merge: feat-lints into main

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

@@ -1,13 +1,13 @@
+use crate::db::{self, DatabasePool, schema};
 use arbiter_proto::{BOOTSTRAP_PATH, home_path};
+
 use diesel::QueryDsl;
 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};
 const TOKEN_LENGTH: usize = 64;
 
 pub async fn generate_token() -> Result<String, std::io::Error> {
@@ -27,7 +27,7 @@ pub async fn generate_token() -> Result<String, std::io::Error> {
 }
 
 #[derive(Error, Debug)]
-pub enum BootstrappError {
+pub enum Error {
     #[error("Database error: {0}")]
     Database(#[from] db::PoolError),
 
@@ -44,7 +44,7 @@ pub struct Bootstrapper {
 }
 
 impl Bootstrapper {
-    pub async fn new(db: &DatabasePool) -> Result<Self, BootstrappError> {
+    pub async fn new(db: &DatabasePool) -> Result<Self, Error> {
         let row_count: i64 = {
             let mut conn = db.get().await?;
 

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

@@ -1,462 +0,0 @@
-use arbiter_crypto::authn::{self, CLIENT_CONTEXT};
-use arbiter_proto::{
-    ClientMetadata,
-    proto::client::auth::{AuthChallenge as ProtoAuthChallenge, AuthResult as ProtoAuthResult},
-    transport::{Bi, expect_message},
-};
-use chrono::Utc;
-use diesel::{
-    ExpressionMethods as _, OptionalExtension as _, QueryDsl as _, SelectableHelper as _,
-    dsl::insert_into, update,
-};
-use diesel_async::RunQueryDsl as _;
-use kameo::{actor::ActorRef, error::SendError};
-use tracing::error;
-
-use crate::{
-    actors::{
-        client::{ClientConnection, ClientCredentials, ClientProfile},
-        flow_coordinator::{self, RequestClientApproval},
-        keyholder::KeyHolder,
-    },
-    crypto::integrity::{self, AttestationStatus},
-    db::{
-        self,
-        models::{ProgramClientMetadata, SqliteTimestamp},
-        schema::program_client,
-    },
-};
-
-#[derive(thiserror::Error, Debug, Clone, PartialEq, Eq)]
-pub enum ClientAuthError {
-    #[error("Client approval request failed")]
-    ApproveError(#[from] ApproveError),
-
-    #[error("Database operation failed")]
-    DatabaseOperationFailed,
-
-    #[error("Database pool unavailable")]
-    DatabasePoolUnavailable,
-
-    #[error("Integrity check failed")]
-    IntegrityCheckFailed,
-
-    #[error("Invalid challenge solution")]
-    InvalidChallengeSolution,
-
-    #[error("Transport error")]
-    Transport,
-}
-
-impl From<diesel::result::Error> for ClientAuthError {
-    fn from(e: diesel::result::Error) -> Self {
-        error!(?e, "Database error");
-        Self::DatabaseOperationFailed
-    }
-}
-
-impl From<ClientAuthError> for arbiter_proto::proto::client::auth::AuthResult {
-    fn from(value: ClientAuthError) -> Self {
-        match value {
-            ClientAuthError::ApproveError(e) => match e {
-                ApproveError::Denied => Self::ApprovalDenied,
-                ApproveError::Internal => Self::Internal,
-                ApproveError::Upstream(flow_coordinator::ApprovalError::NoUserAgentsConnected) => {
-                    Self::NoUserAgentsOnline
-                } // ApproveError::Upstream(_) => Self::Internal,
-            },
-            ClientAuthError::DatabaseOperationFailed
-            | ClientAuthError::DatabasePoolUnavailable
-            | ClientAuthError::IntegrityCheckFailed
-            | ClientAuthError::Transport => Self::Internal,
-            ClientAuthError::InvalidChallengeSolution => Self::InvalidSignature,
-        }
-    }
-}
-
-#[derive(thiserror::Error, Debug, Clone, PartialEq, Eq)]
-pub enum ApproveError {
-    #[error("Client connection denied by user agents")]
-    Denied,
-
-    #[error("Internal error")]
-    Internal,
-
-    #[error("Upstream error: {0}")]
-    Upstream(flow_coordinator::ApprovalError),
-}
-
-#[derive(Debug, Clone)]
-pub enum Inbound {
-    AuthChallengeRequest {
-        pubkey: authn::PublicKey,
-        metadata: ClientMetadata,
-    },
-    AuthChallengeSolution {
-        signature: authn::Signature,
-    },
-}
-
-#[derive(Debug, Clone)]
-pub enum Outbound {
-    AuthChallenge {
-        pubkey: authn::PublicKey,
-        nonce: i32,
-    },
-    AuthSuccess,
-}
-
-impl From<Outbound> for arbiter_proto::proto::client::auth::response::Payload {
-    fn from(value: Outbound) -> Self {
-        match value {
-            Outbound::AuthChallenge { pubkey, nonce } => Self::Challenge(ProtoAuthChallenge {
-                pubkey: pubkey.to_bytes(),
-                nonce,
-            }),
-            Outbound::AuthSuccess => Self::Result(ProtoAuthResult::Success.into()),
-        }
-    }
-}
-
-/// Returns the current nonce and client ID for a registered client.
-/// Returns `None` if the pubkey is not registered.
-async fn get_current_nonce_and_id(
-    db: &db::DatabasePool,
-    pubkey: &authn::PublicKey,
-) -> Result<Option<(i32, i32)>, ClientAuthError> {
-    let pubkey_bytes = pubkey.to_bytes();
-    let mut conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        ClientAuthError::DatabasePoolUnavailable
-    })?;
-    program_client::table
-        .filter(program_client::public_key.eq(&pubkey_bytes))
-        .select((program_client::id, program_client::nonce))
-        .first::<(i32, i32)>(&mut conn)
-        .await
-        .optional()
-        .map_err(|e| {
-            error!(error = ?e, "Database error");
-            ClientAuthError::DatabaseOperationFailed
-        })
-}
-
-async fn verify_integrity(
-    db: &db::DatabasePool,
-    keyholder: &ActorRef<KeyHolder>,
-    pubkey: &authn::PublicKey,
-) -> Result<(), ClientAuthError> {
-    let mut db_conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        ClientAuthError::DatabasePoolUnavailable
-    })?;
-
-    let (id, nonce) = get_current_nonce_and_id(db, pubkey).await?.ok_or_else(|| {
-        error!("Client not found during integrity verification");
-        ClientAuthError::DatabaseOperationFailed
-    })?;
-
-    let attestation = integrity::verify_entity(
-        &mut db_conn,
-        keyholder,
-        &ClientCredentials {
-            pubkey: pubkey.clone(),
-            nonce,
-        },
-        id,
-    )
-    .await
-    .map_err(|e| {
-        error!(?e, "Integrity verification failed");
-        ClientAuthError::IntegrityCheckFailed
-    })?;
-
-    if attestation != AttestationStatus::Attested {
-        error!("Integrity attestation unavailable for client {id}");
-        return Err(ClientAuthError::IntegrityCheckFailed);
-    }
-
-    Ok(())
-}
-
-/// Atomically increments the nonce and re-signs the integrity envelope.
-/// Returns the new nonce, which is used as the challenge nonce.
-async fn create_nonce(
-    db: &db::DatabasePool,
-    keyholder: &ActorRef<KeyHolder>,
-    pubkey: &authn::PublicKey,
-) -> Result<i32, ClientAuthError> {
-    let pubkey_bytes = pubkey.to_bytes();
-    let pubkey = pubkey.clone();
-
-    let mut conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        ClientAuthError::DatabasePoolUnavailable
-    })?;
-
-    conn.exclusive_transaction(|conn| {
-        let keyholder = keyholder.clone();
-        let pubkey = pubkey.clone();
-        Box::pin(async move {
-            let (id, new_nonce): (i32, i32) = update(program_client::table)
-                .filter(program_client::public_key.eq(&pubkey_bytes))
-                .set(program_client::nonce.eq(program_client::nonce + 1))
-                .returning((program_client::id, program_client::nonce))
-                .get_result(conn)
-                .await?;
-
-            integrity::sign_entity(
-                conn,
-                &keyholder,
-                &ClientCredentials {
-                    pubkey: pubkey.clone(),
-                    nonce: new_nonce,
-                },
-                id,
-            )
-            .await
-            .map_err(|e| {
-                error!(?e, "Integrity sign failed after nonce update");
-                ClientAuthError::DatabaseOperationFailed
-            })?;
-
-            Ok(new_nonce)
-        })
-    })
-    .await
-}
-
-async fn approve_new_client(
-    actors: &crate::actors::GlobalActors,
-    profile: ClientProfile,
-) -> Result<(), ClientAuthError> {
-    let result = actors
-        .flow_coordinator
-        .ask(RequestClientApproval { client: profile })
-        .await;
-
-    match result {
-        Ok(true) => Ok(()),
-        Ok(false) => Err(ClientAuthError::ApproveError(ApproveError::Denied)),
-        Err(SendError::HandlerError(e)) => {
-            error!(error = ?e, "Approval upstream error");
-            Err(ClientAuthError::ApproveError(ApproveError::Upstream(e)))
-        }
-        Err(e) => {
-            error!(error = ?e, "Approval request to flow coordinator failed");
-            Err(ClientAuthError::ApproveError(ApproveError::Internal))
-        }
-    }
-}
-
-async fn insert_client(
-    db: &db::DatabasePool,
-    keyholder: &ActorRef<KeyHolder>,
-    pubkey: &authn::PublicKey,
-    metadata: &ClientMetadata,
-) -> Result<i32, ClientAuthError> {
-    use crate::db::schema::client_metadata;
-    let pubkey = pubkey.clone();
-    let metadata = metadata.clone();
-
-    let mut conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        ClientAuthError::DatabasePoolUnavailable
-    })?;
-
-    conn.exclusive_transaction(|conn| {
-        let keyholder = keyholder.clone();
-        let pubkey = pubkey.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),
-                    client_metadata::description.eq(&metadata.description),
-                    client_metadata::version.eq(&metadata.version),
-                ))
-                .returning(client_metadata::id)
-                .get_result::<i32>(conn)
-                .await?;
-
-            let client_id = insert_into(program_client::table)
-                .values((
-                    program_client::public_key.eq(pubkey.to_bytes()),
-                    program_client::metadata_id.eq(metadata_id),
-                    program_client::nonce.eq(NONCE_START),
-                ))
-                .on_conflict_do_nothing()
-                .returning(program_client::id)
-                .get_result::<i32>(conn)
-                .await?;
-
-            integrity::sign_entity(
-                conn,
-                &keyholder,
-                &ClientCredentials {
-                    pubkey: pubkey.clone(),
-                    nonce: NONCE_START,
-                },
-                client_id,
-            )
-            .await
-            .map_err(|e| {
-                error!(error = ?e, "Failed to sign integrity tag for new client key");
-                ClientAuthError::DatabaseOperationFailed
-            })?;
-
-            Ok(client_id)
-        })
-    })
-    .await
-}
-
-async fn sync_client_metadata(
-    db: &db::DatabasePool,
-    client_id: i32,
-    metadata: &ClientMetadata,
-) -> Result<(), ClientAuthError> {
-    use crate::db::schema::{client_metadata, client_metadata_history};
-
-    let now = SqliteTimestamp(Utc::now());
-
-    let mut conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        ClientAuthError::DatabasePoolUnavailable
-    })?;
-
-    conn.exclusive_transaction(|conn| {
-        let metadata = metadata.clone();
-        Box::pin(async move {
-            let (current_metadata_id, current): (i32, ProgramClientMetadata) =
-                program_client::table
-                    .find(client_id)
-                    .inner_join(client_metadata::table)
-                    .select((
-                        program_client::metadata_id,
-                        ProgramClientMetadata::as_select(),
-                    ))
-                    .first(conn)
-                    .await?;
-
-            let unchanged = current.name == metadata.name
-                && current.description == metadata.description
-                && current.version == metadata.version;
-            if unchanged {
-                return Ok(());
-            }
-
-            insert_into(client_metadata_history::table)
-                .values((
-                    client_metadata_history::metadata_id.eq(current_metadata_id),
-                    client_metadata_history::client_id.eq(client_id),
-                ))
-                .execute(conn)
-                .await?;
-
-            let metadata_id = insert_into(client_metadata::table)
-                .values((
-                    client_metadata::name.eq(&metadata.name),
-                    client_metadata::description.eq(&metadata.description),
-                    client_metadata::version.eq(&metadata.version),
-                ))
-                .returning(client_metadata::id)
-                .get_result::<i32>(conn)
-                .await?;
-
-            update(program_client::table.find(client_id))
-                .set((
-                    program_client::metadata_id.eq(metadata_id),
-                    program_client::updated_at.eq(now),
-                ))
-                .execute(conn)
-                .await?;
-
-            Ok::<(), diesel::result::Error>(())
-        })
-    })
-    .await
-    .map_err(|e| {
-        error!(error = ?e, "Database error");
-        ClientAuthError::DatabaseOperationFailed
-    })
-}
-
-async fn challenge_client<T>(
-    transport: &mut T,
-    pubkey: authn::PublicKey,
-    nonce: i32,
-) -> Result<(), ClientAuthError>
-where
-    T: Bi<Inbound, Result<Outbound, ClientAuthError>> + ?Sized,
-{
-    transport
-        .send(Ok(Outbound::AuthChallenge {
-            pubkey: pubkey.clone(),
-            nonce,
-        }))
-        .await
-        .map_err(|e| {
-            error!(error = ?e, "Failed to send auth challenge");
-            ClientAuthError::Transport
-        })?;
-
-    let signature = expect_message(transport, |req: Inbound| match req {
-        Inbound::AuthChallengeSolution { signature } => Some(signature),
-        Inbound::AuthChallengeRequest { .. } => None,
-    })
-    .await
-    .map_err(|e| {
-        error!(error = ?e, "Failed to receive challenge solution");
-        ClientAuthError::Transport
-    })?;
-
-    if !pubkey.verify(nonce, CLIENT_CONTEXT, &signature) {
-        error!("Challenge solution verification failed");
-        return Err(ClientAuthError::InvalidChallengeSolution);
-    }
-
-    Ok(())
-}
-
-pub async fn authenticate<T>(
-    props: &mut ClientConnection,
-    transport: &mut T,
-) -> Result<i32, ClientAuthError>
-where
-    T: Bi<Inbound, Result<Outbound, ClientAuthError>> + Send + ?Sized,
-{
-    let Some(Inbound::AuthChallengeRequest { pubkey, metadata }) = transport.recv().await else {
-        return Err(ClientAuthError::Transport);
-    };
-
-    let client_id = if let Some((id, _)) = get_current_nonce_and_id(&props.db, &pubkey).await? {
-        verify_integrity(&props.db, &props.actors.key_holder, &pubkey).await?;
-        id
-    } else {
-        approve_new_client(
-            &props.actors,
-            ClientProfile {
-                pubkey: pubkey.clone(),
-                metadata: metadata.clone(),
-            },
-        )
-        .await?;
-        insert_client(&props.db, &props.actors.key_holder, &pubkey, &metadata).await?
-    };
-
-    sync_client_metadata(&props.db, client_id, &metadata).await?;
-    let challenge_nonce = create_nonce(&props.db, &props.actors.key_holder, &pubkey).await?;
-    challenge_client(transport, pubkey, challenge_nonce).await?;
-
-    transport
-        .send(Ok(Outbound::AuthSuccess))
-        .await
-        .map_err(|e| {
-            error!(error = ?e, "Failed to send auth success");
-            ClientAuthError::Transport
-        })?;
-
-    Ok(client_id)
-}

