feat(proto)!: Shamir re-key, governance and bootstrapping vault state

Split out of feat-shamir so the wire contract can be reviewed on its own.
Rebased onto main: main's UNSEAL_RESULT_LOCKED_OUT keeps tag 4, so
UNSEAL_RESULT_AWAITING_CONTRIBUTIONS moved to 5.

BREAKING CHANGE: `shared.VaultState` renumbers SEALED/UNSEALED/ERROR to
make room for VAULT_STATE_BOOSTRAPPING = 2. Old and new peers disagree on
every vault state value.

- operator: new `governance` branch in OperatorRequest/Response (field 5)
- vault: new `rekey` branch in vault Request/Response (field 4)
- bootstrap/unseal: passphrase and recovery-passphrase contribution payloads

protobufs/operator.proto

@@ -4,25 +4,28 @@ package arbiter.operator;
 
 import "operator/auth.proto";
 import "operator/evm.proto";
+import "operator/governance.proto";
 import "operator/sdk_client.proto";
 import "operator/vault/vault.proto";
 
 message OperatorRequest {
   int32 id = 16;
   oneof payload {
-    auth.Request auth = 1;
+    auth.Request            auth        = 1;
-    vault.Request vault = 2;
+    vault.Request           vault       = 2;
-    evm.Request evm = 3;
+    evm.Request             evm         = 3;
-    sdk_client.Request sdk_client = 4;
+    sdk_client.Request      sdk_client  = 4;
+    governance.Request      governance  = 5;
   }
 }
 
 message OperatorResponse {
   optional int32 id = 16;
   oneof payload {
-    auth.Response auth = 1;
+    auth.Response           auth        = 1;
-    vault.Response vault = 2;
+    vault.Response          vault       = 2;
-    evm.Response evm = 3;
+    evm.Response            evm         = 3;
-    sdk_client.Response sdk_client = 4;
+    sdk_client.Response     sdk_client  = 4;
+    governance.Response     governance  = 5;
   }
 }

protobufs/operator/governance.proto

@@ -0,0 +1,136 @@
+syntax = "proto3";
+
+package arbiter.operator.governance;
+
+message Request {
+  oneof payload {
+    CreateProposalRequest create = 1;
+    CastVoteRequest       vote   = 2;
+    QueryPendingRequest   query  = 3;
+  }
+}
+
+message CreateProposalRequest {
+  oneof kind {
+    ApproveSdkClientPayload         approve_sdk_client          = 1;
+    GrantWalletAccessPayload        grant_wallet_access         = 3;
+    ApproveServerUpdatePayload      approve_server_update       = 4;
+    ReplaceOperatorPayload          replace_operator            = 5;
+    UpdateShamirParametersPayload   update_shamir_parameters    = 6;
+    ApprovePersistentGrantPayload   approve_persistent_grant    = 7;
+    ApproveOneOffTransactionPayload approve_one_off_transaction = 8;
+  }
+  optional uint32 ttl_secs = 2;
+}
+
+message ReplaceOperatorPayload {
+  int32 old_operator_id = 1;
+  bytes new_pubkey      = 2;
+}
+
+message UpdateShamirParametersPayload {
+  uint32 new_n = 1;
+}
+
+message ApproveServerUpdatePayload {}
+
+message ApproveSdkClientPayload {
+  int32 client_id = 1;
+}
+
+message GrantWalletAccessPayload {
+  int32 wallet_id = 1;
+  int32 client_id = 2;
+}
+
+message CastVoteRequest {
+  int32 proposal_id = 1;
+  bool  approve     = 2;
+  bytes signature   = 3;
+}
+
+message QueryPendingRequest {}
+
+message Response {
+  oneof payload {
+    CreateProposalResponse created = 1;
+    VoteResponse           voted   = 2;
+    QueryPendingResponse   pending = 3;
+  }
+}
+
+message CreateProposalResponse {
+  int32 proposal_id = 1;
+}
+
+message VoteResponse {
+  VoteOutcome outcome = 1;
+}
+
+enum VoteOutcome {
+  VOTE_OUTCOME_UNSPECIFIED = 0;
+  VOTE_OUTCOME_PENDING     = 1;
+  VOTE_OUTCOME_APPROVED    = 2;
+  VOTE_OUTCOME_REJECTED    = 3;
+}
+
+message ProposalSummary {
+  int32  id            = 1;
+  string kind          = 2;
+  int32  initiator_id  = 3;
+  int64  expires_at    = 4;
+  int64  approve_count = 5;
+  int64  reject_count  = 6;
+}
+
+message QueryPendingResponse {
+  repeated ProposalSummary proposals = 1;
+}
+
+message TransactionRateLimitProto {
+  uint32 count       = 1;
+  int64  window_secs = 2;
+}
+
+message VolumeLimitProto {
+  bytes max_volume  = 1;
+  int64 window_secs = 2;
+}
+
+message EtherTransferSpecProto {
+  repeated bytes   targets = 1;
+  VolumeLimitProto limit   = 2;
+}
+
+message TokenTransferSpecProto {
+  bytes                     token_contract = 1;
+  optional bytes            target         = 2;
+  repeated VolumeLimitProto volume_limits  = 3;
+}
+
+message ApproveOneOffTransactionPayload {
+  int32  client_id                = 1;
+  bytes  wallet_address           = 2;
+  uint64 chain_id                 = 3;
+  uint64 nonce                    = 4;
+  uint64 gas_limit                = 5;
+  bytes  max_fee_per_gas          = 6;
+  bytes  max_priority_fee_per_gas = 7;
+  bytes  to                       = 8;
+  bytes  value                    = 9;
+  bytes  input                    = 10;
+}
+
+message ApprovePersistentGrantPayload {
+  int32                              wallet_access_id         = 1;
+  uint64                             chain_id                 = 2;
+  optional int64                     valid_from_secs          = 3;
+  optional int64                     valid_until_secs         = 4;
+  optional bytes                     max_gas_fee_per_gas      = 5;
+  optional bytes                     max_priority_fee_per_gas = 6;
+  optional TransactionRateLimitProto rate_limit               = 7;
+  oneof specific {
+    EtherTransferSpecProto ether_transfer = 8;
+    TokenTransferSpecProto token_transfer = 9;
+  }
+}

