
-            actors,
-        }
+    pub const fn new(db: db::DatabasePool, actors: GlobalActors) -> Self {
+        Self { db, actors }
     }
 }
 
@@ -32,9 +41,11 @@ pub mod session;
 
 pub async fn connect_client<T>(mut props: ClientConnection, transport: &mut T)
 where
-    T: Bi<auth::Inbound, Result<auth::Outbound, auth::Error>> + Send + ?Sized,
+    T: Bi<auth::Inbound, Result<auth::Outbound, auth::ClientAuthError>> + Send + ?Sized,
 {
-    match auth::authenticate(&mut props, transport).await {
+    let fut = auth::authenticate(&mut props, transport);
+    println!("authenticate future size: {}", size_of_val(&fut));
+    match fut.await {
         Ok(client_id) => {
             ClientSession::spawn(ClientSession::new(props, client_id));
             info!("Client authenticated, session started");

server/crates/arbiter-server/src/actors/client/session.rs

@@ -6,11 +6,10 @@ use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
 use crate::{
     actors::{
         GlobalActors,
-        client::ClientConnection, flow_coordinator::RegisterClient,
-       
+        client::ClientConnection,
         evm::{ClientSignTransaction, SignTransactionError},
+        flow_coordinator::RegisterClient,
         keyholder::KeyHolderState,
-       
     },
     db,
     evm::VetError,
@@ -22,7 +21,7 @@ pub struct ClientSession {
 }
 
 impl ClientSession {
-    pub(crate) fn new(props: ClientConnection, client_id: i32) -> Self {
+    pub(crate) const fn new(props: ClientConnection, client_id: i32) -> Self {
         Self { props, client_id }
     }
 }
@@ -30,14 +29,16 @@ impl ClientSession {
 #[messages]
 impl ClientSession {
     #[message]
-    pub(crate) async fn handle_query_vault_state(&mut self) -> Result<KeyHolderState, Error> {
+    pub(crate) async fn handle_query_vault_state(
+        &mut self,
+    ) -> Result<KeyHolderState, ClientSessionError> {
         use crate::actors::keyholder::GetState;
 
         let vault_state = match self.props.actors.key_holder.ask(GetState {}).await {
             Ok(state) => state,
             Err(err) => {
                 error!(?err, actor = "client", "keyholder.query.failed");
-                return Err(Error::Internal);
+                return Err(ClientSessionError::Internal);
             }
         };
 
@@ -76,7 +77,7 @@ impl ClientSession {
 impl Actor for ClientSession {
     type Args = Self;
 
-    type Error = Error;
+    type Error = ClientSessionError;
 
     async fn on_start(
         args: Self::Args,
@@ -87,20 +88,23 @@ impl Actor for ClientSession {
             .flow_coordinator
             .ask(RegisterClient { actor: this })
             .await
-            .map_err(|_| Error::ConnectionRegistrationFailed)?;
+            .map_err(|_| ClientSessionError::ConnectionRegistrationFailed)?;
         Ok(args)
     }
 }
 
 impl ClientSession {
-    pub fn new_test(db: db::DatabasePool, actors: GlobalActors) -> Self {
+    pub const fn new_test(db: db::DatabasePool, actors: GlobalActors) -> Self {
         let props = ClientConnection::new(db, actors);
-        Self { props, client_id: 0 }
+        Self {
+            props,
+            client_id: 0,
+        }
     }
 }
 
 #[derive(Debug, thiserror::Error)]
-pub enum Error {
+pub enum ClientSessionError {
     #[error("Connection registration failed")]
     ConnectionRegistrationFailed,
     #[error("Internal error")]
@@ -109,9 +113,9 @@ pub enum Error {
 
 #[derive(Debug, thiserror::Error)]
 pub enum SignTransactionRpcError {
-    #[error("Policy evaluation failed")]
-    Vet(#[from] VetError),
-
     #[error("Internal error")]
     Internal,
+
+    #[error("Policy evaluation failed")]
+    Vet(#[from] VetError),
 }

server/crates/arbiter-server/src/actors/evm/mod.rs

@@ -1,4 +1,6 @@
-use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
+use alloy::{
+    consensus::TxEip1559, network::TxSignerSync as _, primitives::Address, signers::Signature,
+};
 use diesel::{
     ExpressionMethods, OptionalExtension as _, QueryDsl, SelectableHelper as _, dsl::insert_into,
 };
@@ -8,63 +10,58 @@ use rand::{SeedableRng, rng, rngs::StdRng};
 
 use crate::{
     actors::keyholder::{CreateNew, Decrypt, KeyHolder},
+    crypto::integrity,
     db::{
         DatabaseError, DatabasePool,
-        models::{self, SqliteTimestamp},
+        models::{self},
         schema,
     },
     evm::{
-        self, RunKind,
+        self, ListError, RunKind,
         policies::{
-            FullGrant, Grant, SharedGrantSettings, SpecificGrant, SpecificMeaning,
+            CombinedSettings, Grant, SharedGrantSettings, SpecificGrant, SpecificMeaning,
             ether_transfer::EtherTransfer, token_transfers::TokenTransfer,
         },
     },
-    safe_cell::{SafeCell, SafeCellHandle as _},
 };
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 
 pub use crate::evm::safe_signer;
 
-#[derive(Debug, thiserror::Error, miette::Diagnostic)]
+#[derive(Debug, thiserror::Error)]
 pub enum SignTransactionError {
     #[error("Wallet not found")]
-    #[diagnostic(code(arbiter::evm::sign::wallet_not_found))]
     WalletNotFound,
 
     #[error("Database error: {0}")]
-    #[diagnostic(code(arbiter::evm::sign::database))]
     Database(#[from] DatabaseError),
 
     #[error("Keyholder error: {0}")]
-    #[diagnostic(code(arbiter::evm::sign::keyholder))]
-    Keyholder(#[from] crate::actors::keyholder::Error),
+    Keyholder(#[from] crate::actors::keyholder::KeyHolderError),
 
     #[error("Keyholder mailbox error")]
-    #[diagnostic(code(arbiter::evm::sign::keyholder_send))]
     KeyholderSend,
 
     #[error("Signing error: {0}")]
-    #[diagnostic(code(arbiter::evm::sign::signing))]
     Signing(#[from] alloy::signers::Error),
 
     #[error("Policy error: {0}")]
-    #[diagnostic(code(arbiter::evm::sign::vet))]
     Vet(#[from] evm::VetError),
 }
 
-#[derive(Debug, thiserror::Error, miette::Diagnostic)]
-pub enum Error {
+#[derive(Debug, thiserror::Error)]
+pub enum EvmActorError {
     #[error("Keyholder error: {0}")]
-    #[diagnostic(code(arbiter::evm::keyholder))]
-    Keyholder(#[from] crate::actors::keyholder::Error),
+    Keyholder(#[from] crate::actors::keyholder::KeyHolderError),
 
     #[error("Keyholder mailbox error")]
-    #[diagnostic(code(arbiter::evm::keyholder_send))]
     KeyholderSend,
 
     #[error("Database error: {0}")]
-    #[diagnostic(code(arbiter::evm::database))]
     Database(#[from] DatabaseError),
+
+    #[error("Integrity violation: {0}")]
+    Integrity(#[from] integrity::IntegrityError),
 }
 
 #[derive(Actor)]
@@ -80,7 +77,7 @@ impl EvmActor {
         // is it safe to seed rng from system once?
         // todo: audit
         let rng = StdRng::from_rng(&mut rng());
-        let engine = evm::Engine::new(db.clone());
+        let engine = evm::Engine::new(db.clone(), keyholder.clone());
         Self {
             keyholder,
             db,
@@ -93,7 +90,7 @@ impl EvmActor {
 #[messages]
 impl EvmActor {
     #[message]
-    pub async fn generate(&mut self) -> Result<(i32, Address), Error> {
+    pub async fn generate(&mut self) -> Result<(i32, Address), EvmActorError> {
         let (mut key_cell, address) = safe_signer::generate(&mut self.rng);
 
         let plaintext = key_cell.read_inline(|reader| SafeCell::new(reader.to_vec()));
@@ -102,7 +99,7 @@ impl EvmActor {
             .keyholder
             .ask(CreateNew { plaintext })
             .await
-            .map_err(|_| Error::KeyholderSend)?;
+            .map_err(|_| EvmActorError::KeyholderSend)?;
 
         let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
         let wallet_id = insert_into(schema::evm_wallet::table)
@@ -119,7 +116,7 @@ impl EvmActor {
     }
 
     #[message]
-    pub async fn list_wallets(&self) -> Result<Vec<(i32, Address)>, Error> {
+    pub async fn list_wallets(&self) -> Result<Vec<(i32, Address)>, EvmActorError> {
         let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
         let rows: Vec<models::EvmWallet> = schema::evm_wallet::table
             .select(models::EvmWallet::as_select())
@@ -141,46 +138,64 @@ impl EvmActor {
         &mut self,
         basic: SharedGrantSettings,
         grant: SpecificGrant,
-    ) -> Result<i32, DatabaseError> {
+    ) -> Result<i32, EvmActorError> {
         match grant {
-            SpecificGrant::EtherTransfer(settings) => {
-                self.engine
-                    .create_grant::<EtherTransfer>(FullGrant {
-                        basic,
-                        specific: settings,
-                    })
-                    .await
-            }
-            SpecificGrant::TokenTransfer(settings) => {
-                self.engine
-                    .create_grant::<TokenTransfer>(FullGrant {
-                        basic,
-                        specific: settings,
-                    })
-                    .await
-            }
+            SpecificGrant::EtherTransfer(settings) => self
+                .engine
+                .create_grant::<EtherTransfer>(CombinedSettings {
+                    shared: basic,
+                    specific: settings,
+                })
+                .await
+                .map_err(EvmActorError::from),
+            SpecificGrant::TokenTransfer(settings) => self
+                .engine
+                .create_grant::<TokenTransfer>(CombinedSettings {
+                    shared: basic,
+                    specific: settings,
+                })
+                .await
+                .map_err(EvmActorError::from),
         }
     }
 
     #[message]
-    pub async fn useragent_delete_grant(&mut self, grant_id: i32) -> Result<(), Error> {
-        let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
-        diesel::update(schema::evm_basic_grant::table)
-            .filter(schema::evm_basic_grant::id.eq(grant_id))
-            .set(schema::evm_basic_grant::revoked_at.eq(SqliteTimestamp::now()))
-            .execute(&mut conn)
-            .await
-            .map_err(DatabaseError::from)?;
-        Ok(())
+    #[expect(clippy::unused_async, reason = "reserved for impl")]
+    pub async fn useragent_delete_grant(&mut self, _grant_id: i32) -> Result<(), EvmActorError> {
+        // let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
+        // let keyholder = self.keyholder.clone();
+
+        // diesel_async::AsyncConnection::transaction(&mut conn, |conn| {
+        //     Box::pin(async move {
+        //         diesel::update(schema::evm_basic_grant::table)
+        //             .filter(schema::evm_basic_grant::id.eq(grant_id))
+        //             .set(schema::evm_basic_grant::revoked_at.eq(SqliteTimestamp::now()))
+        //             .execute(conn)
+        //             .await?;
+
+        //         let signed = integrity::evm::load_signed_grant_by_basic_id(conn, grant_id).await?;
+
+        //         diesel::result::QueryResult::Ok(())
+        //     })
+        // })
+        // .await
+        // .map_err(DatabaseError::from)?;
+
+        // Ok(())
+        todo!()
     }
 
     #[message]
-    pub async fn useragent_list_grants(&mut self) -> Result<Vec<Grant<SpecificGrant>>, Error> {
-        Ok(self
-            .engine
-            .list_all_grants()
-            .await
-            .map_err(DatabaseError::from)?)
+    pub async fn useragent_list_grants(
+        &mut self,
+    ) -> Result<Vec<Grant<SpecificGrant>>, EvmActorError> {
+        match self.engine.list_all_grants().await {
+            Ok(grants) => Ok(grants),
+            Err(ListError::Database(db_err)) => Err(EvmActorError::Database(db_err)),
+            Err(ListError::Integrity(integrity_err)) => {
+                Err(EvmActorError::Integrity(integrity_err))
+            }
+        }
     }
 
     #[message]
@@ -259,7 +274,6 @@ impl EvmActor {
             .evaluate_transaction(wallet_access, transaction.clone(), RunKind::Execution)
             .await?;
 
-        use alloy::network::TxSignerSync as _;
         Ok(signer.sign_transaction_sync(&mut transaction)?)
     }
 }

server/crates/arbiter-server/src/actors/flow_coordinator/client_connect_approval.rs

@@ -15,7 +15,7 @@ use crate::actors::{
 pub struct Args {
     pub client: ClientProfile,
     pub user_agents: Vec<ActorRef<UserAgentSession>>,
-    pub reply: ReplySender<Result<bool, ApprovalError>>
+    pub reply: ReplySender<Result<bool, ApprovalError>>,
 }
 
 pub struct ClientApprovalController {
@@ -39,7 +39,11 @@ impl Actor for ClientApprovalController {
     type Error = ();
 
     async fn on_start(
-        Args { client, mut user_agents, reply }: Self::Args,
+        Args {
+            client,
+            user_agents,
+            reply,
+        }: Self::Args,
         actor_ref: ActorRef<Self>,
     ) -> Result<Self, Self::Error> {
         let this = Self {
@@ -48,8 +52,9 @@ impl Actor for ClientApprovalController {
             reply: Some(reply),
         };
 
-        for user_agent in user_agents.drain(..) {
+        for user_agent in user_agents {
             actor_ref.link(&user_agent).await;
+
             let _ = user_agent
                 .tell(BeginNewClientApproval {
                     client: client.clone(),
@@ -81,7 +86,7 @@ impl Actor for ClientApprovalController {
 #[messages]
 impl ClientApprovalController {
     #[message(ctx)]
-    pub async fn client_approval_answer(&mut self, approved: bool, ctx: &mut Context<Self, ()>) {
+    pub fn client_approval_answer(&mut self, approved: bool, ctx: &mut Context<Self, ()>) {
         if !approved {
             // Denial wins immediately regardless of other pending responses.
             self.send_reply(Ok(false));

server/crates/arbiter-server/src/actors/flow_coordinator/mod.rs

@@ -92,7 +92,7 @@ impl FlowCoordinator {
     }
 
     #[message(ctx)]
-    pub async fn request_client_approval(
+    pub fn request_client_approval(
         &mut self,
         client: ClientProfile,
         ctx: &mut Context<Self, DelegatedReply<Result<bool, ApprovalError>>>,

server/crates/arbiter-server/src/actors/keyholder/encryption.rs

@@ -1 +0,0 @@
-pub mod v1;

server/crates/arbiter-server/src/actors/keyholder/encryption/v1.rs

@@ -1,243 +0,0 @@
-use std::ops::Deref as _;
-
-use argon2::{Algorithm, Argon2, password_hash::Salt as ArgonSalt};
-use chacha20poly1305::{
-    AeadInPlace, Key, KeyInit as _, XChaCha20Poly1305, XNonce,
-    aead::{AeadMut, Error, Payload},
-};
-use rand::{
-    Rng as _, SeedableRng,
-    rngs::{StdRng, SysRng},
-};
-
-use crate::safe_cell::{SafeCell, SafeCellHandle as _};
-
-pub const ROOT_KEY_TAG: &[u8] = "arbiter/seal/v1".as_bytes();
-pub const TAG: &[u8] = "arbiter/private-key/v1".as_bytes();
-
-pub const NONCE_LENGTH: usize = 24;
-
-#[derive(Default)]
-pub struct Nonce([u8; NONCE_LENGTH]);
-impl Nonce {
-    pub fn increment(&mut self) {
-        for i in (0..self.0.len()).rev() {
-            if self.0[i] == 0xFF {
-                self.0[i] = 0;
-            } else {
-                self.0[i] += 1;
-                break;
-            }
-        }
-    }
-
-    pub fn to_vec(&self) -> Vec<u8> {
-        self.0.to_vec()
-    }
-}
-impl<'a> TryFrom<&'a [u8]> for Nonce {
-    type Error = ();
-
-    fn try_from(value: &'a [u8]) -> Result<Self, Self::Error> {
-        if value.len() != NONCE_LENGTH {
-            return Err(());
-        }
-        let mut nonce = [0u8; NONCE_LENGTH];
-        nonce.copy_from_slice(value);
-        Ok(Self(nonce))
-    }
-}
-
-pub struct KeyCell(pub SafeCell<Key>);
-impl From<SafeCell<Key>> for KeyCell {
-    fn from(value: SafeCell<Key>) -> Self {
-        Self(value)
-    }
-}
-impl TryFrom<SafeCell<Vec<u8>>> for KeyCell {
-    type Error = ();
-
-    fn try_from(mut value: SafeCell<Vec<u8>>) -> Result<Self, Self::Error> {
-        let value = value.read();
-        if value.len() != size_of::<Key>() {
-            return Err(());
-        }
-        let cell = SafeCell::new_inline(|cell_write: &mut Key| {
-            cell_write.copy_from_slice(&value);
-        });
-        Ok(Self(cell))
-    }
-}
-
-impl KeyCell {
-    pub fn new_secure_random() -> Self {
-        let key = SafeCell::new_inline(|key_buffer: &mut Key| {
-            #[allow(
-                clippy::unwrap_used,
-                reason = "Rng failure is unrecoverable and should panic"
-            )]
-            let mut rng = StdRng::try_from_rng(&mut SysRng).unwrap();
-            rng.fill_bytes(key_buffer);
-        });
-
-        key.into()
-    }
-
-    pub fn encrypt_in_place(
-        &mut self,
-        nonce: &Nonce,
-        associated_data: &[u8],
-        mut buffer: impl AsMut<Vec<u8>>,
-    ) -> Result<(), Error> {
-        let key_reader = self.0.read();
-        let key_ref = key_reader.deref();
-        let cipher = XChaCha20Poly1305::new(key_ref);
-        let nonce = XNonce::from_slice(nonce.0.as_ref());
-        let buffer = buffer.as_mut();
-        cipher.encrypt_in_place(nonce, associated_data, buffer)
-    }
-    pub fn decrypt_in_place(
-        &mut self,
-        nonce: &Nonce,
-        associated_data: &[u8],
-        buffer: &mut SafeCell<Vec<u8>>,
-    ) -> Result<(), Error> {
-        let key_reader = self.0.read();
-        let key_ref = key_reader.deref();
-        let cipher = XChaCha20Poly1305::new(key_ref);
-        let nonce = XNonce::from_slice(nonce.0.as_ref());
-        let mut buffer = buffer.write();
-        let buffer: &mut Vec<u8> = buffer.as_mut();
-        cipher.decrypt_in_place(nonce, associated_data, buffer)
-    }
-
-    pub fn encrypt(
-        &mut self,
-        nonce: &Nonce,
-        associated_data: &[u8],
-        plaintext: impl AsRef<[u8]>,
-    ) -> Result<Vec<u8>, Error> {
-        let key_reader = self.0.read();
-        let key_ref = key_reader.deref();
-        let mut cipher = XChaCha20Poly1305::new(key_ref);
-        let nonce = XNonce::from_slice(nonce.0.as_ref());
-
-        let ciphertext = cipher.encrypt(
-            nonce,
-            Payload {
-                msg: plaintext.as_ref(),
-                aad: associated_data,
-            },
-        )?;
-        Ok(ciphertext)
-    }
-}
-
-pub type Salt = [u8; ArgonSalt::RECOMMENDED_LENGTH];
-
-pub fn generate_salt() -> Salt {
-    let mut salt = Salt::default();
-    #[allow(
-        clippy::unwrap_used,
-        reason = "Rng failure is unrecoverable and should panic"
-    )]
-    let mut rng = StdRng::try_from_rng(&mut SysRng).unwrap();
-    rng.fill_bytes(&mut salt);
-    salt
-}
-
-/// User password might be of different length, have not enough entropy, etc...
-/// Derive a fixed-length key from the password using Argon2id, which is designed for password hashing and key derivation.
-pub fn derive_seal_key(mut password: SafeCell<Vec<u8>>, salt: &Salt) -> KeyCell {
-    #[allow(clippy::unwrap_used)]
-    let params = argon2::Params::new(262_144, 3, 4, None).unwrap();
-    let hasher = Argon2::new(Algorithm::Argon2id, argon2::Version::V0x13, params);
-    let mut key = SafeCell::new(Key::default());
-    password.read_inline(|password_source| {
-        let mut key_buffer = key.write();
-        let key_buffer: &mut [u8] = key_buffer.as_mut();
-
-        #[allow(
-            clippy::unwrap_used,
-            reason = "Better fail completely than return a weak key"
-        )]
-        hasher
-            .hash_password_into(password_source.deref(), salt, key_buffer)
-            .unwrap();
-    });
-
-    key.into()
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::safe_cell::SafeCell;
-
-    #[test]
-    pub fn derive_seal_key_deterministic() {
-        static PASSWORD: &[u8] = b"password";
-        let password = SafeCell::new(PASSWORD.to_vec());
-        let password2 = SafeCell::new(PASSWORD.to_vec());
-        let salt = generate_salt();
-
-        let mut key1 = derive_seal_key(password, &salt);
-        let mut key2 = derive_seal_key(password2, &salt);
-
-        let key1_reader = key1.0.read();
-        let key2_reader = key2.0.read();
-
-        assert_eq!(key1_reader.deref(), key2_reader.deref());
-    }
-
-    #[test]
-    pub fn successful_derive() {
-        static PASSWORD: &[u8] = b"password";
-        let password = SafeCell::new(PASSWORD.to_vec());
-        let salt = generate_salt();
-
-        let mut key = derive_seal_key(password, &salt);
-        let key_reader = key.0.read();
-        let key_ref = key_reader.deref();
-
-        assert_ne!(key_ref.as_slice(), &[0u8; 32][..]);
-    }
-
-    #[test]
-    pub fn encrypt_decrypt() {
-        static PASSWORD: &[u8] = b"password";
-        let password = SafeCell::new(PASSWORD.to_vec());
-        let salt = generate_salt();
-
-        let mut key = derive_seal_key(password, &salt);
-        let nonce = Nonce(*b"unique nonce 123 1231233"); // 24 bytes for XChaCha20Poly1305
-        let associated_data = b"associated data";
-        let mut buffer = b"secret data".to_vec();
-
-        key.encrypt_in_place(&nonce, associated_data, &mut buffer)
-            .unwrap();
-        assert_ne!(buffer, b"secret data");
-
-        let mut buffer = SafeCell::new(buffer);
-
-        key.decrypt_in_place(&nonce, associated_data, &mut buffer)
-            .unwrap();
-
-        let buffer = buffer.read();
-        assert_eq!(*buffer, b"secret data");
-    }
-
-    #[test]
-    // We should fuzz this
-    pub fn test_nonce_increment() {
-        let mut nonce = Nonce([0u8; NONCE_LENGTH]);
-        nonce.increment();
-
-        assert_eq!(
-            nonce.0,
-            [
-                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
-            ]
-        );
-    }
-}

server/crates/arbiter-server/src/actors/keyholder/mod.rs

@@ -4,22 +4,22 @@ use diesel::{
     dsl::{insert_into, update},
 };
 use diesel_async::{AsyncConnection, RunQueryDsl};
+use hmac::Mac as _;
 use kameo::{Actor, Reply, messages};
 use strum::{EnumDiscriminants, IntoDiscriminant};
 use tracing::{error, info};
 
-use crate::safe_cell::SafeCell;
-use crate::{
-    db::{
-        self,
-        models::{self, RootKeyHistory},
-        schema::{self},
-    },
-    safe_cell::SafeCellHandle as _,
+use crate::crypto::{
+    KeyCell, derive_key,
+    encryption::v1::{self, Nonce},
+    integrity::v1::HmacSha256,
 };
-use encryption::v1::{self, KeyCell, Nonce};
-
-pub mod encryption;
+use crate::db::{
+    self,
+    models::{self, RootKeyHistory},
+    schema::{self},
+};
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 
 #[derive(Default, EnumDiscriminants)]
 #[strum_discriminants(derive(Reply), vis(pub), name(KeyHolderState))]
@@ -35,40 +35,35 @@ enum State {
     },
 }
 
-#[derive(Debug, thiserror::Error, miette::Diagnostic)]
-pub enum Error {
+#[derive(Debug, thiserror::Error)]
+pub enum KeyHolderError {
     #[error("Keyholder is already bootstrapped")]
-    #[diagnostic(code(arbiter::keyholder::already_bootstrapped))]
     AlreadyBootstrapped,
-    #[error("Keyholder is not bootstrapped")]
-    #[diagnostic(code(arbiter::keyholder::not_bootstrapped))]
-    NotBootstrapped,
-    #[error("Invalid key provided")]
-    #[diagnostic(code(arbiter::keyholder::invalid_key))]
-    InvalidKey,
 
-    #[error("Requested aead entry not found")]
-    #[diagnostic(code(arbiter::keyholder::aead_not_found))]
-    NotFound,
-
-    #[error("Encryption error: {0}")]
-    #[diagnostic(code(arbiter::keyholder::encryption_error))]
-    Encryption(#[from] chacha20poly1305::aead::Error),
+    #[error("Broken database")]
+    BrokenDatabase,
 
     #[error("Database error: {0}")]
-    #[diagnostic(code(arbiter::keyholder::database_error))]
     DatabaseConnection(#[from] db::PoolError),
 
     #[error("Database transaction error: {0}")]
-    #[diagnostic(code(arbiter::keyholder::database_transaction_error))]
     DatabaseTransaction(#[from] diesel::result::Error),
 
-    #[error("Broken database")]
-    #[diagnostic(code(arbiter::keyholder::broken_database))]
-    BrokenDatabase,
+    #[error("Encryption error: {0}")]
+    Encryption(#[from] chacha20poly1305::aead::Error),
+
+    #[error("Invalid key provided")]
+    InvalidKey,
+
+    #[error("Keyholder is not bootstrapped")]
+    NotBootstrapped,
+
+    #[error("Requested aead entry not found")]
+    NotFound,
 }
 
 /// Manages vault root key and tracks current state of the vault (bootstrapped/unbootstrapped, sealed/unsealed).
+///
 /// Provides API for encrypting and decrypting data using the vault root key.
 /// Abstraction over database to make sure nonces are never reused and encryption keys are never exposed in plaintext outside of this actor.
 #[derive(Actor)]
@@ -79,7 +74,7 @@ pub struct KeyHolder {
 
 #[messages]
 impl KeyHolder {
-    pub async fn new(db: db::DatabasePool) -> Result<Self, Error> {
+    pub async fn new(db: db::DatabasePool) -> Result<Self, KeyHolderError> {
         let state = {
             let mut conn = db.get().await?;
 
@@ -102,7 +97,10 @@ impl KeyHolder {
 
     // Exclusive transaction to avoid race condtions if multiple keyholders write
     // additional layer of protection against nonce-reuse
-    async fn get_new_nonce(pool: &db::DatabasePool, root_key_id: i32) -> Result<Nonce, Error> {
+    async fn get_new_nonce(
+        pool: &db::DatabasePool,
+        root_key_id: i32,
+    ) -> Result<Nonce, KeyHolderError> {
         let mut conn = pool.get().await?;
 
         let nonce = conn
@@ -114,14 +112,13 @@ impl KeyHolder {
                         .first(conn)
                         .await?;
 
-                    let mut nonce =
-                        v1::Nonce::try_from(current_nonce.as_slice()).map_err(|_| {
-                            error!(
-                                "Broken database: invalid nonce for root key history id={}",
-                                root_key_id
-                            );
-                            Error::BrokenDatabase
-                        })?;
+                    let mut nonce = Nonce::try_from(current_nonce.as_slice()).map_err(|()| {
+                        error!(
+                            "Broken database: invalid nonce for root key history id={}",
+                            root_key_id
+                        );
+                        KeyHolderError::BrokenDatabase
+                    })?;
                     nonce.increment();
 
                     update(schema::root_key_history::table)
@@ -130,7 +127,7 @@ impl KeyHolder {
                         .execute(conn)
                         .await?;
 
-                    Result::<_, Error>::Ok(nonce)
+                    Result::<_, KeyHolderError>::Ok(nonce)
                 })
             })
             .await?;
@@ -139,17 +136,20 @@ impl KeyHolder {
     }
 
     #[message]
-    pub async fn bootstrap(&mut self, seal_key_raw: SafeCell<Vec<u8>>) -> Result<(), Error> {
+    pub async fn bootstrap(
+        &mut self,
+        seal_key_raw: SafeCell<Vec<u8>>,
+    ) -> Result<(), KeyHolderError> {
         if !matches!(self.state, State::Unbootstrapped) {
-            return Err(Error::AlreadyBootstrapped);
+            return Err(KeyHolderError::AlreadyBootstrapped);
         }
         let salt = v1::generate_salt();
-        let mut seal_key = v1::derive_seal_key(seal_key_raw, &salt);
+        let mut seal_key = derive_key(seal_key_raw, &salt);
         let mut root_key = KeyCell::new_secure_random();
 
         // Zero nonces are fine because they are one-time
-        let root_key_nonce = v1::Nonce::default();
-        let data_encryption_nonce = v1::Nonce::default();
+        let root_key_nonce = Nonce::default();
+        let data_encryption_nonce = Nonce::default();
 
         let root_key_ciphertext: Vec<u8> = root_key.0.read_inline(|reader| {
             let root_key_reader = reader.as_slice();
@@ -157,7 +157,7 @@ impl KeyHolder {
                 .encrypt(&root_key_nonce, v1::ROOT_KEY_TAG, root_key_reader)
                 .map_err(|err| {
                     error!(?err, "Fatal bootstrap error");
-                    Error::Encryption(err)
+                    KeyHolderError::Encryption(err)
                 })
         })?;
 
@@ -201,12 +201,15 @@ impl KeyHolder {
     }
 
     #[message]
-    pub async fn try_unseal(&mut self, seal_key_raw: SafeCell<Vec<u8>>) -> Result<(), Error> {
+    pub async fn try_unseal(
+        &mut self,
+        seal_key_raw: SafeCell<Vec<u8>>,
+    ) -> Result<(), KeyHolderError> {
         let State::Sealed {
             root_key_history_id,
         } = &self.state
         else {
-            return Err(Error::NotBootstrapped);
+            return Err(KeyHolderError::NotBootstrapped);
         };
 
         // We don't want to hold connection while doing expensive KDF work
@@ -222,16 +225,16 @@ impl KeyHolder {
         let salt = &current_key.salt;
         let salt = v1::Salt::try_from(salt.as_slice()).map_err(|_| {
             error!("Broken database: invalid salt for root key");
-            Error::BrokenDatabase
+            KeyHolderError::BrokenDatabase
         })?;
-        let mut seal_key = v1::derive_seal_key(seal_key_raw, &salt);
+        let mut seal_key = derive_key(seal_key_raw, &salt);
 
         let mut root_key = SafeCell::new(current_key.ciphertext.clone());
 
-        let nonce = v1::Nonce::try_from(current_key.root_key_encryption_nonce.as_slice()).map_err(
-            |_| {
+        let nonce = Nonce::try_from(current_key.root_key_encryption_nonce.as_slice()).map_err(
+            |()| {
                 error!("Broken database: invalid nonce for root key");
-                Error::BrokenDatabase
+                KeyHolderError::BrokenDatabase
             },
         )?;
 
@@ -239,14 +242,14 @@ impl KeyHolder {
             .decrypt_in_place(&nonce, v1::ROOT_KEY_TAG, &mut root_key)
             .map_err(|err| {
                 error!(?err, "Failed to unseal root key: invalid seal key");
-                Error::InvalidKey
+                KeyHolderError::InvalidKey
             })?;
 
         self.state = State::Unsealed {
             root_key_history_id: current_key.id,
-            root_key: v1::KeyCell::try_from(root_key).map_err(|err| {
+            root_key: KeyCell::try_from(root_key).map_err(|err| {
                 error!(?err, "Broken database: invalid encryption key size");
-                Error::BrokenDatabase
+                KeyHolderError::BrokenDatabase
             })?,
         };
 
@@ -255,11 +258,10 @@ impl KeyHolder {
         Ok(())
     }
 
-    // Decrypts the `aead_encrypted` entry with the given ID and returns the plaintext
     #[message]
-    pub async fn decrypt(&mut self, aead_id: i32) -> Result<SafeCell<Vec<u8>>, Error> {
+    pub async fn decrypt(&mut self, aead_id: i32) -> Result<SafeCell<Vec<u8>>, KeyHolderError> {
         let State::Unsealed { root_key, .. } = &mut self.state else {
-            return Err(Error::NotBootstrapped);
+            return Err(KeyHolderError::NotBootstrapped);
         };
 
         let row: models::AeadEncrypted = {
@@ -270,15 +272,15 @@ impl KeyHolder {
                 .first(&mut conn)
                 .await
                 .optional()?
-                .ok_or(Error::NotFound)?
+                .ok_or(KeyHolderError::NotFound)?
         };
 
-        let nonce = v1::Nonce::try_from(row.current_nonce.as_slice()).map_err(|_| {
+        let nonce = Nonce::try_from(row.current_nonce.as_slice()).map_err(|()| {
             error!(
                 "Broken database: invalid nonce for aead_encrypted id={}",
                 aead_id
             );
-            Error::BrokenDatabase
+            KeyHolderError::BrokenDatabase
         })?;
         let mut output = SafeCell::new(row.ciphertext);
         root_key.decrypt_in_place(&nonce, v1::TAG, &mut output)?;
@@ -287,13 +289,17 @@ impl KeyHolder {
 