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

@@ -1,58 +0,0 @@
-use arbiter_crypto::authn;
-use arbiter_proto::{ClientMetadata, transport::Bi};
-use kameo::actor::Spawn;
-use tracing::{error, info};
-
-use crate::{
-    actors::{GlobalActors, client::session::ClientSession},
-    crypto::integrity::Integrable,
-    db,
-};
-
-#[derive(Debug, Clone)]
-pub struct ClientProfile {
-    pub pubkey: authn::PublicKey,
-    pub metadata: ClientMetadata,
-}
-
-#[derive(arbiter_macros::Hashable)]
-pub struct ClientCredentials {
-    pub pubkey: authn::PublicKey,
-    pub nonce: i32,
-}
-
-impl Integrable for ClientCredentials {
-    const KIND: &'static str = "client_credentials";
-}
-
-pub struct ClientConnection {
-    pub(crate) db: db::DatabasePool,
-    pub(crate) actors: GlobalActors,
-}
-
-impl ClientConnection {
-    pub const fn new(db: db::DatabasePool, actors: GlobalActors) -> Self {
-        Self { db, actors }
-    }
-}
-
-pub mod auth;
-pub mod session;
-
-pub async fn connect_client<T>(mut props: ClientConnection, transport: &mut T)
-where
-    T: Bi<auth::Inbound, Result<auth::Outbound, auth::ClientAuthError>> + Send + ?Sized,
-{
-    let fut = auth::authenticate(&mut props, transport);
-    println!("authenticate future size: {}", size_of_val(&fut));
-    match fut.await {
-        Ok(client_id) => {
-            ClientSession::spawn(ClientSession::new(props, client_id));
-            info!("Client authenticated, session started");
-        }
-        Err(err) => {
-            let _ = transport.send(Err(err.clone())).await;
-            error!(?err, "Authentication failed, closing connection");
-        }
-    }
-}

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

@@ -1,121 +0,0 @@
-use kameo::{Actor, messages};
-use tracing::error;
-
-use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
-
-use crate::{
-    actors::{
-        GlobalActors,
-        client::ClientConnection,
-        evm::{ClientSignTransaction, SignTransactionError},
-        flow_coordinator::RegisterClient,
-        keyholder::KeyHolderState,
-    },
-    db,
-    evm::VetError,
-};
-
-pub struct ClientSession {
-    props: ClientConnection,
-    client_id: i32,
-}
-
-impl ClientSession {
-    pub(crate) const fn new(props: ClientConnection, client_id: i32) -> Self {
-        Self { props, client_id }
-    }
-}
-
-#[messages]
-impl ClientSession {
-    #[message]
-    pub(crate) async fn handle_query_vault_state(
-        &mut self,
-    ) -> Result<KeyHolderState, ClientSessionError> {
-        use crate::actors::keyholder::GetState;
-
-        let vault_state = match self.props.actors.key_holder.ask(GetState {}).await {
-            Ok(state) => state,
-            Err(err) => {
-                error!(?err, actor = "client", "keyholder.query.failed");
-                return Err(ClientSessionError::Internal);
-            }
-        };
-
-        Ok(vault_state)
-    }
-
-    #[message]
-    pub(crate) async fn handle_sign_transaction(
-        &mut self,
-        wallet_address: Address,
-        transaction: TxEip1559,
-    ) -> Result<Signature, SignTransactionRpcError> {
-        match self
-            .props
-            .actors
-            .evm
-            .ask(ClientSignTransaction {
-                client_id: self.client_id,
-                wallet_address,
-                transaction,
-            })
-            .await
-        {
-            Ok(signature) => Ok(signature),
-            Err(kameo::error::SendError::HandlerError(SignTransactionError::Vet(vet_error))) => {
-                Err(SignTransactionRpcError::Vet(vet_error))
-            }
-            Err(err) => {
-                error!(?err, "Failed to sign EVM transaction in client session");
-                Err(SignTransactionRpcError::Internal)
-            }
-        }
-    }
-}
-
-impl Actor for ClientSession {
-    type Args = Self;
-
-    type Error = ClientSessionError;
-
-    async fn on_start(
-        args: Self::Args,
-        this: kameo::prelude::ActorRef<Self>,
-    ) -> Result<Self, Self::Error> {
-        args.props
-            .actors
-            .flow_coordinator
-            .ask(RegisterClient { actor: this })
-            .await
-            .map_err(|_| ClientSessionError::ConnectionRegistrationFailed)?;
-        Ok(args)
-    }
-}
-
-impl ClientSession {
-    pub const fn new_test(db: db::DatabasePool, actors: GlobalActors) -> Self {
-        let props = ClientConnection::new(db, actors);
-        Self {
-            props,
-            client_id: 0,
-        }
-    }
-}
-
-#[derive(Debug, thiserror::Error)]
-pub enum ClientSessionError {
-    #[error("Connection registration failed")]
-    ConnectionRegistrationFailed,
-    #[error("Internal error")]
-    Internal,
-}
-
-#[derive(Debug, thiserror::Error)]
-pub enum SignTransactionRpcError {
-    #[error("Internal error")]
-    Internal,
-
-    #[error("Policy evaluation failed")]
-    Vet(#[from] VetError),
-}

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

@@ -1,15 +1,5 @@
-use alloy::{
-    consensus::TxEip1559, network::TxSignerSync as _, primitives::Address, signers::Signature,
-};
-use diesel::{
-    ExpressionMethods, OptionalExtension as _, QueryDsl, SelectableHelper as _, dsl::insert_into,
-};
-use diesel_async::RunQueryDsl;
-use kameo::{Actor, actor::ActorRef, messages};
-use rand::{SeedableRng, rng, rngs::StdRng};
-
 use crate::{
-    actors::keyholder::{CreateNew, Decrypt, KeyHolder},
+    actors::vault::{CreateNew, Decrypt, Vault},
     crypto::integrity,
     db::{
         DatabaseError, DatabasePool,
@@ -26,6 +16,16 @@ use crate::{
 };
 use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 
+use alloy::{
+    consensus::TxEip1559, network::TxSignerSync as _, primitives::Address, signers::Signature,
+};
+use diesel::{
+    ExpressionMethods, OptionalExtension as _, QueryDsl, SelectableHelper as _, dsl::insert_into,
+};
+use diesel_async::RunQueryDsl;
+use kameo::{Actor, actor::ActorRef, messages};
+use rand::{SeedableRng, rng, rngs::StdRng};
+
 pub use crate::evm::safe_signer;
 
 #[derive(Debug, thiserror::Error)]
@@ -36,11 +36,11 @@ pub enum SignTransactionError {
     #[error("Database error: {0}")]
     Database(#[from] DatabaseError),
 
-    #[error("Keyholder error: {0}")]
-    Keyholder(#[from] crate::actors::keyholder::KeyHolderError),
+    #[error("Vault error: {0}")]
+    Vault(#[from] crate::actors::vault::Error),
 
-    #[error("Keyholder mailbox error")]
-    KeyholderSend,
+    #[error("Vault mailbox error")]
+    VaultSend,
 
     #[error("Signing error: {0}")]
     Signing(#[from] alloy::signers::Error),
@@ -50,36 +50,36 @@ pub enum SignTransactionError {
 }
 
 #[derive(Debug, thiserror::Error)]
-pub enum EvmActorError {
-    #[error("Keyholder error: {0}")]
-    Keyholder(#[from] crate::actors::keyholder::KeyHolderError),
+pub enum Error {
+    #[error("Vault error: {0}")]
+    Vault(#[from] crate::actors::vault::Error),
 
