[Auth] Handle errors

Example/IntegrationTests/Auth/AuthTests.swift

@@ -70,7 +70,7 @@ final class AuthTests: XCTestCase {
             Task(priority: .high) {
                 let signature = try! MessageSigner(signer: Signer()).sign(message: message, privateKey: prvKey)
                 let cacaoSignature = CacaoSignature(t: "eip191", s: signature)
-                try! await wallet.respond(.success(RespondParams(id: id, signature: cacaoSignature)))
+                try! await wallet.respond(requestId: id, result: .success(cacaoSignature))
             }
         }
         .store(in: &publishers)
@@ -79,6 +79,6 @@ final class AuthTests: XCTestCase {
             responseExpectation.fulfill()
         }
         .store(in: &publishers)
-        wait(for: [responseExpectation], timeout: 2)
+        wait(for: [responseExpectation], timeout: .infinity)
     }
 }

Sources/Auth/AuthClient.swift

@@ -15,8 +15,8 @@ public class AuthClient {
         authRequestPublisherSubject.eraseToAnyPublisher()
     }
 
-    private var authResponsePublisherSubject = PassthroughSubject<(id: RPCID, result: Result<Cacao, ErrorCode>), Never>()
-    public var authResponsePublisher: AnyPublisher<(id: RPCID, result: Result<Cacao, ErrorCode>), Never> {
+    private var authResponsePublisherSubject = PassthroughSubject<(id: RPCID, result: Result<Cacao, InternalError>), Never>()
+    public var authResponsePublisher: AnyPublisher<(id: RPCID, result: Result<Cacao, InternalError>), Never> {
         authResponsePublisherSubject.eraseToAnyPublisher()
     }
 
@@ -87,9 +87,9 @@ public class AuthClient {
         try await appRequestService.request(params: params, topic: topic)
     }
 
-    public func respond(_ result: Result<RespondParams, ErrorCode>) async throws {
+    public func respond(requestId: RPCID, result: Result<CacaoSignature, ExternalError>) async throws {
         guard let account = account else { throw Errors.unknownWalletAddress }
-        try await walletRespondService.respond(result: result, account: account)
+        try await walletRespondService.respond(requestId: requestId, result: result, account: account)
     }
 
     public func getPendingRequests() throws -> [AuthRequest] {

Sources/Auth/AuthClientFactory.swift

@@ -26,7 +26,7 @@ public struct AuthClientFactory {
         let messageSigner = MessageSigner(signer: Signer())
         let appRespondSubscriber = AppRespondSubscriber(networkingInteractor: networkingInteractor, logger: logger, rpcHistory: history, signatureVerifier: messageSigner, messageFormatter: messageFormatter)
         let walletPairService = WalletPairService(networkingInteractor: networkingInteractor, kms: kms, pairingStorage: pairingStore)
-        let walletRequestSubscriber = WalletRequestSubscriber(networkingInteractor: networkingInteractor, logger: logger, messageFormatter: messageFormatter, address: account?.address)
+        let walletRequestSubscriber = WalletRequestSubscriber(networkingInteractor: networkingInteractor, logger: logger, kms: kms, messageFormatter: messageFormatter, address: account?.address)
         let walletRespondService = WalletRespondService(networkingInteractor: networkingInteractor, logger: logger, kms: kms, rpcHistory: history)
         let pendingRequestsProvider = PendingRequestsProvider(rpcHistory: history)
         let cleanupService = CleanupService(pairingStore: pairingStore, kms: kms)

Sources/Auth/Services/App/AppRespondSubscriber.swift

@@ -10,7 +10,8 @@ class AppRespondSubscriber {
     private let signatureVerifier: MessageSignatureVerifying
     private let messageFormatter: SIWEMessageFormatting
     private var publishers = [AnyCancellable]()
-    var onResponse: ((_ id: RPCID, _ result: Result<Cacao, ErrorCode>) -> Void)?
+
+    var onResponse: ((_ id: RPCID, _ result: Result<Cacao, InternalError>) -> Void)?
 
     init(networkingInteractor: NetworkInteracting,
          logger: ConsoleLogging,
@@ -26,7 +27,6 @@ class AppRespondSubscriber {
     }
 
     private func subscribeForResponse() {
-        // TODO - handle error response
         networkingInteractor.responsePublisher.sink { [unowned self] subscriptionPayload in
             guard
                 let requestId = subscriptionPayload.response.id,
@@ -36,30 +36,23 @@ class AppRespondSubscriber {
 
             networkingInteractor.unsubscribe(topic: subscriptionPayload.topic)
 