     // Creates new `aead_encrypted` entry in the database and returns it's ID
     #[message]
-    pub async fn create_new(&mut self, mut plaintext: SafeCell<Vec<u8>>) -> Result<i32, Error> {
+    pub async fn create_new(
+        &mut self,
+        mut plaintext: SafeCell<Vec<u8>>,
+    ) -> Result<i32, KeyHolderError> {
         let State::Unsealed {
             root_key,
             root_key_history_id,
+            ..
         } = &mut self.state
         else {
-            return Err(Error::NotBootstrapped);
+            return Err(KeyHolderError::NotBootstrapped);
         };
 
         // Order matters here - `get_new_nonce` acquires connection, so we need to call it before next acquire
@@ -329,13 +335,63 @@ impl KeyHolder {
     }
 
     #[message]
-    pub fn seal(&mut self) -> Result<(), Error> {
+    pub fn sign_integrity(&mut self, mac_input: Vec<u8>) -> Result<(i32, Vec<u8>), KeyHolderError> {
+        let State::Unsealed {
+            root_key,
+            root_key_history_id,
+        } = &mut self.state
+        else {
+            return Err(KeyHolderError::NotBootstrapped);
+        };
+
+        let mut hmac = root_key.0.read_inline(|k| {
+            HmacSha256::new_from_slice(k)
+                .unwrap_or_else(|_| unreachable!("HMAC accepts keys of any size"))
+        });
+        hmac.update(&root_key_history_id.to_be_bytes());
+        hmac.update(&mac_input);
+
+        let mac = hmac.finalize().into_bytes().to_vec();
+        Ok((*root_key_history_id, mac))
+    }
+
+    #[message]
+    pub fn verify_integrity(
+        &mut self,
+        mac_input: Vec<u8>,
+        expected_mac: Vec<u8>,
+        key_version: i32,
+    ) -> Result<bool, KeyHolderError> {
+        let State::Unsealed {
+            root_key,
+            root_key_history_id,
+        } = &mut self.state
+        else {
+            return Err(KeyHolderError::NotBootstrapped);
+        };
+
+        if *root_key_history_id != key_version {
+            return Ok(false);
+        }
+
+        let mut hmac = root_key.0.read_inline(|k| {
+            HmacSha256::new_from_slice(k)
+                .unwrap_or_else(|_| unreachable!("HMAC accepts keys of any size"))
+        });
+        hmac.update(&key_version.to_be_bytes());
+        hmac.update(&mac_input);
+
+        Ok(hmac.verify_slice(&expected_mac).is_ok())
+    }
+
+    #[message]
+    pub fn seal(&mut self) -> Result<(), KeyHolderError> {
         let State::Unsealed {
             root_key_history_id,
             ..
         } = &self.state
         else {
-            return Err(Error::NotBootstrapped);
+            return Err(KeyHolderError::NotBootstrapped);
         };
         self.state = State::Sealed {
             root_key_history_id: *root_key_history_id,
@@ -346,14 +402,7 @@ impl KeyHolder {
 
 #[cfg(test)]
 mod tests {
-    use diesel::SelectableHelper;
-
-    use diesel_async::RunQueryDsl;
-
-    use crate::{
-        db::{self},
-        safe_cell::SafeCell,
-    };
+    use arbiter_crypto::safecell::SafeCellHandle as _;
 
     use super::*;
 
@@ -369,12 +418,12 @@ mod tests {
     async fn nonce_monotonic_even_when_nonce_allocation_interleaves() {
         let db = db::create_test_pool().await;
         let mut actor = bootstrapped_actor(&db).await;
-        let root_key_history_id = match actor.state {
-            State::Unsealed {
-                root_key_history_id,
-                ..
-            } => root_key_history_id,
-            _ => panic!("expected unsealed state"),
+        let State::Unsealed {
+            root_key_history_id,
+            ..
+        } = actor.state
+        else {
+            panic!("expected unsealed state");
         };
 
         let n1 = KeyHolder::get_new_nonce(&db, root_key_history_id)
@@ -386,8 +435,8 @@ mod tests {
         assert!(n2.to_vec() > n1.to_vec(), "nonce must increase");
 
         let mut conn = db.get().await.unwrap();
-        let root_row: models::RootKeyHistory = schema::root_key_history::table
-            .select(models::RootKeyHistory::as_select())
+        let root_row = schema::root_key_history::table
+            .select(RootKeyHistory::as_select())
             .first(&mut conn)
             .await
             .unwrap();

server/crates/arbiter-server/src/actors/mod.rs

@@ -1,5 +1,4 @@
 use kameo::actor::{ActorRef, Spawn};
-use miette::Diagnostic;
 use thiserror::Error;
 
 use crate::{
@@ -12,20 +11,18 @@ use crate::{
 
 pub mod bootstrap;
 pub mod client;
-mod evm;
+pub mod evm;
 pub mod flow_coordinator;
 pub mod keyholder;
 pub mod user_agent;
 
-#[derive(Error, Debug, Diagnostic)]
-pub enum SpawnError {
+#[derive(Error, Debug)]
+pub enum GlobalActorsSpawnError {
     #[error("Failed to spawn Bootstrapper actor")]
-    #[diagnostic(code(SpawnError::Bootstrapper))]
-    Bootstrapper(#[from] bootstrap::Error),
+    Bootstrapper(#[from] bootstrap::BootstrappError),
 
     #[error("Failed to spawn KeyHolder actor")]
-    #[diagnostic(code(SpawnError::KeyHolder))]
-    KeyHolder(#[from] keyholder::Error),
+    KeyHolder(#[from] keyholder::KeyHolderError),
 }
 
 /// Long-lived actors that are shared across all connections and handle global state and operations
@@ -38,7 +35,7 @@ pub struct GlobalActors {
 }
 
 impl GlobalActors {
-    pub async fn spawn(db: db::DatabasePool) -> Result<Self, SpawnError> {
+    pub async fn spawn(db: db::DatabasePool) -> Result<Self, GlobalActorsSpawnError> {
         let key_holder = KeyHolder::spawn(KeyHolder::new(db.clone()).await?);
         Ok(Self {
             bootstrapper: Bootstrapper::spawn(Bootstrapper::new(&db).await?),

server/crates/arbiter-server/src/actors/user_agent/auth.rs

@@ -1,18 +1,20 @@
+use arbiter_crypto::authn;
 use arbiter_proto::transport::Bi;
 use tracing::error;
 
 use crate::actors::user_agent::{
-    AuthPublicKey, UserAgentConnection,
+    UserAgentConnection,
     auth::state::{AuthContext, AuthStateMachine},
 };
-
 mod state;
-use state::*;
+use state::{
+    AuthError, AuthEvents, AuthStates, BootstrapAuthRequest, ChallengeRequest, ChallengeSolution,
+};
 
 #[derive(Debug, Clone)]
 pub enum Inbound {
     AuthChallengeRequest {
-        pubkey: AuthPublicKey,
+        pubkey: authn::PublicKey,
         bootstrap_token: Option<String>,
     },
     AuthChallengeSolution {
@@ -37,6 +39,13 @@ impl Error {
     }
 }
 
+impl From<diesel::result::Error> for Error {
+    fn from(e: diesel::result::Error) -> Self {
+        error!(?e, "Database error");
+        Self::internal("Database error")
+    }
+}
+
 #[derive(Debug, Clone)]
 pub enum Outbound {
     AuthChallenge { nonce: i32 },
@@ -64,7 +73,7 @@ fn parse_auth_event(payload: Inbound) -> AuthEvents {
 pub async fn authenticate<T>(
     props: &mut UserAgentConnection,
     transport: T,
-) -> Result<AuthPublicKey, Error>
+) -> Result<authn::PublicKey, Error>
 where
     T: Bi<Inbound, Result<Outbound, Error>> + Send,
 {

server/crates/arbiter-server/src/actors/user_agent/auth/state.rs

@@ -1,29 +1,33 @@
+use arbiter_crypto::authn::{self, USERAGENT_CONTEXT};
 use arbiter_proto::transport::Bi;
 use diesel::{ExpressionMethods as _, OptionalExtension as _, QueryDsl, update};
-use diesel_async::RunQueryDsl;
+use diesel_async::{AsyncConnection, RunQueryDsl};
+use kameo::actor::ActorRef;
 use tracing::error;
 
 use super::Error;
 use crate::{
     actors::{
         bootstrap::ConsumeToken,
-        user_agent::{AuthPublicKey, UserAgentConnection, auth::Outbound},
+        keyholder::KeyHolder,
+        user_agent::{UserAgentConnection, UserAgentCredentials, auth::Outbound},
     },
-    db::schema,
+    crypto::integrity,
+    db::{DatabasePool, schema::useragent_client},
 };
 
 pub struct ChallengeRequest {
-    pub pubkey: AuthPublicKey,
+    pub pubkey: authn::PublicKey,
 }
 
 pub struct BootstrapAuthRequest {
-    pub pubkey: AuthPublicKey,
+    pub pubkey: authn::PublicKey,
     pub token: String,
 }
 
 pub struct ChallengeContext {
     pub challenge_nonce: i32,
-    pub key: AuthPublicKey,
+    pub key: authn::PublicKey,
 }
 
 pub struct ChallengeSolution {
@@ -35,12 +39,16 @@ smlang::statemachine!(
     custom_error: true,
     transitions: {
         *Init + AuthRequest(ChallengeRequest) / async prepare_challenge = SentChallenge(ChallengeContext),
-        Init + BootstrapAuthRequest(BootstrapAuthRequest) / async verify_bootstrap_token = AuthOk(AuthPublicKey),
-        SentChallenge(ChallengeContext) + ReceivedSolution(ChallengeSolution) / async verify_solution = AuthOk(AuthPublicKey),
+        Init + BootstrapAuthRequest(BootstrapAuthRequest) / async verify_bootstrap_token = AuthOk(authn::PublicKey),
+        SentChallenge(ChallengeContext) + ReceivedSolution(ChallengeSolution) / async verify_solution = AuthOk(authn::PublicKey),
     }
 );
 
-async fn create_nonce(db: &crate::db::DatabasePool, pubkey_bytes: &[u8]) -> Result<i32, Error> {
+/// Returns the current nonce, ready to use for the challenge nonce.
+async fn get_current_nonce_and_id(
+    db: &DatabasePool,
+    key: &authn::PublicKey,
+) -> Result<(i32, i32), Error> {
     let mut db_conn = db.get().await.map_err(|e| {
         error!(error = ?e, "Database pool error");
         Error::internal("Database unavailable")
@@ -48,19 +56,11 @@ async fn create_nonce(db: &crate::db::DatabasePool, pubkey_bytes: &[u8]) -> Resu
     db_conn
         .exclusive_transaction(|conn| {
             Box::pin(async move {
-                let current_nonce = schema::useragent_client::table
-                    .filter(schema::useragent_client::public_key.eq(pubkey_bytes.to_vec()))
-                    .select(schema::useragent_client::nonce)
-                    .first::<i32>(conn)
-                    .await?;
-
-                update(schema::useragent_client::table)
-                    .filter(schema::useragent_client::public_key.eq(pubkey_bytes.to_vec()))
-                    .set(schema::useragent_client::nonce.eq(current_nonce + 1))
-                    .execute(conn)
-                    .await?;
-
-                Result::<_, diesel::result::Error>::Ok(current_nonce)
+                useragent_client::table
+                    .filter(useragent_client::public_key.eq(key.to_bytes()))
+                    .select((useragent_client::id, useragent_client::nonce))
+                    .first::<(i32, i32)>(conn)
+                    .await
             })
         })
         .await
@@ -70,31 +70,130 @@ async fn create_nonce(db: &crate::db::DatabasePool, pubkey_bytes: &[u8]) -> Resu
             Error::internal("Database operation failed")
         })?
         .ok_or_else(|| {
-            error!(?pubkey_bytes, "Public key not found in database");
+            error!(?key, "Public key not found in database");
             Error::UnregisteredPublicKey
         })
 }
 
-async fn register_key(db: &crate::db::DatabasePool, pubkey: &AuthPublicKey) -> Result<(), Error> {
-    let pubkey_bytes = pubkey.to_stored_bytes();
-    let key_type = pubkey.key_type();
+async fn verify_integrity(
+    db: &DatabasePool,
+    keyholder: &ActorRef<KeyHolder>,
+    pubkey: &authn::PublicKey,
+) -> Result<(), Error> {
+    let mut db_conn = db.get().await.map_err(|e| {
+        error!(error = ?e, "Database pool error");
+        Error::internal("Database unavailable")
+    })?;
+
+    let (id, nonce) = get_current_nonce_and_id(db, pubkey).await?;
+
+    let _result = integrity::verify_entity(
+        &mut db_conn,
+        keyholder,
+        &UserAgentCredentials {
+            pubkey: pubkey.clone(),
+            nonce,
+        },
+        id,
+    )
+    .await
+    .map_err(|e| {
+        error!(?e, "Integrity verification failed");
+        Error::internal("Integrity verification failed")
+    })?;
+
+    Ok(())
+}
+
+async fn create_nonce(
+    db: &DatabasePool,
+    keyholder: &ActorRef<KeyHolder>,
+    pubkey: &authn::PublicKey,
+) -> Result<i32, Error> {
+    let mut db_conn = db.get().await.map_err(|e| {
+        error!(error = ?e, "Database pool error");
+        Error::internal("Database unavailable")
+    })?;
+    let new_nonce = db_conn
+        .exclusive_transaction(|conn| {
+            Box::pin(async move {
+                let (id, new_nonce): (i32, i32) = update(useragent_client::table)
+                    .filter(useragent_client::public_key.eq(pubkey.to_bytes()))
+                    .set(useragent_client::nonce.eq(useragent_client::nonce + 1))
+                    .returning((useragent_client::id, useragent_client::nonce))
+                    .get_result(conn)
+                    .await
+                    .map_err(|e| {
+                        error!(error = ?e, "Database error");
+                        Error::internal("Database operation failed")
+                    })?;
+
+                integrity::sign_entity(
+                    conn,
+                    keyholder,
+                    &UserAgentCredentials {
+                        pubkey: pubkey.clone(),
+                        nonce: new_nonce,
+                    },
+                    id,
+                )
+                .await
+                .map_err(|e| {
+                    error!(?e, "Integrity signature update failed");
+                    Error::internal("Database error")
+                })?;
+
+                Result::<_, Error>::Ok(new_nonce)
+            })
+        })
+        .await?;
+    Ok(new_nonce)
+}
+
+async fn register_key(
+    db: &DatabasePool,
+    keyholder: &ActorRef<KeyHolder>,
+    pubkey: &authn::PublicKey,
+) -> Result<(), Error> {
+    let pubkey_bytes = pubkey.to_bytes();
     let mut conn = db.get().await.map_err(|e| {
         error!(error = ?e, "Database pool error");
         Error::internal("Database unavailable")
     })?;
 
-    diesel::insert_into(schema::useragent_client::table)
-        .values((
-            schema::useragent_client::public_key.eq(pubkey_bytes),
-            schema::useragent_client::nonce.eq(1),
-            schema::useragent_client::key_type.eq(key_type),
-        ))
-        .execute(&mut conn)
-        .await
-        .map_err(|e| {
-            error!(error = ?e, "Database error");
-            Error::internal("Database operation failed")
-        })?;
+    conn.transaction(|conn| {
+        Box::pin(async move {
+            const NONCE_START: i32 = 1;
+
+            let id: i32 = diesel::insert_into(useragent_client::table)
+                .values((
+                    useragent_client::public_key.eq(pubkey_bytes),
+                    useragent_client::nonce.eq(NONCE_START),
+                ))
+                .returning(useragent_client::id)
+                .get_result(conn)
+                .await
+                .map_err(|e| {
+                    error!(error = ?e, "Database error");
+                    Error::internal("Database operation failed")
+                })?;
+
+            let entity = UserAgentCredentials {
+                pubkey: pubkey.clone(),
+                nonce: NONCE_START,
+            };
+
+            integrity::sign_entity(conn, keyholder, &entity, id)
+                .await
+                .map_err(|e| {
+                    error!(error = ?e, "Failed to sign integrity tag for new user-agent key");
+                    Error::internal("Failed to register public key")
+                })?;
+
+            Result::<_, Error>::Ok(())
+        })
+    })
+    .await?;
 
     Ok(())
 }
@@ -105,14 +204,14 @@ pub struct AuthContext<'a, T> {
 }
 
 impl<'a, T> AuthContext<'a, T> {
-    pub fn new(conn: &'a mut UserAgentConnection, transport: T) -> Self {
+    pub const fn new(conn: &'a mut UserAgentConnection, transport: T) -> Self {
         Self { conn, transport }
     }
 }
 
 impl<T> AuthStateMachineContext for AuthContext<'_, T>
 where
-    T: Bi<super::Inbound, Result<super::Outbound, Error>> + Send,
+    T: Bi<super::Inbound, Result<Outbound, Error>> + Send,
 {
     type Error = Error;
 
@@ -120,8 +219,9 @@ where
         &mut self,
         ChallengeRequest { pubkey }: ChallengeRequest,
     ) -> Result<ChallengeContext, Self::Error> {
-        let stored_bytes = pubkey.to_stored_bytes();
-        let nonce = create_nonce(&self.conn.db, &stored_bytes).await?;
+        verify_integrity(&self.conn.db, &self.conn.actors.key_holder, &pubkey).await?;
+
+        let nonce = create_nonce(&self.conn.db, &self.conn.actors.key_holder, &pubkey).await?;
 
         self.transport
             .send(Ok(Outbound::AuthChallenge { nonce }))
@@ -137,12 +237,10 @@ where
         })
     }
 
-    #[allow(missing_docs)]
-    #[allow(clippy::result_unit_err)]
     async fn verify_bootstrap_token(
         &mut self,
         BootstrapAuthRequest { pubkey, token }: BootstrapAuthRequest,
-    ) -> Result<AuthPublicKey, Self::Error> {
+    ) -> Result<authn::PublicKey, Self::Error> {
         let token_ok: bool = self
             .conn
             .actors
@@ -161,18 +259,23 @@ where
             return Err(Error::InvalidBootstrapToken);
         }
 
-        register_key(&self.conn.db, &pubkey).await?;
-
-        self.transport
-            .send(Ok(Outbound::AuthSuccess))
-            .await
-            .map_err(|_| Error::Transport)?;
-
-        Ok(pubkey)
+        if token_ok {
+            register_key(&self.conn.db, &self.conn.actors.key_holder, &pubkey).await?;
+            self.transport
+                .send(Ok(Outbound::AuthSuccess))
+                .await
+                .map_err(|_| Error::Transport)?;
+            Ok(pubkey)
+        } else {
+            error!("Invalid bootstrap token provided");
+            self.transport
+                .send(Err(Error::InvalidBootstrapToken))
+                .await
+                .map_err(|_| Error::Transport)?;
+            Err(Error::InvalidBootstrapToken)
+        }
     }
 
-    #[allow(missing_docs)]
-    #[allow(clippy::unused_unit)]
     async fn verify_solution(
         &mut self,
         ChallengeContext {
@@ -180,46 +283,26 @@ where
             key,
         }: &ChallengeContext,
         ChallengeSolution { solution }: ChallengeSolution,
-    ) -> Result<AuthPublicKey, Self::Error> {
-        let formatted = arbiter_proto::format_challenge(*challenge_nonce, &key.to_stored_bytes());
+    ) -> Result<authn::PublicKey, Self::Error> {
+        let signature = authn::Signature::try_from(solution.as_slice()).map_err(|()| {
+            error!("Failed to decode signature in challenge solution");
+            Error::InvalidChallengeSolution
+        })?;
 
-        let valid = match key {
-            AuthPublicKey::Ed25519(vk) => {
-                let sig = solution.as_slice().try_into().map_err(|_| {
-                    error!(?solution, "Invalid Ed25519 signature length");
-                    Error::InvalidChallengeSolution
-                })?;
-                vk.verify_strict(&formatted, &sig).is_ok()
-            }
-            AuthPublicKey::EcdsaSecp256k1(vk) => {
-                use k256::ecdsa::signature::Verifier as _;
-                let sig = k256::ecdsa::Signature::try_from(solution.as_slice()).map_err(|_| {
-                    error!(?solution, "Invalid ECDSA signature bytes");
-                    Error::InvalidChallengeSolution
-                })?;
-                vk.verify(&formatted, &sig).is_ok()
-            }
-            AuthPublicKey::Rsa(pk) => {
-                use rsa::signature::Verifier as _;
-                let verifying_key = rsa::pss::VerifyingKey::<sha2::Sha256>::new(pk.clone());
-                let sig = rsa::pss::Signature::try_from(solution.as_slice()).map_err(|_| {
-                    error!(?solution, "Invalid RSA signature bytes");
-                    Error::InvalidChallengeSolution
-                })?;
-                verifying_key.verify(&formatted, &sig).is_ok()
-            }
-        };
+        let valid = key.verify(*challenge_nonce, USERAGENT_CONTEXT, &signature);
 
-        if !valid {
-            error!("Invalid challenge solution signature");
-            return Err(Error::InvalidChallengeSolution);
+        if valid {
+            self.transport
+                .send(Ok(Outbound::AuthSuccess))
+                .await
+                .map_err(|_| Error::Transport)?;
+            Ok(key.clone())
+        } else {
+            self.transport
+                .send(Err(Error::InvalidChallengeSolution))
+                .await
+                .map_err(|_| Error::Transport)?;
+            Err(Error::InvalidChallengeSolution)
         }
-
-        self.transport
-            .send(Ok(Outbound::AuthSuccess))
-            .await
-            .map_err(|_| Error::Transport)?;
-
-        Ok(key.clone())
     }
 }

server/crates/arbiter-server/src/actors/user_agent/mod.rs

@@ -1,79 +1,25 @@
 use crate::{
     actors::{GlobalActors, client::ClientProfile},
-    db::{self, models::KeyType},
+    crypto::integrity::Integrable,
+    db,
 };
+use arbiter_crypto::authn;
 
-/// Abstraction over Ed25519 / ECDSA-secp256k1 / RSA public keys used during the auth handshake.
-#[derive(Clone, Debug)]
-pub enum AuthPublicKey {
-    Ed25519(ed25519_dalek::VerifyingKey),
-    /// Compressed SEC1 public key; signature bytes are raw 64-byte (r||s).
-    EcdsaSecp256k1(k256::ecdsa::VerifyingKey),
-    /// RSA-2048+ public key (Windows Hello / KeyCredentialManager); signature bytes are PSS+SHA-256.
-    Rsa(rsa::RsaPublicKey),
+#[derive(Debug, arbiter_macros::Hashable)]
+pub struct UserAgentCredentials {
+    pub pubkey: authn::PublicKey,
+    pub nonce: i32,
 }
 
-impl AuthPublicKey {
-    /// Canonical bytes stored in DB and echoed back in the challenge.
-    /// Ed25519: raw 32 bytes. ECDSA: SEC1 compressed 33 bytes. RSA: DER-encoded SPKI.
-    pub fn to_stored_bytes(&self) -> Vec<u8> {
-        match self {
-            AuthPublicKey::Ed25519(k) => k.to_bytes().to_vec(),
-            // SEC1 compressed (33 bytes) is the natural compact format for secp256k1
-            AuthPublicKey::EcdsaSecp256k1(k) => k.to_encoded_point(true).as_bytes().to_vec(),
-            AuthPublicKey::Rsa(k) => {
-                use rsa::pkcs8::EncodePublicKey as _;
-                #[allow(clippy::expect_used)]
-                k.to_public_key_der()
-                    .expect("rsa SPKI encoding is infallible")
-                    .to_vec()
-            }
-        }
-    }
-
-    pub fn key_type(&self) -> KeyType {
-        match self {
-            AuthPublicKey::Ed25519(_) => KeyType::Ed25519,
-            AuthPublicKey::EcdsaSecp256k1(_) => KeyType::EcdsaSecp256k1,
-            AuthPublicKey::Rsa(_) => KeyType::Rsa,
-        }
-    }
-}
-
-impl TryFrom<(KeyType, Vec<u8>)> for AuthPublicKey {
-    type Error = &'static str;
-
-    fn try_from(value: (KeyType, Vec<u8>)) -> Result<Self, Self::Error> {
-        let (key_type, bytes) = value;
-        match key_type {
-            KeyType::Ed25519 => {
-                let bytes: [u8; 32] = bytes.try_into().map_err(|_| "invalid Ed25519 key length")?;
-                let key = ed25519_dalek::VerifyingKey::from_bytes(&bytes)
-                    .map_err(|_e| "invalid Ed25519 key")?;
-                Ok(AuthPublicKey::Ed25519(key))
-            }
-            KeyType::EcdsaSecp256k1 => {
-                let point =
-                    k256::EncodedPoint::from_bytes(&bytes).map_err(|_e| "invalid ECDSA key")?;
-                let key = k256::ecdsa::VerifyingKey::from_encoded_point(&point)
-                    .map_err(|_e| "invalid ECDSA key")?;
-                Ok(AuthPublicKey::EcdsaSecp256k1(key))
-            }
-            KeyType::Rsa => {
-                use rsa::pkcs8::DecodePublicKey as _;
-                let key = rsa::RsaPublicKey::from_public_key_der(&bytes)
-                    .map_err(|_e| "invalid RSA key")?;
-                Ok(AuthPublicKey::Rsa(key))
-            }
-        }
-    }
+impl Integrable for UserAgentCredentials {
+    const KIND: &'static str = "useragent_credentials";
 }
 
 // Messages, sent by user agent to connection client without having a request
 #[derive(Debug)]
 pub enum OutOfBand {
     ClientConnectionRequest { profile: ClientProfile },
-    ClientConnectionCancel { pubkey: ed25519_dalek::VerifyingKey },
+    ClientConnectionCancel { pubkey: authn::PublicKey },
 }
 
 pub struct UserAgentConnection {
@@ -82,7 +28,7 @@ pub struct UserAgentConnection {
 }
 
 impl UserAgentConnection {
-    pub fn new(db: db::DatabasePool, actors: GlobalActors) -> Self {
+    pub const fn new(db: db::DatabasePool, actors: GlobalActors) -> Self {
         Self { db, actors }
     }
 }

server/crates/arbiter-server/src/actors/user_agent/session.rs

@@ -1,8 +1,9 @@
+use arbiter_crypto::authn;
+
 use std::{borrow::Cow, collections::HashMap};
 
 use arbiter_proto::transport::Sender;
 use async_trait::async_trait;
-use ed25519_dalek::VerifyingKey;
 use kameo::{Actor, actor::ActorRef, messages};
 use thiserror::Error;
 use tracing::error;
@@ -12,33 +13,32 @@ use crate::actors::{
     flow_coordinator::{RegisterUserAgent, client_connect_approval::ClientApprovalController},
     user_agent::{OutOfBand, UserAgentConnection},
 };
-
 mod state;
 use state::{DummyContext, UserAgentEvents, UserAgentStateMachine};
 
 #[derive(Debug, Error)]
-pub enum Error {
-    #[error("State transition failed")]
-    State,
-
+pub enum UserAgentSessionError {
     #[error("Internal error: {message}")]
     Internal { message: Cow<'static, str> },
+
+    #[error("State transition failed")]
+    State,
 }
 
-impl From<crate::db::PoolError> for Error {
+impl From<crate::db::PoolError> for UserAgentSessionError {
     fn from(err: crate::db::PoolError) -> Self {
         error!(?err, "Database pool error");
         Self::internal("Database pool error")
     }
 }
-impl From<diesel::result::Error> for Error {
+impl From<diesel::result::Error> for UserAgentSessionError {
     fn from(err: diesel::result::Error) -> Self {
         error!(?err, "Database error");
         Self::internal("Database error")
     }
 }
 
-impl Error {
+impl UserAgentSessionError {
     pub fn internal(message: impl Into<Cow<'static, str>>) -> Self {
         Self::Internal {
             message: message.into(),
@@ -47,6 +47,7 @@ impl Error {
 }
 
 pub struct PendingClientApproval {
+    pubkey: authn::PublicKey,
     controller: ActorRef<ClientApprovalController>,
 }
 
@@ -55,7 +56,7 @@ pub struct UserAgentSession {
     state: UserAgentStateMachine<DummyContext>,
     sender: Box<dyn Sender<OutOfBand>>,
 
-    pending_client_approvals: HashMap<VerifyingKey, PendingClientApproval>,
+    pending_client_approvals: HashMap<Vec<u8>, PendingClientApproval>,
 }
 
 pub mod connection;
@@ -66,7 +67,7 @@ impl UserAgentSession {
             props,
             state: UserAgentStateMachine::new(DummyContext),
             sender,
-            pending_client_approvals: Default::default(),
+            pending_client_approvals: HashMap::default(),
         }
     }
 
@@ -86,10 +87,10 @@ impl UserAgentSession {
         Self::new(UserAgentConnection::new(db, actors), Box::new(DummySender))
     }
 
-    fn transition(&mut self, event: UserAgentEvents) -> Result<(), Error> {
+    fn transition(&mut self, event: UserAgentEvents) -> Result<(), UserAgentSessionError> {
         self.state.process_event(event).map_err(|e| {
             error!(?e, "State transition failed");
-            Error::State
+            UserAgentSessionError::State
         })?;
         Ok(())
     }
@@ -118,19 +119,24 @@ impl UserAgentSession {
             return;
         }
 
-        self.pending_client_approvals
-            .insert(client.pubkey, PendingClientApproval { controller });
+        self.pending_client_approvals.insert(
+            client.pubkey.to_bytes(),
+            PendingClientApproval {
+                pubkey: client.pubkey,
+                controller,
+            },
+        );
     }
 }
 
 impl Actor for UserAgentSession {
     type Args = Self;
 
-    type Error = Error;
+    type Error = UserAgentSessionError;
 
     async fn on_start(
         args: Self::Args,
-        this: kameo::prelude::ActorRef<Self>,
+        this: ActorRef<Self>,
     ) -> Result<Self, Self::Error> {
         args.props
             .actors
@@ -144,7 +150,9 @@ impl Actor for UserAgentSession {
                     ?err,
                     "Failed to register user agent connection with flow coordinator"
                 );
-                Error::internal("Failed to register user agent connection with flow coordinator")
+                UserAgentSessionError::internal(
+                    "Failed to register user agent connection with flow coordinator",
+                )
             })?;
         Ok(args)
     }
@@ -158,14 +166,18 @@ impl Actor for UserAgentSession {
         let cancelled_pubkey = self
             .pending_client_approvals
             .iter()
-            .find_map(|(k, v)| (v.controller.id() == id).then_some(*k));
+            .find_map(|(k, v)| (v.controller.id() == id).then_some(k.clone()));
 
-        if let Some(pubkey) = cancelled_pubkey {
-            self.pending_client_approvals.remove(&pubkey);
+        if let Some(pubkey_bytes) = cancelled_pubkey {
+            let Some(approval) = self.pending_client_approvals.remove(&pubkey_bytes) else {
+                return Ok(std::ops::ControlFlow::Continue(()));
+            };
 
             if let Err(e) = self
                 .sender
-                .send(OutOfBand::ClientConnectionCancel { pubkey })
+                .send(OutOfBand::ClientConnectionCancel {
+                    pubkey: approval.pubkey,
+                })
                 .await
             {
                 error!(

server/crates/arbiter-server/src/actors/user_agent/session/connection.rs

@@ -1,43 +1,46 @@
 use std::sync::Mutex;
 
 use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
+use arbiter_crypto::{
+    authn,
+    safecell::{SafeCell, SafeCellHandle as _},
+};
 use chacha20poly1305::{AeadInPlace, XChaCha20Poly1305, XNonce, aead::KeyInit};
 use diesel::{ExpressionMethods as _, QueryDsl as _, SelectableHelper};
 use diesel_async::{AsyncConnection, RunQueryDsl};
 use kameo::error::SendError;
-use kameo::prelude::Context;
 use kameo::messages;
+use kameo::prelude::Context;
+use thiserror::Error;
 use tracing::{error, info};
 use x25519_dalek::{EphemeralSecret, PublicKey};
 
-use crate::actors::flow_coordinator::client_connect_approval::ClientApprovalAnswer;
+use crate::{actors::flow_coordinator::client_connect_approval::ClientApprovalAnswer, evm::policies::SharedGrantSettings};
 use crate::actors::keyholder::KeyHolderState;
-use crate::actors::user_agent::session::Error;
+use crate::actors::user_agent::session::UserAgentSessionError;
+use crate::actors::{
+    evm::{
+        ClientSignTransaction, Generate, ListWallets, SignTransactionError as EvmSignError,
+        UseragentCreateGrant, UseragentListGrants,
+    },
+    keyholder::{self, Bootstrap, TryUnseal},
+    user_agent::session::{
+        UserAgentSession,
+        state::{UnsealContext, UserAgentEvents, UserAgentStates},
+    },
+};
 use crate::db::models::{
     EvmWalletAccess, NewEvmWalletAccess, ProgramClient, ProgramClientMetadata,
 };
 use crate::evm::policies::{Grant, SpecificGrant};
-use crate::safe_cell::SafeCell;
-use crate::{
-    actors::{
-        evm::{
-            ClientSignTransaction, Generate, ListWallets, SignTransactionError as EvmSignError,
-            UseragentCreateGrant, UseragentDeleteGrant, UseragentListGrants,
-        },
-        keyholder::{self, Bootstrap, TryUnseal},
-        user_agent::session::{
-            UserAgentSession,
-            state::{UnsealContext, UserAgentEvents, UserAgentStates},
-        },
-    },
-    safe_cell::SafeCellHandle as _,
-};
 
 impl UserAgentSession {
-    fn take_unseal_secret(&mut self) -> Result<(EphemeralSecret, PublicKey), Error> {
+    fn take_unseal_secret(&self) -> Result<(EphemeralSecret, PublicKey), UserAgentSessionError> {
         let UserAgentStates::WaitingForUnsealKey(unseal_context) = self.state.state() else {
             error!("Received encrypted key in invalid state");
-            return Err(Error::internal("Invalid state for unseal encrypted key"));
+            return Err(UserAgentSessionError::internal(
+                "Invalid state for unseal encrypted key",
+            ));
         };
 
         let ephemeral_secret = {
@@ -47,13 +50,14 @@ impl UserAgentSession {
             )]
             let mut secret_lock = unseal_context.secret.lock().unwrap();
             let secret = secret_lock.take();
-            match secret {
-                Some(secret) => secret,
-                None => {
-                    drop(secret_lock);
-                    error!("Ephemeral secret already taken");
-                    return Err(Error::internal("Ephemeral secret already taken"));
-                }
+            if let Some(secret) = secret {
+                secret
+            } else {
+                drop(secret_lock);
+                error!("Ephemeral secret already taken");
+                return Err(UserAgentSessionError::internal(
+                    "Ephemeral secret already taken",
+                ));
             }
         };
 