protobufs/operator/vault/bootstrap.proto

@@ -8,15 +8,35 @@ message BootstrapEncryptedKey {
   bytes associated_data = 3;
 }
 
+message DeclareCommittee {
+  uint32 count          = 1;
+  uint32 recovery_count = 2;
+}
+
+message ContributePassphrase {
+  bytes passphrase = 1;
+}
+
+message ContributeRecoveryPassphrase {
+  int32 recovery_operator_id = 1;
+  bytes passphrase            = 2;
+}
+
 enum BootstrapResult {
   BOOTSTRAP_RESULT_UNSPECIFIED = 0;
   BOOTSTRAP_RESULT_SUCCESS = 1;
   BOOTSTRAP_RESULT_ALREADY_BOOTSTRAPPED = 2;
   BOOTSTRAP_RESULT_INVALID_KEY = 3;
+  BOOTSTRAP_RESULT_AWAITING_CONTRIBUTIONS = 4;
 }
 
 message Request {
-  BootstrapEncryptedKey encrypted_key = 2;
+  oneof payload {
+    BootstrapEncryptedKey        encrypted_key                    = 2;
+    DeclareCommittee             declare_committee                = 3;
+    ContributePassphrase         contribute_passphrase            = 4;
+    ContributeRecoveryPassphrase contribute_recovery_passphrase   = 5;
+  }
 }
 
 message Response {

protobufs/operator/vault/rekey.proto

@@ -0,0 +1,30 @@
+syntax = "proto3";
+
+package arbiter.operator.vault.rekey;
+
+message ContributePassphrase {
+  bytes passphrase = 1;
+}
+
+message ContributeRecoveryPassphrase {
+  int32 recovery_operator_id = 1;
+  bytes passphrase           = 2;
+}
+
+enum RekeyResult {
+  REKEY_RESULT_UNSPECIFIED            = 0;
+  REKEY_RESULT_SUCCESS                = 1;
+  REKEY_RESULT_AWAITING_CONTRIBUTIONS = 2;
+  REKEY_RESULT_NOT_IN_PROGRESS        = 3;
+}
+
+message Request {
+  oneof payload {
+    ContributePassphrase         contribute_passphrase          = 1;
+    ContributeRecoveryPassphrase contribute_recovery_passphrase = 2;
+  }
+}
+
+message Response {
+  RekeyResult result = 1;
+}

protobufs/operator/vault/unseal.proto

@@ -15,18 +15,30 @@ message UnsealEncryptedKey {
   bytes associated_data = 3;
 }
 