-            do {
-                guard let cacao = try subscriptionPayload.response.result?.get(Cacao.self) else {
-                    return logger.debug("Malformed auth response params")
-                }
+            guard
+                let cacao = try? subscriptionPayload.response.result?.get(Cacao.self),
+                let address = try? DIDPKH(iss: cacao.payload.iss).account.address,
+                let message = try? messageFormatter.formatMessage(from: cacao.payload)
+            else { self.onResponse?(requestId, .failure(.malformedResponseParams)); return }
+
+            guard let requestPayload = try? requestParams.get(AuthRequestParams.self)
+            else { self.onResponse?(requestId, .failure(.malformedRequestParams)); return }
+
+            guard messageFormatter.formatMessage(from: requestPayload.payloadParams, address: address) == message
+            else { self.onResponse?(requestId, .failure(.messageCompromised)); return }
 
-                let requestPayload = try requestParams.get(AuthRequestParams.self)
-                let address = try DIDPKH(iss: cacao.payload.iss).account.address
-                let message = try messageFormatter.formatMessage(from: cacao.payload)
-                let originalMessage = messageFormatter.formatMessage(from: requestPayload.payloadParams, address: address)
+            guard let _ = try? signatureVerifier.verify(signature: cacao.signature.s, message: message, address: address)
+            else { self.onResponse?(requestId, .failure(.messageVerificationFailed)); return }
 
-                guard originalMessage == message else {
-                    return logger.debug("Original message compromised")
-                }
+            onResponse?(requestId, .success(cacao))
 
-                try signatureVerifier.verify(
-                    signature: cacao.signature.s,
-                    message: message,
-                    address: address
-                )
-                logger.debug("Received response with valid signature")
-                onResponse?(requestId, .success(cacao))
-            } catch {
-                logger.debug("Received response with invalid signature")
-            }
         }.store(in: &publishers)
     }
 }

Sources/Auth/Services/Common/NetworkingInteractor.swift

@@ -13,6 +13,7 @@ protocol NetworkInteracting {
     func request(_ request: RPCRequest, topic: String, tag: Int, envelopeType: Envelope.EnvelopeType) async throws
     func requestNetworkAck(_ request: RPCRequest, topic: String, tag: Int) async throws 
     func respond(topic: String, response: RPCResponse, tag: Int, envelopeType: Envelope.EnvelopeType) async throws
+    func respondError(topic: String, requestId: RPCID, tag: Int, reason: Reason, envelopeType: Envelope.EnvelopeType) async throws
 }
 
 extension NetworkInteracting {
@@ -27,14 +28,17 @@ class NetworkingInteractor: NetworkInteracting {
     private let serializer: Serializing
     private let rpcHistory: RPCHistory
     private let logger: ConsoleLogging
+
+    private let requestPublisherSubject = PassthroughSubject<RequestSubscriptionPayload, Never>()
     var requestPublisher: AnyPublisher<RequestSubscriptionPayload, Never> {
         requestPublisherSubject.eraseToAnyPublisher()
     }
-    private let requestPublisherSubject = PassthroughSubject<RequestSubscriptionPayload, Never>()
+
+    private let responsePublisherSubject = PassthroughSubject<ResponseSubscriptionPayload, Never>()
     var responsePublisher: AnyPublisher<ResponseSubscriptionPayload, Never> {
         responsePublisherSubject.eraseToAnyPublisher()
     }
-    private let responsePublisherSubject = PassthroughSubject<ResponseSubscriptionPayload, Never>()
+
     var socketConnectionStatusPublisher: AnyPublisher<SocketConnectionStatus, Never>
 
     init(relayClient: RelayClient,
@@ -99,11 +103,18 @@ class NetworkingInteractor: NetworkInteracting {
         try await relayClient.publish(topic: topic, payload: message, tag: tag)
     }
 
+    func respondError(topic: String, requestId: RPCID, tag: Int, reason: Reason, envelopeType: Envelope.EnvelopeType) async throws {
+        let error = JSONRPCError(code: reason.code, message: reason.message)
+        let response = RPCResponse(id: requestId, error: error)
+        let message = try! serializer.serialize(topic: topic, encodable: response, envelopeType: envelopeType)
+        try await relayClient.publish(topic: topic, payload: message, tag: tag)
+    }
+
     private func manageSubscription(_ topic: String, _ encodedEnvelope: String) {
         if let deserializedJsonRpcRequest: RPCRequest = serializer.tryDeserialize(topic: topic, encodedEnvelope: encodedEnvelope) {
             handleRequest(topic: topic, request: deserializedJsonRpcRequest)
-        } else if let deserializedJsonRpcResponse: RPCResponse = serializer.tryDeserialize(topic: topic, encodedEnvelope: encodedEnvelope) {
-            handleResponse(response: deserializedJsonRpcResponse)
+        } else if let response: RPCResponse = serializer.tryDeserialize(topic: topic, encodedEnvelope: encodedEnvelope) {
+            handleResponse(response: response)
         } else {
             logger.debug("Networking Interactor - Received unknown object type from networking relay")
         }