@@ -79,7 +83,7 @@ impl UserAgentSession {
         });
 
         match decryption_result {
-            Ok(_) => Ok(key_buffer),
+            Ok(()) => Ok(key_buffer),
             Err(err) => {
                 error!(?err, "Failed to decrypt encrypted key material");
                 Err(())
@@ -97,7 +101,7 @@ pub enum UnsealError {
     #[error("Invalid key provided for unsealing")]
     InvalidKey,
     #[error("Internal error during unsealing process")]
-    General(#[from] super::Error),
+    General(#[from] UserAgentSessionError),
 }
 
 #[derive(Debug, Error)]
@@ -108,7 +112,7 @@ pub enum BootstrapError {
     AlreadyBootstrapped,
 
     #[error("Internal error during bootstrapping process")]
-    General(#[from] super::Error),
+    General(#[from] UserAgentSessionError),
 }
 
 #[derive(Debug, Error)]
@@ -120,19 +124,28 @@ pub enum SignTransactionError {
     Internal,
 }
 
+#[derive(Debug, Error)]
+pub enum GrantMutationError {
+    #[error("Vault is sealed")]
+    VaultSealed,
+
+    #[error("Internal grant mutation error")]
+    Internal,
+}
+
 #[messages]
 impl UserAgentSession {
     #[message]
-    pub async fn handle_unseal_request(
+    pub fn handle_unseal_request(
         &mut self,
-        client_pubkey: x25519_dalek::PublicKey,
-    ) -> Result<UnsealStartResponse, Error> {
+        client_pubkey: PublicKey,
+    ) -> Result<UnsealStartResponse, UserAgentSessionError> {
         let secret = EphemeralSecret::random();
         let public_key = PublicKey::from(&secret);
 
         self.transition(UserAgentEvents::UnsealRequest(UnsealContext {
-            secret: Mutex::new(Some(secret)),
             client_public_key: client_pubkey,
+            secret: Mutex::new(Some(secret)),
         }))?;
 
         Ok(UnsealStartResponse {
@@ -149,27 +162,24 @@ impl UserAgentSession {
     ) -> Result<(), UnsealError> {
         let (ephemeral_secret, client_public_key) = match self.take_unseal_secret() {
             Ok(values) => values,
-            Err(Error::State) => {
+            Err(UserAgentSessionError::State) => {
                 self.transition(UserAgentEvents::ReceivedInvalidKey)?;
                 return Err(UnsealError::InvalidKey);
             }
             Err(_err) => {
-                return Err(Error::internal("Failed to take unseal secret").into());
+                return Err(UserAgentSessionError::internal("Failed to take unseal secret").into());
             }
         };
 
-        let seal_key_buffer = match Self::decrypt_client_key_material(
+        let Ok(seal_key_buffer) = Self::decrypt_client_key_material(
             ephemeral_secret,
             client_public_key,
             &nonce,
             &ciphertext,
             &associated_data,
-        ) {
-            Ok(buffer) => buffer,
-            Err(()) => {
-                self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                return Err(UnsealError::InvalidKey);
-            }
+        ) else {
+            self.transition(UserAgentEvents::ReceivedInvalidKey)?;
+            return Err(UnsealError::InvalidKey);
         };
 
         match self
@@ -181,12 +191,12 @@ impl UserAgentSession {
             })
             .await
         {
-            Ok(_) => {
+            Ok(()) => {
                 info!("Successfully unsealed key with client-provided key");
                 self.transition(UserAgentEvents::ReceivedValidKey)?;
                 Ok(())
             }
-            Err(SendError::HandlerError(keyholder::Error::InvalidKey)) => {
+            Err(SendError::HandlerError(keyholder::KeyHolderError::InvalidKey)) => {
                 self.transition(UserAgentEvents::ReceivedInvalidKey)?;
                 Err(UnsealError::InvalidKey)
             }
@@ -198,7 +208,7 @@ impl UserAgentSession {
             Err(err) => {
                 error!(?err, "Failed to send unseal request to keyholder");
                 self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                Err(Error::internal("Vault actor error").into())
+                Err(UserAgentSessionError::internal("Vault actor error").into())
             }
         }
     }
@@ -212,25 +222,22 @@ impl UserAgentSession {
     ) -> Result<(), BootstrapError> {
         let (ephemeral_secret, client_public_key) = match self.take_unseal_secret() {
             Ok(values) => values,
-            Err(Error::State) => {
+            Err(UserAgentSessionError::State) => {
                 self.transition(UserAgentEvents::ReceivedInvalidKey)?;
                 return Err(BootstrapError::InvalidKey);
             }
             Err(err) => return Err(err.into()),
         };
 
-        let seal_key_buffer = match Self::decrypt_client_key_material(
+        let Ok(seal_key_buffer) = Self::decrypt_client_key_material(
             ephemeral_secret,
             client_public_key,
             &nonce,
             &ciphertext,
             &associated_data,
-        ) {
-            Ok(buffer) => buffer,
-            Err(()) => {
-                self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                return Err(BootstrapError::InvalidKey);
-            }
+        ) else {
+            self.transition(UserAgentEvents::ReceivedInvalidKey)?;
+            return Err(BootstrapError::InvalidKey);
         };
 
         match self
@@ -242,12 +249,12 @@ impl UserAgentSession {
             })
             .await
         {
-            Ok(_) => {
+            Ok(()) => {
                 info!("Successfully bootstrapped vault with client-provided key");
                 self.transition(UserAgentEvents::ReceivedValidKey)?;
                 Ok(())
             }
-            Err(SendError::HandlerError(keyholder::Error::AlreadyBootstrapped)) => {
+            Err(SendError::HandlerError(keyholder::KeyHolderError::AlreadyBootstrapped)) => {
                 self.transition(UserAgentEvents::ReceivedInvalidKey)?;
                 Err(BootstrapError::AlreadyBootstrapped)
             }
@@ -259,7 +266,7 @@ impl UserAgentSession {
             Err(err) => {
                 error!(?err, "Failed to send bootstrap request to keyholder");
                 self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                Err(BootstrapError::General(Error::internal(
+                Err(BootstrapError::General(UserAgentSessionError::internal(
                     "Vault actor error",
                 )))
             }
@@ -270,14 +277,16 @@ impl UserAgentSession {
 #[messages]
 impl UserAgentSession {
     #[message]
-    pub(crate) async fn handle_query_vault_state(&mut self) -> Result<KeyHolderState, Error> {
+    pub(crate) async fn handle_query_vault_state(
+        &mut self,
+    ) -> Result<KeyHolderState, UserAgentSessionError> {
         use crate::actors::keyholder::GetState;
 
         let vault_state = match self.props.actors.key_holder.ask(GetState {}).await {
             Ok(state) => state,
             Err(err) => {
                 error!(?err, actor = "useragent", "keyholder.query.failed");
-                return Err(Error::internal("Vault is in broken state"));
+                return Err(UserAgentSessionError::internal("Vault is in broken state"));
             }
         };
 
@@ -288,26 +297,32 @@ impl UserAgentSession {
 #[messages]
 impl UserAgentSession {
     #[message]
-    pub(crate) async fn handle_evm_wallet_create(&mut self) -> Result<(i32, Address), Error> {
+    pub(crate) async fn handle_evm_wallet_create(
+        &mut self,
+    ) -> Result<(i32, Address), UserAgentSessionError> {
         match self.props.actors.evm.ask(Generate {}).await {
             Ok(address) => Ok(address),
-            Err(SendError::HandlerError(err)) => Err(Error::internal(format!(
+            Err(SendError::HandlerError(err)) => Err(UserAgentSessionError::internal(format!(
                 "EVM wallet generation failed: {err}"
             ))),
             Err(err) => {
                 error!(?err, "EVM actor unreachable during wallet create");
-                Err(Error::internal("EVM actor unreachable"))
+                Err(UserAgentSessionError::internal("EVM actor unreachable"))
             }
         }
     }
 
     #[message]
-    pub(crate) async fn handle_evm_wallet_list(&mut self) -> Result<Vec<(i32, Address)>, Error> {
+    pub(crate) async fn handle_evm_wallet_list(
+        &mut self,
+    ) -> Result<Vec<(i32, Address)>, UserAgentSessionError> {
         match self.props.actors.evm.ask(ListWallets {}).await {
             Ok(wallets) => Ok(wallets),
             Err(err) => {
                 error!(?err, "EVM wallet list failed");
-                Err(Error::internal("Failed to list EVM wallets"))
+                Err(UserAgentSessionError::internal(
+                    "Failed to list EVM wallets",
+                ))
             }
         }
     }
@@ -316,12 +331,14 @@ impl UserAgentSession {
 #[messages]
 impl UserAgentSession {
     #[message]
-    pub(crate) async fn handle_grant_list(&mut self) -> Result<Vec<Grant<SpecificGrant>>, Error> {
+    pub(crate) async fn handle_grant_list(
+        &mut self,
+    ) -> Result<Vec<Grant<SpecificGrant>>, UserAgentSessionError> {
         match self.props.actors.evm.ask(UseragentListGrants {}).await {
             Ok(grants) => Ok(grants),
             Err(err) => {
                 error!(?err, "EVM grant list failed");
-                Err(Error::internal("Failed to list EVM grants"))
+                Err(UserAgentSessionError::internal("Failed to list EVM grants"))
             }
         }
     }
@@ -329,9 +346,9 @@ impl UserAgentSession {
     #[message]
     pub(crate) async fn handle_grant_create(
         &mut self,
-        basic: crate::evm::policies::SharedGrantSettings,
-        grant: crate::evm::policies::SpecificGrant,
-    ) -> Result<i32, Error> {
+        basic: SharedGrantSettings,
+        grant: SpecificGrant,
+    ) -> Result<i32, GrantMutationError> {
         match self
             .props
             .actors
@@ -342,26 +359,32 @@ impl UserAgentSession {
             Ok(grant_id) => Ok(grant_id),
             Err(err) => {
                 error!(?err, "EVM grant create failed");
-                Err(Error::internal("Failed to create EVM grant"))
+                Err(GrantMutationError::Internal)
             }
         }
     }
 
     #[message]
-    pub(crate) async fn handle_grant_delete(&mut self, grant_id: i32) -> Result<(), Error> {
-        match self
-            .props
-            .actors
-            .evm
-            .ask(UseragentDeleteGrant { grant_id })
-            .await
-        {
-            Ok(()) => Ok(()),
-            Err(err) => {
-                error!(?err, "EVM grant delete failed");
-                Err(Error::internal("Failed to delete EVM grant"))
-            }
-        }
+    #[expect(clippy::unused_async, reason = "false positive")]
+    pub(crate) async fn handle_grant_delete(
+        &mut self,
+        grant_id: i32,
+    ) -> Result<(), GrantMutationError> {
+        // match self
+        //     .props
+        //     .actors
+        //     .evm
+        //     .ask(UseragentDeleteGrant { grant_id })
+        //     .await
+        // {
+        //     Ok(()) => Ok(()),
+        //     Err(err) => {
+        //         error!(?err, "EVM grant delete failed");
+        //         Err(GrantMutationError::Internal)
+        //     }
+        // }
+        let _ = grant_id;
+        todo!()
     }
 
     #[message]
@@ -397,7 +420,7 @@ impl UserAgentSession {
     pub(crate) async fn handle_grant_evm_wallet_access(
         &mut self,
         entries: Vec<NewEvmWalletAccess>,
-    ) -> Result<(), Error> {
+    ) -> Result<(), UserAgentSessionError> {
         let mut conn = self.props.db.get().await?;
         conn.transaction(|conn| {
             Box::pin(async move {
@@ -411,7 +434,7 @@ impl UserAgentSession {
                         .await?;
                 }
 
-                Result::<_, Error>::Ok(())
+                Result::<_, UserAgentSessionError>::Ok(())
             })
         })
         .await?;
@@ -422,7 +445,7 @@ impl UserAgentSession {
     pub(crate) async fn handle_revoke_evm_wallet_access(
         &mut self,
         entries: Vec<i32>,
-    ) -> Result<(), Error> {
+    ) -> Result<(), UserAgentSessionError> {
         let mut conn = self.props.db.get().await?;
         conn.transaction(|conn| {
             Box::pin(async move {
@@ -434,7 +457,7 @@ impl UserAgentSession {
                         .await?;
                 }
 
-                Result::<_, Error>::Ok(())
+                Result::<_, UserAgentSessionError>::Ok(())
             })
         })
         .await?;
@@ -444,10 +467,9 @@ impl UserAgentSession {
     #[message]
     pub(crate) async fn handle_list_wallet_access(
         &mut self,
-    ) -> Result<Vec<EvmWalletAccess>, Error> {
+    ) -> Result<Vec<EvmWalletAccess>, UserAgentSessionError> {
         let mut conn = self.props.db.get().await?;
-        use crate::db::schema::evm_wallet_access;
-        let access_entries = evm_wallet_access::table
+        let access_entries = crate::db::schema::evm_wallet_access::table
             .select(EvmWalletAccess::as_select())
             .load::<_>(&mut conn)
             .await?;
@@ -461,15 +483,15 @@ impl UserAgentSession {
     pub(crate) async fn handle_new_client_approve(
         &mut self,
         approved: bool,
-        pubkey: ed25519_dalek::VerifyingKey,
-        ctx: &mut Context<Self, Result<(), Error>>,
-    ) -> Result<(), Error> {
-        let pending_approval = match self.pending_client_approvals.remove(&pubkey) {
-            Some(approval) => approval,
-            None => {
-                error!("Received client connection response for unknown client");
-                return Err(Error::internal("Unknown client in connection response"));
-            }
+        pubkey: authn::PublicKey,
+        ctx: &Context<Self, Result<(), UserAgentSessionError>>,
+    ) -> Result<(), UserAgentSessionError> {
+        let Some(pending_approval) = self.pending_client_approvals.remove(&pubkey.to_bytes())
+        else {
+            error!("Received client connection response for unknown client");
+            return Err(UserAgentSessionError::internal(
+                "Unknown client in connection response",
+            ));
         };
 
         pending_approval
@@ -481,7 +503,9 @@ impl UserAgentSession {
                     ?err,
                     "Failed to send client approval response to controller"
                 );
-                Error::internal("Failed to send client approval response to controller")
+                UserAgentSessionError::internal(
+                    "Failed to send client approval response to controller",
+                )
             })?;
 
         ctx.actor_ref().unlink(&pending_approval.controller).await;
@@ -492,7 +516,7 @@ impl UserAgentSession {
     #[message]
     pub(crate) async fn handle_sdk_client_list(
         &mut self,
-    ) -> Result<Vec<(ProgramClient, ProgramClientMetadata)>, Error> {
+    ) -> Result<Vec<(ProgramClient, ProgramClientMetadata)>, UserAgentSessionError> {
         use crate::db::schema::{client_metadata, program_client};
         let mut conn = self.props.db.get().await?;
 

server/crates/arbiter-server/src/actors/user_agent/session/state.rs

@@ -19,8 +19,6 @@ smlang::statemachine!(
 
 pub struct DummyContext;
 impl UserAgentStateMachineContext for DummyContext {
-    #[allow(missing_docs)]
-    #[allow(clippy::unused_unit)]
     fn generate_temp_keypair(&mut self, event_data: UnsealContext) -> Result<UnsealContext, ()> {
         Ok(event_data)
     }

server/crates/arbiter-server/src/context/mod.rs

@@ -1,6 +1,5 @@
 use std::sync::Arc;
 
-use miette::Diagnostic;
 use thiserror::Error;
 
 use crate::{
@@ -11,43 +10,37 @@ use crate::{
 
 pub mod tls;
 
-#[derive(Error, Debug, Diagnostic)]
+#[derive(Error, Debug)]
 pub enum InitError {
     #[error("Database setup failed: {0}")]
-    #[diagnostic(code(arbiter_server::init::database_setup))]
     DatabaseSetup(#[from] db::DatabaseSetupError),
 
     #[error("Connection acquire failed: {0}")]
-    #[diagnostic(code(arbiter_server::init::database_pool))]
     DatabasePool(#[from] db::PoolError),
 
     #[error("Database query error: {0}")]
-    #[diagnostic(code(arbiter_server::init::database_query))]
     DatabaseQuery(#[from] diesel::result::Error),
 
     #[error("TLS initialization failed: {0}")]
-    #[diagnostic(code(arbiter_server::init::tls_init))]
     Tls(#[from] tls::InitError),
 
     #[error("Actor spawn failed: {0}")]
-    #[diagnostic(code(arbiter_server::init::actor_spawn))]
-    ActorSpawn(#[from] crate::actors::SpawnError),
+    ActorSpawn(#[from] crate::actors::GlobalActorsSpawnError),
 
     #[error("I/O Error: {0}")]
-    #[diagnostic(code(arbiter_server::init::io))]
     Io(#[from] std::io::Error),
 }
 
-pub struct _ServerContextInner {
+pub struct __ServerContextInner {
     pub db: db::DatabasePool,
     pub tls: TlsManager,
     pub actors: GlobalActors,
 }
 #[derive(Clone)]
-pub struct ServerContext(Arc<_ServerContextInner>);
+pub struct ServerContext(Arc<__ServerContextInner>);
 
 impl std::ops::Deref for ServerContext {
-    type Target = _ServerContextInner;
+    type Target = __ServerContextInner;
 
     fn deref(&self) -> &Self::Target {
         &self.0
@@ -56,7 +49,7 @@ impl std::ops::Deref for ServerContext {
 
 impl ServerContext {
     pub async fn new(db: db::DatabasePool) -> Result<Self, InitError> {
-        Ok(Self(Arc::new(_ServerContextInner {
+        Ok(Self(Arc::new(__ServerContextInner {
             actors: GlobalActors::spawn(db.clone()).await?,
             tls: TlsManager::new(db.clone()).await?,
             db,

server/crates/arbiter-server/src/context/tls.rs

@@ -1,8 +1,8 @@
-use std::{net::IpAddr, string::FromUtf8Error};
+use std::{net::Ipv4Addr, string::FromUtf8Error};
 
 use diesel::{ExpressionMethods as _, QueryDsl, SelectableHelper as _};
 use diesel_async::{AsyncConnection, RunQueryDsl};
-use miette::Diagnostic;
+
 use pem::Pem;
 use rcgen::{
     BasicConstraints, Certificate, CertificateParams, CertifiedIssuer, DistinguishedName, DnType,
@@ -22,47 +22,45 @@ use crate::db::{
 };
 
 const ENCODE_CONFIG: pem::EncodeConfig = {
-    let line_ending = match cfg!(target_family = "windows") {
-        true => pem::LineEnding::CRLF,
-        false => pem::LineEnding::LF,
+    let line_ending = if cfg!(target_family = "windows") {
+        pem::LineEnding::CRLF
+    } else {
+        pem::LineEnding::LF
     };
     pem::EncodeConfig::new().set_line_ending(line_ending)
 };
 
-#[derive(Error, Debug, Diagnostic)]
+#[derive(Error, Debug)]
 pub enum InitError {
     #[error("Key generation error during TLS initialization: {0}")]
-    #[diagnostic(code(arbiter_server::tls_init::key_generation))]
     KeyGeneration(#[from] rcgen::Error),
 
     #[error("Key invalid format: {0}")]
-    #[diagnostic(code(arbiter_server::tls_init::key_invalid_format))]
     KeyInvalidFormat(#[from] FromUtf8Error),
 
     #[error("Key deserialization error: {0}")]
-    #[diagnostic(code(arbiter_server::tls_init::key_deserialization))]
     KeyDeserializationError(rcgen::Error),
 
     #[error("Database error during TLS initialization: {0}")]
-    #[diagnostic(code(arbiter_server::tls_init::database_error))]
     DatabaseError(#[from] diesel::result::Error),
 
     #[error("Pem deserialization error during TLS initialization: {0}")]
-    #[diagnostic(code(arbiter_server::tls_init::pem_deserialization))]
     PemDeserializationError(#[from] rustls::pki_types::pem::Error),
 
     #[error("Database pool acquire error during TLS initialization: {0}")]
-    #[diagnostic(code(arbiter_server::tls_init::database_pool_acquire))]
     DatabasePoolAcquire(#[from] db::PoolError),
 }
 
 pub type PemCert = String;
 
-pub fn encode_cert_to_pem(cert: &CertificateDer) -> PemCert {
+pub fn encode_cert_to_pem(cert: &CertificateDer<'_>) -> PemCert {
     pem::encode_config(&Pem::new("CERTIFICATE", cert.to_vec()), ENCODE_CONFIG)
 }
 
-#[allow(unused)]
+#[expect(
+    unused,
+    reason = "may be needed for future cert rotation implementation"
+)]
 struct SerializedTls {
     cert_pem: PemCert,
     cert_key_pem: String,
@@ -91,7 +89,7 @@ impl TlsCa {
 
         let cert_key_pem = certified_issuer.key().serialize_pem();
 
-        #[allow(
+        #[expect(
             clippy::unwrap_used,
             reason = "Broken cert couldn't bootstrap server anyway"
         )]
@@ -116,9 +114,7 @@ impl TlsCa {
         ];
         params
             .subject_alt_names
-            .push(SanType::IpAddress(IpAddr::from([
-                127, 0, 0, 1,
-            ])));
+            .push(SanType::IpAddress(Ipv4Addr::LOCALHOST.into()));
 
         let mut dn = DistinguishedName::new();
         dn.push(DnType::CommonName, "Arbiter Instance Leaf");
@@ -132,7 +128,11 @@ impl TlsCa {
         })
     }
 
-    #[allow(unused)]
+    #[expect(
+        unused,
+        clippy::unnecessary_wraps,
+        reason = "may be needed for future cert rotation implementation"
+    )]
     fn serialize(&self) -> Result<SerializedTls, InitError> {
         let cert_key_pem = self.issuer.key().serialize_pem();
         Ok(SerializedTls {
@@ -141,7 +141,10 @@ impl TlsCa {
         })
     }
 
-    #[allow(unused)]
+    #[expect(
+        unused,
+        reason = "may be needed for future cert rotation implementation"
+    )]
     fn try_deserialize(cert_pem: &str, cert_key_pem: &str) -> Result<Self, InitError> {
         let keypair =
             KeyPair::from_pem(cert_key_pem).map_err(InitError::KeyDeserializationError)?;
@@ -242,10 +245,10 @@ impl TlsManager {
         }
     }
 
-    pub fn cert(&self) -> &CertificateDer<'static> {
+    pub const fn cert(&self) -> &CertificateDer<'static> {
         &self.cert
     }
-    pub fn ca_cert(&self) -> &CertificateDer<'static> {
+    pub const fn ca_cert(&self) -> &CertificateDer<'static> {
         &self.ca_cert
     }
 

server/crates/arbiter-server/src/crypto/encryption/mod.rs

@@ -0,0 +1,3 @@
+pub mod v1;
+
+pub use v1::*;

server/crates/arbiter-server/src/crypto/encryption/v1.rs

@@ -0,0 +1,103 @@
+use argon2::password_hash::Salt as ArgonSalt;
+
+use rand::{
+    Rng as _, SeedableRng,
+    rngs::{StdRng, SysRng},
+};
+
+pub const ROOT_KEY_TAG: &[u8] = b"arbiter/seal/v1";
+pub const TAG: &[u8] = b"arbiter/private-key/v1";
+
+pub const NONCE_LENGTH: usize = 24;
+
+#[derive(Default)]
+pub struct Nonce(pub [u8; NONCE_LENGTH]);
+impl Nonce {
+    pub fn increment(&mut self) {
+        for i in (0..self.0.len()).rev() {
+            if let Some(byte) = self.0.get_mut(i) {
+                if *byte == 0xFF {
+                    *byte = 0;
+                } else {
+                    *byte += 1;
+                    break;
+                }
+            }
+        }
+    }
+
+    pub fn to_vec(&self) -> Vec<u8> {
+        self.0.to_vec()
+    }
+}
+impl<'a> TryFrom<&'a [u8]> for Nonce {
+    type Error = ();
+
+    fn try_from(value: &'a [u8]) -> Result<Self, Self::Error> {
+        if value.len() != NONCE_LENGTH {
+            return Err(());
+        }
+        let mut nonce = [0u8; NONCE_LENGTH];
+        nonce.copy_from_slice(value);
+        Ok(Self(nonce))
+    }
+}
+
+pub type Salt = [u8; ArgonSalt::RECOMMENDED_LENGTH];
+
+pub fn generate_salt() -> Salt {
+    let mut salt = Salt::default();
+    let mut rng =
+        StdRng::try_from_rng(&mut SysRng).expect("Rng failure is unrecoverable and should panic");
+    rng.fill_bytes(&mut salt);
+    salt
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::crypto::derive_key;
+    use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+
+    #[test]
+    pub fn derive_seal_key_deterministic() {
+        static PASSWORD: &[u8] = b"password";
+        let password = SafeCell::new(PASSWORD.to_vec());
+        let password2 = SafeCell::new(PASSWORD.to_vec());
+        let salt = generate_salt();
+
+        let mut key1 = derive_key(password, &salt);
+        let mut key2 = derive_key(password2, &salt);
+
+        let key1_reader = key1.0.read();
+        let key2_reader = key2.0.read();
+
+        assert_eq!(&*key1_reader, &*key2_reader);
+    }
+
+    #[test]
+    pub fn successful_derive() {
+        static PASSWORD: &[u8] = b"password";
+        let password = SafeCell::new(PASSWORD.to_vec());
+        let salt = generate_salt();
+
+        let mut key = derive_key(password, &salt);
+        let key_reader = key.0.read();
+
+        assert_ne!(key_reader.as_slice(), &[0u8; 32][..]);
+    }
+
+    #[test]
+    // We should fuzz this
+    pub fn nonce_increment() {
+        let mut nonce = Nonce([0u8; NONCE_LENGTH]);
+        nonce.increment();
+
+        assert_eq!(
+            nonce.0,
+            [
+                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
+            ]
+        );
+    }
+}

server/crates/arbiter-server/src/crypto/integrity/mod.rs

@@ -0,0 +1,3 @@
+pub mod v1;
+
+pub use v1::*;

server/crates/arbiter-server/src/crypto/integrity/v1.rs

@@ -0,0 +1,326 @@
+use crate::actors::keyholder;
+use arbiter_crypto::hashing::Hashable;
+use hmac::Hmac;
+use sha2::Sha256;
+
+use diesel::{ExpressionMethods as _, QueryDsl, dsl::insert_into, sqlite::Sqlite};
+use diesel_async::{AsyncConnection, RunQueryDsl};
+use kameo::{actor::ActorRef, error::SendError};
+use sha2::Digest as _;
+
+use crate::{
+    actors::keyholder::{KeyHolder, SignIntegrity, VerifyIntegrity},
+    db::{
+        self,
+        models::{IntegrityEnvelope, NewIntegrityEnvelope},
+        schema::integrity_envelope,
+    },
+};
+
+#[derive(Debug, thiserror::Error)]
+pub enum IntegrityError {
+    #[error("Database error: {0}")]
+    Database(#[from] db::DatabaseError),
+
+    #[error("KeyHolder error: {0}")]
+    Keyholder(#[from] keyholder::KeyHolderError),
+
+    #[error("KeyHolder mailbox error")]
+    KeyholderSend,
+
+    #[error("Integrity envelope is missing for entity {entity_kind}")]
+    MissingEnvelope { entity_kind: &'static str },
+
+    #[error(
+        "Integrity payload version mismatch for entity {entity_kind}: expected {expected}, found {found}"
+    )]
+    PayloadVersionMismatch {
+        entity_kind: &'static str,
+        expected: i32,
+        found: i32,
+    },
+
+    #[error("Integrity MAC mismatch for entity {entity_kind}")]
+    MacMismatch { entity_kind: &'static str },
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum AttestationStatus {
+    Attested,
+    Unavailable,
+}
+
+pub const CURRENT_PAYLOAD_VERSION: i32 = 1;
+pub const INTEGRITY_SUBKEY_TAG: &[u8] = b"arbiter/db-integrity-key/v1";
+
+pub type HmacSha256 = Hmac<Sha256>;
+
+pub trait Integrable: Hashable {
+    const KIND: &'static str;
+    const VERSION: i32 = 1;
+}
+
+fn payload_hash(payload: &impl Hashable) -> [u8; 32] {
+    let mut hasher = Sha256::new();
+    payload.hash(&mut hasher);
+    hasher.finalize().into()
+}
+
+fn push_len_prefixed(out: &mut Vec<u8>, bytes: &[u8]) {
+    #[expect(
+        clippy::cast_possible_truncation,
+        clippy::as_conversions,
+        reason = "fixme! #85"
+    )]
+    out.extend_from_slice(&(bytes.len() as u32).to_be_bytes());
+    out.extend_from_slice(bytes);
+}
+
+fn build_mac_input(
+    entity_kind: &str,
+    entity_id: &[u8],
+    payload_version: i32,
+    payload_hash: &[u8; 32],
+) -> Vec<u8> {
+    let mut out = Vec::with_capacity(8 + entity_kind.len() + entity_id.len() + 32);
+    push_len_prefixed(&mut out, entity_kind.as_bytes());
+    push_len_prefixed(&mut out, entity_id);
+    out.extend_from_slice(&payload_version.to_be_bytes());
+    out.extend_from_slice(payload_hash);
+    out
+}
+
+pub trait IntoId {
+    fn into_id(self) -> Vec<u8>;
+}
+
+impl IntoId for i32 {
+    fn into_id(self) -> Vec<u8> {
+        self.to_be_bytes().to_vec()
+    }
+}
+
+impl IntoId for &'_ [u8] {
+    fn into_id(self) -> Vec<u8> {
+        self.to_vec()
+    }
+}
+
+pub async fn sign_entity<E: Integrable>(
+    conn: &mut impl AsyncConnection<Backend = Sqlite>,
+    keyholder: &ActorRef<KeyHolder>,
+    entity: &E,
+    entity_id: impl IntoId,
+) -> Result<(), IntegrityError> {
+    let payload_hash = payload_hash(&entity);
+
+    let entity_id = entity_id.into_id();
+
+    let mac_input = build_mac_input(E::KIND, &entity_id, E::VERSION, &payload_hash);
+
+    let (key_version, mac) = keyholder
+        .ask(SignIntegrity { mac_input })
+        .await
+        .map_err(|err| match err {
+            SendError::HandlerError(inner) => IntegrityError::Keyholder(inner),
+            _ => IntegrityError::KeyholderSend,
+        })?;
+
+    insert_into(integrity_envelope::table)
+        .values(NewIntegrityEnvelope {
+            entity_kind: E::KIND.to_owned(),
+            entity_id,
+            payload_version: E::VERSION,
+            key_version,
+            mac: mac.clone(),
+        })
+        .on_conflict((
+            integrity_envelope::entity_id,
+            integrity_envelope::entity_kind,
+        ))
+        .do_update()
+        .set((
+            integrity_envelope::payload_version.eq(E::VERSION),
+            integrity_envelope::key_version.eq(key_version),
+            integrity_envelope::mac.eq(mac),
+        ))
+        .execute(conn)
+        .await
+        .map_err(db::DatabaseError::from)?;
+
+    Ok(())
+}
+
+pub async fn verify_entity<E: Integrable>(
+    conn: &mut impl AsyncConnection<Backend = Sqlite>,
+    keyholder: &ActorRef<KeyHolder>,
+    entity: &E,
+    entity_id: impl IntoId,
+) -> Result<AttestationStatus, IntegrityError> {
+    let entity_id = entity_id.into_id();
+    let envelope: IntegrityEnvelope = integrity_envelope::table
+        .filter(integrity_envelope::entity_kind.eq(E::KIND))
+        .filter(integrity_envelope::entity_id.eq(&entity_id))
+        .first(conn)
+        .await
+        .map_err(|err| match err {
+            diesel::result::Error::NotFound => IntegrityError::MissingEnvelope {
+                entity_kind: E::KIND,
+            },
+            other => IntegrityError::Database(db::DatabaseError::from(other)),
+        })?;
+
+    if envelope.payload_version != E::VERSION {
+        return Err(IntegrityError::PayloadVersionMismatch {
+            entity_kind: E::KIND,
+            expected: E::VERSION,
+            found: envelope.payload_version,
+        });
+    }
+
+    let payload_hash = payload_hash(&entity);
+    let mac_input = build_mac_input(E::KIND, &entity_id, envelope.payload_version, &payload_hash);
+
+    let result = keyholder
+        .ask(VerifyIntegrity {
+            mac_input,
+            expected_mac: envelope.mac,
+            key_version: envelope.key_version,
+        })
+        .await;
+
+    match result {
+        Ok(true) => Ok(AttestationStatus::Attested),
+        Ok(false) => Err(IntegrityError::MacMismatch {
+            entity_kind: E::KIND,
+        }),
+        Err(SendError::HandlerError(keyholder::KeyHolderError::NotBootstrapped)) => {
+            Ok(AttestationStatus::Unavailable)
+        }
+        Err(_) => Err(IntegrityError::KeyholderSend),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use diesel::{ExpressionMethods as _, QueryDsl};
+    use diesel_async::RunQueryDsl;
+    use kameo::{actor::ActorRef, prelude::Spawn};
+
+    use crate::{
+        actors::keyholder::{Bootstrap, KeyHolder},
+        db::{self, schema},
+    };
+    use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+
+    use super::{Integrable, IntegrityError, sign_entity, verify_entity};
+    #[derive(Clone, arbiter_macros::Hashable)]
+    struct DummyEntity {
+        payload_version: i32,
+        payload: Vec<u8>,
+    }
+    impl Integrable for DummyEntity {
+        const KIND: &'static str = "dummy_entity";
+    }
+
+    async fn bootstrapped_keyholder(db: &db::DatabasePool) -> ActorRef<KeyHolder> {
+        let actor = KeyHolder::spawn(KeyHolder::new(db.clone()).await.unwrap());
+        actor
+            .ask(Bootstrap {
+                seal_key_raw: SafeCell::new(b"integrity-test-seal-key".to_vec()),
+            })
+            .await
+            .unwrap();
+        actor
+    }
+
+    #[tokio::test]
+    async fn sign_writes_envelope_and_verify_passes() {
+        const ENTITY_ID: &[u8] = b"entity-id-7";
+
+        let db = db::create_test_pool().await;
+        let keyholder = bootstrapped_keyholder(&db).await;
+        let mut conn = db.get().await.unwrap();
+
+        let entity = DummyEntity {
+            payload_version: 1,
+            payload: b"payload-v1".to_vec(),
+        };
+
+        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();
+
+        let count: i64 = schema::integrity_envelope::table
+            .filter(schema::integrity_envelope::entity_kind.eq("dummy_entity"))
+            .filter(schema::integrity_envelope::entity_id.eq(ENTITY_ID))
+            .count()
+            .get_result(&mut conn)
+            .await
+            .unwrap();
+
+        assert_eq!(count, 1, "envelope row must be created exactly once");
+        verify_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();
+    }
+
+    #[tokio::test]
+    async fn tampered_mac_fails_verification() {
+        const ENTITY_ID: &[u8] = b"entity-id-11";
+
+        let db = db::create_test_pool().await;
+        let keyholder = bootstrapped_keyholder(&db).await;
+        let mut conn = db.get().await.unwrap();
+
+        let entity = DummyEntity {
+            payload_version: 1,
+            payload: b"payload-v1".to_vec(),
+        };
+
+        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();
+
+        diesel::update(schema::integrity_envelope::table)
+            .filter(schema::integrity_envelope::entity_kind.eq("dummy_entity"))
+            .filter(schema::integrity_envelope::entity_id.eq(ENTITY_ID))
+            .set(schema::integrity_envelope::mac.eq(vec![0u8; 32]))
+            .execute(&mut conn)
+            .await
+            .unwrap();
+
+        let err = verify_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap_err();
+        assert!(matches!(err, IntegrityError::MacMismatch { .. }));
+    }
+
+    #[tokio::test]
+    async fn changed_payload_fails_verification() {
+        const ENTITY_ID: &[u8] = b"entity-id-21";
+
+        let db = db::create_test_pool().await;
+        let keyholder = bootstrapped_keyholder(&db).await;
+        let mut conn = db.get().await.unwrap();
+
+        let entity = DummyEntity {
+            payload_version: 1,
+            payload: b"payload-v1".to_vec(),
+        };
+
+        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();
+
+        let tampered = DummyEntity {
+            payload: b"payload-v1-but-tampered".to_vec(),
+            ..entity
+        };
+
+        let err = verify_entity(&mut conn, &keyholder, &tampered, ENTITY_ID)
+            .await
+            .unwrap_err();
+        assert!(matches!(err, IntegrityError::MacMismatch { .. }));
+    }
+}

