feat(integrity): derive-like macro VerifiedFields that allows to inherit Verified<T> type's provenance to all fields of T

Reviewed-on: #77

server/Cargo.lock

@@ -742,8 +742,10 @@ dependencies = [
  "insta",
  "k256",
  "kameo",
+ "macro_rules_attribute",
  "memsafe",
  "mutants",
+ "paste",
  "pem",
  "proptest",
  "prost",
@@ -760,6 +762,7 @@ dependencies = [
  "smlang",
  "spki",
  "strum 0.28.0",
+ "subtle",
  "test-log",
  "thiserror 2.0.18",
  "tokio",
@@ -3056,6 +3059,22 @@ dependencies = [
  "syn 2.0.117",
 ]
 
+[[package]]
+name = "macro_rules_attribute"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "65049d7923698040cd0b1ddcced9b0eb14dd22c5f86ae59c3740eab64a676520"
+dependencies = [
+ "macro_rules_attribute-proc_macro",
+ "paste",
+]
+
+[[package]]
+name = "macro_rules_attribute-proc_macro"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "670fdfda89751bc4a84ac13eaa63e205cf0fd22b4c9a5fbfa085b63c1f1d3a30"
+
 [[package]]
 name = "matchers"
 version = "0.2.0"

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

@@ -59,6 +59,10 @@ pub struct ArbiterEvmWallet {
 }
 
 impl ArbiterEvmWallet {
+    #[expect(
+        dead_code,
+        reason = "constructor may be used in future extensions, e.g. to support wallet listing"
+    )]
     pub(crate) fn new(transport: Arc<Mutex<ClientTransport>>, address: Address) -> Self {
         Self {
             transport,

server/crates/arbiter-server/Cargo.toml

@@ -60,6 +60,9 @@ arbiter-tokens-registry.path = "../arbiter-tokens-registry"
 anyhow = "1.0.102"
 serde_with = "3.18.0"
 mutants.workspace = true
+subtle = "2.6.1"
+macro_rules_attribute = "0.2.2"
+paste = "1.0.15"
 
 [dev-dependencies]
 insta = "1.46.3"

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

@@ -4,6 +4,7 @@ use diesel_async::RunQueryDsl;
 use kameo::{Actor, messages};
 
 use rand::{RngExt, distr::Alphanumeric, make_rng, rngs::StdRng};
+use subtle::ConstantTimeEq as _;
 use thiserror::Error;
 
 use crate::db::{self, DatabasePool, schema};
@@ -44,14 +45,14 @@ pub struct Bootstrapper {
 
 impl Bootstrapper {
     pub async fn new(db: &DatabasePool) -> Result<Self, Error> {
+        let row_count: i64 = {
             let mut conn = db.get().await?;
 
-        let row_count: i64 = schema::useragent_client::table
+            schema::useragent_client::table
                 .count()
                 .get_result(&mut conn)
-            .await?;
-
-        drop(conn);
+                .await?
+        };
 
         let token = if row_count == 0 {
             let token = generate_token().await?;
@@ -69,7 +70,13 @@ impl Bootstrapper {
     #[message]
     pub fn is_correct_token(&self, token: String) -> bool {
         match &self.token {
-            Some(expected) => *expected == token,
+            Some(expected) => {
+                let expected_bytes = expected.as_bytes();
+                let token_bytes = token.as_bytes();
+
+                let choice = expected_bytes.ct_eq(token_bytes);
+                bool::from(choice)
+            }
             None => false,
         }
     }

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

@@ -9,14 +9,16 @@ use diesel::{
 };
 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, Verified, verified::VerifiedFieldsAccessor},
     db::{
         self,
         models::{ProgramClientMetadata, SqliteTimestamp},
@@ -30,6 +32,8 @@ pub enum Error {
     DatabasePoolUnavailable,
     #[error("Database operation failed")]
     DatabaseOperationFailed,
+    #[error("Integrity check failed")]
+    IntegrityCheckFailed,
     #[error("Invalid challenge solution")]
     InvalidChallengeSolution,
     #[error("Client approval request failed")]
@@ -38,6 +42,13 @@ pub enum Error {
     Transport,
 }
 
+impl From<diesel::result::Error> for Error {
+    fn from(e: diesel::result::Error) -> Self {
+        error!(?e, "Database error");
+        Self::DatabaseOperationFailed
+    }
+}
+
 #[derive(thiserror::Error, Debug, Clone, PartialEq, Eq)]
 pub enum ApproveError {
     #[error("Internal error")]
@@ -65,17 +76,36 @@ pub enum Outbound {
     AuthSuccess,
 }
 
-pub struct ClientInfo {
-    pub id: i32,
-    pub current_nonce: i32,
-}
-
-/// 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> {
+) -> Result<Option<(i32, i32)>, Error> {
+    let pubkey_bytes = pubkey.as_bytes().to_vec();
+    let mut conn = db.get().await.map_err(|e| {
+        error!(error = ?e, "Database pool error");
+        Error::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");
+            Error::DatabaseOperationFailed
+        })
+}
+
+/// 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: &VerifyingKey,
+) -> Result<i32, Error> {
     let pubkey_bytes = pubkey.as_bytes().to_vec();
 
     let mut conn = db.get().await.map_err(|e| {
@@ -84,34 +114,35 @@ async fn get_client_and_nonce(
     })?;
 
     conn.exclusive_transaction(|conn| {
+        let keyholder = keyholder.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,
+                    nonce: new_nonce,
+                },
+                id,
+            )
+            .await
+            .map_err(|e| {
+                error!(?e, "Integrity sign failed after nonce update");
+                Error::DatabaseOperationFailed
+            })?
+            .drop_verification_provenance();
+
+            Ok(new_nonce)
         })
     })
     .await
-    .map_err(|e| {
-        error!(error = ?e, "Database error");
-        Error::DatabaseOperationFailed
-    })
 }
 
 async fn approve_new_client(
@@ -139,15 +170,23 @@ async fn approve_new_client(
 
 async fn insert_client(
     db: &db::DatabasePool,
+    keyholder: &ActorRef<KeyHolder>,
     pubkey: &VerifyingKey,
     metadata: &ClientMetadata,
-) -> Result<i32, Error> {
+) -> Result<Verified<i32>, Error> {
     use crate::db::schema::{client_metadata, program_client};
+    let metadata = metadata.clone();
+
     let mut conn = db.get().await.map_err(|e| {
         error!(error = ?e, "Database pool error");
         Error::DatabasePoolUnavailable
     })?;
 
+    conn.exclusive_transaction(|conn| {
+        let keyholder = keyholder.clone();
+        Box::pin(async move {
+            const NONCE_START: i32 = 1;
+
             let metadata_id = insert_into(client_metadata::table)
                 .values((
                     client_metadata::name.eq(&metadata.name),
@@ -155,29 +194,39 @@ async fn insert_client(
                     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
-        })?;
+                .get_result::<i32>(conn)
+                .await?;
 
             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
+                    program_client::nonce.eq(NONCE_START),
                 ))
                 .on_conflict_do_nothing()
                 .returning(program_client::id)
-        .get_result::<i32>(&mut conn)
+                .get_result::<i32>(conn)
+                .await?;
+
+            let verified_id = integrity::sign_entity(
+                conn,
+                &keyholder,
+                &ClientCredentials {
+                    pubkey: *pubkey,
+                    nonce: NONCE_START,
+                },
+                client_id,
+            )
             .await
             .map_err(|e| {
-            error!(error = ?e, "Failed to insert client metadata");
+                error!(error = ?e, "Failed to sign integrity tag for new client key");
                 Error::DatabaseOperationFailed
             })?;
 
-    Ok(client_id)
+            Ok(verified_id)
+        })
+    })
+    .await
 }
 
 async fn sync_client_metadata(
@@ -287,7 +336,10 @@ where
     Ok(())
 }
 
-pub async fn authenticate<T>(props: &mut ClientConnection, transport: &mut T) -> Result<i32, Error>
+pub async fn authenticate<T>(
+    props: &mut ClientConnection,
+    transport: &mut T,
+) -> Result<Verified<i32>, Error>
 where
     T: Bi<Inbound, Result<Outbound, Error>> + Send + ?Sized,
 {
@@ -295,8 +347,28 @@ where
         return Err(Error::Transport);
     };
 
-    let info = match get_client_and_nonce(&props.db, &pubkey).await? {
-        Some(nonce) => nonce,
+    // fixme! triage needed: probable regretion since in match->Some get_current_nonce_and_id called only once instead of twice
+    let client_id = match get_current_nonce_and_id(&props.db, &pubkey).await? {
+        Some((nonce, id)) => {
+            let mut db_conn = props.db.get().await.map_err(|e| {
+                error!(error = ?e, "Database pool error");
+                Error::DatabasePoolUnavailable
+            })?;
+
+            integrity::verify_entity(
+                &mut db_conn,
+                &props.actors.key_holder,
+                ClientCredentials { pubkey, nonce },
+                id,
+            )
+            .await
+            .map_err(|e| {
+                error!(?e, "Integrity verification failed");
+                Error::IntegrityCheckFailed
+            })?
+            .inherit()
+            .entity_id
+        }
         None => {
             approve_new_client(
                 &props.actors,
@@ -306,16 +378,13 @@ where
                 },
             )
             .await?;
-            let client_id = insert_client(&props.db, &pubkey, &metadata).await?;
-            ClientInfo {
-                id: client_id,
-                current_nonce: 0,
-            }
+            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))
@@ -325,5 +394,5 @@ where
             Error::Transport
         })?;
 
-    Ok(info.id)
+    Ok(client_id)
 }

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

@@ -4,6 +4,7 @@ use tracing::{error, info};
 
 use crate::{
     actors::{GlobalActors, client::session::ClientSession},
+    crypto::integrity::{Integrable, hashing::Hashable},
     db,
 };
 
@@ -13,6 +14,22 @@ pub struct ClientProfile {
     pub metadata: ClientMetadata,
 }
 
+pub struct ClientCredentials {
+    pub pubkey: ed25519_dalek::VerifyingKey,
+    pub nonce: i32,
+}
+
+impl Integrable for ClientCredentials {
+    const KIND: &'static str = "client_credentials";
+}
+
+impl Hashable for ClientCredentials {
+    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
+        hasher.update(self.pubkey.as_bytes());
+        self.nonce.hash(hasher);
+    }
+}
+
 pub struct ClientConnection {
     pub(crate) db: db::DatabasePool,
     pub(crate) actors: GlobalActors,