+message ContributePassphrase {
+  bytes passphrase = 1;
+}
+
+message ContributeRecoveryPassphrase {
+  int32 recovery_operator_id = 1;
+  bytes passphrase            = 2;
+}
+
 enum UnsealResult {
   UNSEAL_RESULT_UNSPECIFIED = 0;
   UNSEAL_RESULT_SUCCESS = 1;
   UNSEAL_RESULT_INVALID_KEY = 2;
   UNSEAL_RESULT_UNBOOTSTRAPPED = 3;
   UNSEAL_RESULT_LOCKED_OUT = 4;
+  UNSEAL_RESULT_AWAITING_CONTRIBUTIONS = 5;
 }
 
 message Request {
   oneof payload {
-    UnsealStart start = 1;
+    UnsealStart                  start                          = 1;
-    UnsealEncryptedKey encrypted_key = 2;
+    UnsealEncryptedKey           encrypted_key                  = 2;
+    ContributePassphrase         contribute_passphrase          = 3;
+    ContributeRecoveryPassphrase contribute_recovery_passphrase = 4;
   }
 }
 

protobufs/operator/vault/vault.proto

@@ -5,20 +5,23 @@ package arbiter.operator.vault;
 import "google/protobuf/empty.proto";
 import "shared/vault.proto";
 import "operator/vault/bootstrap.proto";
+import "operator/vault/rekey.proto";
 import "operator/vault/unseal.proto";
 
 message Request {
   oneof payload {
     google.protobuf.Empty query_state = 1;
-    unseal.Request unseal = 2;
+    unseal.Request        unseal      = 2;
-    bootstrap.Request bootstrap = 3;
+    bootstrap.Request     bootstrap   = 3;
+    rekey.Request         rekey       = 4;
   }
 }
 
 message Response {
   oneof payload {
-    arbiter.shared.VaultState state = 1;
+    arbiter.shared.VaultState state     = 1;
-    unseal.Response unseal = 2;
+    unseal.Response           unseal    = 2;
-    bootstrap.Response bootstrap = 3;
+    bootstrap.Response        bootstrap = 3;
+    rekey.Response            rekey     = 4;
   }
 }

protobufs/shared/vault.proto

@@ -5,7 +5,8 @@ package arbiter.shared;
 enum VaultState {
   VAULT_STATE_UNSPECIFIED = 0;
   VAULT_STATE_UNBOOTSTRAPPED = 1;
-  VAULT_STATE_SEALED = 2;
+  VAULT_STATE_BOOSTRAPPING = 2;
-  VAULT_STATE_UNSEALED = 3;
+  VAULT_STATE_SEALED = 3;
-  VAULT_STATE_ERROR = 4;
+  VAULT_STATE_UNSEALED = 4;
+  VAULT_STATE_ERROR = 5;
 }

server/Cargo.lock

@@ -2,6 +2,15 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "addr2line"
+version = "0.25.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b5d307320b3181d6d7954e663bd7c774a838b8220fe0593c86d9fb09f498b4b"
+dependencies = [
+ "gimli",
+]
+
 [[package]]
 name = "adler2"
 version = "2.0.1"
@@ -1157,6 +1166,30 @@ dependencies = [
  "tower-service",
 ]
 
+[[package]]
+name = "backtrace"
+version = "0.3.76"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb531853791a215d7c62a30daf0dde835f381ab5de4589cfe7c649d2cbe92bd6"
+dependencies = [
+ "addr2line",
+ "cfg-if",
+ "libc",
+ "miniz_oxide",
+ "object",
+ "rustc-demangle",
+ "windows-link",
+]
+
+[[package]]
+name = "backtrace-ext"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "537beee3be4a18fb023b570f80e3ae28003db9167a751266b259926e25539d50"
+dependencies = [
+ "backtrace",
+]
+
 [[package]]
 name = "base16ct"
 version = "0.2.0"
@@ -2332,6 +2365,12 @@ dependencies = [
  "wasip3",
 ]
 