server/crates/arbiter-server/src/crypto/mod.rs

@@ -0,0 +1,156 @@
+use argon2::{Algorithm, Argon2};
+use chacha20poly1305::{
+    AeadInPlace, Key, KeyInit as _, XChaCha20Poly1305, XNonce,
+    aead::{AeadMut, Error, Payload},
+};
+use rand::{
+    Rng as _, SeedableRng as _,
+    rngs::{StdRng, SysRng},
+};
+
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+
+pub mod encryption;
+pub mod integrity;
+
+use encryption::v1::{Nonce, Salt};
+
+pub struct KeyCell(pub SafeCell<Key>);
+impl From<SafeCell<Key>> for KeyCell {
+    fn from(value: SafeCell<Key>) -> Self {
+        Self(value)
+    }
+}
+impl TryFrom<SafeCell<Vec<u8>>> for KeyCell {
+    type Error = ();
+
+    fn try_from(mut value: SafeCell<Vec<u8>>) -> Result<Self, Self::Error> {
+        let value = value.read();
+        if value.len() != size_of::<Key>() {
+            return Err(());
+        }
+        let cell = SafeCell::new_inline(|cell_write: &mut Key| {
+            cell_write.copy_from_slice(&value);
+        });
+        Ok(Self(cell))
+    }
+}
+
+impl KeyCell {
+    pub fn new_secure_random() -> Self {
+        let key = SafeCell::new_inline(|key_buffer: &mut Key| {
+            let mut rng = StdRng::try_from_rng(&mut SysRng)
+                .expect("Rng failure is unrecoverable and should panic");
+            rng.fill_bytes(key_buffer);
+        });
+
+        key.into()
+    }
+
+    pub fn encrypt_in_place(
+        &mut self,
+        nonce: &Nonce,
+        associated_data: &[u8],
+        mut buffer: impl AsMut<Vec<u8>>,
+    ) -> Result<(), Error> {
+        let key_reader = self.0.read();
+        let cipher = XChaCha20Poly1305::new(&key_reader);
+        let nonce = XNonce::from_slice(nonce.0.as_ref());
+        let buffer = buffer.as_mut();
+        cipher.encrypt_in_place(nonce, associated_data, buffer)
+    }
+    pub fn decrypt_in_place(
+        &mut self,
+        nonce: &Nonce,
+        associated_data: &[u8],
+        buffer: &mut SafeCell<Vec<u8>>,
+    ) -> Result<(), Error> {
+        let key_reader = self.0.read();
+        let cipher = XChaCha20Poly1305::new(&key_reader);
+        let nonce = XNonce::from_slice(nonce.0.as_ref());
+        let mut buffer = buffer.write();
+        let buffer: &mut Vec<u8> = buffer.as_mut();
+        cipher.decrypt_in_place(nonce, associated_data, buffer)
+    }
+
+    pub fn encrypt(
+        &mut self,
+        nonce: &Nonce,
+        associated_data: &[u8],
+        plaintext: impl AsRef<[u8]>,
+    ) -> Result<Vec<u8>, Error> {
+        let key_reader = self.0.read();
+        let mut cipher = XChaCha20Poly1305::new(&key_reader);
+        let nonce = XNonce::from_slice(nonce.0.as_ref());
+
+        let ciphertext = cipher.encrypt(
+            nonce,
+            Payload {
+                msg: plaintext.as_ref(),
+                aad: associated_data,
+            },
+        )?;
+        Ok(ciphertext)
+    }
+}
+
+/// Derive a fixed-length key from the password using Argon2id, which is designed for password hashing and key derivation.
+pub fn derive_key(mut password: SafeCell<Vec<u8>>, salt: &Salt) -> KeyCell {
+    let params = {
+        #[cfg(debug_assertions)]
+        {
+            argon2::Params::new(8, 1, 1, None).unwrap()
+        }
+
+        #[cfg(not(debug_assertions))]
+        {
+            argon2::Params::new(262_144, 3, 4, None).unwrap()
+        }
+    };
+
+    let hasher = Argon2::new(Algorithm::Argon2id, argon2::Version::V0x13, params);
+    let mut key = SafeCell::new(Key::default());
+    password.read_inline(|password_source| {
+        let mut key_buffer = key.write();
+        let key_buffer: &mut [u8] = key_buffer.as_mut();
+
+        hasher
+            .hash_password_into(password_source, salt, key_buffer)
+            .expect("Better fail completely than return a weak key");
+    });
+
+    key.into()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{
+        derive_key,
+        encryption::v1::{Nonce, generate_salt},
+    };
+    use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+
+    #[test]
+    pub fn encrypt_decrypt() {
+        static PASSWORD: &[u8] = b"password";
+        let password = SafeCell::new(PASSWORD.to_vec());
+        let salt = generate_salt();
+
+        let mut key = derive_key(password, &salt);
+        let nonce = Nonce(*b"unique nonce 123 1231233"); // 24 bytes for XChaCha20Poly1305
+        let associated_data = b"associated data";
+        let mut buffer = b"secret data".to_vec();
+
+        key.encrypt_in_place(&nonce, associated_data, &mut buffer)
+            .unwrap();
+        assert_ne!(buffer, b"secret data");
+
+        let mut buffer = SafeCell::new(buffer);
+
+        key.decrypt_in_place(&nonce, associated_data, &mut buffer)
+            .unwrap();
+
+        let buffer = buffer.read();
+        assert_eq!(*buffer, b"secret data");
+    }
+}

server/crates/arbiter-server/src/db/mod.rs

@@ -5,7 +5,7 @@ use diesel_async::{
     sync_connection_wrapper::SyncConnectionWrapper,
 };
 use diesel_migrations::{EmbeddedMigrations, MigrationHarness, embed_migrations};
-use miette::Diagnostic;
+
 use thiserror::Error;
 use tracing::info;
 
@@ -21,35 +21,31 @@ static DB_FILE: &str = "arbiter.sqlite";
 
 const MIGRATIONS: EmbeddedMigrations = embed_migrations!("migrations");
 
-#[derive(Error, Diagnostic, Debug)]
+#[derive(Error, Debug)]
 pub enum DatabaseSetupError {
-    #[error("Failed to determine home directory")]
-    #[diagnostic(code(arbiter::db::home_dir))]
-    HomeDir(std::io::Error),
-
     #[error(transparent)]
-    #[diagnostic(code(arbiter::db::connection))]
-    Connection(diesel::ConnectionError),
-
-    #[error(transparent)]
-    #[diagnostic(code(arbiter::db::concurrency))]
     ConcurrencySetup(diesel::result::Error),
 
     #[error(transparent)]
-    #[diagnostic(code(arbiter::db::migration))]
+    Connection(diesel::ConnectionError),
+
+    #[error("Failed to determine home directory")]
+    HomeDir(std::io::Error),
+
+    #[error(transparent)]
     Migration(Box<dyn std::error::Error + Send + Sync>),
 
     #[error(transparent)]
-    #[diagnostic(code(arbiter::db::pool))]
     Pool(#[from] PoolInitError),
 }
 
 #[derive(Error, Debug)]
 pub enum DatabaseError {
-    #[error("Database connection error")]
-    Pool(#[from] PoolError),
     #[error("Database query error")]
     Connection(#[from] diesel::result::Error),
+
+    #[error("Database connection error")]
+    Pool(#[from] PoolError),
 }
 
 #[tracing::instrument(level = "info")]
@@ -98,13 +94,16 @@ fn initialize_database(url: &str) -> Result<(), DatabaseSetupError> {
 }
 
 #[tracing::instrument(level = "info")]
+/// Creates a connection pool for the `SQLite` database.
+///
+/// # Panics
+/// Panics if the database path is not valid UTF-8.
 pub async fn create_pool(url: Option<&str>) -> Result<DatabasePool, DatabaseSetupError> {
     let database_url = url.map(String::from).unwrap_or(
-        #[allow(clippy::expect_used)]
         database_path()?
             .to_str()
             .expect("database path is not valid UTF-8")
-            .to_string(),
+            .to_owned(),
     );
 
     initialize_database(&database_url)?;
@@ -138,19 +137,20 @@ pub async fn create_pool(url: Option<&str>) -> Result<DatabasePool, DatabaseSetu
     Ok(pool)
 }
 
+#[mutants::skip]
+#[expect(clippy::missing_panics_doc, reason = "Tests oriented function")]
+/// Creates a test database pool with a temporary `SQLite` database file.
 pub async fn create_test_pool() -> DatabasePool {
     use rand::distr::{Alphanumeric, SampleString as _};
 
     let tempfile_name = Alphanumeric.sample_string(&mut rand::rng(), 16);
 
     let file = std::env::temp_dir().join(tempfile_name);
-    #[allow(clippy::expect_used)]
     let url = file
         .to_str()
         .expect("temp file path is not valid UTF-8")
-        .to_string();
+        .to_owned();
 
-    #[allow(clippy::expect_used)]
     create_pool(Some(&url))
         .await
         .expect("Failed to create test database pool")

server/crates/arbiter-server/src/db/models.rs

@@ -1,13 +1,14 @@
-#![allow(unused)]
-#![allow(clippy::all)]
+#![allow(
+    clippy::duplicated_attributes,
+    reason = "restructed's #[view] causes false positives"
+)]
 
 use crate::db::schema::{
     self, aead_encrypted, arbiter_settings, evm_basic_grant, evm_ether_transfer_grant,
     evm_ether_transfer_grant_target, evm_ether_transfer_limit, evm_token_transfer_grant,
     evm_token_transfer_log, evm_token_transfer_volume_limit, evm_transaction_log, evm_wallet,
-    root_key_history, tls_history,
+    integrity_envelope, root_key_history, tls_history,
 };
-use chrono::{DateTime, Utc};
 use diesel::{prelude::*, sqlite::Sqlite};
 use restructed::Models;
 
@@ -27,16 +28,16 @@ pub mod types {
     pub struct SqliteTimestamp(pub DateTime<Utc>);
     impl SqliteTimestamp {
         pub fn now() -> Self {
-            SqliteTimestamp(Utc::now())
+            Self(Utc::now())
         }
     }
 
-    impl From<chrono::DateTime<Utc>> for SqliteTimestamp {
-        fn from(dt: chrono::DateTime<Utc>) -> Self {
-            SqliteTimestamp(dt)
+    impl From<DateTime<Utc>> for SqliteTimestamp {
+        fn from(dt: DateTime<Utc>) -> Self {
+            Self(dt)
         }
     }
-    impl From<SqliteTimestamp> for chrono::DateTime<Utc> {
+    impl From<SqliteTimestamp> for DateTime<Utc> {
         fn from(ts: SqliteTimestamp) -> Self {
             ts.0
         }
@@ -47,6 +48,11 @@ pub mod types {
             &'b self,
             out: &mut diesel::serialize::Output<'b, '_, Sqlite>,
         ) -> diesel::serialize::Result {
+            #[expect(
+                clippy::cast_possible_truncation,
+                clippy::as_conversions,
+                reason = "fixme! #84; this will break up in 2038 :3"
+            )]
             let unix_timestamp = self.0.timestamp() as i32;
             out.set_value(unix_timestamp);
             Ok(IsNull::No)
@@ -69,41 +75,47 @@ pub mod types {
             let datetime =
                 DateTime::from_timestamp(unix_timestamp, 0).ok_or("Timestamp is out of bounds")?;
 
-            Ok(SqliteTimestamp(datetime))
+            Ok(Self(datetime))
         }
     }
 
-    /// Key algorithm stored in the `useragent_client.key_type` column.
-    /// Values must stay stable — they are persisted in the database.
-    #[derive(Debug, Clone, Copy, PartialEq, Eq, FromSqlRow, AsExpression, strum::FromRepr)]
+    #[derive(Debug, FromSqlRow, AsExpression, Clone)]
     #[diesel(sql_type = Integer)]
-    #[repr(i32)]
-    pub enum KeyType {
-        Ed25519 = 1,
-        EcdsaSecp256k1 = 2,
-        Rsa = 3,
-    }
+    #[repr(transparent)] // hint compiler to optimize the wrapper struct away
+    pub struct ChainId(pub i32);
 
-    impl ToSql<Integer, Sqlite> for KeyType {
+    #[expect(
+        clippy::cast_sign_loss,
+        clippy::cast_possible_truncation,
+        clippy::as_conversions,
+        reason = "safe because chain_id is stored as i32 but is guaranteed to be a valid ChainId by the API when creating grants"
+    )]
+    const _: () = {
+        impl From<ChainId> for alloy::primitives::ChainId {
+            fn from(chain_id: ChainId) -> Self {
+                chain_id.0 as Self
+            }
+        }
+        impl From<alloy::primitives::ChainId> for ChainId {
+            fn from(chain_id: alloy::primitives::ChainId) -> Self {
+                Self(chain_id as _)
+            }
+        }
+    };
+
+    impl FromSql<Integer, Sqlite> for ChainId {
+        fn from_sql(
+            bytes: <Sqlite as diesel::backend::Backend>::RawValue<'_>,
+        ) -> diesel::deserialize::Result<Self> {
+            FromSql::<Integer, Sqlite>::from_sql(bytes).map(Self)
+        }
+    }
+    impl ToSql<Integer, Sqlite> for ChainId {
         fn to_sql<'b>(
             &'b self,
             out: &mut diesel::serialize::Output<'b, '_, Sqlite>,
         ) -> diesel::serialize::Result {
-            out.set_value(*self as i32);
-            Ok(IsNull::No)
-        }
-    }
-
-    impl FromSql<Integer, Sqlite> for KeyType {
-        fn from_sql(
-            mut bytes: <Sqlite as diesel::backend::Backend>::RawValue<'_>,
-        ) -> diesel::deserialize::Result<Self> {
-            let Some(SqliteType::Long) = bytes.value_type() else {
-                return Err("Expected Integer for KeyType".into());
-            };
-            let discriminant = bytes.read_long();
-            KeyType::from_repr(discriminant as i32)
-                .ok_or_else(|| format!("Unknown KeyType discriminant: {discriminant}").into())
+            ToSql::<Integer, Sqlite>::to_sql(&self.0, out)
         }
     }
 }
@@ -244,7 +256,6 @@ pub struct UseragentClient {
     pub public_key: Vec<u8>,
     pub created_at: SqliteTimestamp,
     pub updated_at: SqliteTimestamp,
-    pub key_type: KeyType,
 }
 
 #[derive(Models, Queryable, Debug, Insertable, Selectable)]
@@ -272,7 +283,7 @@ pub struct EvmEtherTransferLimit {
 pub struct EvmBasicGrant {
     pub id: i32,
     pub wallet_access_id: i32, // references evm_wallet_access.id
-    pub chain_id: i32,
+    pub chain_id: ChainId,
     pub valid_from: Option<SqliteTimestamp>,
     pub valid_until: Option<SqliteTimestamp>,
     pub max_gas_fee_per_gas: Option<Vec<u8>>,
@@ -295,7 +306,7 @@ pub struct EvmTransactionLog {
     pub id: i32,
     pub grant_id: i32,
     pub wallet_access_id: i32,
-    pub chain_id: i32,
+    pub chain_id: ChainId,
     pub eth_value: Vec<u8>,
     pub signed_at: SqliteTimestamp,
 }
@@ -370,9 +381,28 @@ pub struct EvmTokenTransferLog {
     pub id: i32,
     pub grant_id: i32,
     pub log_id: i32,
-    pub chain_id: i32,
+    pub chain_id: ChainId,
     pub token_contract: Vec<u8>,
     pub recipient_address: Vec<u8>,
     pub value: Vec<u8>,
     pub created_at: SqliteTimestamp,
 }
+
+#[derive(Models, Queryable, Debug, Insertable, Selectable)]
+#[diesel(table_name = integrity_envelope, check_for_backend(Sqlite))]
+#[view(
+    NewIntegrityEnvelope,
+    derive(Insertable),
+    omit(id, signed_at, created_at),
+    attributes_with = "deriveless"
+)]
+pub struct IntegrityEnvelope {
+    pub id: i32,
+    pub entity_kind: String,
+    pub entity_id: Vec<u8>,
+    pub payload_version: i32,
+    pub key_version: i32,
+    pub mac: Vec<u8>,
+    pub signed_at: SqliteTimestamp,
+    pub created_at: SqliteTimestamp,
+}

server/crates/arbiter-server/src/db/schema.rs

@@ -139,6 +139,19 @@ diesel::table! {
     }
 }
 
+diesel::table! {
+    integrity_envelope (id) {
+        id -> Integer,
+        entity_kind -> Text,
+        entity_id -> Binary,
+        payload_version -> Integer,
+        key_version -> Integer,
+        mac -> Binary,
+        signed_at -> Integer,
+        created_at -> Integer,
+    }
+}
+
 diesel::table! {
     program_client (id) {
         id -> Integer,
@@ -219,6 +232,7 @@ diesel::allow_tables_to_appear_in_same_query!(
     evm_transaction_log,
     evm_wallet,
     evm_wallet_access,
+    integrity_envelope,
     program_client,
     root_key_history,
     tls_history,

server/crates/arbiter-server/src/evm/abi.rs

@@ -45,7 +45,7 @@ sol! {
 
 sol! {
     /// Permit2 — Uniswap's canonical token approval manager.
-    /// Replaces per-contract ERC-20 approve() with a single approval hub.
+    /// Replaces per-contract ERC-20 `approve()` with a single approval hub.
     #[derive(Debug)]
     interface IPermit2 {
         struct TokenPermissions {

server/crates/arbiter-server/src/evm/mod.rs

@@ -8,8 +8,11 @@ use alloy::{
 use chrono::Utc;
 use diesel::{ExpressionMethods as _, QueryDsl as _, QueryResult, insert_into, sqlite::Sqlite};
 use diesel_async::{AsyncConnection, RunQueryDsl};
+use kameo::actor::ActorRef;
 
 use crate::{
+    actors::keyholder::KeyHolder,
+    crypto::integrity,
     db::{
         self, DatabaseError,
         models::{
@@ -18,8 +21,8 @@ use crate::{
         schema::{self, evm_transaction_log},
     },
     evm::policies::{
-        DatabaseID, EvalContext, EvalViolation, FullGrant, Grant, Policy, SharedGrantSettings,
-        SpecificGrant, SpecificMeaning, ether_transfer::EtherTransfer,
+        CombinedSettings, DatabaseID, EvalContext, EvalViolation, Grant, Policy,
+        SharedGrantSettings, SpecificGrant, SpecificMeaning, ether_transfer::EtherTransfer,
         token_transfers::TokenTransfer,
     },
 };
@@ -28,42 +31,47 @@ pub mod policies;
 mod utils;
 
 /// Errors that can only occur once the transaction meaning is known (during policy evaluation)
-#[derive(Debug, thiserror::Error, miette::Diagnostic)]
+#[derive(Debug, thiserror::Error)]
 pub enum PolicyError {
     #[error("Database error")]
-    Database(#[from] crate::db::DatabaseError),
+    Database(#[from] DatabaseError),
     #[error("Transaction violates policy: {0:?}")]
-    #[diagnostic(code(arbiter_server::evm::policy_error::violation))]
     Violations(Vec<EvalViolation>),
     #[error("No matching grant found")]
-    #[diagnostic(code(arbiter_server::evm::policy_error::no_matching_grant))]
     NoMatchingGrant,
+
+    #[error("Integrity error: {0}")]
+    Integrity(#[from] integrity::IntegrityError),
 }
 
-#[derive(Debug, thiserror::Error, miette::Diagnostic)]
+#[derive(Debug, thiserror::Error)]
 pub enum VetError {
     #[error("Contract creation transactions are not supported")]
-    #[diagnostic(code(arbiter_server::evm::vet_error::contract_creation_unsupported))]
     ContractCreationNotSupported,
     #[error("Engine can't classify this transaction")]
-    #[diagnostic(code(arbiter_server::evm::vet_error::unsupported))]
     UnsupportedTransactionType,
     #[error("Policy evaluation failed: {1}")]
-    #[diagnostic(code(arbiter_server::evm::vet_error::evaluated))]
     Evaluated(SpecificMeaning, #[source] PolicyError),
 }
 
-#[derive(Debug, thiserror::Error, miette::Diagnostic)]
+#[derive(Debug, thiserror::Error)]
 pub enum AnalyzeError {
     #[error("Engine doesn't support granting permissions for contract creation")]
-    #[diagnostic(code(arbiter_server::evm::analyze_error::contract_creation_not_supported))]
     ContractCreationNotSupported,
 
     #[error("Unsupported transaction type")]
-    #[diagnostic(code(arbiter_server::evm::analyze_error::unsupported_transaction_type))]
     UnsupportedTransactionType,
 }
 
+#[derive(Debug, thiserror::Error)]
+pub enum ListError {
+    #[error("Database error")]
+    Database(#[from] DatabaseError),
+
+    #[error("Integrity verification failed for grant")]
+    Integrity(#[from] integrity::IntegrityError),
+}
+
 /// Controls whether a transaction should be executed or only validated
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum RunKind {
@@ -82,6 +90,14 @@ async fn check_shared_constraints(
     let mut violations = Vec::new();
     let now = Utc::now();
 
+    if shared.chain != context.chain {
+        violations.push(EvalViolation::MismatchingChainId {
+            expected: shared.chain,
+            actual: context.chain,
+        });
+        return Ok(violations);
+    }
+
     // Validity window
     if shared.valid_from.is_some_and(|t| now < t) || shared.valid_until.is_some_and(|t| now > t) {
         violations.push(EvalViolation::InvalidTime);
@@ -111,7 +127,7 @@ async fn check_shared_constraints(
             .get_result(conn)
             .await?;
 
-        if count >= rate_limit.count as i64 {
+        if count >= rate_limit.count.into() {
             violations.push(EvalViolation::RateLimitExceeded);
         }
     }
@@ -122,6 +138,7 @@ async fn check_shared_constraints(
 // Supporting only EIP-1559 transactions for now, but we can easily extend this to support legacy transactions if needed
 pub struct Engine {
     db: db::DatabasePool,
+    keyholder: ActorRef<KeyHolder>,
 }
 
 impl Engine {
@@ -130,7 +147,10 @@ impl Engine {
         context: EvalContext,
         meaning: &P::Meaning,
         run_kind: RunKind,
-    ) -> Result<(), PolicyError> {
+    ) -> Result<(), PolicyError>
+    where
+        P::Settings: Clone,
+    {
         let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
 
         let grant = P::try_find_grant(&context, &mut conn)
@@ -138,10 +158,16 @@ impl Engine {
             .map_err(DatabaseError::from)?
             .ok_or(PolicyError::NoMatchingGrant)?;
 
-        let mut violations =
-            check_shared_constraints(&context, &grant.shared, grant.shared_grant_id, &mut conn)
-                .await
-                .map_err(DatabaseError::from)?;
+        integrity::verify_entity(&mut conn, &self.keyholder, &grant.settings, grant.id).await?;
+
+        let mut violations = check_shared_constraints(
+            &context,
+            &grant.settings.shared,
+            grant.common_settings_id,
+            &mut conn,
+        )
+        .await
+        .map_err(DatabaseError::from)?;
         violations.extend(
             P::evaluate(&context, meaning, &grant, &mut conn)
                 .await
@@ -150,14 +176,16 @@ impl Engine {
 
         if !violations.is_empty() {
             return Err(PolicyError::Violations(violations));
-        } else if run_kind == RunKind::Execution {
+        }
+
+        if run_kind == RunKind::Execution {
             conn.transaction(|conn| {
                 Box::pin(async move {
                     let log_id: i32 = insert_into(evm_transaction_log::table)
                         .values(&NewEvmTransactionLog {
-                            grant_id: grant.shared_grant_id,
+                            grant_id: grant.common_settings_id,
                             wallet_access_id: context.target.id,
-                            chain_id: context.chain as i32,
+                            chain_id: context.chain.into(),
                             eth_value: utils::u256_to_bytes(context.value).to_vec(),
                             signed_at: Utc::now().into(),
                         })
@@ -179,42 +207,52 @@ impl Engine {
 }
 
 impl Engine {
-    pub fn new(db: db::DatabasePool) -> Self {
-        Self { db }
+    pub const fn new(db: db::DatabasePool, keyholder: ActorRef<KeyHolder>) -> Self {
+        Self { db, keyholder }
     }
 
     pub async fn create_grant<P: Policy>(
         &self,
-        full_grant: FullGrant<P::Settings>,
-    ) -> Result<i32, DatabaseError> {
+        full_grant: CombinedSettings<P::Settings>,
+    ) -> Result<i32, DatabaseError>
+    where
+        P::Settings: Clone,
+    {
         let mut conn = self.db.get().await?;
+        let keyholder = self.keyholder.clone();
 
         let id = conn
             .transaction(|conn| {
                 Box::pin(async move {
                     use schema::evm_basic_grant;
 
+                    #[expect(
+                        clippy::cast_possible_truncation,
+                        clippy::cast_possible_wrap,
+                        clippy::as_conversions,
+                        reason = "fixme! #86"
+                    )]
                     let basic_grant: EvmBasicGrant = insert_into(evm_basic_grant::table)
                         .values(&NewEvmBasicGrant {
-                            chain_id: full_grant.basic.chain as i32,
-                            wallet_access_id: full_grant.basic.wallet_access_id,
-                            valid_from: full_grant.basic.valid_from.map(SqliteTimestamp),
-                            valid_until: full_grant.basic.valid_until.map(SqliteTimestamp),
+                            chain_id: full_grant.shared.chain.into(),
+                            wallet_access_id: full_grant.shared.wallet_access_id,
+                            valid_from: full_grant.shared.valid_from.map(SqliteTimestamp),
+                            valid_until: full_grant.shared.valid_until.map(SqliteTimestamp),
                             max_gas_fee_per_gas: full_grant
-                                .basic
+                                .shared
                                 .max_gas_fee_per_gas
                                 .map(|fee| utils::u256_to_bytes(fee).to_vec()),
                             max_priority_fee_per_gas: full_grant
-                                .basic
+                                .shared
                                 .max_priority_fee_per_gas
                                 .map(|fee| utils::u256_to_bytes(fee).to_vec()),
                             rate_limit_count: full_grant
-                                .basic
+                                .shared
                                 .rate_limit
                                 .as_ref()
                                 .map(|rl| rl.count as i32),
                             rate_limit_window_secs: full_grant
-                                .basic
+                                .shared
                                 .rate_limit
                                 .as_ref()
                                 .map(|rl| rl.window.num_seconds() as i32),
@@ -224,7 +262,13 @@ impl Engine {
                         .get_result(conn)
                         .await?;
 
-                    P::create_grant(&basic_grant, &full_grant.specific, conn).await
+                    P::create_grant(&basic_grant, &full_grant.specific, conn).await?;
+
+                    integrity::sign_entity(conn, &keyholder, &full_grant, basic_grant.id)
+                        .await
+                        .map_err(|_| diesel::result::Error::RollbackTransaction)?;
+
+                    QueryResult::Ok(basic_grant.id)
                 })
             })
             .await?;
@@ -232,33 +276,36 @@ impl Engine {
         Ok(id)
     }
 
-    pub async fn list_all_grants(&self) -> Result<Vec<Grant<SpecificGrant>>, DatabaseError> {
-        let mut conn = self.db.get().await?;
+    async fn list_one_kind<Kind: Policy, Y>(
+        &self,
+        conn: &mut impl AsyncConnection<Backend = Sqlite>,
+    ) -> Result<impl Iterator<Item = Grant<Y>>, ListError>
+    where
+        Y: From<Kind::Settings>,
+    {
+        let all_grants = Kind::find_all_grants(conn)
+            .await
+            .map_err(DatabaseError::from)?;
+
+        // Verify integrity of all grants before returning any results
+        for grant in &all_grants {
+            integrity::verify_entity(conn, &self.keyholder, &grant.settings, grant.id).await?;
+        }
+
+        Ok(all_grants.into_iter().map(|g| Grant {
+            id: g.id,
+            common_settings_id: g.common_settings_id,
+            settings: g.settings.generalize(),
+        }))
+    }
+
+    pub async fn list_all_grants(&self) -> Result<Vec<Grant<SpecificGrant>>, ListError> {
+        let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
 
         let mut grants: Vec<Grant<SpecificGrant>> = Vec::new();
 
-        grants.extend(
-            EtherTransfer::find_all_grants(&mut conn)
-                .await?
-                .into_iter()
-                .map(|g| Grant {
-                    id: g.id,
-                    shared_grant_id: g.shared_grant_id,
-                    shared: g.shared,
-                    settings: SpecificGrant::EtherTransfer(g.settings),
-                }),
-        );
-        grants.extend(
-            TokenTransfer::find_all_grants(&mut conn)
-                .await?
-                .into_iter()
-                .map(|g| Grant {
-                    id: g.id,
-                    shared_grant_id: g.shared_grant_id,
-                    shared: g.shared,
-                    settings: SpecificGrant::TokenTransfer(g.settings),
-                }),
-        );
+        grants.extend(self.list_one_kind::<EtherTransfer, _>(&mut conn).await?);
+        grants.extend(self.list_one_kind::<TokenTransfer, _>(&mut conn).await?);
 