Sources/Auth/Services/Wallet/WalletRequestSubscriber.swift

@@ -2,48 +2,58 @@ import Combine
 import Foundation
 import WalletConnectUtils
 import JSONRPC
+import WalletConnectKMS
 
 class WalletRequestSubscriber {
     private let networkingInteractor: NetworkInteracting
     private let logger: ConsoleLogging
+    private let kms: KeyManagementServiceProtocol
     private let address: String?
     private var publishers = [AnyCancellable]()
     private let messageFormatter: SIWEMessageFormatting
     var onRequest: ((_ id: RPCID, _ message: String) -> Void)?
 
     init(networkingInteractor: NetworkInteracting,
          logger: ConsoleLogging,
+         kms: KeyManagementServiceProtocol,
          messageFormatter: SIWEMessageFormatting,
          address: String?) {
         self.networkingInteractor = networkingInteractor
         self.logger = logger
+        self.kms = kms
         self.address = address
         self.messageFormatter = messageFormatter
         subscribeForRequest()
     }
 
     private func subscribeForRequest() {
-        guard let address = address else {return}
-        networkingInteractor.requestPublisher.sink { [unowned self] subscriptionPayload in
+        guard let address = address else { return }
+
+        networkingInteractor.requestPublisher.sink { [unowned self] payload in
+
             logger.debug("WalletRequestSubscriber: Received request")
-            guard
-                let requestId = subscriptionPayload.request.id,
-                subscriptionPayload.request.method == "wc_authRequest" else { return }
-
-            do {
-                guard let authRequestParams = try subscriptionPayload.request.params?.get(AuthRequestParams.self) else { return logger.debug("Malformed auth request params")
-                }
-
-                let message = messageFormatter.formatMessage(
-                    from: authRequestParams.payloadParams,
-                    address: address
-                )
-
-                onRequest?(requestId, message)
-            } catch {
-                logger.debug(error)
-            }
+
+            guard let requestId = payload.request.id, payload.request.method == "wc_authRequest"
+            else { return }
+
+            guard let authRequestParams = try? payload.request.params?.get(AuthRequestParams.self)
+            else { return respondError(.malformedRequestParams, topic: payload.topic, requestId: requestId) }
+
+            let message = messageFormatter.formatMessage(from: authRequestParams.payloadParams, address: address)
+
+            onRequest?(requestId, message)
         }.store(in: &publishers)
     }
 
+    private func respondError(_ error: InternalError, topic: String, requestId: RPCID) {
+        guard let pubKey = kms.getAgreementSecret(for: topic)?.publicKey
+        else { return logger.error("Agreement key for topic \(topic) not found") }
+
+        let tag = AuthResponseParams.tag
+        let envelopeType = Envelope.EnvelopeType.type1(pubKey: pubKey.rawRepresentation)
+
+        Task(priority: .high) {
+            try await networkingInteractor.respondError(topic: topic, requestId: requestId, tag: tag, reason: error, envelopeType: envelopeType)
+        }
+    }
 }

Sources/Auth/Services/Wallet/WalletRespondService.swift

@@ -22,30 +22,54 @@ actor WalletRespondService {
         self.kms = kms
         self.rpcHistory = rpcHistory
     }
-    
-    func respond(result: Result<RespondParams, ErrorCode>, account: Account) async throws {
+
+    func respond(requestId: RPCID, result: Result<CacaoSignature, ExternalError>, account: Account) async throws {
         switch result {
-        case .success(let params):
-            try await respond(respondParams: params, account: account)
+        case .success(let signature):
+            try await respond(requestId: requestId, signature: signature, account: account)
         case .failure(let error):
-            fatalError("TODO respond with error")
+            try await respond(error: error, requestId: requestId)
         }
     }
 
-    private func respond(respondParams: RespondParams, account: Account) async throws {
-        guard let request = rpcHistory.get(recordId: respondParams.id)?.request else { throw Errors.recordForIdNotFound }
-        guard let authRequestParams = try? request.params?.get(AuthRequestParams.self) else { throw Errors.malformedAuthRequestParams }
+    private func respond(requestId: RPCID, signature: CacaoSignature, account: Account) async throws {
+        let authRequestParams = try getAuthRequestParams(requestId: requestId)
+        let (topic, keys) = try generateAgreementKeys(requestParams: authRequestParams)
 