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

@@ -5,23 +5,25 @@ use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
 
 use crate::{
     actors::{
-        GlobalActors,
         client::ClientConnection,
         evm::{ClientSignTransaction, SignTransactionError},
         flow_coordinator::RegisterClient,
         keyholder::KeyHolderState,
     },
-    db,
+    crypto::integrity::Verified,
     evm::VetError,
 };
 
+#[cfg(test)]
+use crate::{actors::GlobalActors, db};
+
 pub struct ClientSession {
     props: ClientConnection,
-    client_id: i32,
+    client_id: Verified<i32>,
 }
 
 impl ClientSession {
-    pub(crate) fn new(props: ClientConnection, client_id: i32) -> Self {
+    pub(crate) fn new(props: ClientConnection, client_id: Verified<i32>) -> Self {
         Self { props, client_id }
     }
 }
@@ -54,7 +56,7 @@ impl ClientSession {
             .actors
             .evm
             .ask(ClientSignTransaction {
-                client_id: self.client_id,
+                client_id: *self.client_id,
                 wallet_address,
                 transaction,
             })
@@ -92,11 +94,12 @@ impl Actor for ClientSession {
 }
 
 impl ClientSession {
+    #[cfg(test)]
     pub fn new_test(db: db::DatabasePool, actors: GlobalActors) -> Self {
         let props = ClientConnection::new(db, actors);
         Self {
             props,
-            client_id: 0,
+            client_id: Verified::new_unchecked(0),
         }
     }
 }

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

@@ -7,11 +7,11 @@ use kameo::{Actor, actor::ActorRef, messages};
 use rand::{SeedableRng, rng, rngs::StdRng};
 
 use crate::{
-    actors::keyholder::{CreateNew, Decrypt, GetState, KeyHolder, KeyHolderState},
-    crypto::integrity,
+    actors::keyholder::{CreateNew, Decrypt, KeyHolder},
+    crypto::integrity::{self, Integrable, Verified, hashing::Hashable},
     db::{
         DatabaseError, DatabasePool,
-        models::{self, SqliteTimestamp},
+        models::{self},
         schema,
     },
     evm::{
@@ -26,11 +26,37 @@ use crate::{
 
 pub use crate::evm::safe_signer;
 
+/// Hashable structure for wallet integrity protection.
+/// Binds the encrypted private key to the wallet address using HMAC.
+pub struct EvmWalletIntegrity {
+    pub address: Vec<u8>,       // 20-byte Ethereum address
+    pub aead_encrypted_id: i32, // Reference to encrypted key material
+}
+
+impl Hashable for EvmWalletIntegrity {
+    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
+        hasher.update(&self.address);
+        hasher.update(self.aead_encrypted_id.to_be_bytes());
+    }
+}
+
+impl Integrable for EvmWalletIntegrity {
+    const KIND: &'static str = "evm_wallet";
+}
+
 #[derive(Debug, thiserror::Error)]
 pub enum SignTransactionError {
     #[error("Wallet not found")]
     WalletNotFound,
 
+    #[error("Wallet integrity check failed")]
+    WalletIntegrityCheckFailed,
+
+    #[error(
+        "Decrypted key does not correspond to wallet address (CRITICAL: possible key substitution attack)"
+    )]
+    KeyAddressMismatch,
+
     #[error("Database error: {0}")]
     Database(#[from] DatabaseError),
 
@@ -45,6 +71,9 @@ pub enum SignTransactionError {
 
     #[error("Policy error: {0}")]
     Vet(#[from] evm::VetError),
+
+    #[error("Integrity error: {0}")]
+    Integrity(#[from] integrity::Error),
 }
 
 #[derive(Debug, thiserror::Error)]
@@ -88,7 +117,7 @@ impl EvmActor {
 #[messages]
 impl EvmActor {
     #[message]
-    pub async fn generate(&mut self) -> Result<(i32, Address), Error> {
+    pub async fn generate(&mut self) -> Result<(Verified<i32>, Address), Error> {
         let (mut key_cell, address) = safe_signer::generate(&mut self.rng);
 
         let plaintext = key_cell.read_inline(|reader| SafeCell::new(reader.to_vec()));
@@ -110,7 +139,16 @@ impl EvmActor {
             .await
             .map_err(DatabaseError::from)?;
 
-        Ok((wallet_id, address))
+        // Sign integrity envelope to bind encrypted key to wallet address
+        let wallet_integrity = EvmWalletIntegrity {
+            address: address.as_slice().to_vec(),
+            aead_encrypted_id: aead_id,
+        };
+        let verified_wallet_id =
+            integrity::sign_entity(&mut conn, &self.keyholder, &wallet_integrity, wallet_id)
+                .await?;
+
+        Ok((verified_wallet_id, address))
     }
 
     #[message]
@@ -136,7 +174,7 @@ impl EvmActor {
         &mut self,
         basic: SharedGrantSettings,
         grant: SpecificGrant,
-    ) -> Result<i32, Error> {
+    ) -> Result<integrity::Verified<i32>, Error> {
         match grant {
             SpecificGrant::EtherTransfer(settings) => self
                 .engine
@@ -158,7 +196,7 @@ impl EvmActor {
     }
 
     #[message]
-    pub async fn useragent_delete_grant(&mut self, grant_id: i32) -> Result<(), Error> {
+    pub async fn useragent_delete_grant(&mut self, _grant_id: i32) -> Result<(), Error> {
         // let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
         // let keyholder = self.keyholder.clone();
 
@@ -207,9 +245,23 @@ impl EvmActor {
             .optional()
             .map_err(DatabaseError::from)?
             .ok_or(SignTransactionError::WalletNotFound)?;
+
+        // Verify wallet integrity envelope
+        let wallet = integrity::verify_entity(
+            &mut conn,
+            &self.keyholder,
+            EvmWalletIntegrity {
+                address: wallet.address.clone(),
+                aead_encrypted_id: wallet.aead_encrypted_id,
+            },
+            wallet.id,
+        )
+        .await
+        .map_err(|_| SignTransactionError::WalletIntegrityCheckFailed)?;
+
         let wallet_access = schema::evm_wallet_access::table
             .select(models::EvmWalletAccess::as_select())
-            .filter(schema::evm_wallet_access::wallet_id.eq(wallet.id))
+            .filter(schema::evm_wallet_access::wallet_id.eq(wallet.entity_id))
             .filter(schema::evm_wallet_access::client_id.eq(client_id))
             .first(&mut conn)
             .await
@@ -242,9 +294,23 @@ impl EvmActor {
             .optional()
             .map_err(DatabaseError::from)?
             .ok_or(SignTransactionError::WalletNotFound)?;
+
+        // Verify wallet integrity envelope to ensure encrypted key is bound to address
+        let wallet = integrity::verify_entity(
+            &mut conn,
+            &self.keyholder,
+            EvmWalletIntegrity {
+                address: wallet.address.clone(),
+                aead_encrypted_id: wallet.aead_encrypted_id,
+            },
+            wallet.id,
+        )
+        .await
+        .map_err(|_| SignTransactionError::WalletIntegrityCheckFailed)?;
+
         let wallet_access = schema::evm_wallet_access::table
             .select(models::EvmWalletAccess::as_select())
-            .filter(schema::evm_wallet_access::wallet_id.eq(wallet.id))
+            .filter(schema::evm_wallet_access::wallet_id.eq(wallet.entity_id))
             .filter(schema::evm_wallet_access::client_id.eq(client_id))
             .first(&mut conn)
             .await
@@ -263,6 +329,12 @@ impl EvmActor {
 
         let signer = safe_signer::SafeSigner::from_cell(raw_key)?;
 
+        // Verify that the decrypted key's derived address matches the wallet address
+        // This prevents an attacker from substituting one wallet's key with another's even if they compromised the DB
+        if signer.address() != wallet_address {
+            return Err(SignTransactionError::KeyAddressMismatch);
+        }
+
         self.engine
             .evaluate_transaction(wallet_access, transaction.clone(), RunKind::Execution)
             .await?;

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

@@ -30,17 +30,26 @@ pub enum Error {
 }
 
 impl Error {
-    fn internal(details: impl Into<String>) -> Self {
-        Self::Internal {
-            details: details.into(),
-        }
+    #[track_caller]
+    pub(super) fn internal(details: impl Into<String>, err: &impl std::fmt::Debug) -> Self {
+        let details = details.into();
+        let caller = std::panic::Location::caller();
+        error!(
+            caller_file = %caller.file(),
+            caller_line = caller.line(),
+            caller_column = caller.column(),
+            details = %details,
+            error = ?err,
+            "Internal error"
+        );
+
+        Self::Internal { details }
     }
 }
 
 impl From<diesel::result::Error> for Error {
     fn from(e: diesel::result::Error) -> Self {
-        error!(?e, "Database error");
-        Self::internal("Database error")
+        Self::internal("Database error", &e)
     }
 }
 

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

@@ -1,7 +1,7 @@
 use arbiter_proto::transport::Bi;
 use diesel::{ExpressionMethods as _, OptionalExtension as _, QueryDsl, update};
 use diesel_async::{AsyncConnection, RunQueryDsl};
-use kameo::{actor::ActorRef, error::SendError};
+use kameo::actor::ActorRef;
 use tracing::error;
 
 use super::Error;
@@ -11,7 +11,7 @@ use crate::{
         keyholder::KeyHolder,
         user_agent::{AuthPublicKey, UserAgentConnection, UserAgentCredentials, auth::Outbound},
     },
-    crypto::integrity::{self, AttestationStatus},
+    crypto::integrity,
     db::{DatabasePool, schema::useragent_client},
 };
 
@@ -48,10 +48,10 @@ async fn get_current_nonce_and_id(
     db: &DatabasePool,
     key: &AuthPublicKey,
 ) -> Result<(i32, i32), Error> {
-    let mut db_conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        Error::internal("Database unavailable")
-    })?;
+    let mut db_conn = db
+        .get()
+        .await
+        .map_err(|e| Error::internal("Database unavailable", &e))?;
     db_conn
         .exclusive_transaction(|conn| {
             Box::pin(async move {
@@ -65,10 +65,7 @@ async fn get_current_nonce_and_id(
         })
         .await
         .optional()
-        .map_err(|e| {
-            error!(error = ?e, "Database error");
-            Error::internal("Database operation failed")
-        })?
+        .map_err(|e| Error::internal("Database operation failed", &e))?
         .ok_or_else(|| {
             error!(?key, "Public key not found in database");
             Error::UnregisteredPublicKey
@@ -80,14 +77,14 @@ async fn verify_integrity(
     keyholder: &ActorRef<KeyHolder>,
     pubkey: &AuthPublicKey,
 ) -> Result<(), Error> {
-    let mut db_conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        Error::internal("Database unavailable")
-    })?;
+    let mut db_conn = db
+        .get()
+        .await
+        .map_err(|e| Error::internal("Database unavailable", &e))?;
 
     let (id, nonce) = get_current_nonce_and_id(db, pubkey).await?;
 