         Ok(grants)
     }
@@ -272,7 +319,7 @@ impl Engine {
         let TxKind::Call(to) = transaction.to else {
             return Err(VetError::ContractCreationNotSupported);
         };
-        let context = policies::EvalContext {
+        let context = EvalContext {
             target,
             chain: transaction.chain_id,
             to,
@@ -304,3 +351,261 @@ impl Engine {
         Err(VetError::UnsupportedTransactionType)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use alloy::primitives::{Address, Bytes, U256, address};
+    use chrono::{Duration, Utc};
+    use diesel::{SelectableHelper, insert_into};
+    use diesel_async::RunQueryDsl;
+    use rstest::rstest;
+
+    use crate::db::{
+        self, DatabaseConnection,
+        models::{
+            EvmBasicGrant, EvmWalletAccess, NewEvmBasicGrant, NewEvmTransactionLog, SqliteTimestamp,
+        },
+        schema::{evm_basic_grant, evm_transaction_log},
+    };
+    use crate::evm::policies::{
+        EvalContext, EvalViolation, SharedGrantSettings, TransactionRateLimit,
+    };
+
+    use super::check_shared_constraints;
+
+    const WALLET_ACCESS_ID: i32 = 1;
+    const CHAIN_ID: u64 = 1;
+    const RECIPIENT: Address = address!("1111111111111111111111111111111111111111");
+
+    fn context() -> EvalContext {
+        EvalContext {
+            target: EvmWalletAccess {
+                id: WALLET_ACCESS_ID,
+                wallet_id: 10,
+                client_id: 20,
+                created_at: SqliteTimestamp(Utc::now()),
+            },
+            chain: CHAIN_ID,
+            to: RECIPIENT,
+            value: U256::ZERO,
+            calldata: Bytes::new(),
+            max_fee_per_gas: 100,
+            max_priority_fee_per_gas: 10,
+        }
+    }
+
+    fn shared_settings() -> SharedGrantSettings {
+        SharedGrantSettings {
+            wallet_access_id: WALLET_ACCESS_ID,
+            chain: CHAIN_ID,
+            valid_from: None,
+            valid_until: None,
+            max_gas_fee_per_gas: None,
+            max_priority_fee_per_gas: None,
+            rate_limit: None,
+        }
+    }
+
+    async fn insert_basic_grant(
+        conn: &mut DatabaseConnection,
+        shared: &SharedGrantSettings,
+    ) -> EvmBasicGrant {
+        #[expect(
+            clippy::cast_possible_truncation,
+            clippy::cast_possible_wrap,
+            clippy::as_conversions,
+            reason = "fixme! #86"
+        )]
+        insert_into(evm_basic_grant::table)
+            .values(NewEvmBasicGrant {
+                wallet_access_id: shared.wallet_access_id,
+                chain_id: shared.chain.into(),
+                valid_from: shared.valid_from.map(SqliteTimestamp),
+                valid_until: shared.valid_until.map(SqliteTimestamp),
+                max_gas_fee_per_gas: shared
+                    .max_gas_fee_per_gas
+                    .map(|fee| super::utils::u256_to_bytes(fee).to_vec()),
+                max_priority_fee_per_gas: shared
+                    .max_priority_fee_per_gas
+                    .map(|fee| super::utils::u256_to_bytes(fee).to_vec()),
+                rate_limit_count: shared.rate_limit.as_ref().map(|limit| limit.count as i32),
+                rate_limit_window_secs: shared
+                    .rate_limit
+                    .as_ref()
+                    .map(|limit| limit.window.num_seconds() as i32),
+                revoked_at: None,
+            })
+            .returning(EvmBasicGrant::as_select())
+            .get_result(conn)
+            .await
+            .unwrap()
+    }
+
+    #[rstest]
+    #[case::matching_chain(CHAIN_ID, false)]
+    #[case::mismatching_chain(CHAIN_ID + 1, true)]
+    #[tokio::test]
+    async fn check_shared_constraints_enforces_chain_id(
+        #[case] context_chain: u64,
+        #[case] expect_mismatch: bool,
+    ) {
+        let db = db::create_test_pool().await;
+        let mut conn = db.get().await.unwrap();
+
+        let context = EvalContext {
+            chain: context_chain,
+            ..context()
+        };
+
+        let violations = check_shared_constraints(&context, &shared_settings(), 999, &mut *conn)
+            .await
+            .unwrap();
+
+        assert_eq!(
+            violations
+                .iter()
+                .any(|violation| matches!(violation, EvalViolation::MismatchingChainId { .. })),
+            expect_mismatch
+        );
+
+        if expect_mismatch {
+            assert_eq!(violations.len(), 1);
+        } else {
+            assert!(violations.is_empty());
+        }
+    }
+
+    #[rstest]
+    #[case::valid_from_in_bounds(Some(Utc::now() - Duration::hours(1)), None, false)]
+    #[case::valid_from_out_of_bounds(Some(Utc::now() + Duration::hours(1)), None, true)]
+    #[case::valid_until_in_bounds(None, Some(Utc::now() + Duration::hours(1)), false)]
+    #[case::valid_until_out_of_bounds(None, Some(Utc::now() - Duration::hours(1)), true)]
+    #[tokio::test]
+    async fn check_shared_constraints_enforces_validity_window(
+        #[case] valid_from: Option<chrono::DateTime<Utc>>,
+        #[case] valid_until: Option<chrono::DateTime<Utc>>,
+        #[case] expect_invalid_time: bool,
+    ) {
+        let db = db::create_test_pool().await;
+        let mut conn = db.get().await.unwrap();
+
+        let shared = SharedGrantSettings {
+            valid_from,
+            valid_until,
+            ..shared_settings()
+        };
+
+        let violations = check_shared_constraints(&context(), &shared, 999, &mut *conn)
+            .await
+            .unwrap();
+
+        assert_eq!(
+            violations
+                .iter()
+                .any(|violation| matches!(violation, EvalViolation::InvalidTime)),
+            expect_invalid_time
+        );
+
+        if expect_invalid_time {
+            assert_eq!(violations.len(), 1);
+        } else {
+            assert!(violations.is_empty());
+        }
+    }
+
+    #[rstest]
+    #[case::max_fee_within_limit(Some(U256::from(100u64)), None, 100, 10, false)]
+    #[case::max_fee_exceeded(Some(U256::from(99u64)), None, 100, 10, true)]
+    #[case::priority_fee_within_limit(None, Some(U256::from(10u64)), 100, 10, false)]
+    #[case::priority_fee_exceeded(None, Some(U256::from(9u64)), 100, 10, true)]
+    #[tokio::test]
+    async fn check_shared_constraints_enforces_gas_fee_caps(
+        #[case] max_gas_fee_per_gas: Option<U256>,
+        #[case] max_priority_fee_per_gas: Option<U256>,
+        #[case] actual_max_fee_per_gas: u128,
+        #[case] actual_max_priority_fee_per_gas: u128,
+        #[case] expect_gas_limit_violation: bool,
+    ) {
+        let db = db::create_test_pool().await;
+        let mut conn = db.get().await.unwrap();
+
+        let context = EvalContext {
+            max_fee_per_gas: actual_max_fee_per_gas,
+            max_priority_fee_per_gas: actual_max_priority_fee_per_gas,
+            ..context()
+        };
+
+        let shared = SharedGrantSettings {
+            max_gas_fee_per_gas,
+            max_priority_fee_per_gas,
+            ..shared_settings()
+        };
+        let violations = check_shared_constraints(&context, &shared, 999, &mut *conn)
+            .await
+            .unwrap();
+
+        assert_eq!(
+            violations
+                .iter()
+                .any(|violation| matches!(violation, EvalViolation::GasLimitExceeded { .. })),
+            expect_gas_limit_violation
+        );
+
+        if expect_gas_limit_violation {
+            assert_eq!(violations.len(), 1);
+        } else {
+            assert!(violations.is_empty());
+        }
+    }
+
+    #[rstest]
+    #[case::under_rate_limit(2, false)]
+    #[case::at_rate_limit(1, true)]
+    #[tokio::test]
+    async fn check_shared_constraints_enforces_rate_limit(
+        #[case] rate_limit_count: u32,
+        #[case] expect_rate_limit_violation: bool,
+    ) {
+        let db = db::create_test_pool().await;
+        let mut conn = db.get().await.unwrap();
+
+        let shared = SharedGrantSettings {
+            rate_limit: Some(TransactionRateLimit {
+                count: rate_limit_count,
+                window: Duration::hours(1),
+            }),
+            ..shared_settings()
+        };
+
+        let basic_grant = insert_basic_grant(&mut conn, &shared).await;
+
+        insert_into(evm_transaction_log::table)
+            .values(NewEvmTransactionLog {
+                grant_id: basic_grant.id,
+                wallet_access_id: WALLET_ACCESS_ID,
+                chain_id: CHAIN_ID.into(),
+                eth_value: super::utils::u256_to_bytes(U256::ZERO).to_vec(),
+                signed_at: SqliteTimestamp(Utc::now()),
+            })
+            .execute(&mut *conn)
+            .await
+            .unwrap();
+
+        let violations = check_shared_constraints(&context(), &shared, basic_grant.id, &mut *conn)
+            .await
+            .unwrap();
+
+        assert_eq!(
+            violations
+                .iter()
+                .any(|violation| matches!(violation, EvalViolation::RateLimitExceeded)),
+            expect_rate_limit_violation
+        );
+
+        if expect_rate_limit_violation {
+            assert_eq!(violations.len(), 1);
+        } else {
+            assert!(violations.is_empty());
+        }
+    }
+}

server/crates/arbiter-server/src/evm/policies.rs

@@ -6,11 +6,12 @@ use diesel::{
     ExpressionMethods as _, QueryDsl, SelectableHelper, result::QueryResult, sqlite::Sqlite,
 };
 use diesel_async::{AsyncConnection, RunQueryDsl};
-use miette::Diagnostic;
+
 use thiserror::Error;
 
 use crate::{
-    db::models::{self, EvmBasicGrant, EvmWalletAccess},
+    crypto::integrity::v1::Integrable,
+    db::models::{EvmBasicGrant, EvmWalletAccess},
     evm::utils,
 };
 
@@ -33,34 +34,31 @@ pub struct EvalContext {
     pub max_priority_fee_per_gas: u128,
 }
 
-#[derive(Debug, Error, Diagnostic)]
+#[derive(Debug, Error)]
 pub enum EvalViolation {
     #[error("This grant doesn't allow transactions to the target address {target}")]
-    #[diagnostic(code(arbiter_server::evm::eval_violation::invalid_target))]
     InvalidTarget { target: Address },
 
     #[error("Gas limit exceeded for this grant")]
-    #[diagnostic(code(arbiter_server::evm::eval_violation::gas_limit_exceeded))]
     GasLimitExceeded {
         max_gas_fee_per_gas: Option<U256>,
         max_priority_fee_per_gas: Option<U256>,
     },
 
     #[error("Rate limit exceeded for this grant")]
-    #[diagnostic(code(arbiter_server::evm::eval_violation::rate_limit_exceeded))]
     RateLimitExceeded,
 
     #[error("Transaction exceeds volumetric limits of the grant")]
-    #[diagnostic(code(arbiter_server::evm::eval_violation::volumetric_limit_exceeded))]
     VolumetricLimitExceeded,
 
     #[error("Transaction is outside of the grant's validity period")]
-    #[diagnostic(code(arbiter_server::evm::eval_violation::invalid_time))]
     InvalidTime,
 
     #[error("Transaction type is not allowed by this grant")]
-    #[diagnostic(code(arbiter_server::evm::eval_violation::invalid_transaction_type))]
     InvalidTransactionType,
+
+    #[error("Mismatching chain ID")]
+    MismatchingChainId { expected: ChainId, actual: ChainId },
 }
 
 pub type DatabaseID = i32;
@@ -68,13 +66,12 @@ pub type DatabaseID = i32;
 #[derive(Debug)]
 pub struct Grant<PolicySettings> {
     pub id: DatabaseID,
-    pub shared_grant_id: DatabaseID, // ID of the basic grant for shared-logic checks like rate limits and validity periods
-    pub shared: SharedGrantSettings,
-    pub settings: PolicySettings,
+    pub common_settings_id: DatabaseID, // ID of the basic grant for shared-logic checks like rate limits and validity periods
+    pub settings: CombinedSettings<PolicySettings>,
 }
 
 pub trait Policy: Sized {
-    type Settings: Send + Sync + 'static + Into<SpecificGrant>;
+    type Settings: Send + Sync + 'static + Into<SpecificGrant> + Integrable;
     type Meaning: Display + std::fmt::Debug + Send + Sync + 'static + Into<SpecificMeaning>;
 
     fn analyze(context: &EvalContext) -> Option<Self::Meaning>;
@@ -90,10 +87,10 @@ pub trait Policy: Sized {
 
     // Create a new grant in the database based on the provided grant details, and return its ID
     fn create_grant(
-        basic: &models::EvmBasicGrant,
+        basic: &EvmBasicGrant,
         grant: &Self::Settings,
         conn: &mut impl AsyncConnection<Backend = Sqlite>,
-    ) -> impl std::future::Future<Output = QueryResult<DatabaseID>> + Send;
+    ) -> impl Future<Output = QueryResult<DatabaseID>> + Send;
 
     // Try to find an existing grant that matches the transaction context, and return its details if found
     // Additionally, return ID of basic grant for shared-logic checks like rate limits and validity periods
@@ -130,19 +127,19 @@ pub enum SpecificMeaning {
     TokenTransfer(token_transfers::Meaning),
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, arbiter_macros::Hashable)]
 pub struct TransactionRateLimit {
     pub count: u32,
     pub window: Duration,
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, arbiter_macros::Hashable)]
 pub struct VolumeRateLimit {
     pub max_volume: U256,
     pub window: Duration,
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, arbiter_macros::Hashable)]
 pub struct SharedGrantSettings {
     pub wallet_access_id: i32,
     pub chain: ChainId,
@@ -157,10 +154,10 @@ pub struct SharedGrantSettings {
 }
 
 impl SharedGrantSettings {
-    fn try_from_model(model: EvmBasicGrant) -> QueryResult<Self> {
+    pub(crate) fn try_from_model(model: EvmBasicGrant) -> QueryResult<Self> {
         Ok(Self {
             wallet_access_id: model.wallet_access_id,
-            chain: model.chain_id as u64, // safe because chain_id is stored as i32 but is guaranteed to be a valid ChainId by the API when creating grants
+            chain: model.chain_id.into(),
             valid_from: model.valid_from.map(Into::into),
             valid_until: model.valid_until.map(Into::into),
             max_gas_fee_per_gas: model
@@ -171,10 +168,11 @@ impl SharedGrantSettings {
                 .max_priority_fee_per_gas
                 .map(|b| utils::try_bytes_to_u256(&b))
                 .transpose()?,
+            #[expect(clippy::cast_sign_loss, clippy::as_conversions, reason = "fixme! #86")]
             rate_limit: match (model.rate_limit_count, model.rate_limit_window_secs) {
                 (Some(count), Some(window_secs)) => Some(TransactionRateLimit {
                     count: count as u32,
-                    window: Duration::seconds(window_secs as i64),
+                    window: Duration::seconds(window_secs.into()),
                 }),
                 _ => None,
             },
@@ -184,7 +182,7 @@ impl SharedGrantSettings {
     pub async fn query_by_id(
         conn: &mut impl AsyncConnection<Backend = Sqlite>,
         id: i32,
-    ) -> diesel::result::QueryResult<Self> {
+    ) -> QueryResult<Self> {
         use crate::db::schema::evm_basic_grant;
 
         let basic_grant: EvmBasicGrant = evm_basic_grant::table
@@ -203,7 +201,22 @@ pub enum SpecificGrant {
     TokenTransfer(token_transfers::Settings),
 }
 
-pub struct FullGrant<PolicyGrant> {
-    pub basic: SharedGrantSettings,
+#[derive(Debug, arbiter_macros::Hashable)]
+pub struct CombinedSettings<PolicyGrant> {
+    pub shared: SharedGrantSettings,
     pub specific: PolicyGrant,
 }
+
+impl<P> CombinedSettings<P> {
+    pub fn generalize<Y: From<P>>(self) -> CombinedSettings<Y> {
+        CombinedSettings {
+            shared: self.shared,
+            specific: self.specific.into(),
+        }
+    }
+}
+
+impl<P: Integrable> Integrable for CombinedSettings<P> {
+    const KIND: &'static str = P::KIND;
+    const VERSION: i32 = P::VERSION;
+}

server/crates/arbiter-server/src/evm/policies/ether_transfer/mod.rs

@@ -4,21 +4,22 @@ use std::fmt::Display;
 use alloy::primitives::{Address, U256};
 use chrono::{DateTime, Duration, Utc};
 use diesel::dsl::{auto_type, insert_into};
+use diesel::prelude::*;
 use diesel::sqlite::Sqlite;
-use diesel::{ExpressionMethods, JoinOnDsl, prelude::*};
 use diesel_async::{AsyncConnection, RunQueryDsl};
 
+use crate::crypto::integrity::v1::Integrable;
 use crate::db::models::{
     EvmBasicGrant, EvmEtherTransferGrant, EvmEtherTransferGrantTarget, EvmEtherTransferLimit,
     NewEvmEtherTransferLimit, SqliteTimestamp,
 };
 use crate::db::schema::{evm_basic_grant, evm_ether_transfer_limit, evm_transaction_log};
 use crate::evm::policies::{
-    Grant, SharedGrantSettings, SpecificGrant, SpecificMeaning, VolumeRateLimit,
+    CombinedSettings, Grant, SharedGrantSettings, SpecificGrant, SpecificMeaning, VolumeRateLimit,
 };
 use crate::{
     db::{
-        models::{self, NewEvmEtherTransferGrant, NewEvmEtherTransferGrantTarget},
+        models::{NewEvmEtherTransferGrant, NewEvmEtherTransferGrantTarget},
         schema::{evm_ether_transfer_grant, evm_ether_transfer_grant_target},
     },
     evm::{policies::Policy, utils},
@@ -45,21 +46,24 @@ impl Display for Meaning {
     }
 }
 impl From<Meaning> for SpecificMeaning {
-    fn from(val: Meaning) -> SpecificMeaning {
-        SpecificMeaning::EtherTransfer(val)
+    fn from(val: Meaning) -> Self {
+        Self::EtherTransfer(val)
     }
 }
 
 // A grant for ether transfers, which can be scoped to specific target addresses and volume limits
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, arbiter_macros::Hashable)]
 pub struct Settings {
     pub target: Vec<Address>,
     pub limit: VolumeRateLimit,
 }
+impl Integrable for Settings {
+    const KIND: &'static str = "EtherTransfer";
+}
 
 impl From<Settings> for SpecificGrant {
-    fn from(val: Settings) -> SpecificGrant {
-        SpecificGrant::EtherTransfer(val)
+    fn from(val: Settings) -> Self {
+        Self::EtherTransfer(val)
     }
 }
 
@@ -70,9 +74,7 @@ async fn query_relevant_past_transaction(
 ) -> QueryResult<Vec<(U256, DateTime<Utc>)>> {
     let past_transactions: Vec<(Vec<u8>, SqliteTimestamp)> = evm_transaction_log::table
         .filter(evm_transaction_log::grant_id.eq(grant_id))
-        .filter(
-            evm_transaction_log::signed_at.ge(SqliteTimestamp(chrono::Utc::now() - longest_window)),
-        )
+        .filter(evm_transaction_log::signed_at.ge(SqliteTimestamp(Utc::now() - longest_window)))
         .select((
             evm_transaction_log::eth_value,
             evm_transaction_log::signed_at,
@@ -95,17 +97,17 @@ async fn check_rate_limits(
     db: &mut impl AsyncConnection<Backend = Sqlite>,
 ) -> QueryResult<Vec<EvalViolation>> {
     let mut violations = Vec::new();
-    let window = grant.settings.limit.window;
+    let window = grant.settings.specific.limit.window;
 
     let past_transaction = query_relevant_past_transaction(grant.id, window, db).await?;
 
-    let window_start = chrono::Utc::now() - grant.settings.limit.window;
+    let window_start = Utc::now() - grant.settings.specific.limit.window;
     let prospective_cumulative_volume: U256 = past_transaction
         .iter()
         .filter(|(_, timestamp)| timestamp >= &window_start)
         .fold(current_transfer_value, |acc, (value, _)| acc + *value);
 
-    if prospective_cumulative_volume > grant.settings.limit.max_volume {
+    if prospective_cumulative_volume > grant.settings.specific.limit.max_volume {
         violations.push(EvalViolation::VolumetricLimitExceeded);
     }
 
@@ -138,7 +140,7 @@ impl Policy for EtherTransfer {
         let mut violations = Vec::new();
 
         // Check if the target address is within the grant's allowed targets
-        if !grant.settings.target.contains(&meaning.to) {
+        if !grant.settings.specific.target.contains(&meaning.to) {
             violations.push(EvalViolation::InvalidTarget { target: meaning.to });
         }
 
@@ -149,10 +151,15 @@ impl Policy for EtherTransfer {
     }
 
     async fn create_grant(
-        basic: &models::EvmBasicGrant,
+        basic: &EvmBasicGrant,
         grant: &Self::Settings,
         conn: &mut impl AsyncConnection<Backend = Sqlite>,
-    ) -> diesel::result::QueryResult<DatabaseID> {
+    ) -> QueryResult<DatabaseID> {
+        #[expect(
+            clippy::cast_possible_truncation,
+            clippy::as_conversions,
+            reason = "fixme! #86"
+        )]
         let limit_id: i32 = insert_into(evm_ether_transfer_limit::table)
             .values(NewEvmEtherTransferLimit {
                 window_secs: grant.limit.window.num_seconds() as i32,
@@ -187,7 +194,7 @@ impl Policy for EtherTransfer {
     async fn try_find_grant(
         context: &EvalContext,
         conn: &mut impl AsyncConnection<Backend = Sqlite>,
-    ) -> diesel::result::QueryResult<Option<Grant<Self::Settings>>> {
+    ) -> QueryResult<Option<Grant<Self::Settings>>> {
         let target_bytes = context.to.to_vec();
 
         // Find a grant where:
@@ -241,15 +248,17 @@ impl Policy for EtherTransfer {
             limit: VolumeRateLimit {
                 max_volume: utils::try_bytes_to_u256(&limit.max_volume)
                     .map_err(|err| diesel::result::Error::DeserializationError(Box::new(err)))?,
-                window: chrono::Duration::seconds(limit.window_secs as i64),
+                window: Duration::seconds(limit.window_secs.into()),
             },
         };
 
         Ok(Some(Grant {
             id: grant.id,
-            shared_grant_id: grant.basic_grant_id,
-            shared: SharedGrantSettings::try_from_model(basic_grant)?,
-            settings,
+            common_settings_id: grant.basic_grant_id,
+            settings: CombinedSettings {
+                shared: SharedGrantSettings::try_from_model(basic_grant)?,
+                specific: settings,
+            },
         }))
     }
 
@@ -259,7 +268,7 @@ impl Policy for EtherTransfer {
         _log_id: i32,
         _grant: &Grant<Self::Settings>,
         _conn: &mut impl AsyncConnection<Backend = Sqlite>,
-    ) -> diesel::result::QueryResult<()> {
+    ) -> QueryResult<()> {
         // Basic log is sufficient
 
         Ok(())
@@ -312,7 +321,7 @@ impl Policy for EtherTransfer {
             .map(|(basic, specific)| {
                 let targets: Vec<Address> = targets_by_grant
                     .get(&specific.id)
-                    .map(|v| v.as_slice())
+                    .map(Vec::as_slice)
                     .unwrap_or_default()
                     .iter()
                     .filter_map(|t| {
@@ -327,15 +336,17 @@ impl Policy for EtherTransfer {
 
                 Ok(Grant {
                     id: specific.id,
-                    shared_grant_id: specific.basic_grant_id,
-                    shared: SharedGrantSettings::try_from_model(basic)?,
-                    settings: Settings {
-                        target: targets,
-                        limit: VolumeRateLimit {
-                            max_volume: utils::try_bytes_to_u256(&limit.max_volume).map_err(
-                                |e| diesel::result::Error::DeserializationError(Box::new(e)),
-                            )?,
-                            window: Duration::seconds(limit.window_secs as i64),
+                    common_settings_id: specific.basic_grant_id,
+                    settings: CombinedSettings {
+                        shared: SharedGrantSettings::try_from_model(basic)?,
+                        specific: Settings {
+                            target: targets,
+                            limit: VolumeRateLimit {
+                                max_volume: utils::try_bytes_to_u256(&limit.max_volume).map_err(
+                                    |e| diesel::result::Error::DeserializationError(Box::new(e)),
+                                )?,
+                                window: Duration::seconds(limit.window_secs.into()),
+                            },
                         },
                     },
                 })

server/crates/arbiter-server/src/evm/policies/ether_transfer/tests.rs

@@ -11,14 +11,17 @@ use crate::db::{
     schema::{evm_basic_grant, evm_transaction_log},
 };
 use crate::evm::{
-    policies::{EvalContext, EvalViolation, Grant, Policy, SharedGrantSettings, VolumeRateLimit},
+    policies::{
+        CombinedSettings, EvalContext, EvalViolation, Grant, Policy, SharedGrantSettings,
+        VolumeRateLimit,
+    },
     utils,
 };
 
 use super::{EtherTransfer, Settings};
 
 const WALLET_ACCESS_ID: i32 = 1;
-const CHAIN_ID: u64 = 1;
+const CHAIN_ID: alloy::primitives::ChainId = 1;
 
 const ALLOWED: Address = address!("1111111111111111111111111111111111111111");
 const OTHER: Address = address!("2222222222222222222222222222222222222222");
@@ -44,7 +47,7 @@ async fn insert_basic(conn: &mut DatabaseConnection, revoked: bool) -> EvmBasicG
     insert_into(evm_basic_grant::table)
         .values(NewEvmBasicGrant {
             wallet_access_id: WALLET_ACCESS_ID,
-            chain_id: CHAIN_ID as i32,
+            chain_id: CHAIN_ID.into(),
             valid_from: None,
             valid_until: None,
             max_gas_fee_per_gas: None,
@@ -81,8 +84,6 @@ fn shared() -> SharedGrantSettings {
     }
 }
 
-// ── analyze ─────────────────────────────────────────────────────────────
-
 #[test]
 fn analyze_matches_empty_calldata() {
     let m = EtherTransfer::analyze(&ctx(ALLOWED, U256::from(1_000u64))).unwrap();
@@ -99,8 +100,6 @@ fn analyze_rejects_nonempty_calldata() {
     assert!(EtherTransfer::analyze(&context).is_none());
 }
 
-// ── evaluate ────────────────────────────────────────────────────────────
-
 #[tokio::test]
 async fn evaluate_passes_for_allowed_target() {
     let db = db::create_test_pool().await;
@@ -108,9 +107,11 @@ async fn evaluate_passes_for_allowed_target() {
 
     let grant = Grant {
         id: 999,
-        shared_grant_id: 999,
-        shared: shared(),
-        settings: make_settings(vec![ALLOWED], 1_000_000),
+        common_settings_id: 999,
+        settings: CombinedSettings {
+            shared: shared(),
+            specific: make_settings(vec![ALLOWED], 1_000_000),
+        },
     };
     let context = ctx(ALLOWED, U256::from(100u64));
     let m = EtherTransfer::analyze(&context).unwrap();
@@ -127,9 +128,11 @@ async fn evaluate_rejects_disallowed_target() {
 
     let grant = Grant {
         id: 999,
-        shared_grant_id: 999,
-        shared: shared(),
-        settings: make_settings(vec![ALLOWED], 1_000_000),
+        common_settings_id: 999,
+        settings: CombinedSettings {
+            shared: shared(),
+            specific: make_settings(vec![ALLOWED], 1_000_000),
+        },
     };
     let context = ctx(OTHER, U256::from(100u64));
     let m = EtherTransfer::analyze(&context).unwrap();
@@ -157,7 +160,7 @@ async fn evaluate_passes_when_volume_within_limit() {
         .values(NewEvmTransactionLog {
             grant_id,
             wallet_access_id: WALLET_ACCESS_ID,
-            chain_id: CHAIN_ID as i32,
+            chain_id: CHAIN_ID.into(),
             eth_value: utils::u256_to_bytes(U256::from(500u64)).to_vec(),
             signed_at: SqliteTimestamp(Utc::now()),
         })
@@ -167,9 +170,11 @@ async fn evaluate_passes_when_volume_within_limit() {
 
     let grant = Grant {
         id: grant_id,
-        shared_grant_id: basic.id,
-        shared: shared(),
-        settings,
+        common_settings_id: basic.id,
+        settings: CombinedSettings {
+            shared: shared(),
+            specific: settings,
+        },
     };
     let context = ctx(ALLOWED, U256::from(100u64));
     let m = EtherTransfer::analyze(&context).unwrap();
@@ -197,7 +202,7 @@ async fn evaluate_rejects_volume_over_limit() {
         .values(NewEvmTransactionLog {
             grant_id,
             wallet_access_id: WALLET_ACCESS_ID,
-            chain_id: CHAIN_ID as i32,
+            chain_id: CHAIN_ID.into(),
             eth_value: utils::u256_to_bytes(U256::from(1_000u64)).to_vec(),
             signed_at: SqliteTimestamp(Utc::now()),
         })
@@ -207,9 +212,11 @@ async fn evaluate_rejects_volume_over_limit() {
 
     let grant = Grant {
         id: grant_id,
-        shared_grant_id: basic.id,
-        shared: shared(),
-        settings,
+        common_settings_id: basic.id,
+        settings: CombinedSettings {
+            shared: shared(),
+            specific: settings,
+        },
     };
     let context = ctx(ALLOWED, U256::from(1u64));
     let m = EtherTransfer::analyze(&context).unwrap();
@@ -238,7 +245,7 @@ async fn evaluate_passes_at_exactly_volume_limit() {
         .values(NewEvmTransactionLog {
             grant_id,
             wallet_access_id: WALLET_ACCESS_ID,
-            chain_id: CHAIN_ID as i32,
+            chain_id: CHAIN_ID.into(),
             eth_value: utils::u256_to_bytes(U256::from(900u64)).to_vec(),
             signed_at: SqliteTimestamp(Utc::now()),
         })
@@ -248,9 +255,11 @@ async fn evaluate_passes_at_exactly_volume_limit() {
 
     let grant = Grant {
         id: grant_id,
-        shared_grant_id: basic.id,
-        shared: shared(),
-        settings,
+        common_settings_id: basic.id,
+        settings: CombinedSettings {
+            shared: shared(),
+            specific: settings,
+        },
     };
     let context = ctx(ALLOWED, U256::from(100u64));
     let m = EtherTransfer::analyze(&context).unwrap();
@@ -263,8 +272,6 @@ async fn evaluate_passes_at_exactly_volume_limit() {
     );
 }
 
-// ── try_find_grant ───────────────────────────────────────────────────────
-
 #[tokio::test]
 async fn try_find_grant_roundtrip() {
     let db = db::create_test_pool().await;
@@ -282,8 +289,11 @@ async fn try_find_grant_roundtrip() {
 
     assert!(found.is_some());
     let g = found.unwrap();
-    assert_eq!(g.settings.target, vec![ALLOWED]);
-    assert_eq!(g.settings.limit.max_volume, U256::from(1_000_000u64));
+    assert_eq!(g.settings.specific.target, vec![ALLOWED]);
+    assert_eq!(
+        g.settings.specific.limit.max_volume,
+        U256::from(1_000_000u64)
+    );
 }
 
 #[tokio::test]
@@ -320,7 +330,36 @@ async fn try_find_grant_wrong_target_returns_none() {
     assert!(found.is_none());
 }
 
-// ── find_all_grants ──────────────────────────────────────────────────────
+proptest::proptest! {
+    #[test]
+    fn target_order_does_not_affect_hash(
+        raw_addrs in proptest::collection::vec(proptest::prelude::any::<[u8; 20]>(), 0..8),
+        seed in proptest::prelude::any::<u64>(),
+        max_volume in proptest::prelude::any::<u64>(),
+        window_secs in 1i64..=86400,
+    ) {
+        use rand::{SeedableRng, seq::SliceRandom};
+        use sha2::Digest;
+        use arbiter_crypto::hashing::Hashable;
+
+        let addrs: Vec<Address> = raw_addrs.iter().map(|b| Address::from(*b)).collect();
+        let mut shuffled = addrs.clone();
+        shuffled.shuffle(&mut rand::rngs::StdRng::seed_from_u64(seed));
+
+        let limit = VolumeRateLimit {
+            max_volume: U256::from(max_volume),
+            window: Duration::seconds(window_secs),
+        };
+
+        let mut h1 = sha2::Sha256::new();
+        Settings { target: addrs, limit: limit.clone() }.hash(&mut h1);
+
+        let mut h2 = sha2::Sha256::new();
+        Settings { target: shuffled, limit }.hash(&mut h2);
+
+        proptest::prop_assert_eq!(h1.finalize(), h2.finalize());
+    }
+}
 
 #[tokio::test]
 async fn find_all_grants_empty_db() {
@@ -347,7 +386,7 @@ async fn find_all_grants_excludes_revoked() {
 
     let all = EtherTransfer::find_all_grants(&mut *conn).await.unwrap();
     assert_eq!(all.len(), 1);
-    assert_eq!(all[0].settings.target, vec![ALLOWED]);
+    assert_eq!(all[0].settings.specific.target, vec![ALLOWED]);
 }
 