+[[package]]
+name = "gimli"
+version = "0.32.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e629b9b98ef3dd8afe6ca2bd0f89306cec16d43d907889945bc5d6687f2f13c7"
+
 [[package]]
 name = "glob"
 version = "0.3.3"
@@ -2789,6 +2828,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "is_ci"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7655c9839580ee829dfacba1d1278c2b7883e50a277ff7541299489d6bdfdc45"
+
 [[package]]
 name = "itertools"
 version = "0.10.5"
@@ -3124,9 +3169,18 @@ version = "7.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5f98efec8807c63c752b5bd61f862c165c115b0a35685bdcfd9238c7aeb592b7"
 dependencies = [
+ "backtrace",
+ "backtrace-ext",
  "cfg-if",
  "miette-derive",
- "unicode-width",
+ "owo-colors",
+ "serde",
+ "supports-color",
+ "supports-hyperlinks",
+ "supports-unicode",
+ "terminal_size",
+ "textwrap",
+ "unicode-width 0.1.14",
 ]
 
 [[package]]
@@ -3348,6 +3402,15 @@ dependencies = [
  "smallvec",
 ]
 
+[[package]]
+name = "object"
+version = "0.37.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ff76201f031d8863c38aa7f905eca4f53abbfa15f609db4277d44cd8938f33fe"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "oid-registry"
 version = "0.8.1"
@@ -3375,6 +3438,12 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7c87def4c32ab89d880effc9e097653c8da5d6ef28e6b539d313baaacfbafcbe"
 
+[[package]]
+name = "owo-colors"
+version = "4.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d211803b9b6b570f68772237e415a029d5a50c65d382910b879fb19d3271f94d"
+
 [[package]]
 name = "parity-scale-codec"
 version = "3.7.5"
@@ -4178,6 +4247,12 @@ version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "48fd7bd8a6377e15ad9d42a8ec25371b94ddc67abe7c8b9127bec79bebaaae18"
 
+[[package]]
+name = "rustc-demangle"
+version = "0.1.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b50b8869d9fc858ce7266cce0194bd74df58b9d0e3f6df3a9fc8eb470d95c09d"
+
 [[package]]
 name = "rustc-hash"
 version = "2.1.2"
@@ -4817,6 +4892,27 @@ version = "2.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 
+[[package]]
+name = "supports-color"
+version = "3.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c64fc7232dd8d2e4ac5ce4ef302b1d81e0b80d055b9d77c7c4f51f6aa4c867d6"
+dependencies = [
+ "is_ci",
+]
+
+[[package]]
+name = "supports-hyperlinks"
+version = "3.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e396b6523b11ccb83120b115a0b7366de372751aa6edf19844dfb13a6af97e91"
+
+[[package]]
+name = "supports-unicode"
+version = "3.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b7401a30af6cb5818bb64852270bb722533397edcfc7344954a38f420819ece2"
+
 [[package]]
 name = "syn"
 version = "1.0.109"
@@ -4890,6 +4986,16 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "terminal_size"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "230a1b821ccbd75b185820a1f1ff7b14d21da1e442e22c0863ea5f08771a8874"
+dependencies = [
+ "rustix",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "test-log"
 version = "0.2.20"
@@ -4921,6 +5027,16 @@ dependencies = [
  "test-log-core",
 ]
 
+[[package]]
+name = "textwrap"
+version = "0.16.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c13547615a44dc9c452a8a534638acdf07120d4b6847c8178705da06306a3057"
+dependencies = [
+ "unicode-linebreak",
+ "unicode-width 0.2.2",
+]
+
 [[package]]
 name = "thiserror"
 version = "2.0.18"
@@ -5360,6 +5476,12 @@ version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
+[[package]]
+name = "unicode-linebreak"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b09c83c3c29d37506a3e260c08c03743a6bb66a9cd432c6934ab501a190571f"
+
 [[package]]
 name = "unicode-segmentation"
 version = "1.13.2"
@@ -5372,6 +5494,12 @@ version = "0.1.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7dd6e30e90baa6f72411720665d41d89b9a3d039dc45b8faea1ddd07f617f6af"
 
+[[package]]
+name = "unicode-width"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4ac048d71ede7ee76d585517add45da530660ef4390e49b098733c6e897f254"
+
 [[package]]
 name = "unicode-xid"
 version = "0.2.6"

server/Cargo.toml

@@ -15,10 +15,7 @@ k256 = { version = "0.13.4", features = ["ecdsa", "pkcs8"] }
 kameo = {git = "https://github.com/hdbg/kameo.git", rev = "805b417"}
 kameo_actors = {git = "https://github.com/hdbg/kameo.git", rev = "805b417"}
 hmac = "0.13.0"
-# `derive` only: nothing renders a miette Report yet, so `fancy` would drag the
+miette = { version = "7.6.0", features = ["fancy", "serde"] }
-# terminal-formatting stack (owo-colors, supports-color, textwrap, terminal_size)
-# into the headless daemon. A CLI that wants pretty output enables `fancy` itself.
-miette = "7.6.0"
 ml-dsa = { version = "0.1.0-rc.9", features = ["zeroize"] }
 mutants = "0.0.4"
 prost = "0.14.3"