-    let result = integrity::verify_entity(
+    let attestation_status = integrity::check_entity_attestation(
         &mut db_conn,
         keyholder,
         &UserAgentCredentials {
@@ -97,12 +94,17 @@ async fn verify_integrity(
         id,
     )
     .await
-    .map_err(|e| {
-        error!(?e, "Integrity verification failed");
-        Error::internal("Integrity verification failed")
-    })?;
+    .map_err(|e| Error::internal("Integrity verification failed", &e))?;
 
-    Ok(())
+    use integrity::AttestationStatus as AS;
+    // SAFETY (policy): challenge auth must work in both vault states.
+    // While sealed, integrity checks can only report `Unavailable` because key material is not
+    // accessible. While unsealed, the same check can report `Attested`.
+    // This path intentionally accepts both outcomes to keep challenge auth available across state
+    // transitions; stricter verification is enforced in sensitive post-auth flows.
+    match attestation_status {
+        AS::Attested | AS::Unavailable => Ok(()),
+    }
 }
 
 async fn create_nonce(
@@ -110,10 +112,10 @@ async fn create_nonce(
     keyholder: &ActorRef<KeyHolder>,
     pubkey: &AuthPublicKey,
 ) -> Result<i32, Error> {
-    let mut db_conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        Error::internal("Database unavailable")
-    })?;
+    let mut db_conn = db
+        .get()
+        .await
+        .map_err(|e| Error::internal("Database unavailable", &e))?;
     let new_nonce = db_conn
         .exclusive_transaction(|conn| {
             Box::pin(async move {
@@ -124,10 +126,7 @@ async fn create_nonce(
                     .returning((useragent_client::id, useragent_client::nonce))
                     .get_result(conn)
                     .await
-                    .map_err(|e| {
-                        error!(error = ?e, "Database error");
-                        Error::internal("Database operation failed")
-                    })?;
+                    .map_err(|e| Error::internal("Database operation failed", &e))?;
 
                 integrity::sign_entity(
                     conn,
@@ -139,10 +138,8 @@ async fn create_nonce(
                     id,
                 )
                 .await
-                .map_err(|e| {
-                    error!(?e, "Integrity signature update failed");
-                    Error::internal("Database error")
-                })?;
+                .map_err(|e| Error::internal("Database error", &e))?
+                .drop_verification_provenance();
 
                 Result::<_, Error>::Ok(new_nonce)
             })
@@ -158,10 +155,10 @@ async fn register_key(
 ) -> Result<(), Error> {
     let pubkey_bytes = pubkey.to_stored_bytes();
     let key_type = pubkey.key_type();
-    let mut conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        Error::internal("Database unavailable")
-    })?;
+    let mut conn = db
+        .get()
+        .await
+        .map_err(|e| Error::internal("Database unavailable", &e))?;
 
     conn.transaction(|conn| {
         Box::pin(async move {
@@ -176,22 +173,32 @@ async fn register_key(
                 .returning(useragent_client::id)
                 .get_result(conn)
                 .await
-                .map_err(|e| {
-                    error!(error = ?e, "Database error");
-                    Error::internal("Database operation failed")
-                })?;
+                .map_err(|e| Error::internal("Database operation failed", &e))?;
 
-            let entity = UserAgentCredentials {
+            if let Err(e) = integrity::sign_entity(
+                conn,
+                keyholder,
+                &UserAgentCredentials {
                     pubkey: pubkey.clone(),
                     nonce: NONCE_START,
-            };
-
-            integrity::sign_entity(conn, &keyholder, &entity, id)
+                },
+                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")
-                })?;
+            {
+                match e {
+                    integrity::Error::Keyholder(
+                        crate::actors::keyholder::Error::NotBootstrapped,
+                    ) => {
+                        // IMPORTANT: bootstrap-token auth must work before the vault has a root key.
+                        // We intentionally allow creating the DB row first and backfill envelopes
+                        // after bootstrap/unseal to keep the bootstrap flow possible.
+                    }
+                    other => {
+                        return Err(Error::internal("Failed to register public key", &other));
+                    }
+                }
+            }
 
             Result::<_, Error>::Ok(())
         })
@@ -254,10 +261,7 @@ where
                 token: token.clone(),
             })
             .await
-            .map_err(|e| {
-                error!(?e, "Failed to consume bootstrap token");
-                Error::internal("Failed to consume bootstrap token")
-            })?;
+            .map_err(|e| Error::internal("Failed to consume bootstrap token", &e))?;
 
         if !token_ok {
             error!("Invalid bootstrap token provided");

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

@@ -108,7 +108,7 @@ use crate::crypto::integrity::hashing::Hashable;
 
 impl Hashable for AuthPublicKey {
     fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
-        hasher.update(&self.to_stored_bytes());
+        hasher.update(self.to_stored_bytes());
     }
 }
 

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

@@ -10,7 +10,6 @@ use kameo::prelude::Context;
 use tracing::{error, info};
 use x25519_dalek::{EphemeralSecret, PublicKey};
 
-use crate::actors::flow_coordinator::client_connect_approval::ClientApprovalAnswer;
 use crate::actors::keyholder::KeyHolderState;
 use crate::actors::user_agent::session::Error;
 use crate::db::models::{
@@ -18,6 +17,10 @@ use crate::db::models::{
 };
 use crate::evm::policies::{Grant, SpecificGrant};
 use crate::safe_cell::SafeCell;
+use crate::{
+    actors::flow_coordinator::client_connect_approval::ClientApprovalAnswer,
+    crypto::integrity::{self, Verified},
+};
 use crate::{
     actors::{
         evm::{
@@ -29,11 +32,67 @@ use crate::{
             UserAgentSession,
             state::{UnsealContext, UserAgentEvents, UserAgentStates},
         },
+        user_agent::{AuthPublicKey, UserAgentCredentials},
     },
+    db::schema::useragent_client,
     safe_cell::SafeCellHandle as _,
 };
 
+fn is_vault_sealed_from_evm<M>(err: &SendError<M, crate::actors::evm::Error>) -> bool {
+    matches!(
+        err,
+        SendError::HandlerError(crate::actors::evm::Error::Keyholder(
+            keyholder::Error::NotBootstrapped
+        )) | SendError::HandlerError(crate::actors::evm::Error::Integrity(
+            crate::crypto::integrity::Error::Keyholder(keyholder::Error::NotBootstrapped)
+        ))
+    )
+}
+
 impl UserAgentSession {
+    async fn backfill_useragent_integrity(&self) -> Result<(), Error> {
+        let mut conn = self.props.db.get().await?;
+        let keyholder = self.props.actors.key_holder.clone();
+
+        conn.transaction(|conn| {
+            Box::pin(async move {
+                let rows: Vec<(i32, i32, Vec<u8>, crate::db::models::KeyType)> =
+                    useragent_client::table
+                        .select((
+                            useragent_client::id,
+                            useragent_client::nonce,
+                            useragent_client::public_key,
+                            useragent_client::key_type,
+                        ))
+                        .load(conn)
+                        .await?;
+
+                for (id, nonce, public_key, key_type) in rows {
+                    let pubkey = AuthPublicKey::try_from((key_type, public_key)).map_err(|e| {
+                        Error::internal(format!("Invalid user-agent key in db: {e}"))
+                    })?;
+
+                    integrity::sign_entity(
+                        conn,
+                        &keyholder,
+                        &UserAgentCredentials { pubkey, nonce },
+                        id,
+                    )
+                    .await
+                    .map_err(|e| {
+                        Error::internal(format!("Failed to backfill user-agent integrity: {e}"))
+                    })?
+                    .drop_verification_provenance();
+                }
+
+                Result::<_, Error>::Ok(())
+            })
+        })
+        .await?;
+
+        Ok(())
+    }
+
     fn take_unseal_secret(&mut self) -> Result<(EphemeralSecret, PublicKey), Error> {
         let UserAgentStates::WaitingForUnsealKey(unseal_context) = self.state.state() else {
             error!("Received encrypted key in invalid state");
@@ -191,6 +250,7 @@ impl UserAgentSession {
             .await
         {
             Ok(_) => {
+                self.backfill_useragent_integrity().await?;
                 info!("Successfully unsealed key with client-provided key");
                 self.transition(UserAgentEvents::ReceivedValidKey)?;
                 Ok(())
@@ -252,6 +312,7 @@ impl UserAgentSession {
             .await
         {
             Ok(_) => {
+                self.backfill_useragent_integrity().await?;
                 info!("Successfully bootstrapped vault with client-provided key");
                 self.transition(UserAgentEvents::ReceivedValidKey)?;
                 Ok(())
@@ -297,7 +358,9 @@ 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<(Verified<i32>, Address), Error> {
         match self.props.actors.evm.ask(Generate {}).await {
             Ok(address) => Ok(address),
             Err(SendError::HandlerError(err)) => Err(Error::internal(format!(
@@ -325,12 +388,15 @@ 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>>, GrantMutationError> {
         match self.props.actors.evm.ask(UseragentListGrants {}).await {
             Ok(grants) => Ok(grants),
+            Err(err) if is_vault_sealed_from_evm(&err) => Err(GrantMutationError::VaultSealed),
             Err(err) => {
                 error!(?err, "EVM grant list failed");
-                Err(Error::internal("Failed to list EVM grants"))
+                Err(GrantMutationError::Internal)
             }
         }
     }
@@ -340,7 +406,7 @@ impl UserAgentSession {
         &mut self,
         basic: crate::evm::policies::SharedGrantSettings,
         grant: crate::evm::policies::SpecificGrant,
-    ) -> Result<i32, GrantMutationError> {
+    ) -> Result<Verified<i32>, GrantMutationError> {
         match self
             .props
             .actors
@@ -349,6 +415,7 @@ impl UserAgentSession {
             .await
         {
             Ok(grant_id) => Ok(grant_id),
+            Err(err) if is_vault_sealed_from_evm(&err) => Err(GrantMutationError::VaultSealed),
             Err(err) => {
                 error!(?err, "EVM grant create failed");
                 Err(GrantMutationError::Internal)
@@ -365,10 +432,13 @@ impl UserAgentSession {
             .props
             .actors
             .evm
-            .ask(UseragentDeleteGrant { grant_id })
+            .ask(UseragentDeleteGrant {
+                _grant_id: grant_id,
+            })
             .await
         {
             Ok(()) => Ok(()),
+            Err(err) if is_vault_sealed_from_evm(&err) => Err(GrantMutationError::VaultSealed),
             Err(err) => {
                 error!(?err, "EVM grant delete failed");
                 Err(GrantMutationError::Internal)