 #[tokio::test]
@@ -363,8 +402,11 @@ async fn find_all_grants_multiple_targets() {
 
     let all = EtherTransfer::find_all_grants(&mut *conn).await.unwrap();
     assert_eq!(all.len(), 1);
-    assert_eq!(all[0].settings.target.len(), 2);
-    assert_eq!(all[0].settings.limit.max_volume, U256::from(1_000_000u64));
+    assert_eq!(all[0].settings.specific.target.len(), 2);
+    assert_eq!(
+        all[0].settings.specific.limit.max_volume,
+        U256::from(1_000_000u64)
+    );
 }
 
 #[tokio::test]

server/crates/arbiter-server/src/evm/policies/token_transfers/mod.rs

@@ -1,20 +1,5 @@
 use std::collections::HashMap;
 
-use alloy::{
-    primitives::{Address, U256},
-    sol_types::SolCall,
-};
-use arbiter_tokens_registry::evm::nonfungible::{self, TokenInfo};
-use chrono::{DateTime, Duration, Utc};
-use diesel::dsl::{auto_type, insert_into};
-use diesel::sqlite::Sqlite;
-use diesel::{ExpressionMethods, prelude::*};
-use diesel_async::{AsyncConnection, RunQueryDsl};
-
-use crate::db::models::{
-    EvmBasicGrant, EvmTokenTransferGrant, EvmTokenTransferVolumeLimit, NewEvmTokenTransferGrant,
-    NewEvmTokenTransferLog, NewEvmTokenTransferVolumeLimit, SqliteTimestamp,
-};
 use crate::db::schema::{
     evm_basic_grant, evm_token_transfer_grant, evm_token_transfer_log,
     evm_token_transfer_volume_limit,
@@ -26,6 +11,25 @@ use crate::evm::{
     },
     utils,
 };
+use crate::{
+    crypto::integrity::Integrable,
+    db::models::{
+        EvmBasicGrant, EvmTokenTransferGrant, EvmTokenTransferVolumeLimit,
+        NewEvmTokenTransferGrant, NewEvmTokenTransferLog, NewEvmTokenTransferVolumeLimit,
+        SqliteTimestamp,
+    },
+    evm::policies::CombinedSettings,
+};
+use alloy::{
+    primitives::{Address, U256},
+    sol_types::SolCall,
+};
+use arbiter_tokens_registry::evm::nonfungible::{self, TokenInfo};
+use chrono::{DateTime, Duration, Utc};
+use diesel::dsl::{auto_type, insert_into};
+use diesel::prelude::*;
+use diesel::sqlite::Sqlite;
+use diesel_async::{AsyncConnection, RunQueryDsl};
 
 use super::{DatabaseID, EvalContext, EvalViolation};
 
@@ -38,9 +42,9 @@ fn grant_join() -> _ {
 
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct Meaning {
-    pub(crate) token: &'static TokenInfo,
-    pub(crate) to: Address,
-    pub(crate) value: U256,
+    pub token: &'static TokenInfo,
+    pub to: Address,
+    pub value: U256,
 }
 impl std::fmt::Display for Meaning {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
@@ -52,21 +56,25 @@ impl std::fmt::Display for Meaning {
     }
 }
 impl From<Meaning> for SpecificMeaning {
-    fn from(val: Meaning) -> SpecificMeaning {
-        SpecificMeaning::TokenTransfer(val)
+    fn from(val: Meaning) -> Self {
+        Self::TokenTransfer(val)
     }
 }
 
 // A grant for token transfers, which can be scoped to specific target addresses and volume limits
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, arbiter_macros::Hashable)]
 pub struct Settings {
     pub token_contract: Address,
     pub target: Option<Address>,
     pub volume_limits: Vec<VolumeRateLimit>,
 }
+impl Integrable for Settings {
+    const KIND: &'static str = "TokenTransfer";
+}
+
 impl From<Settings> for SpecificGrant {
-    fn from(val: Settings) -> SpecificGrant {
-        SpecificGrant::TokenTransfer(val)
+    fn from(val: Settings) -> Self {
+        Self::TokenTransfer(val)
     }
 }
 
@@ -77,10 +85,7 @@ async fn query_relevant_past_transfers(
 ) -> QueryResult<Vec<(U256, DateTime<Utc>)>> {
     let past_logs: Vec<(Vec<u8>, SqliteTimestamp)> = evm_token_transfer_log::table
         .filter(evm_token_transfer_log::grant_id.eq(grant_id))
-        .filter(
-            evm_token_transfer_log::created_at
-                .ge(SqliteTimestamp(chrono::Utc::now() - longest_window)),
-        )
+        .filter(evm_token_transfer_log::created_at.ge(SqliteTimestamp(Utc::now() - longest_window)))
         .select((
             evm_token_transfer_log::value,
             evm_token_transfer_log::created_at,
@@ -106,14 +111,21 @@ async fn check_volume_rate_limits(
 ) -> QueryResult<Vec<EvalViolation>> {
     let mut violations = Vec::new();
 
-    let Some(longest_window) = grant.settings.volume_limits.iter().map(|l| l.window).max() else {
+    let Some(longest_window) = grant
+        .settings
+        .specific
+        .volume_limits
+        .iter()
+        .map(|l| l.window)
+        .max()
+    else {
         return Ok(violations);
     };
 
     let past_transfers = query_relevant_past_transfers(grant.id, longest_window, db).await?;
 
-    for limit in &grant.settings.volume_limits {
-        let window_start = chrono::Utc::now() - limit.window;
+    for limit in &grant.settings.specific.volume_limits {
+        let window_start = Utc::now() - limit.window;
         let prospective_cumulative_volume: U256 = past_transfers
             .iter()
             .filter(|(_, timestamp)| timestamp >= &window_start)
@@ -158,7 +170,7 @@ impl Policy for TokenTransfer {
             return Ok(violations);
         }
 
-        if let Some(allowed) = grant.settings.target
+        if let Some(allowed) = grant.settings.specific.target
             && allowed != meaning.to
         {
             violations.push(EvalViolation::InvalidTarget { target: meaning.to });
@@ -189,6 +201,11 @@ impl Policy for TokenTransfer {
             .await?;
 
         for limit in &grant.volume_limits {
+            #[expect(
+                clippy::cast_possible_truncation,
+                clippy::as_conversions,
+                reason = "fixme! #86"
+            )]
             insert_into(evm_token_transfer_volume_limit::table)
                 .values(NewEvmTokenTransferVolumeLimit {
                     grant_id,
@@ -238,7 +255,7 @@ impl Policy for TokenTransfer {
                     max_volume: utils::try_bytes_to_u256(&row.max_volume).map_err(|err| {
                         diesel::result::Error::DeserializationError(Box::new(err))
                     })?,
-                    window: Duration::seconds(row.window_secs as i64),
+                    window: Duration::seconds(row.window_secs.into()),
                 })
             })
             .collect::<QueryResult<Vec<_>>>()?;
@@ -269,9 +286,11 @@ impl Policy for TokenTransfer {
 
         Ok(Some(Grant {
             id: token_grant.id,
-            shared_grant_id: token_grant.basic_grant_id,
-            shared: SharedGrantSettings::try_from_model(basic_grant)?,
-            settings,
+            common_settings_id: token_grant.basic_grant_id,
+            settings: CombinedSettings {
+                shared: SharedGrantSettings::try_from_model(basic_grant)?,
+                specific: settings,
+            },
         }))
     }
 
@@ -286,7 +305,7 @@ impl Policy for TokenTransfer {
             .values(NewEvmTokenTransferLog {
                 grant_id: grant.id,
                 log_id,
-                chain_id: context.chain as i32,
+                chain_id: context.chain.into(),
                 token_contract: context.to.to_vec(),
                 recipient_address: meaning.to.to_vec(),
                 value: utils::u256_to_bytes(meaning.value).to_vec(),
@@ -335,7 +354,7 @@ impl Policy for TokenTransfer {
             .map(|(basic, specific)| {
                 let volume_limits: Vec<VolumeRateLimit> = limits_by_grant
                     .get(&specific.id)
-                    .map(|v| v.as_slice())
+                    .map(Vec::as_slice)
                     .unwrap_or_default()
                     .iter()
                     .map(|row| {
@@ -343,7 +362,7 @@ impl Policy for TokenTransfer {
                             max_volume: utils::try_bytes_to_u256(&row.max_volume).map_err(|e| {
                                 diesel::result::Error::DeserializationError(Box::new(e))
                             })?,
-                            window: Duration::seconds(row.window_secs as i64),
+                            window: Duration::seconds(row.window_secs.into()),
                         })
                     })
                     .collect::<QueryResult<Vec<_>>>()?;
@@ -369,12 +388,14 @@ impl Policy for TokenTransfer {
 
                 Ok(Grant {
                     id: specific.id,
-                    shared_grant_id: specific.basic_grant_id,
-                    shared: SharedGrantSettings::try_from_model(basic)?,
-                    settings: Settings {
-                        token_contract: Address::from(token_contract),
-                        target,
-                        volume_limits,
+                    common_settings_id: specific.basic_grant_id,
+                    settings: CombinedSettings {
+                        shared: SharedGrantSettings::try_from_model(basic)?,
+                        specific: Settings {
+                            token_contract: Address::from(token_contract),
+                            target,
+                            volume_limits,
+                        },
                     },
                 })
             })

server/crates/arbiter-server/src/evm/policies/token_transfers/tests.rs

@@ -11,7 +11,10 @@ use crate::db::{
 };
 use crate::evm::{
     abi::IERC20::transferCall,
-    policies::{EvalContext, EvalViolation, Grant, Policy, SharedGrantSettings, VolumeRateLimit},
+    policies::{
+        CombinedSettings, EvalContext, EvalViolation, Grant, Policy, SharedGrantSettings,
+        VolumeRateLimit,
+    },
     utils,
 };
 
@@ -56,7 +59,7 @@ async fn insert_basic(conn: &mut DatabaseConnection, revoked: bool) -> EvmBasicG
     insert_into(evm_basic_grant::table)
         .values(NewEvmBasicGrant {
             wallet_access_id: WALLET_ACCESS_ID,
-            chain_id: CHAIN_ID as i32,
+            chain_id: CHAIN_ID.into(),
             valid_from: None,
             valid_until: None,
             max_gas_fee_per_gas: None,
@@ -98,8 +101,6 @@ fn shared() -> SharedGrantSettings {
     }
 }
 
-// ── analyze ─────────────────────────────────────────────────────────────
-
 #[test]
 fn analyze_known_token_valid_calldata() {
     let calldata = transfer_calldata(RECIPIENT, U256::from(100u64));
@@ -125,8 +126,6 @@ fn analyze_empty_calldata_returns_none() {
     assert!(TokenTransfer::analyze(&ctx(DAI, Bytes::new())).is_none());
 }
 
-// ── evaluate ────────────────────────────────────────────────────────────
-
 #[tokio::test]
 async fn evaluate_rejects_nonzero_eth_value() {
     let db = db::create_test_pool().await;
@@ -134,9 +133,11 @@ async fn evaluate_rejects_nonzero_eth_value() {
 
     let grant = Grant {
         id: 999,
-        shared_grant_id: 999,
-        shared: shared(),
-        settings: make_settings(None, None),
+        common_settings_id: 999,
+        settings: CombinedSettings {
+            shared: shared(),
+            specific: make_settings(None, None),
+        },
     };
     let calldata = transfer_calldata(RECIPIENT, U256::from(100u64));
     let mut context = ctx(DAI, calldata);
@@ -163,9 +164,11 @@ async fn evaluate_passes_any_recipient_when_no_restriction() {
 
     let grant = Grant {
         id: 999,
-        shared_grant_id: 999,
-        shared: shared(),
-        settings: make_settings(None, None),
+        common_settings_id: 999,
+        settings: CombinedSettings {
+            shared: shared(),
+            specific: make_settings(None, None),
+        },
     };
     let calldata = transfer_calldata(RECIPIENT, U256::from(100u64));
     let context = ctx(DAI, calldata);
@@ -183,9 +186,11 @@ async fn evaluate_passes_matching_restricted_recipient() {
 
     let grant = Grant {
         id: 999,
-        shared_grant_id: 999,
-        shared: shared(),
-        settings: make_settings(Some(RECIPIENT), None),
+        common_settings_id: 999,
+        settings: CombinedSettings {
+            shared: shared(),
+            specific: make_settings(Some(RECIPIENT), None),
+        },
     };
     let calldata = transfer_calldata(RECIPIENT, U256::from(100u64));
     let context = ctx(DAI, calldata);
@@ -203,9 +208,11 @@ async fn evaluate_rejects_wrong_restricted_recipient() {
 
     let grant = Grant {
         id: 999,
-        shared_grant_id: 999,
-        shared: shared(),
-        settings: make_settings(Some(RECIPIENT), None),
+        common_settings_id: 999,
+        settings: CombinedSettings {
+            shared: shared(),
+            specific: make_settings(Some(RECIPIENT), None),
+        },
     };
     let calldata = transfer_calldata(OTHER, U256::from(100u64));
     let context = ctx(DAI, calldata);
@@ -231,12 +238,11 @@ async fn evaluate_passes_volume_at_exact_limit() {
         .unwrap();
 
     // Record a past transfer of 900, with current transfer 100 => exactly 1000 limit
-    use crate::db::{models::NewEvmTokenTransferLog, schema::evm_token_transfer_log};
-    insert_into(evm_token_transfer_log::table)
-        .values(NewEvmTokenTransferLog {
+    insert_into(db::schema::evm_token_transfer_log::table)
+        .values(db::models::NewEvmTokenTransferLog {
             grant_id,
             log_id: 0,
-            chain_id: CHAIN_ID as i32,
+            chain_id: CHAIN_ID.into(),
             token_contract: DAI.to_vec(),
             recipient_address: RECIPIENT.to_vec(),
             value: utils::u256_to_bytes(U256::from(900u64)).to_vec(),
@@ -247,9 +253,11 @@ async fn evaluate_passes_volume_at_exact_limit() {
 
     let grant = Grant {
         id: grant_id,
-        shared_grant_id: basic.id,
-        shared: shared(),
-        settings,
+        common_settings_id: basic.id,
+        settings: CombinedSettings {
+            shared: shared(),
+            specific: settings,
+        },
     };
     let calldata = transfer_calldata(RECIPIENT, U256::from(100u64));
     let context = ctx(DAI, calldata);
@@ -274,12 +282,11 @@ async fn evaluate_rejects_volume_over_limit() {
         .await
         .unwrap();
 
-    use crate::db::{models::NewEvmTokenTransferLog, schema::evm_token_transfer_log};
-    insert_into(evm_token_transfer_log::table)
-        .values(NewEvmTokenTransferLog {
+    insert_into(db::schema::evm_token_transfer_log::table)
+        .values(db::models::NewEvmTokenTransferLog {
             grant_id,
             log_id: 0,
-            chain_id: CHAIN_ID as i32,
+            chain_id: CHAIN_ID.into(),
             token_contract: DAI.to_vec(),
             recipient_address: RECIPIENT.to_vec(),
             value: utils::u256_to_bytes(U256::from(1_000u64)).to_vec(),
@@ -290,9 +297,11 @@ async fn evaluate_rejects_volume_over_limit() {
 
     let grant = Grant {
         id: grant_id,
-        shared_grant_id: basic.id,
-        shared: shared(),
-        settings,
+        common_settings_id: basic.id,
+        settings: CombinedSettings {
+            shared: shared(),
+            specific: settings,
+        },
     };
     let calldata = transfer_calldata(RECIPIENT, U256::from(1u64));
     let context = ctx(DAI, calldata);
@@ -313,9 +322,11 @@ async fn evaluate_no_volume_limits_always_passes() {
 
     let grant = Grant {
         id: 999,
-        shared_grant_id: 999,
-        shared: shared(),
-        settings: make_settings(None, None), // no volume limits
+        common_settings_id: 999,
+        settings: CombinedSettings {
+            shared: shared(),
+            specific: make_settings(None, None), // no volume limits
+        },
     };
     let calldata = transfer_calldata(RECIPIENT, U256::from(u64::MAX));
     let context = ctx(DAI, calldata);
@@ -349,10 +360,13 @@ async fn try_find_grant_roundtrip() {
 
     assert!(found.is_some());
     let g = found.unwrap();
-    assert_eq!(g.settings.token_contract, DAI);
-    assert_eq!(g.settings.target, Some(RECIPIENT));
-    assert_eq!(g.settings.volume_limits.len(), 1);
-    assert_eq!(g.settings.volume_limits[0].max_volume, U256::from(5_000u64));
+    assert_eq!(g.settings.specific.token_contract, DAI);
+    assert_eq!(g.settings.specific.target, Some(RECIPIENT));
+    assert_eq!(g.settings.specific.volume_limits.len(), 1);
+    assert_eq!(
+        g.settings.specific.volume_limits[0].max_volume,
+        U256::from(5_000u64)
+    );
 }
 
 #[tokio::test]
@@ -392,7 +406,39 @@ async fn try_find_grant_unknown_token_returns_none() {
     assert!(found.is_none());
 }
 
-// ── find_all_grants ──────────────────────────────────────────────────────
+proptest::proptest! {
+    #[test]
+    fn volume_limits_order_does_not_affect_hash(
+        raw_limits in proptest::collection::vec(
+            (proptest::prelude::any::<u64>(), 1i64..=86400),
+            0..8,
+        ),
+        seed in proptest::prelude::any::<u64>(),
+    ) {
+        use rand::{SeedableRng, seq::SliceRandom};
+        use sha2::Digest;
+        use arbiter_crypto::hashing::Hashable;
+
+        let limits: Vec<VolumeRateLimit> = raw_limits
+            .iter()
+            .map(|(max_vol, window_secs)| VolumeRateLimit {
+                max_volume: U256::from(*max_vol),
+                window: Duration::seconds(*window_secs),
+            })
+            .collect();
+
+        let mut shuffled = limits.clone();
+        shuffled.shuffle(&mut rand::rngs::StdRng::seed_from_u64(seed));
+
+        let mut h1 = sha2::Sha256::new();
+        Settings { token_contract: DAI, target: None, volume_limits: limits }.hash(&mut h1);
+
+        let mut h2 = sha2::Sha256::new();
+        Settings { token_contract: DAI, target: None, volume_limits: shuffled }.hash(&mut h2);
+
+        proptest::prop_assert_eq!(h1.finalize(), h2.finalize());
+    }
+}
 
 #[tokio::test]
 async fn find_all_grants_empty_db() {
@@ -434,9 +480,9 @@ async fn find_all_grants_loads_volume_limits() {
 
     let all = TokenTransfer::find_all_grants(&mut *conn).await.unwrap();
     assert_eq!(all.len(), 1);
-    assert_eq!(all[0].settings.volume_limits.len(), 1);
+    assert_eq!(all[0].settings.specific.volume_limits.len(), 1);
     assert_eq!(
-        all[0].settings.volume_limits[0].max_volume,
+        all[0].settings.specific.volume_limits[0].max_volume,
         U256::from(9_999u64)
     );
 }

server/crates/arbiter-server/src/evm/safe_signer.rs

@@ -1,12 +1,12 @@
 use std::sync::Mutex;
 
-use crate::safe_cell::{SafeCell, SafeCellHandle as _};
 use alloy::{
     consensus::SignableTransaction,
     network::{TxSigner, TxSignerSync},
     primitives::{Address, B256, ChainId, Signature},
     signers::{Error, Result, Signer, SignerSync, utils::secret_key_to_address},
 };
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 use async_trait::async_trait;
 use k256::ecdsa::{self, RecoveryId, SigningKey, signature::hazmat::PrehashSigner};
 
@@ -82,8 +82,8 @@ impl SafeSigner {
         })
     }
 
+    #[expect(clippy::significant_drop_tightening, reason = "false positive")]
     fn sign_hash_inner(&self, hash: &B256) -> Result<Signature> {
-        #[allow(clippy::expect_used)]
         let mut cell = self.key.lock().expect("SafeSigner mutex poisoned");
         let reader = cell.read();
         let sig: (ecdsa::Signature, RecoveryId) = reader.sign_prehash(hash.as_ref())?;
@@ -96,7 +96,6 @@ impl SafeSigner {
         {
             return Err(Error::TransactionChainIdMismatch {
                 signer: chain_id,
-                #[allow(clippy::expect_used)]
                 tx: tx.chain_id().expect("Chain ID is guaranteed to be set"),
             });
         }

server/crates/arbiter-server/src/evm/utils.rs

@@ -7,7 +7,7 @@ pub struct LengthError {
     pub actual: usize,
 }
 
-pub fn u256_to_bytes(value: U256) -> [u8; 32] {
+pub const fn u256_to_bytes(value: U256) -> [u8; 32] {
     value.to_le_bytes()
 }
 pub fn bytes_to_u256(bytes: &[u8]) -> Option<U256> {

server/crates/arbiter-server/src/grpc/client.rs

@@ -98,8 +98,7 @@ pub async fn start(mut conn: ClientConnection, mut bi: GrpcBi<ClientRequest, Cli
         Err(err) => {
             let _ = bi
                 .send(Err(Status::unauthenticated(format!(
-                    "Authentication failed: {}",
-                    err
+                    "Authentication failed: {err}",
                 ))))
                 .await;
             warn!(error = ?err, "Client authentication failed");

server/crates/arbiter-server/src/grpc/client/auth.rs

@@ -1,11 +1,11 @@
+use arbiter_crypto::authn;
 use arbiter_proto::{
     ClientMetadata,
     proto::{
         client::{
             ClientRequest, ClientResponse,
             auth::{
-                self as proto_auth, AuthChallenge as ProtoAuthChallenge,
-                AuthChallengeRequest as ProtoAuthChallengeRequest,
+                self as proto_auth, AuthChallengeRequest as ProtoAuthChallengeRequest,
                 AuthChallengeSolution as ProtoAuthChallengeSolution, AuthResult as ProtoAuthResult,
                 request::Payload as AuthRequestPayload, response::Payload as AuthResponsePayload,
             },
@@ -21,7 +21,7 @@ use tonic::Status;
 use tracing::warn;
 
 use crate::{
-    actors::client::{self, ClientConnection, auth},
+    actors::client::{ClientConnection, auth},
     grpc::request_tracker::RequestTracker,
 };
 
@@ -31,7 +31,7 @@ pub struct AuthTransportAdapter<'a> {
 }
 
 impl<'a> AuthTransportAdapter<'a> {
-    pub fn new(
+    pub const fn new(
         bi: &'a mut GrpcBi<ClientRequest, ClientResponse>,
         request_tracker: &'a mut RequestTracker,
     ) -> Self {
@@ -41,39 +41,6 @@ impl<'a> AuthTransportAdapter<'a> {
         }
     }
 
-    fn response_to_proto(response: auth::Outbound) -> AuthResponsePayload {
-        match response {
-            auth::Outbound::AuthChallenge { pubkey, nonce } => {
-                AuthResponsePayload::Challenge(ProtoAuthChallenge {
-                    pubkey: pubkey.to_bytes().to_vec(),
-                    nonce,
-                })
-            }
-            auth::Outbound::AuthSuccess => {
-                AuthResponsePayload::Result(ProtoAuthResult::Success.into())
-            }
-        }
-    }
-
-    fn error_to_proto(error: auth::Error) -> AuthResponsePayload {
-        AuthResponsePayload::Result(
-            match error {
-                auth::Error::InvalidChallengeSolution => ProtoAuthResult::InvalidSignature,
-                auth::Error::ApproveError(auth::ApproveError::Denied) => {
-                    ProtoAuthResult::ApprovalDenied
-                }
-                auth::Error::ApproveError(auth::ApproveError::Upstream(
-                    crate::actors::flow_coordinator::ApprovalError::NoUserAgentsConnected,
-                )) => ProtoAuthResult::NoUserAgentsOnline,
-                auth::Error::ApproveError(auth::ApproveError::Internal)
-                | auth::Error::DatabasePoolUnavailable
-                | auth::Error::DatabaseOperationFailed
-                | auth::Error::Transport => ProtoAuthResult::Internal,
-            }
-            .into(),
-        )
-    }
-
     async fn send_client_response(
         &mut self,
         payload: AuthResponsePayload,
@@ -95,14 +62,14 @@ impl<'a> AuthTransportAdapter<'a> {
 }
 
 #[async_trait]
-impl Sender<Result<auth::Outbound, auth::Error>> for AuthTransportAdapter<'_> {
+impl Sender<Result<auth::Outbound, auth::ClientAuthError>> for AuthTransportAdapter<'_> {
     async fn send(
         &mut self,
-        item: Result<auth::Outbound, auth::Error>,
+        item: Result<auth::Outbound, auth::ClientAuthError>,
     ) -> Result<(), TransportError> {
         let payload = match item {
-            Ok(message) => AuthTransportAdapter::response_to_proto(message),
-            Err(err) => AuthTransportAdapter::error_to_proto(err),
+            Ok(message) => message.into(),
+            Err(err) => AuthResponsePayload::Result(ProtoAuthResult::from(err).into()),
         };
 
         self.send_client_response(payload).await
@@ -140,7 +107,9 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
         let Some(payload) = auth_request.payload else {
             let _ = self
                 .bi
-                .send(Err(Status::invalid_argument("Missing client auth request payload")))
+                .send(Err(Status::invalid_argument(
+                    "Missing client auth request payload",
+                )))
                 .await;
             return None;
         };
@@ -157,11 +126,7 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
                         .await;
                     return None;
                 };
-                let Ok(pubkey) = <[u8; 32]>::try_from(pubkey) else {
-                    let _ = self.send_auth_result(ProtoAuthResult::InvalidKey).await;
-                    return None;
-                };
-                let Ok(pubkey) = ed25519_dalek::VerifyingKey::from_bytes(&pubkey) else {
+                let Ok(pubkey) = authn::PublicKey::try_from(pubkey.as_slice()) else {
                     let _ = self.send_auth_result(ProtoAuthResult::InvalidKey).await;
                     return None;
                 };
@@ -170,10 +135,8 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
                     metadata: client_metadata_from_proto(client_info),
                 })
             }
-            AuthRequestPayload::ChallengeSolution(ProtoAuthChallengeSolution {
-                signature,
-            }) => {
-                let Ok(signature) = ed25519_dalek::Signature::try_from(signature.as_slice()) else {
+            AuthRequestPayload::ChallengeSolution(ProtoAuthChallengeSolution { signature }) => {
+                let Ok(signature) = authn::Signature::try_from(signature.as_slice()) else {
                     let _ = self
                         .send_auth_result(ProtoAuthResult::InvalidSignature)
                         .await;
@@ -185,7 +148,7 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
     }
 }
 
-impl Bi<auth::Inbound, Result<auth::Outbound, auth::Error>> for AuthTransportAdapter<'_> {}
+impl Bi<auth::Inbound, Result<auth::Outbound, auth::ClientAuthError>> for AuthTransportAdapter<'_> {}
 
 fn client_metadata_from_proto(metadata: ProtoClientInfo) -> ClientMetadata {
     ClientMetadata {
@@ -199,7 +162,7 @@ pub async fn start(
     conn: &mut ClientConnection,
     bi: &mut GrpcBi<ClientRequest, ClientResponse>,
     request_tracker: &mut RequestTracker,
-) -> Result<i32, auth::Error> {
+) -> Result<i32, auth::ClientAuthError> {
     let mut transport = AuthTransportAdapter::new(bi, request_tracker);
-    client::auth::authenticate(conn, &mut transport).await
+    auth::authenticate(conn, &mut transport).await
 }

server/crates/arbiter-server/src/grpc/client/evm.rs

@@ -23,7 +23,7 @@ use crate::{
     },
 };
 
-fn wrap_response(payload: EvmResponsePayload) -> ClientResponsePayload {
+const fn wrap_response(payload: EvmResponsePayload) -> ClientResponsePayload {
     ClientResponsePayload::Evm(proto_evm::Response {
         payload: Some(payload),
     })
@@ -34,7 +34,9 @@ pub(super) async fn dispatch(
     req: proto_evm::Request,
 ) -> Result<ClientResponsePayload, Status> {
     let Some(payload) = req.payload else {
-        return Err(Status::invalid_argument("Missing client EVM request payload"));
+        return Err(Status::invalid_argument(
+            "Missing client EVM request payload",
+        ));
     };
 
     match payload {
@@ -59,13 +61,13 @@ pub(super) async fn dispatch(
                 ))) => EvmSignTransactionResponse {
                     result: Some(vet_error.convert()),
                 },
-                Err(kameo::error::SendError::HandlerError(
-                    SignTransactionRpcError::Internal,
-                )) => EvmSignTransactionResponse {
-                    result: Some(EvmSignTransactionResult::Error(
-                        ProtoEvmError::Internal.into(),
-                    )),
-                },
+                Err(kameo::error::SendError::HandlerError(SignTransactionRpcError::Internal)) => {
+                    EvmSignTransactionResponse {
+                        result: Some(EvmSignTransactionResult::Error(
+                            ProtoEvmError::Internal.into(),
+                        )),
+                    }
+                }
                 Err(err) => {
                     warn!(error = ?err, "Failed to sign EVM transaction");
                     EvmSignTransactionResponse {
@@ -78,8 +80,8 @@ pub(super) async fn dispatch(
 
             Ok(wrap_response(EvmResponsePayload::SignTransaction(response)))
         }
-        EvmRequestPayload::AnalyzeTransaction(_) => {
-            Err(Status::unimplemented("EVM transaction analysis is not yet implemented"))
-        }
+        EvmRequestPayload::AnalyzeTransaction(_) => Err(Status::unimplemented(
+            "EVM transaction analysis is not yet implemented",
+        )),
     }
 }

server/crates/arbiter-server/src/grpc/client/inbound.rs

@@ -0,0 +1 @@
+

server/crates/arbiter-server/src/grpc/client/outbound.rs

@@ -0,0 +1 @@
+

server/crates/arbiter-server/src/grpc/client/vault.rs

@@ -12,11 +12,9 @@ use kameo::{actor::ActorRef, error::SendError};
 use tonic::Status;
 use tracing::warn;
 
-use crate::{
-    actors::{
-        client::session::{ClientSession, Error, HandleQueryVaultState},
-        keyholder::KeyHolderState,
-    },
+use crate::actors::{
+    client::session::{ClientSession, ClientSessionError, HandleQueryVaultState},
+    keyholder::KeyHolderState,
 };
 
 pub(super) async fn dispatch(
@@ -24,16 +22,20 @@ pub(super) async fn dispatch(
     req: proto_vault::Request,
 ) -> Result<ClientResponsePayload, Status> {
     let Some(payload) = req.payload else {
-        return Err(Status::invalid_argument("Missing client vault request payload"));
+        return Err(Status::invalid_argument(
+            "Missing client vault request payload",
+        ));
     };
 
     match payload {
-        VaultRequestPayload::QueryState(_) => {
+        VaultRequestPayload::QueryState(()) => {
             let state = match actor.ask(HandleQueryVaultState {}).await {
                 Ok(KeyHolderState::Unbootstrapped) => ProtoVaultState::Unbootstrapped,
                 Ok(KeyHolderState::Sealed) => ProtoVaultState::Sealed,
                 Ok(KeyHolderState::Unsealed) => ProtoVaultState::Unsealed,
-                Err(SendError::HandlerError(Error::Internal)) => ProtoVaultState::Error,
+                Err(SendError::HandlerError(ClientSessionError::Internal)) => {
+                    ProtoVaultState::Error
+                }
                 Err(err) => {
                     warn!(error = ?err, "Failed to query vault state");
                     ProtoVaultState::Error

server/crates/arbiter-server/src/grpc/common/inbound.rs

@@ -28,9 +28,8 @@ impl TryConvert for RawEvmTransaction {
     type Error = tonic::Status;
 
     fn try_convert(self) -> Result<Self::Output, Self::Error> {
-        let tx = TxEip1559::decode(&mut self.0.as_slice()).map_err(|_| {
-            tonic::Status::invalid_argument("Invalid EVM transaction format")
-        })?;
+        let tx = TxEip1559::decode(&mut self.0.as_slice())
+            .map_err(|_| tonic::Status::invalid_argument("Invalid EVM transaction format"))?;
         Ok(tx)
     }
 }

server/crates/arbiter-server/src/grpc/common/outbound.rs

@@ -1,11 +1,14 @@
 use alloy::primitives::U256;
 use arbiter_proto::proto::{
-    evm::{EvmError as ProtoEvmError, evm_sign_transaction_response::Result as EvmSignTransactionResult},
+    evm::{
+        EvmError as ProtoEvmError,
+        evm_sign_transaction_response::Result as EvmSignTransactionResult,
+    },
     shared::evm::{
-        EvalViolation as ProtoEvalViolation, GasLimitExceededViolation,
-        NoMatchingGrantError, PolicyViolationsError, SpecificMeaning as ProtoSpecificMeaning,
+        EvalViolation as ProtoEvalViolation, GasLimitExceededViolation, NoMatchingGrantError,
+        PolicyViolationsError, SpecificMeaning as ProtoSpecificMeaning,
         TokenInfo as ProtoTokenInfo, TransactionEvalError as ProtoTransactionEvalError,
-        eval_violation::Kind as ProtoEvalViolationKind,
+        eval_violation as proto_eval_violation, eval_violation::Kind as ProtoEvalViolationKind,
         specific_meaning::Meaning as ProtoSpecificMeaningKind,
         transaction_eval_error::Kind as ProtoTransactionEvalErrorKind,
     },
@@ -28,16 +31,16 @@ impl Convert for SpecificMeaning {
 
     fn convert(self) -> Self::Output {
         let kind = match self {
-            SpecificMeaning::EtherTransfer(meaning) => ProtoSpecificMeaningKind::EtherTransfer(
+            Self::EtherTransfer(meaning) => ProtoSpecificMeaningKind::EtherTransfer(
                 arbiter_proto::proto::shared::evm::EtherTransferMeaning {
                     to: meaning.to.to_vec(),
                     value: u256_to_proto_bytes(meaning.value),
                 },
             ),
-            SpecificMeaning::TokenTransfer(meaning) => ProtoSpecificMeaningKind::TokenTransfer(
+            Self::TokenTransfer(meaning) => ProtoSpecificMeaningKind::TokenTransfer(
                 arbiter_proto::proto::shared::evm::TokenTransferMeaning {
                     token: Some(ProtoTokenInfo {
-                        symbol: meaning.token.symbol.to_string(),
+                        symbol: meaning.token.symbol.to_owned(),
                         address: meaning.token.contract.to_vec(),
                         chain_id: meaning.token.chain,
                     }),
@@ -58,23 +61,25 @@ impl Convert for EvalViolation {
 
     fn convert(self) -> Self::Output {
         let kind = match self {
-            EvalViolation::InvalidTarget { target } => {
+            Self::InvalidTarget { target } => {
                 ProtoEvalViolationKind::InvalidTarget(target.to_vec())
             }
-            EvalViolation::GasLimitExceeded {
+            Self::GasLimitExceeded {
                 max_gas_fee_per_gas,
                 max_priority_fee_per_gas,
             } => ProtoEvalViolationKind::GasLimitExceeded(GasLimitExceededViolation {
                 max_gas_fee_per_gas: max_gas_fee_per_gas.map(u256_to_proto_bytes),
                 max_priority_fee_per_gas: max_priority_fee_per_gas.map(u256_to_proto_bytes),
             }),
-            EvalViolation::RateLimitExceeded => ProtoEvalViolationKind::RateLimitExceeded(()),
-            EvalViolation::VolumetricLimitExceeded => {
-                ProtoEvalViolationKind::VolumetricLimitExceeded(())
-            }
-            EvalViolation::InvalidTime => ProtoEvalViolationKind::InvalidTime(()),
-            EvalViolation::InvalidTransactionType => {
-                ProtoEvalViolationKind::InvalidTransactionType(())
+            Self::RateLimitExceeded => ProtoEvalViolationKind::RateLimitExceeded(()),
+            Self::VolumetricLimitExceeded => ProtoEvalViolationKind::VolumetricLimitExceeded(()),
+            Self::InvalidTime => ProtoEvalViolationKind::InvalidTime(()),
+            Self::InvalidTransactionType => ProtoEvalViolationKind::InvalidTransactionType(()),
+            Self::MismatchingChainId { expected, actual } => {
+                ProtoEvalViolationKind::ChainIdMismatch(proto_eval_violation::ChainIdMismatch {
+                    expected,
+                    actual,
+                })
             }
         };
 