-    #[error("Keyholder mailbox error")]
-    KeyholderSend,
+    #[error("Vault mailbox error")]
+    VaultSend,
 
     #[error("Database error: {0}")]
     Database(#[from] DatabaseError),
 
     #[error("Integrity violation: {0}")]
-    Integrity(#[from] integrity::IntegrityError),
+    Integrity(#[from] integrity::Error),
 }
 
 #[derive(Actor)]
 pub struct EvmActor {
-    pub keyholder: ActorRef<KeyHolder>,
+    pub vault: ActorRef<Vault>,
     pub db: DatabasePool,
     pub rng: StdRng,
     pub engine: evm::Engine,
 }
 
 impl EvmActor {
-    pub fn new(keyholder: ActorRef<KeyHolder>, db: DatabasePool) -> Self {
+    pub fn new(vault: ActorRef<Vault>, db: DatabasePool) -> Self {
         // is it safe to seed rng from system once?
         // todo: audit
         let rng = StdRng::from_rng(&mut rng());
-        let engine = evm::Engine::new(db.clone(), keyholder.clone());
+        let engine = evm::Engine::new(db.clone(), vault.clone());
         Self {
-            keyholder,
+            vault,
             db,
             rng,
             engine,
@@ -90,16 +90,16 @@ impl EvmActor {
 #[messages]
 impl EvmActor {
     #[message]
-    pub async fn generate(&mut self) -> Result<(i32, Address), EvmActorError> {
+    pub async fn generate(&mut self) -> Result<(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()));
 
         let aead_id: i32 = self
-            .keyholder
+            .vault
             .ask(CreateNew { plaintext })
             .await
-            .map_err(|_| EvmActorError::KeyholderSend)?;
+            .map_err(|_| Error::VaultSend)?;
 
         let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
         let wallet_id = insert_into(schema::evm_wallet::table)
@@ -116,7 +116,7 @@ impl EvmActor {
     }
 
     #[message]
-    pub async fn list_wallets(&self) -> Result<Vec<(i32, Address)>, EvmActorError> {
+    pub async fn list_wallets(&self) -> Result<Vec<(i32, Address)>, Error> {
         let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
         let rows: Vec<models::EvmWallet> = schema::evm_wallet::table
             .select(models::EvmWallet::as_select())
@@ -138,7 +138,7 @@ impl EvmActor {
         &mut self,
         basic: SharedGrantSettings,
         grant: SpecificGrant,
-    ) -> Result<i32, EvmActorError> {
+    ) -> Result<i32, Error> {
         match grant {
             SpecificGrant::EtherTransfer(settings) => self
                 .engine
@@ -147,7 +147,7 @@ impl EvmActor {
                     specific: settings,
                 })
                 .await
-                .map_err(EvmActorError::from),
+                .map_err(Error::from),
             SpecificGrant::TokenTransfer(settings) => self
                 .engine
                 .create_grant::<TokenTransfer>(CombinedSettings {
@@ -155,15 +155,15 @@ impl EvmActor {
                     specific: settings,
                 })
                 .await
-                .map_err(EvmActorError::from),
+                .map_err(Error::from),
         }
     }
 
     #[message]
     #[expect(clippy::unused_async, reason = "reserved for impl")]
-    pub async fn useragent_delete_grant(&mut self, _grant_id: i32) -> Result<(), EvmActorError> {
+    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();
+        // let vault = self.vault.clone();
 
         // diesel_async::AsyncConnection::transaction(&mut conn, |conn| {
         //     Box::pin(async move {
@@ -186,15 +186,11 @@ impl EvmActor {
     }
 
     #[message]
-    pub async fn useragent_list_grants(
-        &mut self,
-    ) -> Result<Vec<Grant<SpecificGrant>>, EvmActorError> {
+    pub async fn useragent_list_grants(&mut self) -> Result<Vec<Grant<SpecificGrant>>, Error> {
         match self.engine.list_all_grants().await {
             Ok(grants) => Ok(grants),
-            Err(ListError::Database(db_err)) => Err(EvmActorError::Database(db_err)),
-            Err(ListError::Integrity(integrity_err)) => {
-                Err(EvmActorError::Integrity(integrity_err))
-            }
+            Err(ListError::Database(db_err)) => Err(Error::Database(db_err)),
+            Err(ListError::Integrity(integrity_err)) => Err(Error::Integrity(integrity_err)),
         }
     }
 
@@ -261,12 +257,12 @@ impl EvmActor {
         drop(conn);
 
         let raw_key: SafeCell<Vec<u8>> = self
-            .keyholder
+            .vault
             .ask(Decrypt {
                 aead_id: wallet.aead_encrypted_id,
             })
             .await
-            .map_err(|_| SignTransactionError::KeyholderSend)?;
+            .map_err(|_| SignTransactionError::VaultSend)?;
 
         let signer = safe_signer::SafeSigner::from_cell(raw_key)?;
 

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

@@ -1,16 +1,17 @@
-use std::ops::ControlFlow;
+use crate::{
+    actors::flow_coordinator::ApprovalError,
+    peers::{
+        client::ClientProfile,
+        user_agent::{UserAgentSession, session::BeginNewClientApproval},
+    },
+};
 
 use kameo::{
     Actor, messages,
     prelude::{ActorId, ActorRef, ActorStopReason, Context, WeakActorRef},
     reply::ReplySender,
 };
-
-use crate::actors::{
-    client::ClientProfile,
-    flow_coordinator::ApprovalError,
-    user_agent::{UserAgentSession, session::BeginNewClientApproval},
-};
+use std::ops::ControlFlow;
 
 pub struct Args {
     pub client: ClientProfile,

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

@@ -1,4 +1,10 @@
-use std::{collections::HashMap, ops::ControlFlow};
+use crate::{
+    actors::{
+        flow_coordinator::client_connect_approval::ClientApprovalController,
+        useragent_registry::{GetConnected, UserAgentRegistry},
+    },
+    peers::client::{ClientProfile, session::ClientSession},
+};
 
 use kameo::{
     Actor,
@@ -7,20 +13,23 @@ use kameo::{
     prelude::{ActorStopReason, Context, WeakActorRef},
     reply::DelegatedReply,
 };
+use std::{collections::HashMap, ops::ControlFlow};
 use tracing::info;
 
-use crate::actors::{
-    client::{ClientProfile, session::ClientSession},
-    flow_coordinator::client_connect_approval::ClientApprovalController,
-    user_agent::session::UserAgentSession,
-};
-
 pub mod client_connect_approval;
 
-#[derive(Default)]
 pub struct FlowCoordinator {
-    pub user_agents: HashMap<ActorId, ActorRef<UserAgentSession>>,
     pub clients: HashMap<ActorId, ActorRef<ClientSession>>,
+    useragent_registry: ActorRef<UserAgentRegistry>,
+}
+
+impl FlowCoordinator {
+    pub fn new(useragent_registry: ActorRef<UserAgentRegistry>) -> Self {
+        Self {
+            clients: HashMap::default(),
+            useragent_registry,
+        }
+    }
 }
 
 impl Actor for FlowCoordinator {
@@ -38,13 +47,7 @@ impl Actor for FlowCoordinator {
         id: ActorId,
         _: ActorStopReason,
     ) -> Result<ControlFlow<ActorStopReason>, Self::Error> {
-        if self.user_agents.remove(&id).is_some() {
-            info!(
-                ?id,
-                actor = "FlowCoordinator",
-                event = "useragent.disconnected"
-            );
-        } else if self.clients.remove(&id).is_some() {
+        if self.clients.remove(&id).is_some() {
             info!(
                 ?id,
                 actor = "FlowCoordinator",
@@ -69,17 +72,6 @@ pub enum ApprovalError {
 
 #[messages]
 impl FlowCoordinator {
-    #[message(ctx)]
-    pub async fn register_user_agent(
-        &mut self,
-        actor: ActorRef<UserAgentSession>,
-        ctx: &mut Context<Self, ()>,
-    ) {
-        info!(id = %actor.id(), actor = "FlowCoordinator", event = "useragent.connected");
-        ctx.actor_ref().link(&actor).await;
-        self.user_agents.insert(actor.id(), actor);
-    }
-
     #[message(ctx)]
     pub async fn register_client(
         &mut self,
@@ -92,7 +84,7 @@ impl FlowCoordinator {
     }
 
     #[message(ctx)]
-    pub fn request_client_approval(
+    pub async fn request_client_approval(
         &mut self,
         client: ClientProfile,
         ctx: &mut Context<Self, DelegatedReply<Result<bool, ApprovalError>>>,
@@ -101,7 +93,11 @@ impl FlowCoordinator {
             unreachable!("Expected `request_client_approval` to have callback channel");
         };
 
-        let refs: Vec<_> = self.user_agents.values().cloned().collect();
+        let Ok(refs) = self.useragent_registry.ask(GetConnected).await else {
+            reply_sender.send(Err(ApprovalError::NoUserAgentsConnected));
+            return reply;
+        };
+
         if refs.is_empty() {
             reply_sender.send(Err(ApprovalError::NoUserAgentsConnected));
             return reply;

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

@@ -1,47 +1,59 @@
-use kameo::actor::{ActorRef, Spawn};
-use thiserror::Error;
-
 use crate::{
     actors::{
         bootstrap::Bootstrapper, evm::EvmActor, flow_coordinator::FlowCoordinator,
-        keyholder::KeyHolder,
+        useragent_registry::UserAgentRegistry, vault::Vault,
     },
     db,
 };
 
+use kameo::actor::{ActorRef, Spawn};
+use kameo_actors::{DeliveryStrategy, message_bus::MessageBus};
+use thiserror::Error;
+
 pub mod bootstrap;
-pub mod client;
 pub mod evm;
 pub mod flow_coordinator;
-pub mod keyholder;
-pub mod user_agent;
+pub mod useragent_registry;
+pub mod vault;
 
 #[derive(Error, Debug)]
-pub enum GlobalActorsSpawnError {
+pub enum SpawnError {
     #[error("Failed to spawn Bootstrapper actor")]
-    Bootstrapper(#[from] bootstrap::BootstrappError),
+    Bootstrapper(#[from] bootstrap::Error),
 
-    #[error("Failed to spawn KeyHolder actor")]
-    KeyHolder(#[from] keyholder::KeyHolderError),
+    #[error("Failed to spawn Vault actor")]
+    Vault(#[from] vault::Error),
 }
 
 /// Long-lived actors that are shared across all connections and handle global state and operations
 #[derive(Clone)]
 pub struct GlobalActors {
-    pub key_holder: ActorRef<KeyHolder>,
+    pub vault: ActorRef<Vault>,
     pub bootstrapper: ActorRef<Bootstrapper>,
     pub flow_coordinator: ActorRef<FlowCoordinator>,
+    pub useragent_registry: ActorRef<UserAgentRegistry>,
     pub evm: ActorRef<EvmActor>,
+    pub events: ActorRef<MessageBus>,
 }
 
 impl GlobalActors {
-    pub async fn spawn(db: db::DatabasePool) -> Result<Self, GlobalActorsSpawnError> {
-        let key_holder = KeyHolder::spawn(KeyHolder::new(db.clone()).await?);
+    pub fn spawn_message_bus() -> ActorRef<MessageBus> {
+        MessageBus::spawn(MessageBus::new(DeliveryStrategy::Guaranteed))
+    }
+
+    pub async fn spawn(db: db::DatabasePool) -> Result<Self, SpawnError> {
+        let message_bus = Self::spawn_message_bus();
+        let key_holder = Vault::spawn(Vault::new(db.clone(), message_bus.clone()).await?);
+        let useragent_registry = UserAgentRegistry::spawn(UserAgentRegistry::default());
         Ok(Self {
             bootstrapper: Bootstrapper::spawn(Bootstrapper::new(&db).await?),
             evm: EvmActor::spawn(EvmActor::new(key_holder.clone(), db)),
-            key_holder,
-            flow_coordinator: FlowCoordinator::spawn(FlowCoordinator::default()),
+            vault: key_holder,
+            flow_coordinator: FlowCoordinator::spawn(FlowCoordinator::new(
+                useragent_registry.clone(),
+            )),
+            useragent_registry,
+            events: message_bus,
         })
     }
 }