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

@@ -1,8 +1,9 @@
-use crate::{
-    actors::keyholder, crypto::integrity::hashing::Hashable, safe_cell::SafeCellHandle as _,
-};
-use hmac::{Hmac, Mac as _};
+use crate::actors::keyholder;
+use hmac::Hmac;
 use sha2::Sha256;
+use std::future::Future;
+use std::ops::Deref;
+use std::pin::Pin;
 
 use diesel::{ExpressionMethods as _, QueryDsl, dsl::insert_into, sqlite::Sqlite};
 use diesel_async::{AsyncConnection, RunQueryDsl};
@@ -10,16 +11,24 @@ use kameo::{actor::ActorRef, error::SendError};
 use sha2::Digest as _;
 
 pub mod hashing;
+pub mod verified;
+use self::hashing::Hashable;
 
 use crate::{
     actors::keyholder::{KeyHolder, SignIntegrity, VerifyIntegrity},
     db::{
         self,
-        models::{IntegrityEnvelope, NewIntegrityEnvelope},
+        models::{IntegrityEnvelope as IntegrityEnvelopeRow, NewIntegrityEnvelope},
         schema::integrity_envelope,
     },
 };
 
+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 use self::verified::Verified;
+
 #[derive(Debug, thiserror::Error)]
 pub enum Error {
     #[error("Database error: {0}")]
@@ -48,71 +57,90 @@ pub enum Error {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[must_use]
 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()
+impl<T: Integrable> Integrable for &T {
+    const KIND: &'static str = T::KIND;
+    const VERSION: i32 = T::VERSION;
 }
 
-fn push_len_prefixed(out: &mut Vec<u8>, bytes: &[u8]) {
-    out.extend_from_slice(&(bytes.len() as u32).to_be_bytes());
-    out.extend_from_slice(bytes);
-}
+#[derive(Debug, Clone)]
+pub struct EntityId(Vec<u8>);
 
-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
-}
+impl Deref for EntityId {
+    type Target = [u8];
 
-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()
+    fn deref(&self) -> &Self::Target {
+        &self.0
     }
 }
 
-impl IntoId for &'_ [u8] {
-    fn into_id(self) -> Vec<u8> {
-        self.to_vec()
+impl From<i32> for EntityId {
+    fn from(value: i32) -> Self {
+        Self(value.to_be_bytes().to_vec())
     }
 }
 
-pub async fn sign_entity<E: Integrable>(
+impl From<&'_ [u8]> for EntityId {
+    fn from(bytes: &'_ [u8]) -> Self {
+        Self(bytes.to_vec())
+    }
+}
+
+pub async fn lookup_verified<E, Id, C, F, Fut>(
+    conn: &mut C,
+    keyholder: &ActorRef<KeyHolder>,
+    entity_id: Id,
+    load: F,
+) -> Result<Verified<Entity<E, Id>>, Error>
+where
+    C: AsyncConnection<Backend = Sqlite>,
+    E: Integrable,
+    Id: Into<EntityId> + Clone,
+    F: FnOnce(&mut C) -> Fut,
+    Fut: Future<Output = Result<E, db::DatabaseError>>,
+{
+    let entity = load(conn).await?;
+    verify_entity(conn, keyholder, entity, entity_id).await
+}
+
+pub async fn lookup_verified_from_query<E, Id, C, F>(
+    conn: &mut C,
+    keyholder: &ActorRef<KeyHolder>,
+    load: F,
+) -> Result<Verified<Entity<E, Id>>, Error>
+where
+    C: AsyncConnection<Backend = Sqlite> + Send,
+    E: Integrable,
+    Id: Into<EntityId> + Clone,
+    F: for<'a> FnOnce(
+        &'a mut C,
+    ) -> Pin<
+        Box<dyn Future<Output = Result<(Id, E), db::DatabaseError>> + Send + 'a>,
+    >,
+{
+    let (entity_id, entity) = load(conn).await?;
+    verify_entity(conn, keyholder, entity, entity_id).await
+}
+
+pub async fn sign_entity<E: Integrable, Id: Into<EntityId> + Clone>(
     conn: &mut impl AsyncConnection<Backend = Sqlite>,
     keyholder: &ActorRef<KeyHolder>,
     entity: &E,
-    entity_id: impl IntoId,
-) -> Result<(), Error> {
-    let payload_hash = payload_hash(&entity);
+    as_entity_id: Id,
+) -> Result<Verified<Id>, Error> {
+    let payload_hash = payload_hash(entity);
 
-    let entity_id = entity_id.into_id();
+    let entity_id = as_entity_id.clone().into();
 
     let mac_input = build_mac_input(E::KIND, &entity_id, E::VERSION, &payload_hash);
 
@@ -127,7 +155,7 @@ pub async fn sign_entity<E: Integrable>(
     insert_into(integrity_envelope::table)
         .values(NewIntegrityEnvelope {
             entity_kind: E::KIND.to_owned(),
-            entity_id: entity_id,
+            entity_id: entity_id.to_vec(),
             payload_version: E::VERSION,
             key_version,
             mac: mac.to_vec(),
@@ -146,19 +174,19 @@ pub async fn sign_entity<E: Integrable>(
         .await
         .map_err(db::DatabaseError::from)?;
 
-    Ok(())
+    Ok(Verified::new(as_entity_id))
 }
 
-pub async fn verify_entity<E: Integrable>(
+pub async fn check_entity_attestation<E: Integrable>(
     conn: &mut impl AsyncConnection<Backend = Sqlite>,
     keyholder: &ActorRef<KeyHolder>,
     entity: &E,
-    entity_id: impl IntoId,
+    entity_id: impl Into<EntityId>,
 ) -> Result<AttestationStatus, Error> {
-    let entity_id = entity_id.into_id();
-    let envelope: IntegrityEnvelope = integrity_envelope::table
+    let entity_id = entity_id.into();
+    let envelope: IntegrityEnvelopeRow = integrity_envelope::table
         .filter(integrity_envelope::entity_kind.eq(E::KIND))
-        .filter(integrity_envelope::entity_id.eq(&entity_id))
+        .filter(integrity_envelope::entity_id.eq(&*entity_id))
         .first(conn)
         .await
         .map_err(|err| match err {
@@ -176,7 +204,7 @@ pub async fn verify_entity<E: Integrable>(
         });
     }
 
-    let payload_hash = payload_hash(&entity);
+    let payload_hash = payload_hash(entity);
     let mac_input = build_mac_input(E::KIND, &entity_id, envelope.payload_version, &payload_hash);
 
     let result = keyholder
@@ -199,139 +227,87 @@ pub async fn verify_entity<E: Integrable>(
     }
 }
 
-#[cfg(test)]
-mod tests {
-    use diesel::{ExpressionMethods as _, QueryDsl};
-    use diesel_async::RunQueryDsl;
-    use kameo::{actor::ActorRef, prelude::Spawn};
-    use rand::seq::SliceRandom;
-    use sha2::Digest;
+#[derive(Debug, Clone, crate::VerifiedFields!)]
+#[repr(C)]
+pub struct Entity<E, Id> {
+    pub entity: E,
+    pub entity_id: Id,
+}
 
-    use proptest::prelude::*;
+impl<E, Id> Deref for Entity<E, Id> {
+    type Target = E;
 
-    use crate::{
-        actors::keyholder::{Bootstrap, KeyHolder},
-        db::{self, schema},
-        safe_cell::{SafeCell, SafeCellHandle as _},
-    };
-
-    use super::{Error, Integrable, sign_entity, verify_entity};
-    use super::{hashing::Hashable, payload_hash};
-
-    #[derive(Clone)]
-    struct DummyEntity {
-        payload_version: i32,
-        payload: Vec<u8>,
-    }
-
-    impl Hashable for DummyEntity {
-        fn hash<H: Digest>(&self, hasher: &mut H) {
-            self.payload_version.hash(hasher);
-            self.payload.hash(hasher);
-        }
-    }
-    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() {
-        let db = db::create_test_pool().await;
-        let keyholder = bootstrapped_keyholder(&db).await;
-        let mut conn = db.get().await.unwrap();
-
-        const ENTITY_ID: &[u8] = b"entity-id-7";
-
-        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() {
-        let db = db::create_test_pool().await;
-        let keyholder = bootstrapped_keyholder(&db).await;
-        let mut conn = db.get().await.unwrap();
-
-        const ENTITY_ID: &[u8] = b"entity-id-11";
-
-        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, Error::MacMismatch { .. }));
-    }
-
-    #[tokio::test]
-    async fn changed_payload_fails_verification() {
-        let db = db::create_test_pool().await;
-        let keyholder = bootstrapped_keyholder(&db).await;
-        let mut conn = db.get().await.unwrap();
-
-        const ENTITY_ID: &[u8] = b"entity-id-21";
-
-        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, Error::MacMismatch { .. }));
+    fn deref(&self) -> &Self::Target {
+        &self.entity
     }
 }
+
+pub async fn verify_entity<E: Integrable, Id: Into<EntityId> + Clone>(
+    conn: &mut impl AsyncConnection<Backend = Sqlite>,
+    keyholder: &ActorRef<KeyHolder>,
+    entity: E,
+    entity_id: Id,
+) -> Result<Verified<Entity<E, Id>>, Error> {
+    match check_entity_attestation(conn, keyholder, &entity, entity_id.clone()).await? {
+        AttestationStatus::Attested => Ok(Verified::new(Entity { entity, entity_id })),
+        AttestationStatus::Unavailable => Err(Error::Keyholder(keyholder::Error::NotBootstrapped)),
+    }
+}
+
+pub async fn verify_entity_ref<'e, E: Integrable, Id: Into<EntityId> + Clone>(
+    conn: &mut impl AsyncConnection<Backend = Sqlite>,
+    keyholder: &ActorRef<KeyHolder>,
+    entity: &'e E,
+    entity_id: Id,
+) -> Result<Verified<Entity<&'e E, Id>>, Error> {
+    match check_entity_attestation(conn, keyholder, entity, entity_id.clone()).await? {
+        AttestationStatus::Attested => Ok(Verified::new(Entity { entity, entity_id })),
+        AttestationStatus::Unavailable => Err(Error::Keyholder(keyholder::Error::NotBootstrapped)),
+    }
+}
+
+pub async fn delete_envelope<E: Integrable>(
+    conn: &mut impl AsyncConnection<Backend = Sqlite>,
+    entity_id: impl Into<EntityId>,
+) -> Result<usize, Error> {
+    let entity_id = entity_id.into();
+
+    let affected = diesel::delete(
+        integrity_envelope::table
+            .filter(integrity_envelope::entity_kind.eq(E::KIND))
+            .filter(integrity_envelope::entity_id.eq(&*entity_id)),
+    )
+    .execute(conn)
+    .await
+    .map_err(db::DatabaseError::from)?;
+
+    Ok(affected)
+}
+
+fn payload_hash(payload: &impl Hashable) -> [u8; 32] {
+    let mut hasher = Sha256::new();
+    payload.hash(&mut hasher);
+    hasher.finalize().into()
+}
+
+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
+}
+
+fn push_len_prefixed(out: &mut Vec<u8>, bytes: &[u8]) {
+    out.extend_from_slice(&(bytes.len() as u32).to_be_bytes());
+    out.extend_from_slice(bytes);
+}
+
+#[cfg(test)]
+mod tests;