@@ -87,13 +92,13 @@ impl Convert for VetError {
 
     fn convert(self) -> Self::Output {
         let kind = match self {
-            VetError::ContractCreationNotSupported => {
+            Self::ContractCreationNotSupported => {
                 ProtoTransactionEvalErrorKind::ContractCreationNotSupported(())
             }
-            VetError::UnsupportedTransactionType => {
+            Self::UnsupportedTransactionType => {
                 ProtoTransactionEvalErrorKind::UnsupportedTransactionType(())
             }
-            VetError::Evaluated(meaning, policy_error) => match policy_error {
+            Self::Evaluated(meaning, policy_error) => match policy_error {
                 PolicyError::NoMatchingGrant => {
                     ProtoTransactionEvalErrorKind::NoMatchingGrant(NoMatchingGrantError {
                         meaning: Some(meaning.convert()),
@@ -105,12 +110,12 @@ impl Convert for VetError {
                         violations: violations.into_iter().map(Convert::convert).collect(),
                     })
                 }
-                PolicyError::Database(_) => {
+                PolicyError::Database(_) | PolicyError::Integrity(_) => {
                     return EvmSignTransactionResult::Error(ProtoEvmError::Internal.into());
                 }
             },
         };
 
-        EvmSignTransactionResult::EvalError(ProtoTransactionEvalError { kind: Some(kind) }.into())
+        EvmSignTransactionResult::EvalError(ProtoTransactionEvalError { kind: Some(kind) })
     }
 }

server/crates/arbiter-server/src/grpc/request_tracker.rs

@@ -20,7 +20,7 @@ impl RequestTracker {
 
     // This is used to set the response id for auth responses, which need to match the request id of the auth challenge request.
     // -1 offset is needed because request() increments the next_request_id after returning the current request id.
-    pub fn current_request_id(&self) -> i32 {
+    pub const fn current_request_id(&self) -> i32 {
         self.next_request_id - 1
     }
 }

server/crates/arbiter-server/src/grpc/user_agent.rs

@@ -1,12 +1,10 @@
 use tokio::sync::mpsc;
 
 use arbiter_proto::{
-    proto::{
-        user_agent::{
-            UserAgentRequest, UserAgentResponse,
-            user_agent_request::Payload as UserAgentRequestPayload,
-            user_agent_response::Payload as UserAgentResponsePayload,
-        },
+    proto::user_agent::{
+        UserAgentRequest, UserAgentResponse,
+        user_agent_request::Payload as UserAgentRequestPayload,
+        user_agent_response::Payload as UserAgentResponsePayload,
     },
     transport::{Error as TransportError, Receiver, Sender, grpc::GrpcBi},
 };
@@ -19,6 +17,7 @@ use crate::{
     actors::user_agent::{OutOfBand, UserAgentConnection, UserAgentSession},
     grpc::request_tracker::RequestTracker,
 };
+
 mod auth;
 mod evm;
 mod inbound;

server/crates/arbiter-server/src/grpc/user_agent/auth.rs

@@ -1,12 +1,14 @@
+use arbiter_crypto::authn;
 use arbiter_proto::{
     proto::user_agent::{
-        UserAgentRequest, UserAgentResponse, auth::{
+        UserAgentRequest, UserAgentResponse,
+        auth::{
             self as proto_auth, AuthChallenge as ProtoAuthChallenge,
             AuthChallengeRequest as ProtoAuthChallengeRequest,
             AuthChallengeSolution as ProtoAuthChallengeSolution, AuthResult as ProtoAuthResult,
-            KeyType as ProtoKeyType, request::Payload as AuthRequestPayload,
-            response::Payload as AuthResponsePayload,
-        }, user_agent_request::Payload as UserAgentRequestPayload,
+            request::Payload as AuthRequestPayload, response::Payload as AuthResponsePayload,
+        },
+        user_agent_request::Payload as UserAgentRequestPayload,
         user_agent_response::Payload as UserAgentResponsePayload,
     },
     transport::{Bi, Error as TransportError, Receiver, Sender, grpc::GrpcBi},
@@ -16,8 +18,7 @@ use tonic::Status;
 use tracing::warn;
 
 use crate::{
-    actors::user_agent::{AuthPublicKey, UserAgentConnection, auth},
-    db::models::KeyType,
+    actors::user_agent::{UserAgentConnection, auth},
     grpc::request_tracker::RequestTracker,
 };
 
@@ -27,7 +28,7 @@ pub struct AuthTransportAdapter<'a> {
 }
 
 impl<'a> AuthTransportAdapter<'a> {
-    pub fn new(
+    pub const fn new(
         bi: &'a mut GrpcBi<UserAgentRequest, UserAgentResponse>,
         request_tracker: &'a mut RequestTracker,
     ) -> Self {
@@ -63,7 +64,9 @@ impl Sender<Result<auth::Outbound, auth::Error>> for AuthTransportAdapter<'_> {
             Ok(Outbound::AuthChallenge { nonce }) => {
                 AuthResponsePayload::Challenge(ProtoAuthChallenge { nonce })
             }
-            Ok(Outbound::AuthSuccess) => AuthResponsePayload::Result(ProtoAuthResult::Success.into()),
+            Ok(Outbound::AuthSuccess) => {
+                AuthResponsePayload::Result(ProtoAuthResult::Success.into())
+            }
             Err(Error::UnregisteredPublicKey) => {
                 AuthResponsePayload::Result(ProtoAuthResult::InvalidKey.into())
             }
@@ -137,28 +140,9 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
             AuthRequestPayload::ChallengeRequest(ProtoAuthChallengeRequest {
                 pubkey,
                 bootstrap_token,
-                key_type,
+                ..
             }) => {
-                let Ok(key_type) = ProtoKeyType::try_from(key_type) else {
-                    warn!(
-                        event = "received request with invalid key type",
-                        "grpc.useragent.auth_adapter"
-                    );
-                    return None;
-                };
-                let key_type = match key_type {
-                    ProtoKeyType::Ed25519 => KeyType::Ed25519,
-                    ProtoKeyType::EcdsaSecp256k1 => KeyType::EcdsaSecp256k1,
-                    ProtoKeyType::Rsa => KeyType::Rsa,
-                    ProtoKeyType::Unspecified => {
-                        warn!(
-                            event = "received request with unspecified key type",
-                            "grpc.useragent.auth_adapter"
-                        );
-                        return None;
-                    }
-                };
-                let Ok(pubkey) = AuthPublicKey::try_from((key_type, pubkey)) else {
+                let Ok(pubkey) = authn::PublicKey::try_from(pubkey.as_slice()) else {
                     warn!(
                         event = "received request with invalid public key",
                         "grpc.useragent.auth_adapter"
@@ -171,9 +155,9 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
                     bootstrap_token,
                 })
             }
-            AuthRequestPayload::ChallengeSolution(ProtoAuthChallengeSolution {
-                signature,
-            }) => Some(auth::Inbound::AuthChallengeSolution { signature }),
+            AuthRequestPayload::ChallengeSolution(ProtoAuthChallengeSolution { signature }) => {
+                Some(auth::Inbound::AuthChallengeSolution { signature })
+            }
         }
     }
 }
@@ -184,7 +168,7 @@ pub async fn start(
     conn: &mut UserAgentConnection,
     bi: &mut GrpcBi<UserAgentRequest, UserAgentResponse>,
     request_tracker: &mut RequestTracker,
-) -> Result<AuthPublicKey, auth::Error> {
+) -> Result<authn::PublicKey, auth::Error> {
     let transport = AuthTransportAdapter::new(bi, request_tracker);
     auth::authenticate(conn, transport).await
 }

server/crates/arbiter-server/src/grpc/user_agent/evm.rs

@@ -3,8 +3,7 @@ use arbiter_proto::proto::{
         EvmError as ProtoEvmError, EvmGrantCreateRequest, EvmGrantCreateResponse,
         EvmGrantDeleteRequest, EvmGrantDeleteResponse, EvmGrantList, EvmGrantListResponse,
         EvmSignTransactionResponse, GrantEntry, WalletCreateResponse, WalletEntry, WalletList,
-        WalletListResponse,
-        evm_grant_create_response::Result as EvmGrantCreateResult,
+        WalletListResponse, evm_grant_create_response::Result as EvmGrantCreateResult,
         evm_grant_delete_response::Result as EvmGrantDeleteResult,
         evm_grant_list_response::Result as EvmGrantListResult,
         evm_sign_transaction_response::Result as EvmSignTransactionResult,
@@ -27,8 +26,8 @@ use crate::{
     actors::user_agent::{
         UserAgentSession,
         session::connection::{
-            HandleEvmWalletCreate, HandleEvmWalletList, HandleGrantCreate, HandleGrantDelete,
-            HandleGrantList, HandleSignTransaction,
+            GrantMutationError, HandleEvmWalletCreate, HandleEvmWalletList, HandleGrantCreate,
+            HandleGrantDelete, HandleGrantList, HandleSignTransaction,
             SignTransactionError as SessionSignTransactionError,
         },
     },
@@ -38,7 +37,7 @@ use crate::{
     },
 };
 
-fn wrap_evm_response(payload: EvmResponsePayload) -> UserAgentResponsePayload {
+const fn wrap_evm_response(payload: EvmResponsePayload) -> UserAgentResponsePayload {
     UserAgentResponsePayload::Evm(proto_evm::Response {
         payload: Some(payload),
     })
@@ -53,8 +52,8 @@ pub(super) async fn dispatch(
     };
 
     match payload {
-        EvmRequestPayload::WalletCreate(_) => handle_wallet_create(actor).await,
-        EvmRequestPayload::WalletList(_) => handle_wallet_list(actor).await,
+        EvmRequestPayload::WalletCreate(()) => handle_wallet_create(actor).await,
+        EvmRequestPayload::WalletList(()) => handle_wallet_list(actor).await,
         EvmRequestPayload::GrantCreate(req) => handle_grant_create(actor, req).await,
         EvmRequestPayload::GrantDelete(req) => handle_grant_delete(actor, req).await,
         EvmRequestPayload::GrantList(_) => handle_grant_list(actor).await,
@@ -115,10 +114,10 @@ async fn handle_grant_list(
             grants: grants
                 .into_iter()
                 .map(|grant| GrantEntry {
-                    id: grant.id,
-                    wallet_access_id: grant.shared.wallet_access_id,
-                    shared: Some(grant.shared.convert()),
-                    specific: Some(grant.settings.convert()),
+                    id: grant.common_settings_id,
+                    wallet_access_id: grant.settings.shared.wallet_access_id,
+                    shared: Some(grant.settings.shared.convert()),
+                    specific: Some(grant.settings.specific.convert()),
                 })
                 .collect(),
         }),
@@ -149,6 +148,9 @@ async fn handle_grant_create(
 
     let result = match actor.ask(HandleGrantCreate { basic, grant }).await {
         Ok(grant_id) => EvmGrantCreateResult::GrantId(grant_id),
+        Err(kameo::error::SendError::HandlerError(GrantMutationError::VaultSealed)) => {
+            EvmGrantCreateResult::Error(ProtoEvmError::VaultSealed.into())
+        }
         Err(err) => {
             warn!(error = ?err, "Failed to create EVM grant");
             EvmGrantCreateResult::Error(ProtoEvmError::Internal.into())
@@ -165,8 +167,16 @@ async fn handle_grant_delete(
     actor: &ActorRef<UserAgentSession>,
     req: EvmGrantDeleteRequest,
 ) -> Result<Option<UserAgentResponsePayload>, Status> {
-    let result = match actor.ask(HandleGrantDelete { grant_id: req.grant_id }).await {
+    let result = match actor
+        .ask(HandleGrantDelete {
+            grant_id: req.grant_id,
+        })
+        .await
+    {
         Ok(()) => EvmGrantDeleteResult::Ok(()),
+        Err(kameo::error::SendError::HandlerError(GrantMutationError::VaultSealed)) => {
+            EvmGrantDeleteResult::Error(ProtoEvmError::VaultSealed.into())
+        }
         Err(err) => {
             warn!(error = ?err, "Failed to delete EVM grant");
             EvmGrantDeleteResult::Error(ProtoEvmError::Internal.into())
@@ -202,18 +212,18 @@ async fn handle_sign_transaction(
                 signature.as_bytes().to_vec(),
             )),
         },
-        Err(kameo::error::SendError::HandlerError(
-            SessionSignTransactionError::Vet(vet_error),
-        )) => EvmSignTransactionResponse {
-            result: Some(vet_error.convert()),
-        },
-        Err(kameo::error::SendError::HandlerError(
-            SessionSignTransactionError::Internal,
-        )) => EvmSignTransactionResponse {
-            result: Some(EvmSignTransactionResult::Error(
-                ProtoEvmError::Internal.into(),
-            )),
-        },
+        Err(kameo::error::SendError::HandlerError(SessionSignTransactionError::Vet(vet_error))) => {
+            EvmSignTransactionResponse {
+                result: Some(vet_error.convert()),
+            }
+        }
+        Err(kameo::error::SendError::HandlerError(SessionSignTransactionError::Internal)) => {
+            EvmSignTransactionResponse {
+                result: Some(EvmSignTransactionResult::Error(
+                    ProtoEvmError::Internal.into(),
+                )),
+            }
+        }
         Err(err) => {
             warn!(error = ?err, "Failed to sign EVM transaction");
             EvmSignTransactionResponse {
@@ -224,7 +234,7 @@ async fn handle_sign_transaction(
         }
     };
 
-    Ok(Some(wrap_evm_response(EvmResponsePayload::SignTransaction(
-        response,
-    ))))
+    Ok(Some(wrap_evm_response(
+        EvmResponsePayload::SignTransaction(response),
+    )))
 }

server/crates/arbiter-server/src/grpc/user_agent/inbound.rs

@@ -22,11 +22,11 @@ use crate::{
     grpc::TryConvert,
 };
 
-fn address_from_bytes(bytes: Vec<u8>) -> Result<Address, Status> {
+fn address_from_bytes(bytes: &[u8]) -> Result<Address, Status> {
     if bytes.len() != 20 {
         return Err(Status::invalid_argument("Invalid EVM address"));
     }
-    Ok(Address::from_slice(&bytes))
+    Ok(Address::from_slice(bytes))
 }
 
 fn u256_from_proto_bytes(bytes: &[u8]) -> Result<U256, Status> {
@@ -41,7 +41,7 @@ impl TryConvert for ProtoTimestamp {
     type Error = Status;
 
     fn try_convert(self) -> Result<DateTime<Utc>, Status> {
-        Utc.timestamp_opt(self.seconds, self.nanos as u32)
+        Utc.timestamp_opt(self.seconds, self.nanos.try_into().unwrap_or_default())
             .single()
             .ok_or_else(|| Status::invalid_argument("Invalid timestamp"))
     }
@@ -116,7 +116,8 @@ impl TryConvert for ProtoSpecificGrant {
                 limit,
             })) => Ok(SpecificGrant::EtherTransfer(ether_transfer::Settings {
                 target: targets
-                    .into_iter()
+                    .iter()
+                    .map(Vec::as_slice)
                     .map(address_from_bytes)
                     .collect::<Result<_, _>>()?,
                 limit: limit
@@ -130,8 +131,10 @@ impl TryConvert for ProtoSpecificGrant {
                 target,
                 volume_limits,
             })) => Ok(SpecificGrant::TokenTransfer(token_transfers::Settings {
-                token_contract: address_from_bytes(token_contract)?,
-                target: target.map(address_from_bytes).transpose()?,
+                token_contract: address_from_bytes(&token_contract)?,
+                target: target
+                    .map(|target| address_from_bytes(&target))
+                    .transpose()?,
                 volume_limits: volume_limits
                     .into_iter()
                     .map(ProtoVolumeRateLimit::try_convert)

server/crates/arbiter-server/src/grpc/user_agent/outbound.rs

@@ -5,9 +5,7 @@ use arbiter_proto::proto::{
         TransactionRateLimit as ProtoTransactionRateLimit, VolumeRateLimit as ProtoVolumeRateLimit,
         specific_grant::Grant as ProtoSpecificGrantType,
     },
-    user_agent::sdk_client::{
-        WalletAccess, WalletAccessEntry as ProtoSdkClientWalletAccess,
-    },
+    user_agent::sdk_client::{WalletAccess, WalletAccessEntry as ProtoSdkClientWalletAccess},
 };
 use chrono::{DateTime, Utc};
 use prost_types::Timestamp as ProtoTimestamp;
@@ -24,7 +22,7 @@ impl Convert for DateTime<Utc> {
     fn convert(self) -> ProtoTimestamp {
         ProtoTimestamp {
             seconds: self.timestamp(),
-            nanos: self.timestamp_subsec_nanos() as i32,
+            nanos: self.timestamp_subsec_nanos().try_into().unwrap_or(i32::MAX),
         }
     }
 }
@@ -76,13 +74,13 @@ impl Convert for SpecificGrant {
 
     fn convert(self) -> ProtoSpecificGrant {
         let grant = match self {
-            SpecificGrant::EtherTransfer(s) => {
+            Self::EtherTransfer(s) => {
                 ProtoSpecificGrantType::EtherTransfer(ProtoEtherTransferSettings {
                     targets: s.target.into_iter().map(|a| a.to_vec()).collect(),
                     limit: Some(s.limit.convert()),
                 })
             }
-            SpecificGrant::TokenTransfer(s) => {
+            Self::TokenTransfer(s) => {
                 ProtoSpecificGrantType::TokenTransfer(ProtoTokenTransferSettings {
                     token_contract: s.token_contract.to_vec(),
                     target: s.target.map(|a| a.to_vec()),

server/crates/arbiter-server/src/grpc/user_agent/sdk_client.rs

@@ -1,4 +1,6 @@
+use arbiter_crypto::authn;
 use arbiter_proto::proto::{
+    shared::ClientInfo as ProtoClientMetadata,
     user_agent::{
         sdk_client::{
             self as proto_sdk_client, ConnectionCancel as ProtoSdkClientConnectionCancel,
@@ -13,7 +15,6 @@ use arbiter_proto::proto::{
         },
         user_agent_response::Payload as UserAgentResponsePayload,
     },
-    shared::ClientInfo as ProtoClientMetadata,
 };
 use kameo::actor::ActorRef;
 use tonic::Status;
@@ -31,7 +32,7 @@ use crate::{
     grpc::Convert,
 };
 
-fn wrap_sdk_client_response(payload: SdkClientResponsePayload) -> UserAgentResponsePayload {
+const fn wrap_sdk_client_response(payload: SdkClientResponsePayload) -> UserAgentResponsePayload {
     UserAgentResponsePayload::SdkClient(proto_sdk_client::Response {
         payload: Some(payload),
     })
@@ -41,7 +42,7 @@ pub(super) fn out_of_band_payload(oob: OutOfBand) -> UserAgentResponsePayload {
     match oob {
         OutOfBand::ClientConnectionRequest { profile } => wrap_sdk_client_response(
             SdkClientResponsePayload::ConnectionRequest(ProtoSdkClientConnectionRequest {
-                pubkey: profile.pubkey.to_bytes().to_vec(),
+                pubkey: profile.pubkey.to_bytes(),
                 info: Some(ProtoClientMetadata {
                     name: profile.metadata.name,
                     description: profile.metadata.description,
@@ -51,7 +52,7 @@ pub(super) fn out_of_band_payload(oob: OutOfBand) -> UserAgentResponsePayload {
         ),
         OutOfBand::ClientConnectionCancel { pubkey } => wrap_sdk_client_response(
             SdkClientResponsePayload::ConnectionCancel(ProtoSdkClientConnectionCancel {
-                pubkey: pubkey.to_bytes().to_vec(),
+                pubkey: pubkey.to_bytes(),
             }),
         ),
     }
@@ -62,22 +63,26 @@ pub(super) async fn dispatch(
     req: proto_sdk_client::Request,
 ) -> Result<Option<UserAgentResponsePayload>, Status> {
     let Some(payload) = req.payload else {
-        return Err(Status::invalid_argument("Missing SDK client request payload"));
+        return Err(Status::invalid_argument(
+            "Missing SDK client request payload",
+        ));
     };
 
     match payload {
         SdkClientRequestPayload::ConnectionResponse(resp) => {
             handle_connection_response(actor, resp).await
         }
-        SdkClientRequestPayload::Revoke(_) => {
-            Err(Status::unimplemented("SdkClientRevoke is not yet implemented"))
+        SdkClientRequestPayload::Revoke(_) => Err(Status::unimplemented(
+            "SdkClientRevoke is not yet implemented",
+        )),
+        SdkClientRequestPayload::List(()) => handle_list(actor).await,
+        SdkClientRequestPayload::GrantWalletAccess(req) => {
+            handle_grant_wallet_access(actor, req).await
         }
-        SdkClientRequestPayload::List(_) => handle_list(actor).await,
-        SdkClientRequestPayload::GrantWalletAccess(req) => handle_grant_wallet_access(actor, req).await,
         SdkClientRequestPayload::RevokeWalletAccess(req) => {
             handle_revoke_wallet_access(actor, req).await
         }
-        SdkClientRequestPayload::ListWalletAccess(_) => handle_list_wallet_access(actor).await,
+        SdkClientRequestPayload::ListWalletAccess(()) => handle_list_wallet_access(actor).await,
     }
 }
 
@@ -85,10 +90,8 @@ async fn handle_connection_response(
     actor: &ActorRef<UserAgentSession>,
     resp: ProtoSdkClientConnectionResponse,
 ) -> Result<Option<UserAgentResponsePayload>, Status> {
-    let pubkey_bytes = <[u8; 32]>::try_from(resp.pubkey)
-        .map_err(|_| Status::invalid_argument("Invalid Ed25519 public key length"))?;
-    let pubkey = ed25519_dalek::VerifyingKey::from_bytes(&pubkey_bytes)
-        .map_err(|_| Status::invalid_argument("Invalid Ed25519 public key"))?;
+    let pubkey = authn::PublicKey::try_from(resp.pubkey.as_slice())
+        .map_err(|()| Status::invalid_argument("Invalid ML-DSA public key"))?;
 
     actor
         .ask(HandleNewClientApprove {
@@ -113,12 +116,17 @@ async fn handle_list(
                 .into_iter()
                 .map(|(client, metadata)| ProtoSdkClientEntry {
                     id: client.id,
-                    pubkey: client.public_key,
+                    pubkey: client.public_key.clone(),
                     info: Some(ProtoClientMetadata {
                         name: metadata.name,
                         description: metadata.description,
                         version: metadata.version,
                     }),
+                    #[expect(
+                        clippy::cast_possible_truncation,
+                        clippy::as_conversions,
+                        reason = "fixme! #84"
+                    )]
                     created_at: client.created_at.0.timestamp() as i32,
                 })
                 .collect(),
@@ -128,18 +136,18 @@ async fn handle_list(
             ProtoSdkClientListResult::Error(ProtoSdkClientError::Internal.into())
         }
     };
-    Ok(Some(wrap_sdk_client_response(SdkClientResponsePayload::List(
-        ProtoSdkClientListResponse {
+    Ok(Some(wrap_sdk_client_response(
+        SdkClientResponsePayload::List(ProtoSdkClientListResponse {
             result: Some(result),
-        },
-    ))))
+        }),
+    )))
 }
 
 async fn handle_grant_wallet_access(
     actor: &ActorRef<UserAgentSession>,
     req: ProtoSdkClientGrantWalletAccess,
 ) -> Result<Option<UserAgentResponsePayload>, Status> {
-    let entries: Vec<NewEvmWalletAccess> = req.accesses.into_iter().map(|a| a.convert()).collect();
+    let entries: Vec<NewEvmWalletAccess> = req.accesses.into_iter().map(Convert::convert).collect();
     match actor.ask(HandleGrantEvmWalletAccess { entries }).await {
         Ok(()) => {
             info!("Successfully granted wallet access");
@@ -179,7 +187,7 @@ async fn handle_list_wallet_access(
     match actor.ask(HandleListWalletAccess {}).await {
         Ok(accesses) => Ok(Some(wrap_sdk_client_response(
             SdkClientResponsePayload::ListWalletAccess(ListWalletAccessResponse {
-                accesses: accesses.into_iter().map(|a| a.convert()).collect(),
+                accesses: accesses.into_iter().map(Convert::convert).collect(),
             }),
         ))),
         Err(err) => {

server/crates/arbiter-server/src/grpc/user_agent/vault.rs

@@ -1,3 +1,4 @@
+use arbiter_proto::proto::shared::VaultState as ProtoVaultState;
 use arbiter_proto::proto::user_agent::{
     user_agent_response::Payload as UserAgentResponsePayload,
     vault::{
@@ -11,36 +12,32 @@ use arbiter_proto::proto::user_agent::{
         unseal::{
             self as proto_unseal, UnsealEncryptedKey as ProtoUnsealEncryptedKey,
             UnsealResult as ProtoUnsealResult, UnsealStart,
-            request::Payload as UnsealRequestPayload,
-            response::Payload as UnsealResponsePayload,
+            request::Payload as UnsealRequestPayload, response::Payload as UnsealResponsePayload,
         },
     },
 };
-use arbiter_proto::proto::shared::VaultState as ProtoVaultState;
 use kameo::{actor::ActorRef, error::SendError};
 use tonic::Status;
 use tracing::warn;
 
-use crate::{
-    actors::{
-        keyholder::KeyHolderState,
-        user_agent::{
-            UserAgentSession,
-            session::connection::{
-                BootstrapError, HandleBootstrapEncryptedKey, HandleQueryVaultState,
-                HandleUnsealEncryptedKey, HandleUnsealRequest, UnsealError,
-            },
+use crate::actors::{
+    keyholder::KeyHolderState,
+    user_agent::{
+        UserAgentSession,
+        session::connection::{
+            BootstrapError, HandleBootstrapEncryptedKey, HandleQueryVaultState,
+            HandleUnsealEncryptedKey, HandleUnsealRequest, UnsealError,
         },
     },
 };
 
-fn wrap_vault_response(payload: VaultResponsePayload) -> UserAgentResponsePayload {
+const fn wrap_vault_response(payload: VaultResponsePayload) -> UserAgentResponsePayload {
     UserAgentResponsePayload::Vault(proto_vault::Response {
         payload: Some(payload),
     })
 }
 
-fn wrap_unseal_response(payload: UnsealResponsePayload) -> UserAgentResponsePayload {
+const fn wrap_unseal_response(payload: UnsealResponsePayload) -> UserAgentResponsePayload {
     wrap_vault_response(VaultResponsePayload::Unseal(proto_unseal::Response {
         payload: Some(payload),
     }))
@@ -61,7 +58,7 @@ pub(super) async fn dispatch(
     };
 
     match payload {
-        VaultRequestPayload::QueryState(_) => handle_query_vault_state(actor).await,
+        VaultRequestPayload::QueryState(()) => handle_query_vault_state(actor).await,
         VaultRequestPayload::Unseal(req) => dispatch_unseal_request(actor, req).await,
         VaultRequestPayload::Bootstrap(req) => handle_bootstrap_request(actor, req).await,
     }
@@ -151,7 +148,9 @@ async fn handle_bootstrap_encrypted_key(
         .await
     {
         Ok(()) => ProtoBootstrapResult::Success,
-        Err(SendError::HandlerError(BootstrapError::InvalidKey)) => ProtoBootstrapResult::InvalidKey,
+        Err(SendError::HandlerError(BootstrapError::InvalidKey)) => {
+            ProtoBootstrapResult::InvalidKey
+        }
         Err(SendError::HandlerError(BootstrapError::AlreadyBootstrapped)) => {
             ProtoBootstrapResult::AlreadyBootstrapped
         }

server/crates/arbiter-server/src/lib.rs

@@ -1,12 +1,11 @@
-#![forbid(unsafe_code)]
 use crate::context::ServerContext;
 
 pub mod actors;
 pub mod context;
+pub mod crypto;
 pub mod db;
 pub mod evm;
 pub mod grpc;
-pub mod safe_cell;
 pub mod utils;
 
 pub struct Server {
@@ -14,7 +13,7 @@ pub struct Server {
 }
 
 impl Server {
-    pub fn new(context: ServerContext) -> Self {
+    pub const fn new(context: ServerContext) -> Self {
         Self { context }
     }
 }

server/crates/arbiter-server/src/main.rs

@@ -1,8 +1,8 @@
 use std::net::SocketAddr;
 
+use anyhow::anyhow;
 use arbiter_proto::{proto::arbiter_service_server::ArbiterServiceServer, url::ArbiterUrl};
 use arbiter_server::{Server, actors::bootstrap::GetToken, context::ServerContext, db};
-use miette::miette;
 use rustls::crypto::aws_lc_rs;
 use tonic::transport::{Identity, ServerTlsConfig};
 use tracing::info;
@@ -10,7 +10,8 @@ use tracing::info;
 const PORT: u16 = 50051;
 
 #[tokio::main]
-async fn main() -> miette::Result<()> {
+#[mutants::skip]
+async fn main() -> anyhow::Result<()> {
     aws_lc_rs::default_provider().install_default().unwrap();
 
     tracing_subscriber::fmt()
@@ -46,11 +47,11 @@ async fn main() -> miette::Result<()> {
 
     tonic::transport::Server::builder()
         .tls_config(tls)
-        .map_err(|err| miette!("Faild to setup TLS: {err}"))?
+        .map_err(|err| anyhow!("Failed to setup TLS: {err}"))?
         .add_service(ArbiterServiceServer::new(Server::new(context)))
         .serve(addr)
         .await
-        .map_err(|e| miette::miette!("gRPC server error: {e}"))?;
+        .map_err(|e| anyhow!("gRPC server error: {e}"))?;
 
     unreachable!("gRPC server should run indefinitely");
 }

server/crates/arbiter-server/tests/client/auth.rs

@@ -1,13 +1,21 @@
+use arbiter_crypto::{
+    authn::{self, CLIENT_CONTEXT, format_challenge},
+    safecell::{SafeCell, SafeCellHandle as _},
+};
 use arbiter_proto::ClientMetadata;
 use arbiter_proto::transport::{Receiver, Sender};
-use arbiter_server::actors::GlobalActors;
 use arbiter_server::{
-    actors::client::{ClientConnection, auth, connect_client},
-    db,
+    actors::{
+        GlobalActors,
+        client::{ClientConnection, ClientCredentials, auth, connect_client},
+        keyholder::Bootstrap,
+    },
+    crypto::integrity,
+    db::{self, schema},
 };
 use diesel::{ExpressionMethods as _, NullableExpressionMethods as _, QueryDsl as _, insert_into};
 use diesel_async::RunQueryDsl;
-use ed25519_dalek::Signer as _;
+use ml_dsa::{KeyGen, MlDsa87, SigningKey, VerifyingKey, signature::Keypair};
 
 use super::common::ChannelTransport;
 
@@ -19,9 +27,14 @@ fn metadata(name: &str, description: Option<&str>, version: Option<&str>) -> Cli
     }
 }
 