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

@@ -1,110 +0,0 @@
-use arbiter_crypto::authn;
-use arbiter_proto::transport::Bi;
-use tracing::error;
-
-use crate::actors::user_agent::{
-    UserAgentConnection,
-    auth::state::{AuthContext, AuthStateMachine},
-};
-mod state;
-use state::{
-    AuthError, AuthEvents, AuthStates, BootstrapAuthRequest, ChallengeRequest, ChallengeSolution,
-};
-
-#[derive(Debug, Clone)]
-pub enum Inbound {
-    AuthChallengeRequest {
-        pubkey: authn::PublicKey,
-        bootstrap_token: Option<String>,
-    },
-    AuthChallengeSolution {
-        signature: Vec<u8>,
-    },
-}
-
-#[derive(Debug)]
-pub enum Error {
-    UnregisteredPublicKey,
-    InvalidChallengeSolution,
-    InvalidBootstrapToken,
-    Internal { details: String },
-    Transport,
-}
-
-impl Error {
-    fn internal(details: impl Into<String>) -> Self {
-        Self::Internal {
-            details: details.into(),
-        }
-    }
-}
-
-impl From<diesel::result::Error> for Error {
-    fn from(e: diesel::result::Error) -> Self {
-        error!(?e, "Database error");
-        Self::internal("Database error")
-    }
-}
-
-#[derive(Debug, Clone)]
-pub enum Outbound {
-    AuthChallenge { nonce: i32 },
-    AuthSuccess,
-}
-
-fn parse_auth_event(payload: Inbound) -> AuthEvents {
-    match payload {
-        Inbound::AuthChallengeRequest {
-            pubkey,
-            bootstrap_token: None,
-        } => AuthEvents::AuthRequest(ChallengeRequest { pubkey }),
-        Inbound::AuthChallengeRequest {
-            pubkey,
-            bootstrap_token: Some(token),
-        } => AuthEvents::BootstrapAuthRequest(BootstrapAuthRequest { pubkey, token }),
-        Inbound::AuthChallengeSolution { signature } => {
-            AuthEvents::ReceivedSolution(ChallengeSolution {
-                solution: signature,
-            })
-        }
-    }
-}
-
-pub async fn authenticate<T>(
-    props: &mut UserAgentConnection,
-    transport: T,
-) -> Result<authn::PublicKey, Error>
-where
-    T: Bi<Inbound, Result<Outbound, Error>> + Send,
-{
-    let mut state = AuthStateMachine::new(AuthContext::new(props, transport));
-
-    loop {
-        // `state` holds a mutable reference to `props` so we can't access it directly here
-        let Some(payload) = state.context_mut().transport.recv().await else {
-            return Err(Error::Transport);
-        };
-
-        match state.process_event(parse_auth_event(payload)).await {
-            Ok(AuthStates::AuthOk(key)) => return Ok(key.clone()),
-            Err(AuthError::ActionFailed(err)) => {
-                error!(?err, "State machine action failed");
-                return Err(err);
-            }
-            Err(AuthError::GuardFailed(err)) => {
-                error!(?err, "State machine guard failed");
-                return Err(err);
-            }
-            Err(AuthError::InvalidEvent) => {
-                error!("Invalid event for current state");
-                return Err(Error::InvalidChallengeSolution);
-            }
-            Err(AuthError::TransitionsFailed) => {
-                error!("Invalid state transition");
-                return Err(Error::InvalidChallengeSolution);
-            }
-
-            _ => (),
-        }
-    }
-}

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

@@ -1,308 +0,0 @@
-use arbiter_crypto::authn::{self, USERAGENT_CONTEXT};
-use arbiter_proto::transport::Bi;
-use diesel::{ExpressionMethods as _, OptionalExtension as _, QueryDsl, update};
-use diesel_async::{AsyncConnection, RunQueryDsl};
-use kameo::actor::ActorRef;
-use tracing::error;
-
-use super::Error;
-use crate::{
-    actors::{
-        bootstrap::ConsumeToken,
-        keyholder::KeyHolder,
-        user_agent::{UserAgentConnection, UserAgentCredentials, auth::Outbound},
-    },
-    crypto::integrity,
-    db::{DatabasePool, schema::useragent_client},
-};
-
-pub struct ChallengeRequest {
-    pub pubkey: authn::PublicKey,
-}
-
-pub struct BootstrapAuthRequest {
-    pub pubkey: authn::PublicKey,
-    pub token: String,
-}
-
-pub struct ChallengeContext {
-    pub challenge_nonce: i32,
-    pub key: authn::PublicKey,
-}
-
-pub struct ChallengeSolution {
-    pub solution: Vec<u8>,
-}
-
-smlang::statemachine!(
-    name: Auth,
-    custom_error: true,
-    transitions: {
-        *Init + AuthRequest(ChallengeRequest) / async prepare_challenge = SentChallenge(ChallengeContext),
-        Init + BootstrapAuthRequest(BootstrapAuthRequest) / async verify_bootstrap_token = AuthOk(authn::PublicKey),
-        SentChallenge(ChallengeContext) + ReceivedSolution(ChallengeSolution) / async verify_solution = AuthOk(authn::PublicKey),
-    }
-);
-
-/// Returns the current nonce, ready to use for the challenge nonce.
-async fn get_current_nonce_and_id(
-    db: &DatabasePool,
-    key: &authn::PublicKey,
-) -> Result<(i32, i32), Error> {
-    let mut db_conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        Error::internal("Database unavailable")
-    })?;
-    db_conn
-        .exclusive_transaction(|conn| {
-            Box::pin(async move {
-                useragent_client::table
-                    .filter(useragent_client::public_key.eq(key.to_bytes()))
-                    .select((useragent_client::id, useragent_client::nonce))
-                    .first::<(i32, i32)>(conn)
-                    .await
-            })
-        })
-        .await
-        .optional()
-        .map_err(|e| {
-            error!(error = ?e, "Database error");
-            Error::internal("Database operation failed")
-        })?
-        .ok_or_else(|| {
-            error!(?key, "Public key not found in database");
-            Error::UnregisteredPublicKey
-        })
-}
-
-async fn verify_integrity(
-    db: &DatabasePool,
-    keyholder: &ActorRef<KeyHolder>,
-    pubkey: &authn::PublicKey,
-) -> Result<(), Error> {
-    let mut db_conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        Error::internal("Database unavailable")
-    })?;
-
-    let (id, nonce) = get_current_nonce_and_id(db, pubkey).await?;
-
-    let _result = integrity::verify_entity(
-        &mut db_conn,
-        keyholder,
-        &UserAgentCredentials {
-            pubkey: pubkey.clone(),
-            nonce,
-        },
-        id,
-    )
-    .await
-    .map_err(|e| {
-        error!(?e, "Integrity verification failed");
-        Error::internal("Integrity verification failed")
-    })?;
-
-    Ok(())
-}
-
-async fn create_nonce(
-    db: &DatabasePool,
-    keyholder: &ActorRef<KeyHolder>,
-    pubkey: &authn::PublicKey,
-) -> Result<i32, Error> {
-    let mut db_conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        Error::internal("Database unavailable")
-    })?;
-    let new_nonce = db_conn
-        .exclusive_transaction(|conn| {
-            Box::pin(async move {
-                let (id, new_nonce): (i32, i32) = update(useragent_client::table)
-                    .filter(useragent_client::public_key.eq(pubkey.to_bytes()))
-                    .set(useragent_client::nonce.eq(useragent_client::nonce + 1))
-                    .returning((useragent_client::id, useragent_client::nonce))
-                    .get_result(conn)
-                    .await
-                    .map_err(|e| {
-                        error!(error = ?e, "Database error");
-                        Error::internal("Database operation failed")
-                    })?;
-
-                integrity::sign_entity(
-                    conn,
-                    keyholder,
-                    &UserAgentCredentials {
-                        pubkey: pubkey.clone(),
-                        nonce: new_nonce,
-                    },
-                    id,
-                )
-                .await
-                .map_err(|e| {
-                    error!(?e, "Integrity signature update failed");
-                    Error::internal("Database error")
-                })?;
-
-                Result::<_, Error>::Ok(new_nonce)
-            })
-        })
-        .await?;
-    Ok(new_nonce)
-}
-
-async fn register_key(
-    db: &DatabasePool,
-    keyholder: &ActorRef<KeyHolder>,
-    pubkey: &authn::PublicKey,
-) -> Result<(), Error> {
-    let pubkey_bytes = pubkey.to_bytes();
-    let mut conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        Error::internal("Database unavailable")
-    })?;
-
-    conn.transaction(|conn| {
-        Box::pin(async move {
-            const NONCE_START: i32 = 1;
-
-            let id: i32 = diesel::insert_into(useragent_client::table)
-                .values((
-                    useragent_client::public_key.eq(pubkey_bytes),
-                    useragent_client::nonce.eq(NONCE_START),
-                ))
-                .returning(useragent_client::id)
-                .get_result(conn)
-                .await
-                .map_err(|e| {
-                    error!(error = ?e, "Database error");
-                    Error::internal("Database operation failed")
-                })?;
-
-            let entity = UserAgentCredentials {
-                pubkey: pubkey.clone(),
-                nonce: NONCE_START,
-            };
-
-            integrity::sign_entity(conn, keyholder, &entity, id)
-                .await
-                .map_err(|e| {
-                    error!(error = ?e, "Failed to sign integrity tag for new user-agent key");
-                    Error::internal("Failed to register public key")
-                })?;
-
-            Result::<_, Error>::Ok(())
-        })
-    })
-    .await?;
-
-    Ok(())
-}
-
-pub struct AuthContext<'a, T> {
-    pub(super) conn: &'a mut UserAgentConnection,
-    pub(super) transport: T,
-}
-
-impl<'a, T> AuthContext<'a, T> {
-    pub const fn new(conn: &'a mut UserAgentConnection, transport: T) -> Self {
-        Self { conn, transport }
-    }
-}
-
-impl<T> AuthStateMachineContext for AuthContext<'_, T>
-where
-    T: Bi<super::Inbound, Result<Outbound, Error>> + Send,
-{
-    type Error = Error;
-
-    async fn prepare_challenge(
-        &mut self,
-        ChallengeRequest { pubkey }: ChallengeRequest,
-    ) -> Result<ChallengeContext, Self::Error> {
-        verify_integrity(&self.conn.db, &self.conn.actors.key_holder, &pubkey).await?;
-
-        let nonce = create_nonce(&self.conn.db, &self.conn.actors.key_holder, &pubkey).await?;
-
-        self.transport
-            .send(Ok(Outbound::AuthChallenge { nonce }))
-            .await
-            .map_err(|e| {
-                error!(?e, "Failed to send auth challenge");
-                Error::Transport
-            })?;
-
-        Ok(ChallengeContext {
-            challenge_nonce: nonce,
-            key: pubkey,
-        })
-    }
-
-    async fn verify_bootstrap_token(
-        &mut self,
-        BootstrapAuthRequest { pubkey, token }: BootstrapAuthRequest,
-    ) -> Result<authn::PublicKey, Self::Error> {
-        let token_ok: bool = self
-            .conn
-            .actors
-            .bootstrapper
-            .ask(ConsumeToken {
-                token: token.clone(),
-            })
-            .await
-            .map_err(|e| {
-                error!(?e, "Failed to consume bootstrap token");
-                Error::internal("Failed to consume bootstrap token")
-            })?;
-
-        if !token_ok {
-            error!("Invalid bootstrap token provided");
-            return Err(Error::InvalidBootstrapToken);
-        }
-
-        if token_ok {
-            register_key(&self.conn.db, &self.conn.actors.key_holder, &pubkey).await?;
-            self.transport
-                .send(Ok(Outbound::AuthSuccess))
-                .await
-                .map_err(|_| Error::Transport)?;
-            Ok(pubkey)
-        } else {
-            error!("Invalid bootstrap token provided");
-            self.transport
-                .send(Err(Error::InvalidBootstrapToken))
-                .await
-                .map_err(|_| Error::Transport)?;
-            Err(Error::InvalidBootstrapToken)
-        }
-    }
-
-    async fn verify_solution(
-        &mut self,
-        ChallengeContext {
-            challenge_nonce,
-            key,
-        }: &ChallengeContext,
-        ChallengeSolution { solution }: ChallengeSolution,
-    ) -> Result<authn::PublicKey, Self::Error> {
-        let signature = authn::Signature::try_from(solution.as_slice()).map_err(|()| {
-            error!("Failed to decode signature in challenge solution");
-            Error::InvalidChallengeSolution
-        })?;
-
-        let valid = key.verify(*challenge_nonce, USERAGENT_CONTEXT, &signature);
-
-        if valid {
-            self.transport
-                .send(Ok(Outbound::AuthSuccess))
-                .await
-                .map_err(|_| Error::Transport)?;
-            Ok(key.clone())
-        } else {
-            self.transport
-                .send(Err(Error::InvalidChallengeSolution))
-                .await
-                .map_err(|_| Error::Transport)?;
-            Err(Error::InvalidChallengeSolution)
-        }
-    }
-}