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

@@ -62,10 +62,10 @@ impl<T: Hashable> Hashable for Option<T> {
     fn hash<H: Digest>(&self, hasher: &mut H) {
         match self {
             Some(value) => {
-                hasher.update(&[1]);
+                hasher.update([1]);
                 value.hash(hasher);
             }
-            None => hasher.update(&[0]),
+            None => hasher.update([0]),
         }
     }
 }
@@ -96,12 +96,12 @@ impl Hashable for alloy::primitives::U256 {
 
 impl Hashable for chrono::Duration {
     fn hash<H: Digest>(&self, hasher: &mut H) {
-        hasher.update(&self.num_seconds().to_be_bytes());
+        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());
+        hasher.update(self.timestamp_millis().to_be_bytes());
     }
 }

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

@@ -0,0 +1,298 @@
+use diesel::{ExpressionMethods as _, QueryDsl};
+use diesel_async::RunQueryDsl;
+use kameo::{actor::ActorRef, prelude::Spawn};
+use sha2::Digest;
+
+use crate::{
+    actors::keyholder::{Bootstrap, KeyHolder},
+    db::{self, schema},
+    safe_cell::{SafeCell, SafeCellHandle as _},
+};
+
+use super::hashing::Hashable;
+use super::{
+    Error, Integrable, check_entity_attestation, lookup_verified, lookup_verified_from_query,
+    sign_entity, verify_entity,
+};
+
+#[derive(Clone, Debug)]
+struct DummyEntity {
+    payload_version: i32,
+    payload: Vec<u8>,
+}
+
+impl Hashable for DummyEntity {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        self.payload_version.hash(hasher);
+        self.payload.hash(hasher);
+    }
+}
+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() {
+    let db = db::create_test_pool().await;
+    let keyholder = bootstrapped_keyholder(&db).await;
+    let mut conn = db.get().await.unwrap();
+
+    const ENTITY_ID: &[u8] = b"entity-id-7";
+
+    let entity = DummyEntity {
+        payload_version: 1,
+        payload: b"payload-v1".to_vec(),
+    };
+
+    sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+        .await
+        .unwrap()
+        .drop_verification_provenance();
+
+    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");
+    let _ = check_entity_attestation(&mut conn, &keyholder, &entity, ENTITY_ID)
+        .await
+        .unwrap();
+}
+
+#[tokio::test]
+async fn tampered_mac_fails_verification() {
+    let db = db::create_test_pool().await;
+    let keyholder = bootstrapped_keyholder(&db).await;
+    let mut conn = db.get().await.unwrap();
+
+    const ENTITY_ID: &[u8] = b"entity-id-11";
+
+    let entity = DummyEntity {
+        payload_version: 1,
+        payload: b"payload-v1".to_vec(),
+    };
+
+    sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+        .await
+        .unwrap()
+        .drop_verification_provenance();
+
+    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 = check_entity_attestation(&mut conn, &keyholder, &entity, ENTITY_ID)
+        .await
+        .unwrap_err();
+    assert!(matches!(err, Error::MacMismatch { .. }));
+}
+
+#[tokio::test]
+async fn changed_payload_fails_verification() {
+    let db = db::create_test_pool().await;
+    let keyholder = bootstrapped_keyholder(&db).await;
+    let mut conn = db.get().await.unwrap();
+
+    const ENTITY_ID: &[u8] = b"entity-id-21";
+
+    let entity = DummyEntity {
+        payload_version: 1,
+        payload: b"payload-v1".to_vec(),
+    };
+
+    sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+        .await
+        .unwrap()
+        .drop_verification_provenance();
+
+    let tampered = DummyEntity {
+        payload: b"payload-v1-but-tampered".to_vec(),
+        ..entity
+    };
+
+    let err = check_entity_attestation(&mut conn, &keyholder, &tampered, ENTITY_ID)
+        .await
+        .unwrap_err();
+    assert!(matches!(err, Error::MacMismatch { .. }));
+}
+
+#[tokio::test]
+async fn strict_verify_fails_closed_while_sealed() {
+    let db = db::create_test_pool().await;
+    let keyholder = bootstrapped_keyholder(&db).await;
+    let mut conn = db.get().await.unwrap();
+
+    const ENTITY_ID: &[u8] = b"entity-id-41";
+
+    let entity = DummyEntity {
+        payload_version: 1,
+        payload: b"payload-v1".to_vec(),
+    };
+
+    sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+        .await
+        .unwrap()
+        .drop_verification_provenance();
+    drop(keyholder);
+
+    let sealed_keyholder = KeyHolder::spawn(KeyHolder::new(db.clone()).await.unwrap());
+
+    let err = verify_entity(&mut conn, &sealed_keyholder, &entity, ENTITY_ID)
+        .await
+        .unwrap_err();
+    assert!(matches!(
+        err,
+        Error::Keyholder(crate::actors::keyholder::Error::NotBootstrapped)
+    ));
+
+    let err = lookup_verified(&mut conn, &sealed_keyholder, ENTITY_ID, |_| async {
+        Ok::<_, db::DatabaseError>(DummyEntity {
+            payload_version: 1,
+            payload: b"payload-v1".to_vec(),
+        })
+    })
+    .await
+    .unwrap_err();
+    assert!(matches!(
+        err,
+        Error::Keyholder(crate::actors::keyholder::Error::NotBootstrapped)
+    ));
+}
+
+#[tokio::test]
+async fn lookup_verified_supports_loaded_aggregate() {
+    let db = db::create_test_pool().await;
+    let keyholder = bootstrapped_keyholder(&db).await;
+    let mut conn = db.get().await.unwrap();
+
+    const ENTITY_ID: i32 = 77;
+
+    let entity = DummyEntity {
+        payload_version: 1,
+        payload: b"payload-v1".to_vec(),
+    };
+
+    sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+        .await
+        .unwrap()
+        .drop_verification_provenance();
+
+    let verified = lookup_verified(&mut conn, &keyholder, ENTITY_ID, |_| async {
+        Ok::<_, db::DatabaseError>(DummyEntity {
+            payload_version: 1,
+            payload: b"payload-v1".to_vec(),
+        })
+    })
+    .await
+    .unwrap();
+
+    assert_eq!(verified.entity.payload, b"payload-v1".to_vec());
+}
+
+#[tokio::test]
+async fn extension_trait_lookup_verified_required_works() {
+    let db = db::create_test_pool().await;
+    let keyholder = bootstrapped_keyholder(&db).await;
+    let mut conn = db.get().await.unwrap();
+
+    const ENTITY_ID: i32 = 79;
+
+    let entity = DummyEntity {
+        payload_version: 1,
+        payload: b"payload-v1".to_vec(),
+    };
+
+    sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+        .await
+        .unwrap()
+        .drop_verification_provenance();
+
+    let verified = lookup_verified(&mut conn, &keyholder, ENTITY_ID, |_| {
+        Box::pin(async {
+            Ok::<_, db::DatabaseError>(DummyEntity {
+                payload_version: 1,
+                payload: b"payload-v1".to_vec(),
+            })
+        })
+    })
+    .await
+    .unwrap();
+
+    assert_eq!(verified.entity.payload, b"payload-v1".to_vec());
+}
+
+#[tokio::test]
+async fn lookup_verified_from_query_helpers_work() {
+    let db = db::create_test_pool().await;
+    let keyholder = bootstrapped_keyholder(&db).await;
+    let mut conn = db.get().await.unwrap();
+
+    const ENTITY_ID: i32 = 80;
+
+    let entity = DummyEntity {
+        payload_version: 1,
+        payload: b"payload-v1".to_vec(),
+    };
+
+    sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+        .await
+        .unwrap()
+        .drop_verification_provenance();
+
+    let verified = lookup_verified_from_query(&mut conn, &keyholder, |_| {
+        Box::pin(async {
+            Ok::<_, db::DatabaseError>((
+                ENTITY_ID,
+                DummyEntity {
+                    payload_version: 1,
+                    payload: b"payload-v1".to_vec(),
+                },
+            ))
+        })
+    })
+    .await
+    .unwrap();
+
+    assert_eq!(verified.entity.payload, b"payload-v1".to_vec());
+
+    drop(keyholder);
+    let sealed_keyholder = KeyHolder::spawn(KeyHolder::new(db.clone()).await.unwrap());
+
+    let err = lookup_verified_from_query(&mut conn, &sealed_keyholder, |_| {
+        Box::pin(async {
+            Ok::<_, db::DatabaseError>((
+                ENTITY_ID,
+                DummyEntity {
+                    payload_version: 1,
+                    payload: b"payload-v1".to_vec(),
+                },
+            ))
+        })
+    })
+    .await
+    .unwrap_err();
+
+    assert!(matches!(
+        err,
+        Error::Keyholder(crate::actors::keyholder::Error::NotBootstrapped)
+    ));
+}