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

@@ -23,7 +23,6 @@ use arbiter_proto::{
 use chrono::DateTime;
 
 #[derive(Debug, thiserror::Error)]
-#[non_exhaustive]
 pub enum AuthError {
     #[error("Server sent invalid auth challenge")]
     InvalidChallenge,

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

@@ -17,7 +17,6 @@ use tokio_stream::wrappers::ReceiverStream;
 use tonic::transport::ClientTlsConfig;
 
 #[derive(Debug, thiserror::Error)]
-#[non_exhaustive]
 pub enum ArbiterClientError {
     #[error("Authentication error")]
     Authentication(#[from] AuthError),

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

@@ -4,7 +4,6 @@ use arbiter_proto::home_path;
 use std::path::{Path, PathBuf};
 
 #[derive(Debug, thiserror::Error)]
-#[non_exhaustive]
 pub enum StorageError {
     #[error("Invalid signing key length in storage: expected {expected} bytes, got {actual} bytes")]
     InvalidKeyLength { expected: usize, actual: usize },

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

@@ -11,7 +11,6 @@ pub fn next_request_id() -> i32 {
 }
 
 #[derive(Debug, thiserror::Error)]
-#[non_exhaustive]
 pub enum ClientSignError {
     #[error("Transport channel closed")]
     ChannelClosed,

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

@@ -30,7 +30,6 @@ impl Display for ArbiterUrl {
 }
 
 #[derive(Debug, thiserror::Error, miette::Diagnostic)]
-#[non_exhaustive]
 pub enum Error {
     #[error("Invalid URL scheme, expected '{ARBITER_URL_SCHEME}://'")]
     #[diagnostic(

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

@@ -13,7 +13,6 @@ use diesel_async::{AsyncConnection, RunQueryDsl};
 use hmac::Hmac;
 use kameo::{actor::ActorRef, error::SendError};
 use sha2::{Digest as _, Sha256};
-use tracing::error;
 
 #[derive(Debug, thiserror::Error)]
 pub enum Error {
@@ -122,10 +121,7 @@ pub async fn sign_entity<E: Integrable>(
             .await
             .map_err(|err| match err {
                 SendError::HandlerError(inner) => Error::Vault(inner),
-                other => {
+                _ => Error::VaultSend,
-                    error!(?other, "Vault unreachable while signing integrity envelope");
-                    Error::VaultSend
-                }
             })?;
 
     insert_into(integrity_envelope::table)
@@ -199,18 +195,12 @@ pub async fn verify_entity<E: Integrable>(
         Err(SendError::HandlerError(
             vault::Error::Sealed | vault::Error::KeyVersionMismatch { .. },
         )) => Ok(AttestationStatus::Unavailable),
-        Err(other) => {
+        Err(_) => Err(Error::VaultSend),
-            error!(?other, "Vault unreachable while verifying integrity envelope");
-            Err(Error::VaultSend)
-        }
     }
 }
 
 pub async fn is_signing_available(vault: &ActorRef<Vault>) -> Result<bool, Error> {
-    let state = vault.ask(GetState).await.map_err(|err| {
+    let state = vault.ask(GetState).await.map_err(|_| Error::VaultSend)?;
-        error!(?err, "Vault unreachable while querying signing availability");
-        Error::VaultSend
-    })?;
     Ok(matches!(state, vault::VaultState::Unsealed))
 }
 

server/crates/arbiter-server/src/peers/operator/auth/mod.rs

@@ -26,22 +26,21 @@ pub enum Error {
     UnregisteredPublicKey,
     InvalidChallengeSolution,
     InvalidBootstrapToken,
-    /// Reaches the operator verbatim via `Status::internal`, so the payload is
+    Internal { details: String },
-    /// `&'static str`: the type makes it impossible to interpolate an inner
-    /// error. Log the cause, send the constant.
-    Internal { details: &'static str },
     Transport,
 }
 
 impl Error {
-    const fn internal(details: &'static str) -> Self {
+    fn internal(details: impl Into<String>) -> Self {
-        Self::Internal { details }
+        Self::Internal {
+            details: details.into(),
+        }
     }
 }
 
 impl From<diesel::result::Error> for Error {
     fn from(e: diesel::result::Error) -> Self {
-        error!(error = %crate::utils::error_chain(&e), "Database error");
+        error!(?e, "Database error");
         Self::internal("Database error")
     }
 }

server/crates/arbiter-server/src/peers/operator/vault_gate/mod.rs

@@ -31,11 +31,13 @@ pub enum Error {
     #[error("State transition failed")]
     State,
 