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

@@ -1,40 +0,0 @@
-use crate::{
-    actors::{GlobalActors, client::ClientProfile},
-    crypto::integrity::Integrable,
-    db,
-};
-use arbiter_crypto::authn;
-
-#[derive(Debug, arbiter_macros::Hashable)]
-pub struct UserAgentCredentials {
-    pub pubkey: authn::PublicKey,
-    pub nonce: i32,
-}
-
-impl Integrable for UserAgentCredentials {
-    const KIND: &'static str = "useragent_credentials";
-}
-
-// Messages, sent by user agent to connection client without having a request
-#[derive(Debug)]
-pub enum OutOfBand {
-    ClientConnectionRequest { profile: ClientProfile },
-    ClientConnectionCancel { pubkey: authn::PublicKey },
-}
-
-pub struct UserAgentConnection {
-    pub(crate) db: db::DatabasePool,
-    pub(crate) actors: GlobalActors,
-}
-
-impl UserAgentConnection {
-    pub const fn new(db: db::DatabasePool, actors: GlobalActors) -> Self {
-        Self { db, actors }
-    }
-}
-
-pub mod auth;
-pub mod session;
-
-pub use auth::authenticate;
-pub use session::UserAgentSession;

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

@@ -1,193 +0,0 @@
-use arbiter_crypto::authn;
-
-use std::{borrow::Cow, collections::HashMap};
-
-use arbiter_proto::transport::Sender;
-use async_trait::async_trait;
-use kameo::{Actor, actor::ActorRef, messages};
-use thiserror::Error;
-use tracing::error;
-
-use crate::actors::{
-    client::ClientProfile,
-    flow_coordinator::{RegisterUserAgent, client_connect_approval::ClientApprovalController},
-    user_agent::{OutOfBand, UserAgentConnection},
-};
-mod state;
-use state::{DummyContext, UserAgentEvents, UserAgentStateMachine};
-
-#[derive(Debug, Error)]
-pub enum UserAgentSessionError {
-    #[error("Internal error: {message}")]
-    Internal { message: Cow<'static, str> },
-
-    #[error("State transition failed")]
-    State,
-}
-
-impl From<crate::db::PoolError> for UserAgentSessionError {
-    fn from(err: crate::db::PoolError) -> Self {
-        error!(?err, "Database pool error");
-        Self::internal("Database pool error")
-    }
-}
-impl From<diesel::result::Error> for UserAgentSessionError {
-    fn from(err: diesel::result::Error) -> Self {
-        error!(?err, "Database error");
-        Self::internal("Database error")
-    }
-}
-
-impl UserAgentSessionError {
-    pub fn internal(message: impl Into<Cow<'static, str>>) -> Self {
-        Self::Internal {
-            message: message.into(),
-        }
-    }
-}
-
-pub struct PendingClientApproval {
-    pubkey: authn::PublicKey,
-    controller: ActorRef<ClientApprovalController>,
-}
-
-pub struct UserAgentSession {
-    props: UserAgentConnection,
-    state: UserAgentStateMachine<DummyContext>,
-    sender: Box<dyn Sender<OutOfBand>>,
-
-    pending_client_approvals: HashMap<Vec<u8>, PendingClientApproval>,
-}
-
-pub mod connection;
-
-impl UserAgentSession {
-    pub(crate) fn new(props: UserAgentConnection, sender: Box<dyn Sender<OutOfBand>>) -> Self {
-        Self {
-            props,
-            state: UserAgentStateMachine::new(DummyContext),
-            sender,
-            pending_client_approvals: HashMap::default(),
-        }
-    }
-
-    pub fn new_test(db: crate::db::DatabasePool, actors: crate::actors::GlobalActors) -> Self {
-        struct DummySender;
-
-        #[async_trait]
-        impl Sender<OutOfBand> for DummySender {
-            async fn send(
-                &mut self,
-                _item: OutOfBand,
-            ) -> Result<(), arbiter_proto::transport::Error> {
-                Ok(())
-            }
-        }
-
-        Self::new(UserAgentConnection::new(db, actors), Box::new(DummySender))
-    }
-
-    fn transition(&mut self, event: UserAgentEvents) -> Result<(), UserAgentSessionError> {
-        self.state.process_event(event).map_err(|e| {
-            error!(?e, "State transition failed");
-            UserAgentSessionError::State
-        })?;
-        Ok(())
-    }
-}
-
-#[messages]
-impl UserAgentSession {
-    #[message]
-    pub async fn begin_new_client_approval(
-        &mut self,
-        client: ClientProfile,
-        controller: ActorRef<ClientApprovalController>,
-    ) {
-        if let Err(e) = self
-            .sender
-            .send(OutOfBand::ClientConnectionRequest {
-                profile: client.clone(),
-            })
-            .await
-        {
-            error!(
-                ?e,
-                actor = "user_agent",
-                event = "failed to announce new client connection"
-            );
-            return;
-        }
-
-        self.pending_client_approvals.insert(
-            client.pubkey.to_bytes(),
-            PendingClientApproval {
-                pubkey: client.pubkey,
-                controller,
-            },
-        );
-    }
-}
-
-impl Actor for UserAgentSession {
-    type Args = Self;
-
-    type Error = UserAgentSessionError;
-
-    async fn on_start(
-        args: Self::Args,
-        this: ActorRef<Self>,
-    ) -> Result<Self, Self::Error> {
-        args.props
-            .actors
-            .flow_coordinator
-            .ask(RegisterUserAgent {
-                actor: this.clone(),
-            })
-            .await
-            .map_err(|err| {
-                error!(
-                    ?err,
-                    "Failed to register user agent connection with flow coordinator"
-                );
-                UserAgentSessionError::internal(
-                    "Failed to register user agent connection with flow coordinator",
-                )
-            })?;
-        Ok(args)
-    }
-
-    async fn on_link_died(
-        &mut self,
-        _: kameo::prelude::WeakActorRef<Self>,
-        id: kameo::prelude::ActorId,
-        _: kameo::prelude::ActorStopReason,
-    ) -> Result<std::ops::ControlFlow<kameo::prelude::ActorStopReason>, Self::Error> {
-        let cancelled_pubkey = self
-            .pending_client_approvals
-            .iter()
-            .find_map(|(k, v)| (v.controller.id() == id).then_some(k.clone()));
-
-        if let Some(pubkey_bytes) = cancelled_pubkey {
-            let Some(approval) = self.pending_client_approvals.remove(&pubkey_bytes) else {
-                return Ok(std::ops::ControlFlow::Continue(()));
-            };
-
-            if let Err(e) = self
-                .sender
-                .send(OutOfBand::ClientConnectionCancel {
-                    pubkey: approval.pubkey,
-                })
-                .await
-            {
-                error!(
-                    ?e,
-                    actor = "user_agent",
-                    event = "failed to announce client connection cancellation"
-                );
-            }
-        }
-
-        Ok(std::ops::ControlFlow::Continue(()))
-    }
-}