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

@@ -0,0 +1,463 @@
+use std::ops::Deref;
+
+// todo! rewrite macro_rules to derive crate
+#[macro_export]
+macro_rules! VerifiedFields {
+    // --- Entry point ---
+    (
+        $(#$attr:tt)*
+        $vis:vis struct $name:ident $(<$($gen:tt),*>)?
+        {
+            $(
+                $field_vis:vis $field_name:ident : $field_ty:ty
+            ),* $(,)?
+        }
+    ) => {
+        // Attribute-list checks run in isolation — they only receive the attrs,
+        // not the struct body.
+        $crate::VerifiedFields!(@require_repr [$(#$attr)*]);
+        $crate::VerifiedFields!(@reject_packed [$(#$attr)*]);
+
+        paste::paste! {
+            #[doc = concat!(
+                "Field-wise verified counterpart of [`", stringify!($name), "`]."
+            )]
+            //
+            // `#[repr(C)]` is required for the pointer casts in `inherit_ref`
+            // and `inherit` to be sound. Both the source struct (enforced by
+            // `@require_repr`) and this counterpart carry `#[repr(C)]`, which
+            // guarantees matching field offsets. Combined with each
+            // `Verified<F>` being `#[repr(transparent)]` over `F`, the two
+            // structs have identical memory layout.
+            //
+            // `#[repr(transparent)]` is not usable here because it only permits
+            // a single non-ZST field; multi-field structs would fail to compile.
+            #[repr(C)]
+            $vis struct [<Verified $name>] $(<$($gen),*>)?
+            {
+                $(
+                    $field_vis $field_name : $crate::crypto::integrity::Verified<$field_ty>
+                ),*
+            }
+
+            impl $(<$($gen),*>)?
+                $crate::crypto::integrity::v1::verified::VerifiedFieldsAccessor
+                for $crate::crypto::integrity::Verified<$name $(<$($gen),*>)?>
+            {
+                type Counterpart = [<Verified $name>] $(<$($gen),*>)?;
+
+                fn inherit_ref(&self) -> &Self::Counterpart {
+                    // SAFETY: `Self` is `Verified<T>` (transparent over
+                    // `T #[repr(C)]`) and `Self::Counterpart` is `#[repr(C)]`
+                    // with the same fields in the same order, each wrapped in
+                    // a `#[repr(transparent)]` `Verified<F>`. The two types
+                    // therefore have identical memory layout, which
+                    // `reinterpret_layout_ref` re-checks as size/align
+                    // equality at monomorphization.
+                    unsafe {
+                        $crate::crypto::integrity::v1::verified::reinterpret_layout_ref::<
+                            Self,
+                            Self::Counterpart,
+                        >(self)
+                    }
+                }
+
+                fn inherit(self) -> Self::Counterpart {
+                    // SAFETY: identical layout — see `inherit_ref`. The owned
+                    // helper additionally suppresses the source destructor so
+                    // the returned counterpart owns the original bytes (no
+                    // double-drop is possible).
+                    unsafe {
+                        $crate::crypto::integrity::v1::verified::reinterpret_layout::<
+                            Self,
+                            Self::Counterpart,
+                        >(self)
+                    }
+                }
+            }
+        }
+    };
+
+    // --- @require_repr: ensure `#[repr(C)]` appears in the attribute list ---
+    (@require_repr [#[repr(C)] $($rest:tt)*]) => {};
+    (@require_repr [#$other:tt $($rest:tt)*]) => {
+        $crate::VerifiedFields!(@require_repr [$($rest)*]);
+    };
+    (@require_repr []) => {
+        ::std::compile_error!(
+            "VerifiedFields requires `#[repr(C)]` on the struct to guarantee field layout"
+        );
+    };
+
+    // --- @reject_packed: walk attrs and reject any `#[repr(..., packed, ...)]`.
+    //
+    // Without this, a packed struct would still fail at monomorphization via
+    // the const assertions inside the `reinterpret_layout*` helpers, but the
+    // diagnostic would be much harder to read. `align(N)` is *not* rejected
+    // here because const assertions catch alignment mismatches cleanly, and
+    // forbidding it would be unnecessarily restrictive.
+    (@reject_packed [#[repr($($inner:tt)*)] $($rest:tt)*]) => {
+        $crate::VerifiedFields!(@reject_packed_inner [$($inner)*]);
+        $crate::VerifiedFields!(@reject_packed [$($rest)*]);
+    };
+    (@reject_packed [#$other:tt $($rest:tt)*]) => {
+        $crate::VerifiedFields!(@reject_packed [$($rest)*]);
+    };
+    (@reject_packed []) => {};
+
+    (@reject_packed_inner [packed $($rest:tt)*]) => {
+        ::std::compile_error!(
+            "VerifiedFields does not support packed layouts; the generated \
+             counterpart would not share layout with the source struct"
+        );
+    };
+    (@reject_packed_inner [$first:tt $($rest:tt)*]) => {
+        $crate::VerifiedFields!(@reject_packed_inner [$($rest)*]);
+    };
+    (@reject_packed_inner []) => {};
+}
+
+/// Implemented on `Verified<T>` by [`VerifiedFields!`], exposing the field-wise counterpart.
+///
+/// ## Disclaimer
+/// Do not implement this trait manually. It is intended to be implemented only
+/// by the `VerifiedFields!` macro, which generates the necessary layout
+/// guarantees for sound pointer casts.
+///
+/// ## Soundness
+/// When [`verify_entity`][crate::crypto::integrity::verify_entity] attests an
+/// entity, it returns `Verified<T>` — an aggregate proof over the whole value.
+/// This trait converts that wrapper into `Counterpart` (e.g.
+/// `VerifiedMyStruct`), where every field is individually wrapped in
+/// [`Verified`], allowing verified data to flow into functions that require
+/// `Verified<FieldType>` without re-verifying.
+///
+/// ## Safety
+/// The conversion is a zero-cost reinterpretation — no copying (beyond a
+/// bitwise move in the owned variant) or HMAC work occurs. Soundness rests on
+/// identical memory layout between `Verified<T>` and `Counterpart`:
+///
+/// - `T` carries `#[repr(C)]` (enforced by `@require_repr` in the macro).
+/// - `T` does **not** carry `packed` (enforced by `@reject_packed`).
+/// - `Counterpart` also carries `#[repr(C)]`, with the same fields in the same
+///   order.
+/// - Each `Verified<F>` field is `#[repr(transparent)]` over `F`, so its size
+///   and alignment match `F` exactly.
+/// - `Verified<T>` itself is `#[repr(transparent)]` over `T`.
+///
+/// As an additional machine-checked guard, [`reinterpret_layout`] and
+/// [`reinterpret_layout_ref`] assert size/align equality of the two types at
+/// monomorphization time.
+///
+/// The trait is implemented directly on `Verified<T>` (not on `T`), so no
+/// `Deref`-coercion or auto-ref stripping is needed at call sites — the impl
+/// is unambiguous.
+pub trait VerifiedFieldsAccessor {
+    /// The field-wise verified counterpart, e.g. `VerifiedMyStruct`.
+    type Counterpart;
+
+    /// Reinterprets `&self` as `&Counterpart` via a layout-preserving pointer cast.
+    ///
+    /// No data is copied and no re-verification occurs. The returned reference
+    /// borrows from `self` and has the same lifetime.
+    fn inherit_ref(&self) -> &Self::Counterpart;
+
+    /// Consumes `self` and returns `Counterpart` via a layout-preserving
+    /// bitwise move.
+    ///
+    /// The original `Verified<T>` is moved without running its destructor
+    /// (there is none — `Verified` is a transparent wrapper with no heap
+    /// allocation), and the returned counterpart owns the original bytes. No
+    /// re-verification occurs.
+    fn inherit(self) -> Self::Counterpart;
+}
+
+/// A value whose integrity has been verified against the HMAC envelope stored
+/// in the database.
+///
+/// `Verified<T>` is a zero-cost transparent wrapper produced exclusively by
+/// [`crate::crypto::integrity`](super) module's functions. Holding one is proof
+/// that the underlying value passed an HMAC check keyed with the vault's
+/// integrity subkey.
+///
+/// The wrapper is intentionally narrow: it does not expose a constructor and
+/// the inner value cannot be moved out without explicitly calling
+/// [`drop_verification_provenance`][Verified::drop_verification_provenance],
+/// making accidental provenance loss visible at the call site.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(transparent)]
+#[must_use = "Verified<T> is a proof-bearing wrapper; use self.drop_verification_provenance() to explicitly discard integrity provenance when needed"]
+pub struct Verified<T>(T);
+
+impl<T> AsRef<Verified<T>> for Verified<&T> {
+    fn as_ref(&self) -> &Verified<T> {
+        // SAFETY: `Verified<T>` is `#[repr(transparent)]` over `T`, so `&T`
+        // and `&Verified<T>` have identical layout.
+        unsafe { reinterpret_layout_ref::<T, Verified<T>>(self.0) }
+    }
+}
+
+impl<T> Deref for Verified<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<T> Verified<T> {
+    /// Unwraps the verified value, discarding the integrity provenance.
+    ///
+    /// The name is intentionally verbose — call sites where provenance is
+    /// dropped should be easy to find and audit.
+    pub fn drop_verification_provenance(self) -> T {
+        self.0
+    }
+
+    /// Constructs a `Verified<T>` by wrapping a `T`.
+    pub(super) fn new(value: T) -> Self {
+        Self(value)
+    }
+
+    /// Constructs a `Verified<T>` from a raw value without performing any
+    /// integrity check. Only available in test builds; use the integrity
+    /// module's functions to obtain a `Verified<T>` in production code.
+    #[cfg(test)]
+    pub(crate) fn new_unchecked(value: T) -> Self {
+        Self(value)
+    }
+
+    /// Reinterprets `&T` as `&Verified<T>`.
+    #[allow(dead_code)]
+    pub(super) fn from_ref(from: &T) -> &Self {
+        // SAFETY: `Self` is `#[repr(transparent)]` over `T`.
+        unsafe { reinterpret_layout_ref::<T, Self>(from) }
+    }
+}
+
+/// Bit-copies `value: From` into a `To`, suppressing the source destructor so
+/// the destination owns the bytes.
+///
+/// # Safety
+///
+/// The caller must guarantee that `From` and `To` have identical in-memory
+/// layout — the raw bytes that encode a valid `From` must also encode a valid
+/// `To`.
+///
+/// A `union` is used instead of [`std::mem::transmute`] because `transmute`
+/// rejects generic source/destination types at the call site even when their
+/// sizes are provably equal at monomorphization time.
+#[allow(dead_code)]
+#[inline]
+pub const unsafe fn reinterpret_layout<From, To>(value: From) -> To {
+    const {
+        assert!(
+            ::std::mem::size_of::<From>() == ::std::mem::size_of::<To>(),
+            "reinterpret_layout: source and destination must have identical size"
+        );
+        assert!(
+            ::std::mem::align_of::<From>() == ::std::mem::align_of::<To>(),
+            "reinterpret_layout: source and destination must have identical alignment"
+        );
+    }
+    union Reinterpret<A, B> {
+        from: ::std::mem::ManuallyDrop<A>,
+        to: ::std::mem::ManuallyDrop<B>,
+    }
+    // SAFETY: caller guarantees layout equivalence (see fn docs). The union
+    // write-read copies the raw bytes of `value` into a `To` slot, and
+    // `ManuallyDrop` on the source side suppresses its destructor so the
+    // destination owns the bytes unambiguously — no double-drop is possible.
+    unsafe {
+        ::std::mem::ManuallyDrop::into_inner(
+            Reinterpret {
+                from: ::std::mem::ManuallyDrop::new(value),
+            }
+            .to,
+        )
+    }
+}
+
+/// Reinterprets `&From` as `&To` via a layout-preserving pointer cast.
+///
+/// # Safety
+///
+/// Same invariants as [`reinterpret_layout`].
+#[inline]
+pub const unsafe fn reinterpret_layout_ref<From, To>(value: &From) -> &To {
+    const {
+        assert!(
+            ::std::mem::size_of::<From>() == ::std::mem::size_of::<To>(),
+            "reinterpret_layout_ref: source and destination must have identical size"
+        );
+        assert!(
+            ::std::mem::align_of::<From>() == ::std::mem::align_of::<To>(),
+            "reinterpret_layout_ref: source and destination must have identical alignment"
+        );
+    }
+    // SAFETY: caller guarantees layout equivalence (see fn docs). A reference
+    // cast between identically-laid-out types produces a reference with the
+    // same address and lifetime, which is sound.
+    unsafe { &*(value as *const From as *const To) }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[derive(VerifiedFields!)]
+    #[repr(C)]
+    #[derive(Default, Clone)]
+    pub struct MyStruct<T> {
+        pub field1: String,
+        pub field2: T,
+    }
+
+    fn verify<T>(t: T) -> Verified<T> {
+        Verified(t)
+    }
+
+    // --- inherit_ref ---
+
+    // Verifies that `inherit_ref` returns a reference to the same memory
+    // address, confirming that no copy is made and the cast is purely a
+    // reinterpretation.
+    #[test]
+    fn inherit_ref_is_same_address() {
+        let v = verify(MyStruct {
+            field1: "hello".into(),
+            field2: 42u32,
+        });
+        let fields = v.inherit_ref();
+        assert_eq!(
+            &v as *const _ as *const u8, fields as *const _ as *const u8,
+            "inherit_ref must return a pointer to the same memory, not a copy"
+        );
+    }
+
+    // Verifies that field values are correctly accessible after `inherit_ref`.
+    #[test]
+    fn inherit_ref_field_values() {
+        let v = verify(MyStruct {
+            field1: "hello".into(),
+            field2: 99u32,
+        });
+        let fields = v.inherit_ref();
+        assert_eq!(*fields.field1, "hello");
+        assert_eq!(*fields.field2, 99u32);
+    }
+
+    // Verifies that casting the counterpart back to `Verified<T>` via a raw
+    // pointer lands on the original address — confirms the round-trip is a
+    // pure reinterpretation.
+    #[test]
+    fn inherit_ref_cast_roundtrip() {
+        let v = verify(MyStruct {
+            field1: "x".into(),
+            field2: 7u32,
+        });
+        let fields: &VerifiedMyStruct<u32> = v.inherit_ref();
+        let back_ptr = fields as *const VerifiedMyStruct<u32> as *const Verified<MyStruct<u32>>;
+        assert_eq!(
+            back_ptr as *const u8, &v as *const _ as *const u8,
+            "cast of counterpart must point back to the same Verified<T>"
+        );
+    }
+
+    // ZST fields must still produce a counterpart with identical layout — the
+    // const asserts in `reinterpret_layout_ref` guard this at monomorphization.
+    #[test]
+    fn inherit_ref_with_zst_field() {
+        #[derive(VerifiedFields!)]
+        #[repr(C)]
+        struct WithZst {
+            pub unit: (),
+            pub val: u64,
+        }
+
+        let v = Verified(WithZst { unit: (), val: 777 });
+        let fields = v.inherit_ref();
+        assert_eq!(*fields.val, 777);
+        assert_eq!(*fields.unit, ());
+    }
+
+    // --- inherit ---
+
+    // Verifies that `inherit` preserves field values in the owned counterpart.
+    #[test]
+    fn inherit_field_values() {
+        let v = verify(MyStruct {
+            field1: "world".into(),
+            field2: 1234u64,
+        });
+        let VerifiedMyStruct { field1, field2 } = v.inherit();
+        assert_eq!(*field1, "world");
+        assert_eq!(*field2, 1234u64);
+    }
+
+    // Verifies that `inherit` does not double-drop the inner value.
+    // If `ManuallyDrop` handling is wrong, running under Miri or with a drop
+    // counter catches a double-free.
+    #[test]
+    fn inherit_no_double_drop() {
+        use std::sync::atomic::{AtomicUsize, Ordering};
+
+        static DROP_COUNT: AtomicUsize = AtomicUsize::new(0);
+
+        struct DropCounter;
+        impl Drop for DropCounter {
+            fn drop(&mut self) {
+                DROP_COUNT.fetch_add(1, Ordering::Relaxed);
+            }
+        }
+
+        #[derive(VerifiedFields!)]
+        #[repr(C)]
+        struct WithDrop {
+            pub val: DropCounter,
+        }
+
+        DROP_COUNT.store(0, Ordering::Relaxed);
+        {
+            let v = Verified(WithDrop { val: DropCounter });
+            let _ = v.inherit();
+        }
+        assert_eq!(
+            DROP_COUNT.load(Ordering::Relaxed),
+            1,
+            "DropCounter must be dropped exactly once"
+        );
+    }
+
+    // --- Verified::from_ref ---
+
+    #[test]
+    fn from_ref_is_same_address() {
+        let val = 42u32;
+        let verified: &Verified<u32> = Verified::from_ref(&val);
+        assert_eq!(
+            &val as *const u32 as *const u8, verified as *const _ as *const u8,
+            "from_ref must alias the original reference, not copy the value"
+        );
+    }
+
+    #[test]
+    fn from_ref_value_preserved() {
+        let val = String::from("test");
+        let verified: &Verified<String> = Verified::from_ref(&val);
+        assert_eq!(**verified, "test");
+    }
+
+    // --- AsRef<Verified<T>> for Verified<&T> ---
+
+    #[test]
+    fn verified_ref_as_ref_is_same_address() {
+        let val = 99u32;
+        let vref: Verified<&u32> = Verified(&val);
+        let v: &Verified<u32> = vref.as_ref();
+        assert_eq!(
+            &val as *const u32 as *const u8, v as *const _ as *const u8,
+            "AsRef<Verified<T>> for Verified<&T> must alias the referent, not copy it"
+        );
+    }
+}