-    /// Reaches the operator verbatim via `Status::internal`, so the payload is
-    /// `&'static str`: the type makes it impossible to interpolate an inner
-    /// error. Log the cause, send the constant.
     #[error("Internal error: {0}")]
-    Internal(&'static str),
+    Internal(String),
+}
+impl Error {
+    fn internal(message: impl Into<String>) -> Self {
+        Self::Internal(message.into())
+    }
 }
 
 pub struct HandshakeResponse {
@@ -177,7 +179,7 @@ impl VaultGate {
             }
             Err(err) => {
                 error!(?err, "Failed to send unseal request to vault");
-                Err(Error::Internal("Vault actor error"))
+                Err(Error::internal("Vault actor error"))
             }
         }
     }
@@ -219,7 +221,7 @@ impl VaultGate {
             }
             Err(err) => {
                 error!(?err, "Failed to send bootstrap request to vault");
-                Err(Error::Internal("Vault error"))
+                Err(Error::internal("Vault error"))
             }
         }
     }
@@ -231,10 +233,7 @@ impl VaultGate {
             .vault
             .ask(GetState {})
             .await
-            .map_err(|err| {
+            .map_err(|_| Error::internal("failed to query vault"))?;
-                error!(?err, "Failed to query vault state");
-                Error::Internal("failed to query vault")
-            })?;
 
         Ok(answer)
     }
@@ -253,10 +252,7 @@ impl Message<events::Bootstrapped> for VaultGate {
                 .db
                 .get()
                 .await
-                .map_err(|err| {
+                .map_err(|_| Error::internal("DB unavailable"))?;
-                    error!(error = %crate::utils::error_chain(&err), "DB unavailable on bootstrap");
-                    Error::Internal("DB unavailable")
-                })?;
             integrity::sign_entity(
                 &mut conn,
                 &self.actors.vault,
@@ -264,12 +260,9 @@ impl Message<events::Bootstrapped> for VaultGate {
                 self.auth_creds.id,
             )
             .await
-            .map_err(|err| {
+            .map_err(|e| {
-                error!(
+                error!(?e, "Failed to sign integrity envelope on bootstrap");
-                    error = %crate::utils::error_chain(&err),
+                Error::internal("Integrity sign failed")
-                    "Failed to sign integrity envelope on bootstrap"
-                );
-                Error::Internal("Integrity sign failed")
             })?;
             Ok(())
         }

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

@@ -14,47 +14,3 @@ impl<F: FnOnce()> Drop for DeferClosure<F> {
 pub fn defer<F: FnOnce()>(f: F) -> impl Drop + Sized {
     DeferClosure { f: Some(f) }
 }
-
-/// Renders an error together with its full `source` chain as `outer: inner: root`.
-///
-/// Error variants in this crate deliberately keep `Display` terse so that no
-/// internal detail can leak across the gRPC boundary. That same terseness would
-/// hide the cause in the logs, so use this for `tracing` fields, never in a
-/// wire payload.
-pub fn error_chain(err: &dyn core::error::Error) -> String {
-    let mut out = err.to_string();
-    let mut current = err.source();
-    while let Some(source) = current {
-        out.push_str(": ");
-        out.push_str(&source.to_string());
-        current = source.source();
-    }
-    out
-}
-
-#[cfg(test)]
-mod tests {
-    use super::error_chain;
-
-    #[derive(Debug, thiserror::Error)]
-    #[error("root")]
-    struct Root;
-
-    #[derive(Debug, thiserror::Error)]
-    #[error("middle")]
-    struct Middle(#[source] Root);
-
-    #[derive(Debug, thiserror::Error)]
-    #[error("outer")]
-    struct Outer(#[source] Middle);
-
-    #[test]
-    fn walks_the_whole_source_chain() {
-        assert_eq!(error_chain(&Root), "root", "a leaf error renders alone");
-        assert_eq!(
-            error_chain(&Outer(Middle(Root))),
-            "outer: middle: root",
-            "every source link must appear, in order"
-        );
-    }
-}