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

@@ -1,534 +0,0 @@
-use std::sync::Mutex;
-
-use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
-use arbiter_crypto::{
-    authn,
-    safecell::{SafeCell, SafeCellHandle as _},
-};
-use chacha20poly1305::{AeadInPlace, XChaCha20Poly1305, XNonce, aead::KeyInit};
-use diesel::{ExpressionMethods as _, QueryDsl as _, SelectableHelper};
-use diesel_async::{AsyncConnection, RunQueryDsl};
-use kameo::error::SendError;
-use kameo::messages;
-use kameo::prelude::Context;
-use thiserror::Error;
-use tracing::{error, info};
-use x25519_dalek::{EphemeralSecret, PublicKey};
-
-use crate::{actors::flow_coordinator::client_connect_approval::ClientApprovalAnswer, evm::policies::SharedGrantSettings};
-use crate::actors::keyholder::KeyHolderState;
-use crate::actors::user_agent::session::UserAgentSessionError;
-use crate::actors::{
-    evm::{
-        ClientSignTransaction, Generate, ListWallets, SignTransactionError as EvmSignError,
-        UseragentCreateGrant, UseragentListGrants,
-    },
-    keyholder::{self, Bootstrap, TryUnseal},
-    user_agent::session::{
-        UserAgentSession,
-        state::{UnsealContext, UserAgentEvents, UserAgentStates},
-    },
-};
-use crate::db::models::{
-    EvmWalletAccess, NewEvmWalletAccess, ProgramClient, ProgramClientMetadata,
-};
-use crate::evm::policies::{Grant, SpecificGrant};
-
-impl UserAgentSession {
-    fn take_unseal_secret(&self) -> Result<(EphemeralSecret, PublicKey), UserAgentSessionError> {
-        let UserAgentStates::WaitingForUnsealKey(unseal_context) = self.state.state() else {
-            error!("Received encrypted key in invalid state");
-            return Err(UserAgentSessionError::internal(
-                "Invalid state for unseal encrypted key",
-            ));
-        };
-
-        let ephemeral_secret = {
-            #[allow(
-                clippy::unwrap_used,
-                reason = "Mutex poison is unrecoverable and should panic"
-            )]
-            let mut secret_lock = unseal_context.secret.lock().unwrap();
-            let secret = secret_lock.take();
-            if let Some(secret) = secret {
-                secret
-            } else {
-                drop(secret_lock);
-                error!("Ephemeral secret already taken");
-                return Err(UserAgentSessionError::internal(
-                    "Ephemeral secret already taken",
-                ));
-            }
-        };
-
-        Ok((ephemeral_secret, unseal_context.client_public_key))
-    }
-
-    fn decrypt_client_key_material(
-        ephemeral_secret: EphemeralSecret,
-        client_public_key: PublicKey,
-        nonce: &[u8],
-        ciphertext: &[u8],
-        associated_data: &[u8],
-    ) -> Result<SafeCell<Vec<u8>>, ()> {
-        let nonce = XNonce::from_slice(nonce);
-
-        let shared_secret = ephemeral_secret.diffie_hellman(&client_public_key);
-        let cipher = XChaCha20Poly1305::new(shared_secret.as_bytes().into());
-
-        let mut key_buffer = SafeCell::new(ciphertext.to_vec());
-
-        let decryption_result = key_buffer.write_inline(|write_handle| {
-            cipher.decrypt_in_place(nonce, associated_data, write_handle)
-        });
-
-        match decryption_result {
-            Ok(()) => Ok(key_buffer),
-            Err(err) => {
-                error!(?err, "Failed to decrypt encrypted key material");
-                Err(())
-            }
-        }
-    }
-}
-
-pub struct UnsealStartResponse {
-    pub server_pubkey: PublicKey,
-}
-
-#[derive(Debug, Error)]
-pub enum UnsealError {
-    #[error("Invalid key provided for unsealing")]
-    InvalidKey,
-    #[error("Internal error during unsealing process")]
-    General(#[from] UserAgentSessionError),
-}
-
-#[derive(Debug, Error)]
-pub enum BootstrapError {
-    #[error("Invalid key provided for bootstrapping")]
-    InvalidKey,
-    #[error("Vault is already bootstrapped")]
-    AlreadyBootstrapped,
-
-    #[error("Internal error during bootstrapping process")]
-    General(#[from] UserAgentSessionError),
-}
-
-#[derive(Debug, Error)]
-pub enum SignTransactionError {
-    #[error("Policy evaluation failed")]
-    Vet(#[from] crate::evm::VetError),
-
-    #[error("Internal signing error")]
-    Internal,
-}
-
-#[derive(Debug, Error)]
-pub enum GrantMutationError {
-    #[error("Vault is sealed")]
-    VaultSealed,
-
-    #[error("Internal grant mutation error")]
-    Internal,
-}
-
-#[messages]
-impl UserAgentSession {
-    #[message]
-    pub fn handle_unseal_request(
-        &mut self,
-        client_pubkey: PublicKey,
-    ) -> Result<UnsealStartResponse, UserAgentSessionError> {
-        let secret = EphemeralSecret::random();
-        let public_key = PublicKey::from(&secret);
-
-        self.transition(UserAgentEvents::UnsealRequest(UnsealContext {
-            client_public_key: client_pubkey,
-            secret: Mutex::new(Some(secret)),
-        }))?;
-
-        Ok(UnsealStartResponse {
-            server_pubkey: public_key,
-        })
-    }
-
-    #[message]
-    pub async fn handle_unseal_encrypted_key(
-        &mut self,
-        nonce: Vec<u8>,
-        ciphertext: Vec<u8>,
-        associated_data: Vec<u8>,
-    ) -> Result<(), UnsealError> {
-        let (ephemeral_secret, client_public_key) = match self.take_unseal_secret() {
-            Ok(values) => values,
-            Err(UserAgentSessionError::State) => {
-                self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                return Err(UnsealError::InvalidKey);
-            }
-            Err(_err) => {
-                return Err(UserAgentSessionError::internal("Failed to take unseal secret").into());
-            }
-        };
-
-        let Ok(seal_key_buffer) = Self::decrypt_client_key_material(
-            ephemeral_secret,
-            client_public_key,
-            &nonce,
-            &ciphertext,
-            &associated_data,
-        ) else {
-            self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-            return Err(UnsealError::InvalidKey);
-        };
-
-        match self
-            .props
-            .actors
-            .key_holder
-            .ask(TryUnseal {
-                seal_key_raw: seal_key_buffer,
-            })
-            .await
-        {
-            Ok(()) => {
-                info!("Successfully unsealed key with client-provided key");
-                self.transition(UserAgentEvents::ReceivedValidKey)?;
-                Ok(())
-            }
-            Err(SendError::HandlerError(keyholder::KeyHolderError::InvalidKey)) => {
-                self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                Err(UnsealError::InvalidKey)
-            }
-            Err(SendError::HandlerError(err)) => {
-                error!(?err, "Keyholder failed to unseal key");
-                self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                Err(UnsealError::InvalidKey)
-            }
-            Err(err) => {
-                error!(?err, "Failed to send unseal request to keyholder");
-                self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                Err(UserAgentSessionError::internal("Vault actor error").into())
-            }
-        }
-    }
-
-    #[message]
-    pub(crate) async fn handle_bootstrap_encrypted_key(
-        &mut self,
-        nonce: Vec<u8>,
-        ciphertext: Vec<u8>,
-        associated_data: Vec<u8>,
-    ) -> Result<(), BootstrapError> {
-        let (ephemeral_secret, client_public_key) = match self.take_unseal_secret() {
-            Ok(values) => values,
-            Err(UserAgentSessionError::State) => {
-                self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                return Err(BootstrapError::InvalidKey);
-            }
-            Err(err) => return Err(err.into()),
-        };
-
-        let Ok(seal_key_buffer) = Self::decrypt_client_key_material(
-            ephemeral_secret,
-            client_public_key,
-            &nonce,
-            &ciphertext,
-            &associated_data,
-        ) else {
-            self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-            return Err(BootstrapError::InvalidKey);
-        };
-
-        match self
-            .props
-            .actors
-            .key_holder
-            .ask(Bootstrap {
-                seal_key_raw: seal_key_buffer,
-            })
-            .await
-        {
-            Ok(()) => {
-                info!("Successfully bootstrapped vault with client-provided key");
-                self.transition(UserAgentEvents::ReceivedValidKey)?;
-                Ok(())
-            }
-            Err(SendError::HandlerError(keyholder::KeyHolderError::AlreadyBootstrapped)) => {
-                self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                Err(BootstrapError::AlreadyBootstrapped)
-            }
-            Err(SendError::HandlerError(err)) => {
-                error!(?err, "Keyholder failed to bootstrap vault");
-                self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                Err(BootstrapError::InvalidKey)
-            }
-            Err(err) => {
-                error!(?err, "Failed to send bootstrap request to keyholder");
-                self.transition(UserAgentEvents::ReceivedInvalidKey)?;
-                Err(BootstrapError::General(UserAgentSessionError::internal(
-                    "Vault actor error",
-                )))
-            }
-        }
-    }
-}
-
-#[messages]
-impl UserAgentSession {
-    #[message]
-    pub(crate) async fn handle_query_vault_state(
-        &mut self,
-    ) -> Result<KeyHolderState, UserAgentSessionError> {
-        use crate::actors::keyholder::GetState;
-
-        let vault_state = match self.props.actors.key_holder.ask(GetState {}).await {
-            Ok(state) => state,
-            Err(err) => {
-                error!(?err, actor = "useragent", "keyholder.query.failed");
-                return Err(UserAgentSessionError::internal("Vault is in broken state"));
-            }
-        };
-
-        Ok(vault_state)
-    }
-}
-
-#[messages]
-impl UserAgentSession {
-    #[message]
-    pub(crate) async fn handle_evm_wallet_create(
-        &mut self,
-    ) -> Result<(i32, Address), UserAgentSessionError> {
-        match self.props.actors.evm.ask(Generate {}).await {
-            Ok(address) => Ok(address),
-            Err(SendError::HandlerError(err)) => Err(UserAgentSessionError::internal(format!(
-                "EVM wallet generation failed: {err}"
-            ))),
-            Err(err) => {
-                error!(?err, "EVM actor unreachable during wallet create");
-                Err(UserAgentSessionError::internal("EVM actor unreachable"))
-            }
-        }
-    }
-
-    #[message]
-    pub(crate) async fn handle_evm_wallet_list(
-        &mut self,
-    ) -> Result<Vec<(i32, Address)>, UserAgentSessionError> {
-        match self.props.actors.evm.ask(ListWallets {}).await {
-            Ok(wallets) => Ok(wallets),
-            Err(err) => {
-                error!(?err, "EVM wallet list failed");
-                Err(UserAgentSessionError::internal(
-                    "Failed to list EVM wallets",
-                ))
-            }
-        }
-    }
-}
-
-#[messages]
-impl UserAgentSession {
-    #[message]
-    pub(crate) async fn handle_grant_list(
-        &mut self,
-    ) -> Result<Vec<Grant<SpecificGrant>>, UserAgentSessionError> {
-        match self.props.actors.evm.ask(UseragentListGrants {}).await {
-            Ok(grants) => Ok(grants),
-            Err(err) => {
-                error!(?err, "EVM grant list failed");
-                Err(UserAgentSessionError::internal("Failed to list EVM grants"))
-            }
-        }
-    }
-
-    #[message]
-    pub(crate) async fn handle_grant_create(
-        &mut self,
-        basic: SharedGrantSettings,
-        grant: SpecificGrant,
-    ) -> Result<i32, GrantMutationError> {
-        match self
-            .props
-            .actors
-            .evm
-            .ask(UseragentCreateGrant { basic, grant })
-            .await
-        {
-            Ok(grant_id) => Ok(grant_id),
-            Err(err) => {
-                error!(?err, "EVM grant create failed");
-                Err(GrantMutationError::Internal)
-            }
-        }
-    }
-
-    #[message]
-    #[expect(clippy::unused_async, reason = "false positive")]
-    pub(crate) async fn handle_grant_delete(
-        &mut self,
-        grant_id: i32,
-    ) -> Result<(), GrantMutationError> {
-        // match self
-        //     .props
-        //     .actors
-        //     .evm
-        //     .ask(UseragentDeleteGrant { grant_id })
-        //     .await
-        // {
-        //     Ok(()) => Ok(()),
-        //     Err(err) => {
-        //         error!(?err, "EVM grant delete failed");
-        //         Err(GrantMutationError::Internal)
-        //     }
-        // }
-        let _ = grant_id;
-        todo!()
-    }
-
-    #[message]
-    pub(crate) async fn handle_sign_transaction(
-        &mut self,
-        client_id: i32,
-        wallet_address: Address,
-        transaction: TxEip1559,
-    ) -> Result<Signature, SignTransactionError> {
-        match self
-            .props
-            .actors
-            .evm
-            .ask(ClientSignTransaction {
-                client_id,
-                wallet_address,
-                transaction,
-            })
-            .await
-        {
-            Ok(signature) => Ok(signature),
-            Err(SendError::HandlerError(EvmSignError::Vet(vet_error))) => {
-                Err(SignTransactionError::Vet(vet_error))
-            }
-            Err(err) => {
-                error!(?err, "EVM sign transaction failed in user-agent session");
-                Err(SignTransactionError::Internal)
-            }
-        }
-    }
-
-    #[message]
-    pub(crate) async fn handle_grant_evm_wallet_access(
-        &mut self,
-        entries: Vec<NewEvmWalletAccess>,
-    ) -> Result<(), UserAgentSessionError> {
-        let mut conn = self.props.db.get().await?;
-        conn.transaction(|conn| {
-            Box::pin(async move {
-                use crate::db::schema::evm_wallet_access;
-
-                for entry in entries {
-                    diesel::insert_into(evm_wallet_access::table)
-                        .values(&entry)
-                        .on_conflict_do_nothing()
-                        .execute(conn)
-                        .await?;
-                }
-
-                Result::<_, UserAgentSessionError>::Ok(())
-            })
-        })
-        .await?;
-        Ok(())
-    }
-
-    #[message]
-    pub(crate) async fn handle_revoke_evm_wallet_access(
-        &mut self,
-        entries: Vec<i32>,
-    ) -> Result<(), UserAgentSessionError> {
-        let mut conn = self.props.db.get().await?;
-        conn.transaction(|conn| {
-            Box::pin(async move {
-                use crate::db::schema::evm_wallet_access;
-                for entry in entries {
-                    diesel::delete(evm_wallet_access::table)
-                        .filter(evm_wallet_access::wallet_id.eq(entry))
-                        .execute(conn)
-                        .await?;
-                }
-
-                Result::<_, UserAgentSessionError>::Ok(())
-            })
-        })
-        .await?;
-        Ok(())
-    }
-
-    #[message]
-    pub(crate) async fn handle_list_wallet_access(
-        &mut self,
-    ) -> Result<Vec<EvmWalletAccess>, UserAgentSessionError> {
-        let mut conn = self.props.db.get().await?;
-        let access_entries = crate::db::schema::evm_wallet_access::table
-            .select(EvmWalletAccess::as_select())
-            .load::<_>(&mut conn)
-            .await?;
-        Ok(access_entries)
-    }
-}
-
-#[messages]
-impl UserAgentSession {
-    #[message(ctx)]
-    pub(crate) async fn handle_new_client_approve(
-        &mut self,
-        approved: bool,
-        pubkey: authn::PublicKey,
-        ctx: &Context<Self, Result<(), UserAgentSessionError>>,
-    ) -> Result<(), UserAgentSessionError> {
-        let Some(pending_approval) = self.pending_client_approvals.remove(&pubkey.to_bytes())
-        else {
-            error!("Received client connection response for unknown client");
-            return Err(UserAgentSessionError::internal(
-                "Unknown client in connection response",
-            ));
-        };
-
-        pending_approval
-            .controller
-            .tell(ClientApprovalAnswer { approved })
-            .await
-            .map_err(|err| {
-                error!(
-                    ?err,
-                    "Failed to send client approval response to controller"
-                );
-                UserAgentSessionError::internal(
-                    "Failed to send client approval response to controller",
-                )
-            })?;
-
-        ctx.actor_ref().unlink(&pending_approval.controller).await;
-
-        Ok(())
-    }
-
-    #[message]
-    pub(crate) async fn handle_sdk_client_list(
-        &mut self,
-    ) -> Result<Vec<(ProgramClient, ProgramClientMetadata)>, UserAgentSessionError> {
-        use crate::db::schema::{client_metadata, program_client};
-        let mut conn = self.props.db.get().await?;
-
-        let clients = program_client::table
-            .inner_join(client_metadata::table)
-            .select((
-                ProgramClient::as_select(),
-                ProgramClientMetadata::as_select(),
-            ))
-            .load::<(ProgramClient, ProgramClientMetadata)>(&mut conn)
-            .await?;
-
-        Ok(clients)
-    }
-}