+fn verifying_key(key: &SigningKey<MlDsa87>) -> VerifyingKey<MlDsa87> {
+    <SigningKey<MlDsa87> as Keypair>::verifying_key(key)
+}
+
 async fn insert_registered_client(
     db: &db::DatabasePool,
-    pubkey: Vec<u8>,
+    actors: &GlobalActors,
+    pubkey: VerifyingKey<MlDsa87>,
     metadata: &ClientMetadata,
 ) {
     use arbiter_server::db::schema::{client_metadata, program_client};
@@ -37,34 +50,90 @@ async fn insert_registered_client(
         .get_result(&mut conn)
         .await
         .unwrap();
-    insert_into(program_client::table)
+    let client_id: i32 = insert_into(program_client::table)
         .values((
-            program_client::public_key.eq(pubkey),
+            program_client::public_key.eq(pubkey.encode().0.to_vec()),
             program_client::metadata_id.eq(metadata_id),
         ))
+        .returning(program_client::id)
+        .get_result(&mut conn)
+        .await
+        .unwrap();
+
+    integrity::sign_entity(
+        &mut conn,
+        &actors.key_holder,
+        &ClientCredentials {
+            pubkey: pubkey.into(),
+            nonce: 1,
+        },
+        client_id,
+    )
+    .await
+    .unwrap();
+}
+
+fn sign_client_challenge(
+    key: &SigningKey<MlDsa87>,
+    nonce: i32,
+    pubkey: &authn::PublicKey,
+) -> authn::Signature {
+    let challenge = format_challenge(nonce, &pubkey.to_bytes());
+    key.signing_key()
+        .sign_deterministic(&challenge, CLIENT_CONTEXT)
+        .unwrap()
+        .into()
+}
+
+async fn insert_bootstrap_sentinel_useragent(db: &db::DatabasePool) {
+    let mut conn = db.get().await.unwrap();
+    let sentinel_key = verifying_key(&MlDsa87::key_gen(&mut rand::rng()))
+        .encode()
+        .0
+        .to_vec();
+
+    insert_into(schema::useragent_client::table)
+        .values((
+            schema::useragent_client::public_key.eq(sentinel_key),
+            schema::useragent_client::key_type.eq(1i32),
+        ))
         .execute(&mut conn)
         .await
         .unwrap();
 }
 
+async fn spawn_test_actors(db: &db::DatabasePool) -> GlobalActors {
+    insert_bootstrap_sentinel_useragent(db).await;
+
+    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    actors
+        .key_holder
+        .ask(Bootstrap {
+            seal_key_raw: SafeCell::new(b"test-seal-key".to_vec()),
+        })
+        .await
+        .unwrap();
+    actors
+}
+
 #[tokio::test]
 #[test_log::test]
-pub async fn test_unregistered_pubkey_rejected() {
+pub async fn unregistered_pubkey_rejected() {
     let db = db::create_test_pool().await;
 
     let (server_transport, mut test_transport) = ChannelTransport::new();
-    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    let actors = spawn_test_actors(&db).await;
     let props = ClientConnection::new(db.clone(), actors);
     let task = tokio::spawn(async move {
         let mut server_transport = server_transport;
         connect_client(props, &mut server_transport).await;
     });
 
-    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
+    let new_key = MlDsa87::key_gen(&mut rand::rng());
 
     test_transport
         .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key(),
+            pubkey: verifying_key(&new_key).into(),
             metadata: metadata("client", Some("desc"), Some("1.0.0")),
         })
         .await
@@ -76,22 +145,21 @@ pub async fn test_unregistered_pubkey_rejected() {
 
 #[tokio::test]
 #[test_log::test]
-pub async fn test_challenge_auth() {
+pub async fn challenge_auth() {
     let db = db::create_test_pool().await;
+    let actors = spawn_test_actors(&db).await;
 
-    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
-    let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();
+    let new_key = MlDsa87::key_gen(&mut rand::rng());
 
-    insert_registered_client(
+    Box::pin(insert_registered_client(
         &db,
-        pubkey_bytes.clone(),
+        &actors,
+        verifying_key(&new_key),
         &metadata("client", Some("desc"), Some("1.0.0")),
-    )
+    ))
     .await;
 
     let (server_transport, mut test_transport) = ChannelTransport::new();
-    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
-
     let props = ClientConnection::new(db.clone(), actors);
     let task = tokio::spawn(async move {
         let mut server_transport = server_transport;
@@ -101,7 +169,7 @@ pub async fn test_challenge_auth() {
     // Send challenge request
     test_transport
         .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key(),
+            pubkey: verifying_key(&new_key).into(),
             metadata: metadata("client", Some("desc"), Some("1.0.0")),
         })
         .await
@@ -115,14 +183,13 @@ pub async fn test_challenge_auth() {
     let challenge = match response {
         Ok(resp) => match resp {
             auth::Outbound::AuthChallenge { pubkey, nonce } => (pubkey, nonce),
-            other => panic!("Expected AuthChallenge, got {other:?}"),
+            other @ auth::Outbound::AuthSuccess => panic!("Expected AuthChallenge, got {other:?}"),
         },
         Err(err) => panic!("Expected Ok response, got Err({err:?})"),
     };
 
     // Sign the challenge and send solution
-    let formatted_challenge = arbiter_proto::format_challenge(challenge.1, challenge.0.as_bytes());
-    let signature = new_key.sign(&formatted_challenge);
+    let signature = sign_client_challenge(&new_key, challenge.1, &challenge.0);
 
     test_transport
         .send(auth::Inbound::AuthChallengeSolution { signature })
@@ -145,36 +212,21 @@ pub async fn test_challenge_auth() {
 
 #[tokio::test]
 #[test_log::test]
-pub async fn test_metadata_unchanged_does_not_append_history() {
+pub async fn metadata_unchanged_does_not_append_history() {
     let db = db::create_test_pool().await;
-    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
-    let props = ClientConnection::new(db.clone(), actors);
-
-    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
+    let actors = spawn_test_actors(&db).await;
+    let new_key = MlDsa87::key_gen(&mut rand::rng());
     let requested = metadata("client", Some("desc"), Some("1.0.0"));
 
-    {
-        use arbiter_server::db::schema::{client_metadata, program_client};
-        let mut conn = db.get().await.unwrap();
-        let metadata_id: i32 = insert_into(client_metadata::table)
-            .values((
-                client_metadata::name.eq(&requested.name),
-                client_metadata::description.eq(&requested.description),
-                client_metadata::version.eq(&requested.version),
-            ))
-            .returning(client_metadata::id)
-            .get_result(&mut conn)
-            .await
-            .unwrap();
-        insert_into(program_client::table)
-            .values((
-                program_client::public_key.eq(new_key.verifying_key().to_bytes().to_vec()),
-                program_client::metadata_id.eq(metadata_id),
-            ))
-            .execute(&mut conn)
-            .await
-            .unwrap();
-    }
+    Box::pin(insert_registered_client(
+        &db,
+        &actors,
+        verifying_key(&new_key),
+        &requested,
+    ))
+    .await;
+
+    let props = ClientConnection::new(db.clone(), actors);
 
     let (server_transport, mut test_transport) = ChannelTransport::new();
     let task = tokio::spawn(async move {
@@ -184,7 +236,7 @@ pub async fn test_metadata_unchanged_does_not_append_history() {
 
     test_transport
         .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key(),
+            pubkey: verifying_key(&new_key).into(),
             metadata: requested,
         })
         .await
@@ -193,9 +245,9 @@ pub async fn test_metadata_unchanged_does_not_append_history() {
     let response = test_transport.recv().await.unwrap().unwrap();
     let (pubkey, nonce) = match response {
         auth::Outbound::AuthChallenge { pubkey, nonce } => (pubkey, nonce),
-        other => panic!("Expected AuthChallenge, got {other:?}"),
+        auth::Outbound::AuthSuccess => panic!("Expected AuthChallenge, got AuthSuccess"),
     };
-    let signature = new_key.sign(&arbiter_proto::format_challenge(nonce, pubkey.as_bytes()));
+    let signature = sign_client_challenge(&new_key, nonce, &pubkey);
     test_transport
         .send(auth::Inbound::AuthChallengeSolution { signature })
         .await
@@ -223,36 +275,21 @@ pub async fn test_metadata_unchanged_does_not_append_history() {
 
 #[tokio::test]
 #[test_log::test]
-pub async fn test_metadata_change_appends_history_and_repoints_binding() {
+pub async fn metadata_change_appends_history_and_repoints_binding() {
     let db = db::create_test_pool().await;
-    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    let actors = spawn_test_actors(&db).await;
+    let new_key = MlDsa87::key_gen(&mut rand::rng());
+
+    Box::pin(insert_registered_client(
+        &db,
+        &actors,
+        verifying_key(&new_key),
+        &metadata("client", Some("old"), Some("1.0.0")),
+    ))
+    .await;
+
     let props = ClientConnection::new(db.clone(), actors);
 
-    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
-
-    {
-        use arbiter_server::db::schema::{client_metadata, program_client};
-        let mut conn = db.get().await.unwrap();
-        let metadata_id: i32 = insert_into(client_metadata::table)
-            .values((
-                client_metadata::name.eq("client"),
-                client_metadata::description.eq(Some("old")),
-                client_metadata::version.eq(Some("1.0.0")),
-            ))
-            .returning(client_metadata::id)
-            .get_result(&mut conn)
-            .await
-            .unwrap();
-        insert_into(program_client::table)
-            .values((
-                program_client::public_key.eq(new_key.verifying_key().to_bytes().to_vec()),
-                program_client::metadata_id.eq(metadata_id),
-            ))
-            .execute(&mut conn)
-            .await
-            .unwrap();
-    }
-
     let (server_transport, mut test_transport) = ChannelTransport::new();
     let task = tokio::spawn(async move {
         let mut server_transport = server_transport;
@@ -261,7 +298,7 @@ pub async fn test_metadata_change_appends_history_and_repoints_binding() {
 
     test_transport
         .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key(),
+            pubkey: verifying_key(&new_key).into(),
             metadata: metadata("client", Some("new"), Some("2.0.0")),
         })
         .await
@@ -270,14 +307,14 @@ pub async fn test_metadata_change_appends_history_and_repoints_binding() {
     let response = test_transport.recv().await.unwrap().unwrap();
     let (pubkey, nonce) = match response {
         auth::Outbound::AuthChallenge { pubkey, nonce } => (pubkey, nonce),
-        other => panic!("Expected AuthChallenge, got {other:?}"),
+        auth::Outbound::AuthSuccess => panic!("Expected AuthChallenge, got AuthSuccess"),
     };
-    let signature = new_key.sign(&arbiter_proto::format_challenge(nonce, pubkey.as_bytes()));
+    let signature = sign_client_challenge(&new_key, nonce, &pubkey);
     test_transport
         .send(auth::Inbound::AuthChallengeSolution { signature })
         .await
         .unwrap();
-    let _ = test_transport.recv().await.unwrap();
+    drop(test_transport.recv().await.unwrap());
     task.await.unwrap();
 
     {
@@ -322,3 +359,62 @@ pub async fn test_metadata_change_appends_history_and_repoints_binding() {
         );
     }
 }
+
+#[tokio::test]
+#[test_log::test]
+pub async fn challenge_auth_rejects_integrity_tag_mismatch() {
+    let db = db::create_test_pool().await;
+    let actors = spawn_test_actors(&db).await;
+
+    let new_key = MlDsa87::key_gen(&mut rand::rng());
+    let requested = metadata("client", Some("desc"), Some("1.0.0"));
+
+    {
+        use arbiter_server::db::schema::{client_metadata, program_client};
+        let mut conn = db.get().await.unwrap();
+        let metadata_id: i32 = insert_into(client_metadata::table)
+            .values((
+                client_metadata::name.eq(&requested.name),
+                client_metadata::description.eq(&requested.description),
+                client_metadata::version.eq(&requested.version),
+            ))
+            .returning(client_metadata::id)
+            .get_result(&mut conn)
+            .await
+            .unwrap();
+        insert_into(program_client::table)
+            .values((
+                program_client::public_key.eq(verifying_key(&new_key).encode().0.to_vec()),
+                program_client::metadata_id.eq(metadata_id),
+            ))
+            .execute(&mut conn)
+            .await
+            .unwrap();
+    }
+
+    let (server_transport, mut test_transport) = ChannelTransport::new();
+    let props = ClientConnection::new(db.clone(), actors);
+    let task = tokio::spawn(async move {
+        let mut server_transport = server_transport;
+        connect_client(props, &mut server_transport).await;
+    });
+
+    test_transport
+        .send(auth::Inbound::AuthChallengeRequest {
+            pubkey: verifying_key(&new_key).into(),
+            metadata: requested,
+        })
+        .await
+        .unwrap();
+
+    let response = test_transport
+        .recv()
+        .await
+        .expect("should receive auth rejection");
+    assert!(matches!(
+        response,
+        Err(auth::ClientAuthError::IntegrityCheckFailed)
+    ));
+
+    task.await.unwrap();
+}

server/crates/arbiter-server/tests/common/mod.rs

@@ -1,15 +1,16 @@
+#![allow(dead_code, reason = "Common test utilities that may not be used in every test")]
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 use arbiter_proto::transport::{Bi, Error, Receiver, Sender};
 use arbiter_server::{
     actors::keyholder::KeyHolder,
     db::{self, schema},
-    safe_cell::{SafeCell, SafeCellHandle as _},
 };
+
 use async_trait::async_trait;
 use diesel::QueryDsl;
 use diesel_async::RunQueryDsl;
 use tokio::sync::mpsc;
 
-#[allow(dead_code)]
 pub async fn bootstrapped_keyholder(db: &db::DatabasePool) -> KeyHolder {
     let mut actor = KeyHolder::new(db.clone()).await.unwrap();
     actor
@@ -19,7 +20,6 @@ pub async fn bootstrapped_keyholder(db: &db::DatabasePool) -> KeyHolder {
     actor
 }
 
-#[allow(dead_code)]
 pub async fn root_key_history_id(db: &db::DatabasePool) -> i32 {
     let mut conn = db.get().await.unwrap();
     let id = schema::arbiter_settings::table
@@ -30,14 +30,12 @@ pub async fn root_key_history_id(db: &db::DatabasePool) -> i32 {
     id.expect("root_key_id should be set after bootstrap")
 }
 
-#[allow(dead_code)]
 pub struct ChannelTransport<T, Y> {
     receiver: mpsc::Receiver<T>,
     sender: mpsc::Sender<Y>,
 }
 
 impl<T, Y> ChannelTransport<T, Y> {
-    #[allow(dead_code)]
     pub fn new() -> (Self, ChannelTransport<Y, T>) {
         let (tx1, rx1) = mpsc::channel(10);
         let (tx2, rx2) = mpsc::channel(10);

server/crates/arbiter-server/tests/keyholder/concurrency.rs

@@ -1,10 +1,11 @@
 use std::collections::{HashMap, HashSet};
 
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 use arbiter_server::{
-    actors::keyholder::{CreateNew, Error, KeyHolder},
+    actors::keyholder::{CreateNew, KeyHolder, KeyHolderError},
     db::{self, models, schema},
-    safe_cell::{SafeCell, SafeCellHandle as _},
 };
+
 use diesel::{ExpressionMethods as _, QueryDsl, SelectableHelper, dsl::sql_query};
 use diesel_async::RunQueryDsl;
 use kameo::actor::{ActorRef, Spawn as _};
@@ -121,7 +122,7 @@ async fn insert_failure_does_not_create_partial_row() {
         .create_new(SafeCell::new(b"should fail".to_vec()))
         .await
         .unwrap_err();
-    assert!(matches!(err, Error::DatabaseTransaction(_)));
+    assert!(matches!(err, KeyHolderError::DatabaseTransaction(_)));
 
     let mut conn = db.get().await.unwrap();
     sql_query("DROP TRIGGER fail_aead_insert;")

server/crates/arbiter-server/tests/keyholder/lifecycle.rs

@@ -1,8 +1,10 @@
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 use arbiter_server::{
-    actors::keyholder::{Error, KeyHolder},
+    actors::keyholder::{KeyHolder, KeyHolderError},
+    crypto::encryption::v1::{Nonce, ROOT_KEY_TAG},
     db::{self, models, schema},
-    safe_cell::{SafeCell, SafeCellHandle as _},
 };
+
 use diesel::{QueryDsl, SelectableHelper};
 use diesel_async::RunQueryDsl;
 
@@ -10,7 +12,7 @@ use crate::common;
 
 #[tokio::test]
 #[test_log::test]
-async fn test_bootstrap() {
+async fn bootstrap() {
     let db = db::create_test_pool().await;
     let mut actor = KeyHolder::new(db.clone()).await.unwrap();
 
@@ -25,32 +27,26 @@ async fn test_bootstrap() {
         .unwrap();
 
     assert_eq!(row.schema_version, 1);
-    assert_eq!(
-        row.tag,
-        arbiter_server::actors::keyholder::encryption::v1::ROOT_KEY_TAG
-    );
+    assert_eq!(row.tag, ROOT_KEY_TAG);
     assert!(!row.ciphertext.is_empty());
     assert!(!row.salt.is_empty());
-    assert_eq!(
-        row.data_encryption_nonce,
-        arbiter_server::actors::keyholder::encryption::v1::Nonce::default().to_vec()
-    );
+    assert_eq!(row.data_encryption_nonce, Nonce::default().to_vec());
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_bootstrap_rejects_double() {
+async fn bootstrap_rejects_double() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_keyholder(&db).await;
 
     let seal_key2 = SafeCell::new(b"test-seal-key".to_vec());
     let err = actor.bootstrap(seal_key2).await.unwrap_err();
-    assert!(matches!(err, Error::AlreadyBootstrapped));
+    assert!(matches!(err, KeyHolderError::AlreadyBootstrapped));
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_create_new_before_bootstrap_fails() {
+async fn create_new_before_bootstrap_fails() {
     let db = db::create_test_pool().await;
     let mut actor = KeyHolder::new(db).await.unwrap();
 
@@ -58,34 +54,34 @@ async fn test_create_new_before_bootstrap_fails() {
         .create_new(SafeCell::new(b"data".to_vec()))
         .await
         .unwrap_err();
-    assert!(matches!(err, Error::NotBootstrapped));
+    assert!(matches!(err, KeyHolderError::NotBootstrapped));
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_decrypt_before_bootstrap_fails() {
+async fn decrypt_before_bootstrap_fails() {
     let db = db::create_test_pool().await;
     let mut actor = KeyHolder::new(db).await.unwrap();
 
     let err = actor.decrypt(1).await.unwrap_err();
-    assert!(matches!(err, Error::NotBootstrapped));
+    assert!(matches!(err, KeyHolderError::NotBootstrapped));
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_new_restores_sealed_state() {
+async fn new_restores_sealed_state() {
     let db = db::create_test_pool().await;
     let actor = common::bootstrapped_keyholder(&db).await;
     drop(actor);
 
     let mut actor2 = KeyHolder::new(db).await.unwrap();
     let err = actor2.decrypt(1).await.unwrap_err();
-    assert!(matches!(err, Error::NotBootstrapped));
+    assert!(matches!(err, KeyHolderError::NotBootstrapped));
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_unseal_correct_password() {
+async fn unseal_correct_password() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_keyholder(&db).await;
 
@@ -106,7 +102,7 @@ async fn test_unseal_correct_password() {
 
 #[tokio::test]
 #[test_log::test]
-async fn test_unseal_wrong_then_correct_password() {
+async fn unseal_wrong_then_correct_password() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_keyholder(&db).await;
 
@@ -121,7 +117,7 @@ async fn test_unseal_wrong_then_correct_password() {
 
     let bad_key = SafeCell::new(b"wrong-password".to_vec());
     let err = actor.try_unseal(bad_key).await.unwrap_err();
-    assert!(matches!(err, Error::InvalidKey));
+    assert!(matches!(err, KeyHolderError::InvalidKey));
 
     let good_key = SafeCell::new(b"test-seal-key".to_vec());
     actor.try_unseal(good_key).await.unwrap();

server/crates/arbiter-server/tests/keyholder/storage.rs

@@ -1,10 +1,12 @@
 use std::collections::HashSet;
 
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 use arbiter_server::{
-    actors::keyholder::{Error, encryption::v1},
+    actors::keyholder::KeyHolderError,
+    crypto::encryption::v1::Nonce,
     db::{self, models, schema},
-    safe_cell::{SafeCell, SafeCellHandle as _},
 };
+
 use diesel::{ExpressionMethods as _, QueryDsl, SelectableHelper, dsl::update};
 use diesel_async::RunQueryDsl;
 
@@ -12,7 +14,7 @@ use crate::common;
 
 #[tokio::test]
 #[test_log::test]
-async fn test_create_decrypt_roundtrip() {
+async fn create_decrypt_roundtrip() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_keyholder(&db).await;
 
@@ -28,17 +30,17 @@ async fn test_create_decrypt_roundtrip() {
 
 #[tokio::test]
 #[test_log::test]
-async fn test_decrypt_nonexistent_returns_not_found() {
+async fn decrypt_nonexistent_returns_not_found() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_keyholder(&db).await;
 
     let err = actor.decrypt(9999).await.unwrap_err();
-    assert!(matches!(err, Error::NotFound));
+    assert!(matches!(err, KeyHolderError::NotFound));
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_ciphertext_differs_across_entries() {
+async fn ciphertext_differs_across_entries() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_keyholder(&db).await;
 
@@ -76,7 +78,7 @@ async fn test_ciphertext_differs_across_entries() {
 
 #[tokio::test]
 #[test_log::test]
-async fn test_nonce_never_reused() {
+async fn nonce_never_reused() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_keyholder(&db).await;
 
@@ -102,7 +104,7 @@ async fn test_nonce_never_reused() {
     assert_eq!(nonces.len(), unique.len(), "all nonces must be unique");
 
     for (i, row) in rows.iter().enumerate() {
-        let mut expected = v1::Nonce::default();
+        let mut expected = Nonce::default();
         for _ in 0..=i {
             expected.increment();
         }
@@ -140,7 +142,7 @@ async fn broken_db_nonce_format_fails_closed() {
         .create_new(SafeCell::new(b"must fail".to_vec()))
         .await
         .unwrap_err();
-    assert!(matches!(err, Error::BrokenDatabase));
+    assert!(matches!(err, KeyHolderError::BrokenDatabase));
 
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_keyholder(&db).await;
@@ -157,5 +159,5 @@ async fn broken_db_nonce_format_fails_closed() {
     drop(conn);
 
     let err = actor.decrypt(id).await.unwrap_err();
-    assert!(matches!(err, Error::BrokenDatabase));
+    assert!(matches!(err, KeyHolderError::BrokenDatabase));
 }

server/crates/arbiter-server/tests/user_agent/auth.rs

@@ -1,23 +1,53 @@
+use arbiter_crypto::{
+    authn::{self, USERAGENT_CONTEXT, format_challenge},
+    safecell::{SafeCell, SafeCellHandle as _},
+};
+
 use arbiter_proto::transport::{Receiver, Sender};
 use arbiter_server::{
     actors::{
         GlobalActors,
         bootstrap::GetToken,
-        user_agent::{AuthPublicKey, UserAgentConnection, auth},
+        keyholder::Bootstrap,
+        user_agent::{UserAgentConnection, UserAgentCredentials, auth},
     },
+    crypto::integrity,
     db::{self, schema},
 };
 use diesel::{ExpressionMethods as _, QueryDsl, insert_into};
 use diesel_async::RunQueryDsl;
-use ed25519_dalek::Signer as _;
+use ml_dsa::{KeyGen, MlDsa87, SigningKey, VerifyingKey, signature::Keypair};
 
 use super::common::ChannelTransport;
 
+fn verifying_key(key: &SigningKey<MlDsa87>) -> VerifyingKey<MlDsa87> {
+    <SigningKey<MlDsa87> as Keypair>::verifying_key(key)
+}
+
+fn sign_useragent_challenge(
+    key: &SigningKey<MlDsa87>,
+    nonce: i32,
+    pubkey_bytes: &[u8],
+) -> authn::Signature {
+    let challenge = format_challenge(nonce, pubkey_bytes);
+    key.signing_key()
+        .sign_deterministic(&challenge, USERAGENT_CONTEXT)
+        .unwrap()
+        .into()
+}
+
 #[tokio::test]
 #[test_log::test]
-pub async fn test_bootstrap_token_auth() {
+pub async fn bootstrap_token_auth() {
     let db = db::create_test_pool().await;
     let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    actors
+        .key_holder
+        .ask(Bootstrap {
+            seal_key_raw: SafeCell::new(b"test-seal-key".to_vec()),
+        })
+        .await
+        .unwrap();
     let token = actors.bootstrapper.ask(GetToken).await.unwrap().unwrap();
 
     let (server_transport, mut test_transport) = ChannelTransport::new();
@@ -27,10 +57,10 @@ pub async fn test_bootstrap_token_auth() {
         auth::authenticate(&mut props, server_transport).await
     });
 
-    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
+    let new_key = MlDsa87::key_gen(&mut rand::rng());
     test_transport
         .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
+            pubkey: verifying_key(&new_key).into(),
             bootstrap_token: Some(token),
         })
         .await
@@ -53,12 +83,12 @@ pub async fn test_bootstrap_token_auth() {
         .first::<Vec<u8>>(&mut conn)
         .await
         .unwrap();
-    assert_eq!(stored_pubkey, new_key.verifying_key().to_bytes().to_vec());
+    assert_eq!(stored_pubkey, verifying_key(&new_key).encode().0.to_vec());
 }
 
 #[tokio::test]
 #[test_log::test]
-pub async fn test_bootstrap_invalid_token_auth() {
+pub async fn bootstrap_invalid_token_auth() {
     let db = db::create_test_pool().await;
     let actors = GlobalActors::spawn(db.clone()).await.unwrap();
 
@@ -69,11 +99,11 @@ pub async fn test_bootstrap_invalid_token_auth() {
         auth::authenticate(&mut props, server_transport).await
     });
 
-    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
+    let new_key = MlDsa87::key_gen(&mut rand::rng());
     test_transport
         .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
-            bootstrap_token: Some("invalid_token".to_string()),
+            pubkey: verifying_key(&new_key).into(),
+            bootstrap_token: Some("invalid_token".to_owned()),
         })
         .await
         .unwrap();
@@ -83,7 +113,6 @@ pub async fn test_bootstrap_invalid_token_auth() {
         Err(auth::Error::InvalidBootstrapToken)
     ));
 
-    // Verify no key was registered
     let mut conn = db.get().await.unwrap();
     let count: i64 = schema::useragent_client::table
         .count()
@@ -95,24 +124,42 @@ pub async fn test_bootstrap_invalid_token_auth() {
 
 #[tokio::test]
 #[test_log::test]
-pub async fn test_challenge_auth() {
+pub async fn challenge_auth() {
     let db = db::create_test_pool().await;
     let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    actors
+        .key_holder
+        .ask(Bootstrap {
+            seal_key_raw: SafeCell::new(b"test-seal-key".to_vec()),
+        })
+        .await
+        .unwrap();
 
-    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
-    let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();
+    let new_key = MlDsa87::key_gen(&mut rand::rng());
+    let pubkey_bytes = authn::PublicKey::from(verifying_key(&new_key)).to_bytes();
 
-    // Pre-register key with key_type
     {
         let mut conn = db.get().await.unwrap();
-        insert_into(schema::useragent_client::table)
+        let id: i32 = insert_into(schema::useragent_client::table)
             .values((
                 schema::useragent_client::public_key.eq(pubkey_bytes.clone()),
                 schema::useragent_client::key_type.eq(1i32),
             ))
-            .execute(&mut conn)
+            .returning(schema::useragent_client::id)
+            .get_result(&mut conn)
             .await
             .unwrap();
+        integrity::sign_entity(
+            &mut conn,
+            &actors.key_holder,
+            &UserAgentCredentials {
+                pubkey: verifying_key(&new_key).into(),
+                nonce: 1,
+            },
+            id,
+        )
+        .await
+        .unwrap();
     }
 
     let (server_transport, mut test_transport) = ChannelTransport::new();
@@ -122,16 +169,14 @@ pub async fn test_challenge_auth() {
         auth::authenticate(&mut props, server_transport).await
     });
 
-    // Send challenge request
     test_transport
         .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
+            pubkey: verifying_key(&new_key).into(),
             bootstrap_token: None,
         })
         .await
         .unwrap();
 
-    // Read the challenge response
     let response = test_transport
         .recv()
         .await
@@ -139,17 +184,16 @@ pub async fn test_challenge_auth() {
     let challenge = match response {
         Ok(resp) => match resp {
             auth::Outbound::AuthChallenge { nonce } => nonce,
-            other => panic!("Expected AuthChallenge, got {other:?}"),
+            auth::Outbound::AuthSuccess => panic!("Expected AuthChallenge, got AuthSuccess"),
         },
         Err(err) => panic!("Expected Ok response, got Err({err:?})"),
     };
 
-    let formatted_challenge = arbiter_proto::format_challenge(challenge, &pubkey_bytes);
-    let signature = new_key.sign(&formatted_challenge);
+    let signature = sign_useragent_challenge(&new_key, challenge, &pubkey_bytes);
 
     test_transport
         .send(auth::Inbound::AuthChallengeSolution {
-            signature: signature.to_bytes().to_vec(),
+            signature: signature.to_bytes(),
         })
         .await
         .unwrap();
@@ -168,14 +212,21 @@ pub async fn test_challenge_auth() {
 
 #[tokio::test]
 #[test_log::test]
-pub async fn test_challenge_auth_rejects_invalid_signature() {
+pub async fn challenge_auth_rejects_integrity_tag_mismatch_when_unsealed() {
     let db = db::create_test_pool().await;
     let actors = GlobalActors::spawn(db.clone()).await.unwrap();
 
-    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
-    let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();
+    actors
+        .key_holder
+        .ask(Bootstrap {
+            seal_key_raw: SafeCell::new(b"test-seal-key".to_vec()),
+        })
+        .await
+        .unwrap();
+
+    let new_key = MlDsa87::key_gen(&mut rand::rng());
+    let pubkey_bytes = authn::PublicKey::from(verifying_key(&new_key)).to_bytes();
 
-    // Pre-register key with key_type
     {
         let mut conn = db.get().await.unwrap();
         insert_into(schema::useragent_client::table)
@@ -197,7 +248,68 @@ pub async fn test_challenge_auth_rejects_invalid_signature() {
 
     test_transport
         .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
+            pubkey: verifying_key(&new_key).into(),
+            bootstrap_token: None,
+        })
+        .await
+        .unwrap();
+
+    assert!(matches!(
+        task.await.unwrap(),
+        Err(auth::Error::Internal { .. })
+    ));
+}
+
+#[tokio::test]
+#[test_log::test]
+pub async fn challenge_auth_rejects_invalid_signature() {
+    let db = db::create_test_pool().await;
+    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    actors
+        .key_holder
+        .ask(Bootstrap {
+            seal_key_raw: SafeCell::new(b"test-seal-key".to_vec()),
+        })
+        .await
+        .unwrap();
+
+    let new_key = MlDsa87::key_gen(&mut rand::rng());
+    let pubkey_bytes = authn::PublicKey::from(verifying_key(&new_key)).to_bytes();
+
+    {
+        let mut conn = db.get().await.unwrap();
+        let id: i32 = insert_into(schema::useragent_client::table)
+            .values((
+                schema::useragent_client::public_key.eq(pubkey_bytes.clone()),
+                schema::useragent_client::key_type.eq(1i32),
+            ))
+            .returning(schema::useragent_client::id)
+            .get_result(&mut conn)
+            .await
+            .unwrap();
+        integrity::sign_entity(
+            &mut conn,
+            &actors.key_holder,
+            &UserAgentCredentials {
+                pubkey: verifying_key(&new_key).into(),
+                nonce: 1,
+            },
+            id,
+        )
+        .await
+        .unwrap();
+    }
+
+    let (server_transport, mut test_transport) = ChannelTransport::new();
+    let db_for_task = db.clone();
+    let task = tokio::spawn(async move {
+        let mut props = UserAgentConnection::new(db_for_task, actors);
+        auth::authenticate(&mut props, server_transport).await
+    });
+
+    test_transport
+        .send(auth::Inbound::AuthChallengeRequest {
+            pubkey: verifying_key(&new_key).into(),
             bootstrap_token: None,
         })
         .await
@@ -210,24 +322,24 @@ pub async fn test_challenge_auth_rejects_invalid_signature() {
     let challenge = match response {
         Ok(resp) => match resp {
             auth::Outbound::AuthChallenge { nonce } => nonce,
-            other => panic!("Expected AuthChallenge, got {other:?}"),
+            auth::Outbound::AuthSuccess => panic!("Expected AuthChallenge, got AuthSuccess"),
         },
         Err(err) => panic!("Expected Ok response, got Err({err:?})"),
     };
 
-    // Sign a different challenge value so signature format is valid but verification must fail.
-    let wrong_challenge = arbiter_proto::format_challenge(challenge + 1, &pubkey_bytes);
-    let signature = new_key.sign(&wrong_challenge);
+    let signature = sign_useragent_challenge(&new_key, challenge + 1, &pubkey_bytes);
 
     test_transport
         .send(auth::Inbound::AuthChallengeSolution {
-            signature: signature.to_bytes().to_vec(),
+            signature: signature.to_bytes(),
         })
         .await
         .unwrap();
 
+    let expected_err = task.await.unwrap();
+    println!("Received expected error: {expected_err:#?}");
     assert!(matches!(
-        task.await.unwrap(),
+        expected_err,
         Err(auth::Error::InvalidChallengeSolution)
     ));
 }