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

@@ -12,7 +12,7 @@ use kameo::actor::ActorRef;
 
 use crate::{
     actors::keyholder::KeyHolder,
-    crypto::integrity,
+    crypto::integrity::{self, Verified, VerifiedEntity, verified::VerifiedFieldsAccessor},
     db::{
         self, DatabaseError,
         models::{
@@ -153,12 +153,39 @@ impl Engine {
     {
         let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
 
-        let grant = P::try_find_grant(&context, &mut conn)
+        let verified_settings =
+            match integrity::lookup_verified_from_query(&mut conn, &self.keyholder, |conn| {
+                let context = context.clone();
+                Box::pin(async move {
+                    let grant = P::try_find_grant(&context, conn)
+                        .await
+                        .map_err(DatabaseError::from)?
+                        .ok_or_else(|| DatabaseError::from(diesel::result::Error::NotFound))?;
+
+                    Ok::<_, DatabaseError>((grant.common_settings_id, grant.settings))
+                })
+            })
+            .await
+            {
+                Ok(verified) => verified,
+                Err(integrity::Error::Database(DatabaseError::Connection(
+                    diesel::result::Error::NotFound,
+                ))) => return Err(PolicyError::NoMatchingGrant),
+                Err(err) => return Err(PolicyError::Integrity(err)),
+            };
+
+        let mut grant = P::try_find_grant(&context, &mut conn)
             .await
             .map_err(DatabaseError::from)?
             .ok_or(PolicyError::NoMatchingGrant)?;
 
-        integrity::verify_entity(&mut conn, &self.keyholder, &grant.settings, grant.id).await?;
+        // IMPORTANT: policy evaluation uses extra non-integrity fields from Grant
+        // (e.g., per-policy ids), so we currently reload Grant after the query-native
+        // integrity check over canonicalized settings.
+        grant.settings = verified_settings
+            .inherit()
+            .entity
+            .drop_verification_provenance();
 
         let mut violations = check_shared_constraints(
             &context,
@@ -214,7 +241,7 @@ impl Engine {
     pub async fn create_grant<P: Policy>(
         &self,
         full_grant: CombinedSettings<P::Settings>,
-    ) -> Result<i32, DatabaseError>
+    ) -> Result<Verified<i32>, DatabaseError>
     where
         P::Settings: Clone,
     {
@@ -258,11 +285,12 @@ impl Engine {
 
                     P::create_grant(&basic_grant, &full_grant.specific, conn).await?;
 
+                    let verified_entity_id =
                         integrity::sign_entity(conn, &keyholder, &full_grant, basic_grant.id)
                             .await
                             .map_err(|_| diesel::result::Error::RollbackTransaction)?;
 
-                    QueryResult::Ok(basic_grant.id)
+                    QueryResult::Ok(verified_entity_id)
                 })
             })
             .await?;
@@ -273,7 +301,7 @@ impl Engine {
     async fn list_one_kind<Kind: Policy, Y>(
         &self,
         conn: &mut impl AsyncConnection<Backend = Sqlite>,
-    ) -> Result<impl Iterator<Item = Grant<Y>>, ListError>
+    ) -> Result<Vec<Grant<Y>>, ListError>
     where
         Y: From<Kind::Settings>,
     {
@@ -281,16 +309,32 @@ impl Engine {
             .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?;
+        let mut verified_grants = Vec::with_capacity(all_grants.len());
+
+        // Verify integrity of all grants before returning any results.
+        for grant in all_grants {
+            let VerifiedEntity {
+                entity: verified_settings,
+                entity_id: _,
+            } = integrity::verify_entity(
+                conn,
+                &self.keyholder,
+                grant.settings,
+                grant.common_settings_id,
+            )
+            .await?
+            .inherit();
+
+            verified_grants.push(Grant {
+                id: grant.id,
+                common_settings_id: grant.common_settings_id,
+                settings: verified_settings
+                    .drop_verification_provenance()
+                    .generalize(),
+            });
         }
 
-        Ok(all_grants.into_iter().map(|g| Grant {
-            id: g.id,
-            common_settings_id: g.common_settings_id,
-            settings: g.settings.generalize(),
-        }))
+        Ok(verified_grants)
     }
 
     pub async fn list_all_grants(&self) -> Result<Vec<Grant<SpecificGrant>>, ListError> {