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

@@ -1,25 +0,0 @@
-use std::sync::Mutex;
-
-use x25519_dalek::{EphemeralSecret, PublicKey};
-
-pub struct UnsealContext {
-    pub client_public_key: PublicKey,
-    pub secret: Mutex<Option<EphemeralSecret>>,
-}
-
-smlang::statemachine!(
-    name: UserAgent,
-    custom_error: false,
-    transitions: {
-        *Idle + UnsealRequest(UnsealContext) / generate_temp_keypair = WaitingForUnsealKey(UnsealContext),
-        WaitingForUnsealKey(UnsealContext) + ReceivedValidKey = Unsealed,
-        WaitingForUnsealKey(UnsealContext) + ReceivedInvalidKey = Idle,
-    }
-);
-
-pub struct DummyContext;
-impl UserAgentStateMachineContext for DummyContext {
-    fn generate_temp_keypair(&mut self, event_data: UnsealContext) -> Result<UnsealContext, ()> {
-        Ok(event_data)
-    }
-}

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

@@ -0,0 +1,61 @@
+use crate::peers::user_agent::UserAgentSession;
+
+use kameo::{
+    Actor,
+    actor::{ActorId, ActorRef},
+    error::Infallible,
+    messages,
+    prelude::{ActorStopReason, Context, WeakActorRef},
+};
+use std::{collections::HashMap, ops::ControlFlow};
+use tracing::info;
+
+#[derive(Default)]
+pub struct UserAgentRegistry {
+    connected: HashMap<ActorId, ActorRef<UserAgentSession>>,
+}
+
+impl Actor for UserAgentRegistry {
+    type Args = Self;
+
+    type Error = Infallible;
+
+    async fn on_start(args: Self::Args, _: ActorRef<Self>) -> Result<Self, Self::Error> {
+        Ok(args)
+    }
+
+    async fn on_link_died(
+        &mut self,
+        _: WeakActorRef<Self>,
+        id: ActorId,
+        _: ActorStopReason,
+    ) -> Result<ControlFlow<ActorStopReason>, Self::Error> {
+        if self.connected.remove(&id).is_some() {
+            info!(
+                ?id,
+                actor = "UserAgentRegistry",
+                event = "useragent.disconnected"
+            );
+        }
+        Ok(ControlFlow::Continue(()))
+    }
+}
+
+#[messages]
+impl UserAgentRegistry {
+    #[message(ctx)]
+    pub async fn connect_useragent(
+        &mut self,
+        actor: ActorRef<UserAgentSession>,
+        ctx: &mut Context<Self, ()>,
+    ) {
+        info!(id = %actor.id(), actor = "UserAgentRegistry", event = "useragent.connected");
+        ctx.actor_ref().link(&actor).await;
+        self.connected.insert(actor.id(), actor);
+    }
+
+    #[message]
+    pub fn get_connected(&self) -> Vec<ActorRef<UserAgentSession>> {
+        self.connected.values().cloned().collect()
+    }
+}

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

@@ -1,47 +1,57 @@
+use crate::{
+    crypto::{
+        KeyCell, derive_key,
+        encryption::v1::{self, Nonce},
+        integrity::v1::HmacSha256,
+    },
+    db::{
+        self,
+        models::{self, RootKeyHistory},
+        schema::{self},
+    },
+};
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+
 use chrono::Utc;
 use diesel::{
     ExpressionMethods as _, OptionalExtension, QueryDsl, SelectableHelper,
     dsl::{insert_into, update},
 };
 use diesel_async::{AsyncConnection, RunQueryDsl};
-use hmac::Mac as _;
-use kameo::{Actor, Reply, messages};
+use hmac::{KeyInit as _, Mac as _};
+use kameo::{Actor, Reply, actor::ActorRef, messages};
+use kameo_actors::message_bus::{MessageBus, Publish};
 use strum::{EnumDiscriminants, IntoDiscriminant};
 use tracing::{error, info};
 
-use crate::crypto::{
-    KeyCell, derive_key,
-    encryption::v1::{self, Nonce},
-    integrity::v1::HmacSha256,
-};
-use crate::db::{
-    self,
-    models::{self, RootKeyHistory},
-    schema::{self},
-};
-use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+pub mod events {
 
-#[derive(Default, EnumDiscriminants)]
-#[strum_discriminants(derive(Reply), vis(pub), name(KeyHolderState))]
-enum State {
-    #[default]
-    Unbootstrapped,
-    Sealed {
-        root_key_history_id: i32,
-    },
-    Unsealed {
-        root_key_history_id: i32,
-        root_key: KeyCell,
-    },
+    #[derive(Clone, Copy)]
+    pub struct Bootstrapped;
+
+    #[derive(Clone, Copy)]
+    pub struct Unsealed;
+
+    #[derive(Clone, Copy)]
+    pub struct VaultResealed;
 }
 
 #[derive(Debug, thiserror::Error)]
-pub enum KeyHolderError {
-    #[error("Keyholder is already bootstrapped")]
+pub enum Error {
+    #[error("Vault is already bootstrapped")]
     AlreadyBootstrapped,
+    #[error("Vault is not bootstrapped")]
+    NotBootstrapped,
+    #[error("Vault is sealed")]
+    Sealed,
+    #[error("Invalid key provided")]
+    InvalidKey,
 
-    #[error("Broken database")]
-    BrokenDatabase,
+    #[error("Requested aead entry not found")]
+    NotFound,
+
+    #[error("Encryption error: {0}")]
+    Encryption(#[from] chacha20poly1305::aead::Error),
 
     #[error("Database error: {0}")]
     DatabaseConnection(#[from] db::PoolError),
@@ -49,17 +59,24 @@ pub enum KeyHolderError {
     #[error("Database transaction error: {0}")]
     DatabaseTransaction(#[from] diesel::result::Error),
 
-    #[error("Encryption error: {0}")]
-    Encryption(#[from] chacha20poly1305::aead::Error),
+    #[error("Broken database")]
+    BrokenDatabase,
+}
 
-    #[error("Invalid key provided")]
-    InvalidKey,
+struct Unsealed {
+    root_key_history_id: i32,
+    root_key: KeyCell,
+}
 
-    #[error("Keyholder is not bootstrapped")]
-    NotBootstrapped,
-
-    #[error("Requested aead entry not found")]
-    NotFound,
+#[derive(Default, EnumDiscriminants)]
+#[strum_discriminants(derive(Reply), vis(pub), name(VaultState))]
+enum State {
+    #[default]
+    Unbootstrapped,
+    Sealed {
+        root_key_history_id: i32,
+    },
+    Unsealed(Unsealed),
 }
 
 /// Manages vault root key and tracks current state of the vault (bootstrapped/unbootstrapped, sealed/unsealed).
@@ -67,14 +84,15 @@ pub enum KeyHolderError {
 /// Provides API for encrypting and decrypting data using the vault root key.
 /// Abstraction over database to make sure nonces are never reused and encryption keys are never exposed in plaintext outside of this actor.
 #[derive(Actor)]
-pub struct KeyHolder {
+pub struct Vault {
     db: db::DatabasePool,
     state: State,
+    events: ActorRef<MessageBus>,
 }
 
 #[messages]
-impl KeyHolder {
-    pub async fn new(db: db::DatabasePool) -> Result<Self, KeyHolderError> {
+impl Vault {
+    pub async fn new(db: db::DatabasePool, events: ActorRef<MessageBus>) -> Result<Self, Error> {
         let state = {
             let mut conn = db.get().await?;
 
@@ -92,15 +110,12 @@ impl KeyHolder {
             }
         };
 
-        Ok(Self { db, state })
+        Ok(Self { db, state, events })
     }
 
-    // Exclusive transaction to avoid race condtions if multiple keyholders write
+    // Exclusive transaction to avoid race condtions if multiple vaults write
     // additional layer of protection against nonce-reuse
-    async fn get_new_nonce(
-        pool: &db::DatabasePool,
-        root_key_id: i32,
-    ) -> Result<Nonce, KeyHolderError> {
+    async fn get_new_nonce(pool: &db::DatabasePool, root_key_id: i32) -> Result<Nonce, Error> {
         let mut conn = pool.get().await?;
 
         let nonce = conn
@@ -117,7 +132,7 @@ impl KeyHolder {
                             "Broken database: invalid nonce for root key history id={}",
                             root_key_id
                         );
-                        KeyHolderError::BrokenDatabase
+                        Error::BrokenDatabase
                     })?;
                     nonce.increment();
 
@@ -127,7 +142,7 @@ impl KeyHolder {
                         .execute(conn)
                         .await?;
 
-                    Result::<_, KeyHolderError>::Ok(nonce)
+                    Result::<_, Error>::Ok(nonce)
                 })
             })
             .await?;
@@ -135,13 +150,18 @@ impl KeyHolder {
         Ok(nonce)
     }
 