-        let peerPubKey = try AgreementPublicKey(hex: authRequestParams.requester.publicKey)
-        let responseTopic = peerPubKey.rawRepresentation.sha256().toHexString()
-        let selfPubKey = try kms.createX25519KeyPair()
-        let agreementKeys = try kms.performKeyAgreement(selfPublicKey: selfPubKey, peerPublicKey: peerPubKey.hexRepresentation)
-        try kms.setAgreementSecret(agreementKeys, topic: responseTopic)
+        try kms.setAgreementSecret(keys, topic: topic)
 
         let didpkh = DIDPKH(account: account)
-        let cacao = CacaoFormatter().format(authRequestParams, respondParams.signature, didpkh)
-        let response = RPCResponse(id: request.id!, result: cacao)
+        let cacao = CacaoFormatter().format(authRequestParams, signature, didpkh)
+        let response = RPCResponse(id: requestId, result: cacao)
+        try await networkingInteractor.respond(topic: topic, response: response, tag: AuthResponseParams.tag, envelopeType: .type1(pubKey: keys.publicKey.rawRepresentation))
+    }
+
+    private func respond(error: ExternalError, requestId: RPCID) async throws {
+        let authRequestParams = try getAuthRequestParams(requestId: requestId)
+        let (topic, keys) = try generateAgreementKeys(requestParams: authRequestParams)
+
+        try kms.setAgreementSecret(keys, topic: topic)
+
+        let tag = AuthResponseParams.tag
+        let envelopeType = Envelope.EnvelopeType.type1(pubKey: keys.publicKey.rawRepresentation)
+        try await networkingInteractor.respondError(topic: topic, requestId: requestId, tag: tag, reason: error, envelopeType: envelopeType)
+    }
+
+    private func getAuthRequestParams(requestId: RPCID) throws -> AuthRequestParams {
+        guard let request = rpcHistory.get(recordId: requestId)?.request
+        else { throw Errors.recordForIdNotFound }
+
+        guard let authRequestParams = try request.params?.get(AuthRequestParams.self)
+        else { throw Errors.malformedAuthRequestParams }
 
-        try await networkingInteractor.respond(topic: responseTopic, response: response, tag: AuthResponseParams.tag, envelopeType: .type1(pubKey: selfPubKey.rawRepresentation))
+        return authRequestParams
+    }
+
+    private func generateAgreementKeys(requestParams: AuthRequestParams) throws -> (topic: String, keys: AgreementKeys) {
+        let peerPubKey = try AgreementPublicKey(hex: requestParams.requester.publicKey)
+        let topic = peerPubKey.rawRepresentation.sha256().toHexString()
+        let selfPubKey = try kms.createX25519KeyPair()
+        let keys = try kms.performKeyAgreement(selfPublicKey: selfPubKey, peerPublicKey: peerPubKey.hexRepresentation)
+        return (topic, keys)
     }
 }

Sources/Auth/Types/Cacao/CacaoSignature.swift

@@ -1,7 +1,7 @@
 import Foundation
 
-struct CacaoSignature: Codable, Equatable {
-    let t: String
-    let s: String
-    let m: String? = nil
+public struct CacaoSignature: Codable, Equatable {
+    public let t: String
+    public let s: String
+    public let m: String? = nil
 }

Sources/Auth/Types/Error/ExternalError.swift

@@ -0,0 +1,22 @@
+import Foundation
+
+public enum ExternalError: Codable, Equatable, Error {
+    case userRejeted
+}
+
+extension ExternalError: Reason {
+
+    public var code: Int {
+        switch self {
+        case .userRejeted:
+            return 2001
+        }
+    }
+
+    public var message: String {
+        switch self {
+        case .userRejeted:
+            return "Auth request rejected by user"
+        }
+    }
+}

Sources/Auth/Types/Error/InternalError.swift

@@ -0,0 +1,37 @@
+import Foundation
+
+public enum InternalError: Codable, Equatable, Error {
+    case malformedResponseParams
+    case malformedRequestParams
+    case messageCompromised
+    case messageVerificationFailed
+}
+
+extension InternalError: Reason {
+
+    public var code: Int {
+        switch self {
+        case .malformedResponseParams:
+            return 1001
+        case .malformedRequestParams:
+            return 1002
+        case .messageCompromised:
+            return 1003
+        case .messageVerificationFailed:
+            return 1004
+        }
+    }
+
+    public var message: String {
+        switch self {
+        case .malformedResponseParams:
+            return "Response params malformed"
+        case .malformedRequestParams:
+            return "Request params malformed"
+        case .messageCompromised:
+            return "Original message compromised"
+        case .messageVerificationFailed:
+            return "Message verification failed"
+        }
+    }
+}

Sources/Auth/Types/Error/Reason.swift

@@ -0,0 +1,7 @@
+import Foundation
+
+protocol Reason {
+    var code: Int { get }
+    var message: String { get }
+}
+