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

@@ -200,7 +200,7 @@ pub enum SpecificGrant {
     TokenTransfer(token_transfers::Settings),
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct CombinedSettings<PolicyGrant> {
     pub shared: SharedGrantSettings,
     pub specific: PolicyGrant,

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

@@ -110,7 +110,8 @@ async fn check_rate_limits(
     let mut violations = Vec::new();
     let window = grant.settings.specific.limit.window;
 
-    let past_transaction = query_relevant_past_transaction(grant.id, window, db).await?;
+    let past_transaction =
+        query_relevant_past_transaction(grant.common_settings_id, window, db).await?;
 
     let window_start = chrono::Utc::now() - grant.settings.specific.limit.window;
     let prospective_cumulative_volume: U256 = past_transaction
@@ -249,21 +250,20 @@ impl Policy for EtherTransfer {
             })
             .collect();
 
-        let settings = Settings {
-            target: targets,
-            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),
-            },
-        };
-
         Ok(Some(Grant {
             id: grant.id,
             common_settings_id: grant.basic_grant_id,
             settings: CombinedSettings {
                 shared: SharedGrantSettings::try_from_model(basic_grant)?,
-                specific: settings,
+                specific: Settings {
+                    target: targets,
+                    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),
+                    },
+                },
             },
         }))
     }

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

@@ -286,18 +286,16 @@ impl Policy for TokenTransfer {
             }
         };
 
-        let settings = Settings {
-            token_contract: Address::from(token_contract),
-            target,
-            volume_limits,
-        };
-
         Ok(Some(Grant {
             id: token_grant.id,
             common_settings_id: token_grant.basic_grant_id,
             settings: CombinedSettings {
                 shared: SharedGrantSettings::try_from_model(basic_grant)?,
-                specific: settings,
+                specific: Settings {
+                    token_contract: Address::from(token_contract),
+                    target,
+                    volume_limits,
+                },
             },
         }))
     }

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

@@ -22,6 +22,7 @@ use tracing::warn;
 
 use crate::{
     actors::client::{self, ClientConnection, auth},
+    crypto::integrity::Verified,
     grpc::request_tracker::RequestTracker,
 };
 
@@ -68,6 +69,7 @@ impl<'a> AuthTransportAdapter<'a> {
                 auth::Error::ApproveError(auth::ApproveError::Internal)
                 | auth::Error::DatabasePoolUnavailable
                 | auth::Error::DatabaseOperationFailed
+                | auth::Error::IntegrityCheckFailed
                 | auth::Error::Transport => ProtoAuthResult::Internal,
             }
             .into(),
@@ -199,7 +201,7 @@ pub async fn start(
     conn: &mut ClientConnection,
     bi: &mut GrpcBi<ClientRequest, ClientResponse>,
     request_tracker: &mut RequestTracker,
-) -> Result<i32, auth::Error> {
+) -> Result<Verified<i32>, auth::Error> {
     let mut transport = AuthTransportAdapter::new(bi, request_tracker);
     client::auth::authenticate(conn, &mut transport).await
 }

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

@@ -66,7 +66,7 @@ async fn handle_wallet_create(
 ) -> Result<Option<UserAgentResponsePayload>, Status> {
     let result = match actor.ask(HandleEvmWalletCreate {}).await {
         Ok((wallet_id, address)) => WalletCreateResult::Wallet(WalletEntry {
-            id: wallet_id,
+            id: wallet_id.drop_verification_provenance(),
             address: address.to_vec(),
         }),
         Err(err) => {
@@ -121,6 +121,9 @@ async fn handle_grant_list(
                 })
                 .collect(),
         }),
+        Err(kameo::error::SendError::HandlerError(GrantMutationError::VaultSealed)) => {
+            EvmGrantListResult::Error(ProtoEvmError::VaultSealed.into())
+        }
         Err(err) => {
             warn!(error = ?err, "Failed to list EVM grants");
             EvmGrantListResult::Error(ProtoEvmError::Internal.into())
@@ -147,7 +150,7 @@ async fn handle_grant_create(
         .try_convert()?;
 
     let result = match actor.ask(HandleGrantCreate { basic, grant }).await {
-        Ok(grant_id) => EvmGrantCreateResult::GrantId(grant_id),
+        Ok(grant_id) => EvmGrantCreateResult::GrantId(grant_id.drop_verification_provenance()),
         Err(kameo::error::SendError::HandlerError(GrantMutationError::VaultSealed)) => {
             EvmGrantCreateResult::Error(ProtoEvmError::VaultSealed.into())
         }

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

@@ -1,6 +1,8 @@
-#![forbid(unsafe_code)]
 use crate::context::ServerContext;
 
+#[macro_use]
+extern crate macro_rules_attribute;
+
 pub mod actors;
 pub mod context;
 pub mod crypto;

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

@@ -1,3 +1,5 @@
+use std::ops::Deref;
+
 struct DeferClosure<F: FnOnce()> {
     f: Option<F>,
 }
@@ -14,3 +16,19 @@ impl<F: FnOnce()> Drop for DeferClosure<F> {
 pub fn defer<F: FnOnce()>(f: F) -> impl Drop + Sized {
     DeferClosure { f: Some(f) }
 }
+
+/// A trait for casting between two transparently wrapped types with identical memory layouts.
+///
+/// [`ReinterpretWrapper`] enables zero-cost conversions between two types (`Self` and `Counterpart`)
+/// that wrap the same underlying data but differ in how that data is presented. Both types must
+/// transparently wrap the same "deref target" and provide bidirectional `AsRef` conversions.
+pub trait ReinterpretWrapper<Counterpart>
+where
+    Self: Deref<Target = Self::Inner> + AsRef<Counterpart>,
+    Counterpart: Deref<Target = Self::Inner> + AsRef<Self>,
+{
+    /// The shared target type that both `Self` and `Counterpart` transparently wrap.
+    type Inner;
+    /// Reinterprets `Self` as `Counterpart`.
+    fn reinterpret(self) -> Counterpart;
+}

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

@@ -1,9 +1,14 @@
 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},
+    safe_cell::{SafeCell, SafeCellHandle as _},
 };
 use diesel::{ExpressionMethods as _, NullableExpressionMethods as _, QueryDsl as _, insert_into};
 use diesel_async::RunQueryDsl;
@@ -21,7 +26,8 @@ fn metadata(name: &str, description: Option<&str>, version: Option<&str>) -> Cli
 
 async fn insert_registered_client(
     db: &db::DatabasePool,
-    pubkey: Vec<u8>,
+    actors: &GlobalActors,
+    pubkey: ed25519_dalek::VerifyingKey,
     metadata: &ClientMetadata,
 ) {
     use arbiter_server::db::schema::{client_metadata, program_client};
@@ -37,23 +43,64 @@ 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.to_bytes().to_vec()),
             program_client::metadata_id.eq(metadata_id),
         ))
+        .returning(program_client::id)
+        .get_result(&mut conn)
+        .await
+        .unwrap();
+
+    let _ = integrity::sign_entity(
+        &mut conn,
+        &actors.key_holder,
+        &ClientCredentials { pubkey, nonce: 1 },
+        client_id,
+    )
+    .await
+    .unwrap();
+}
+
+async fn insert_bootstrap_sentinel_useragent(db: &db::DatabasePool) {
+    let mut conn = db.get().await.unwrap();
+    let sentinel_key = ed25519_dalek::SigningKey::generate(&mut rand::rng())
+        .verifying_key()
+        .to_bytes()
+        .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() {
     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;
@@ -78,20 +125,19 @@ pub async fn test_unregistered_pubkey_rejected() {
 #[test_log::test]
 pub async fn test_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();
 
     insert_registered_client(
         &db,
-        pubkey_bytes.clone(),
+        &actors,
+        new_key.verifying_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;
@@ -147,34 +193,13 @@ pub async fn test_challenge_auth() {
 #[test_log::test]
 pub async fn test_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 actors = spawn_test_actors(&db).await;
     let new_key = ed25519_dalek::SigningKey::generate(&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();
-    }
+    insert_registered_client(&db, &actors, new_key.verifying_key(), &requested).await;
+
+    let props = ClientConnection::new(db.clone(), actors);
 
     let (server_transport, mut test_transport) = ChannelTransport::new();
     let task = tokio::spawn(async move {
@@ -225,33 +250,18 @@ pub async fn test_metadata_unchanged_does_not_append_history() {
 #[test_log::test]
 pub async fn test_metadata_change_appends_history_and_repoints_binding() {
     let db = db::create_test_pool().await;
-    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
-    let props = ClientConnection::new(db.clone(), actors);
-
+    let actors = spawn_test_actors(&db).await;
     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();
-    }
+    insert_registered_client(
+        &db,
+        &actors,
+        new_key.verifying_key(),
+        &metadata("client", Some("old"), Some("1.0.0")),
+    )
+    .await;
+
+    let props = ClientConnection::new(db.clone(), actors);
 
     let (server_transport, mut test_transport) = ChannelTransport::new();
     let task = tokio::spawn(async move {
@@ -322,3 +332,59 @@ pub async fn test_metadata_change_appends_history_and_repoints_binding() {
         );
     }
 }
+
+#[tokio::test]
+#[test_log::test]
+pub async fn test_challenge_auth_rejects_integrity_tag_mismatch() {
+    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 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();
+    }
+
+    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: new_key.verifying_key(),
+            metadata: requested,
+        })
+        .await
+        .unwrap();
+
+    let response = test_transport
+        .recv()
+        .await
+        .expect("should receive auth rejection");
+    assert!(matches!(response, Err(auth::Error::IntegrityCheckFailed)));
+
+    task.await.unwrap();
+}

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

@@ -139,7 +139,8 @@ pub async fn test_challenge_auth() {
             id,
         )
         .await
-        .unwrap();
+        .unwrap()
+        .drop_verification_provenance();
     }
 
     let (server_transport, mut test_transport) = ChannelTransport::new();
@@ -278,7 +279,8 @@ pub async fn test_challenge_auth_rejects_invalid_signature() {
             id,
         )
         .await
-        .unwrap();
+        .unwrap()
+        .drop_verification_provenance();
     }
 
     let (server_transport, mut test_transport) = ChannelTransport::new();

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

@@ -11,8 +11,6 @@ use arbiter_server::{
     safe_cell::{SafeCell, SafeCellHandle as _},
 };
 use chacha20poly1305::{AeadInPlace, XChaCha20Poly1305, XNonce, aead::KeyInit};
-use diesel::{ExpressionMethods as _, QueryDsl as _, insert_into};
-use diesel_async::RunQueryDsl;
 use kameo::actor::Spawn as _;
 use x25519_dalek::{EphemeralSecret, PublicKey};