+    const fn expect_unsealed(state: &mut State) -> Result<&mut Unsealed, Error> {
+        match state {
+            State::Unsealed(unsealed) => Ok(unsealed),
+            State::Unbootstrapped => Err(Error::NotBootstrapped),
+            State::Sealed { .. } => Err(Error::Sealed),
+        }
+    }
+
     #[message]
-    pub async fn bootstrap(
-        &mut self,
-        seal_key_raw: SafeCell<Vec<u8>>,
-    ) -> Result<(), KeyHolderError> {
+    pub async fn bootstrap(&mut self, seal_key_raw: SafeCell<Vec<u8>>) -> Result<(), Error> {
         if !matches!(self.state, State::Unbootstrapped) {
-            return Err(KeyHolderError::AlreadyBootstrapped);
+            return Err(Error::AlreadyBootstrapped);
         }
         let salt = v1::generate_salt();
         let mut seal_key = derive_key(seal_key_raw, &salt);
@@ -157,7 +177,7 @@ impl KeyHolder {
                 .encrypt(&root_key_nonce, v1::ROOT_KEY_TAG, root_key_reader)
                 .map_err(|err| {
                     error!(?err, "Fatal bootstrap error");
-                    KeyHolderError::Encryption(err)
+                    Error::Encryption(err)
                 })
         })?;
 
@@ -190,26 +210,24 @@ impl KeyHolder {
             })
             .await?;
 
-        self.state = State::Unsealed {
+        self.state = State::Unsealed(Unsealed {
             root_key,
             root_key_history_id,
-        };
+        });
 
-        info!("Keyholder bootstrapped successfully");
+        info!("Vault bootstrapped successfully");
+        let _ = self.events.tell(Publish(events::Bootstrapped)).await;
 
         Ok(())
     }
 
     #[message]
-    pub async fn try_unseal(
-        &mut self,
-        seal_key_raw: SafeCell<Vec<u8>>,
-    ) -> Result<(), KeyHolderError> {
+    pub async fn try_unseal(&mut self, seal_key_raw: SafeCell<Vec<u8>>) -> Result<(), Error> {
         let State::Sealed {
             root_key_history_id,
         } = &self.state
         else {
-            return Err(KeyHolderError::NotBootstrapped);
+            return Err(Error::NotBootstrapped);
         };
 
         // We don't want to hold connection while doing expensive KDF work
@@ -225,44 +243,42 @@ impl KeyHolder {
         let salt = &current_key.salt;
         let salt = v1::Salt::try_from(salt.as_slice()).map_err(|_| {
             error!("Broken database: invalid salt for root key");
-            KeyHolderError::BrokenDatabase
+            Error::BrokenDatabase
         })?;
         let mut seal_key = derive_key(seal_key_raw, &salt);
 
         let mut root_key = SafeCell::new(current_key.ciphertext.clone());
 
-        let nonce = Nonce::try_from(current_key.root_key_encryption_nonce.as_slice()).map_err(
-            |()| {
+        let nonce =
+            Nonce::try_from(current_key.root_key_encryption_nonce.as_slice()).map_err(|()| {
                 error!("Broken database: invalid nonce for root key");
-                KeyHolderError::BrokenDatabase
-            },
-        )?;
+                Error::BrokenDatabase
+            })?;
 
         seal_key
             .decrypt_in_place(&nonce, v1::ROOT_KEY_TAG, &mut root_key)
             .map_err(|err| {
                 error!(?err, "Failed to unseal root key: invalid seal key");
-                KeyHolderError::InvalidKey
+                Error::InvalidKey
             })?;
 
-        self.state = State::Unsealed {
+        self.state = State::Unsealed(Unsealed {
             root_key_history_id: current_key.id,
             root_key: KeyCell::try_from(root_key).map_err(|err| {
                 error!(?err, "Broken database: invalid encryption key size");
-                KeyHolderError::BrokenDatabase
+                Error::BrokenDatabase
             })?,
-        };
+        });
 
-        info!("Keyholder unsealed successfully");
+        info!("Vault unsealed successfully");
+        let _ = self.events.tell(Publish(events::Unsealed)).await;
 
         Ok(())
     }
 
     #[message]
-    pub async fn decrypt(&mut self, aead_id: i32) -> Result<SafeCell<Vec<u8>>, KeyHolderError> {
-        let State::Unsealed { root_key, .. } = &mut self.state else {
-            return Err(KeyHolderError::NotBootstrapped);
-        };
+    pub async fn decrypt(&mut self, aead_id: i32) -> Result<SafeCell<Vec<u8>>, Error> {
+        let Unsealed { root_key, .. } = Self::expect_unsealed(&mut self.state)?;
 
         let row: models::AeadEncrypted = {
             let mut conn = self.db.get().await?;
@@ -272,7 +288,7 @@ impl KeyHolder {
                 .first(&mut conn)
                 .await
                 .optional()?
-                .ok_or(KeyHolderError::NotFound)?
+                .ok_or(Error::NotFound)?
         };
 
         let nonce = Nonce::try_from(row.current_nonce.as_slice()).map_err(|()| {
@@ -280,7 +296,7 @@ impl KeyHolder {
                 "Broken database: invalid nonce for aead_encrypted id={}",
                 aead_id
             );
-            KeyHolderError::BrokenDatabase
+            Error::BrokenDatabase
         })?;
         let mut output = SafeCell::new(row.ciphertext);
         root_key.decrypt_in_place(&nonce, v1::TAG, &mut output)?;
@@ -289,18 +305,11 @@ impl KeyHolder {
 
     // Creates new `aead_encrypted` entry in the database and returns it's ID
     #[message]
-    pub async fn create_new(
-        &mut self,
-        mut plaintext: SafeCell<Vec<u8>>,
-    ) -> Result<i32, KeyHolderError> {
-        let State::Unsealed {
+    pub async fn create_new(&mut self, mut plaintext: SafeCell<Vec<u8>>) -> Result<i32, Error> {
+        let Unsealed {
             root_key,
             root_key_history_id,
-            ..
-        } = &mut self.state
-        else {
-            return Err(KeyHolderError::NotBootstrapped);
-        };
+        } = Self::expect_unsealed(&mut self.state)?;
 
         // Order matters here - `get_new_nonce` acquires connection, so we need to call it before next acquire
         // Borrow checker note: &mut borrow a few lines above is disjoint from this field
@@ -330,24 +339,23 @@ impl KeyHolder {
     }
 
     #[message]
-    pub fn get_state(&self) -> KeyHolderState {
+    pub fn get_state(&self) -> VaultState {
         self.state.discriminant()
     }
 
     #[message]
-    pub fn sign_integrity(&mut self, mac_input: Vec<u8>) -> Result<(i32, Vec<u8>), KeyHolderError> {
-        let State::Unsealed {
+    pub fn sign_integrity(&mut self, mac_input: Vec<u8>) -> Result<(i32, Vec<u8>), Error> {
+        let Unsealed {
             root_key,
             root_key_history_id,
-        } = &mut self.state
-        else {
-            return Err(KeyHolderError::NotBootstrapped);
-        };
+        } = Self::expect_unsealed(&mut self.state)?;
 
-        let mut hmac = root_key.0.read_inline(|k| {
-            HmacSha256::new_from_slice(k)
-                .unwrap_or_else(|_| unreachable!("HMAC accepts keys of any size"))
-        });
+        let mut hmac = root_key
+            .0
+            .read_inline(|k| match HmacSha256::new_from_slice(k) {
+                Ok(v) => v,
+                Err(_) => unreachable!("HMAC accepts keys of any size"),
+            });
         hmac.update(&root_key_history_id.to_be_bytes());
         hmac.update(&mac_input);
 
@@ -361,23 +369,22 @@ impl KeyHolder {
         mac_input: Vec<u8>,
         expected_mac: Vec<u8>,
         key_version: i32,
-    ) -> Result<bool, KeyHolderError> {
-        let State::Unsealed {
+    ) -> Result<bool, Error> {
+        let Unsealed {
             root_key,
             root_key_history_id,
-        } = &mut self.state
-        else {
-            return Err(KeyHolderError::NotBootstrapped);
-        };
+        } = Self::expect_unsealed(&mut self.state)?;
 
         if *root_key_history_id != key_version {
             return Ok(false);
         }
 
-        let mut hmac = root_key.0.read_inline(|k| {
-            HmacSha256::new_from_slice(k)
-                .unwrap_or_else(|_| unreachable!("HMAC accepts keys of any size"))
-        });
+        let mut hmac = root_key
+            .0
+            .read_inline(|k| match HmacSha256::new_from_slice(k) {
+                Ok(v) => v,
+                Err(_) => unreachable!("HMAC accepts keys of any size"),
+            });
         hmac.update(&key_version.to_be_bytes());
         hmac.update(&mac_input);
 
@@ -385,29 +392,31 @@ impl KeyHolder {
     }
 
     #[message]
-    pub fn seal(&mut self) -> Result<(), KeyHolderError> {
-        let State::Unsealed {
+    pub async fn seal(&mut self) -> Result<(), Error> {
+        let Unsealed {
             root_key_history_id,
             ..
-        } = &self.state
-        else {
-            return Err(KeyHolderError::NotBootstrapped);
-        };
+        } = Self::expect_unsealed(&mut self.state)?;
+
         self.state = State::Sealed {
             root_key_history_id: *root_key_history_id,
         };
+        let _ = self.events.tell(Publish(events::VaultResealed)).await;
         Ok(())
     }
 }
 
 #[cfg(test)]
 mod tests {
+    use crate::actors::GlobalActors;
     use arbiter_crypto::safecell::SafeCellHandle as _;
 
     use super::*;
 
-    async fn bootstrapped_actor(db: &db::DatabasePool) -> KeyHolder {
-        let mut actor = KeyHolder::new(db.clone()).await.unwrap();
+    async fn bootstrapped_actor(db: &db::DatabasePool) -> Vault {
+        let mut actor = Vault::new(db.clone(), GlobalActors::spawn_message_bus())
+            .await
+            .unwrap();
         let seal_key = SafeCell::new(b"test-seal-key".to_vec());
         actor.bootstrap(seal_key).await.unwrap();
         actor
@@ -418,25 +427,25 @@ mod tests {
     async fn nonce_monotonic_even_when_nonce_allocation_interleaves() {
         let db = db::create_test_pool().await;
         let mut actor = bootstrapped_actor(&db).await;
-        let State::Unsealed {
-            root_key_history_id,
-            ..
-        } = actor.state
-        else {
-            panic!("expected unsealed state");
+        let root_key_history_id = match actor.state {
+            State::Unsealed(Unsealed {
+                root_key_history_id,
+                ..
+            }) => root_key_history_id,
+            _ => panic!("expected unsealed state"),
         };
 
-        let n1 = KeyHolder::get_new_nonce(&db, root_key_history_id)
+        let n1 = Vault::get_new_nonce(&db, root_key_history_id)
             .await
             .unwrap();
-        let n2 = KeyHolder::get_new_nonce(&db, root_key_history_id)
+        let n2 = Vault::get_new_nonce(&db, root_key_history_id)
             .await
             .unwrap();
         assert!(n2.to_vec() > n1.to_vec(), "nonce must increase");
 
         let mut conn = db.get().await.unwrap();
-        let root_row = schema::root_key_history::table
-            .select(RootKeyHistory::as_select())
+        let root_row: models::RootKeyHistory = schema::root_key_history::table
+            .select(models::RootKeyHistory::as_select())
             .first(&mut conn)
             .await
             .unwrap();