Challenge-response, SwiftData, new UI

Sesame-Watch Watch App/ContentView.swift

@@ -1,4 +1,5 @@
 import SwiftUI
+import SwiftData
 import SFSafeSymbols
 import CryptoKit
 
@@ -7,73 +8,20 @@ struct ContentView: View {
     @Binding
     var didLaunchFromComplication: Bool
 
-    @AppStorage("connectionType")
+    @ObservedObject
-    var connectionType: ConnectionStrategy = .remoteFirst
+    var coordinator: RequestCoordinator
     
-    @AppStorage("server")
+    init(coordinator: RequestCoordinator, didLaunchFromComplication: Binding<Bool>) {
-    var serverPath: String = "https://christophhagen.de/sesame/"
+        self._didLaunchFromComplication = didLaunchFromComplication
-    
+        self.coordinator = coordinator
-    @AppStorage("localIP")
-    var localAddress: String = "192.168.178.104/"
-
-    @AppStorage("counter")
-    var nextMessageCounter: Int = 0
-
-    @AppStorage("compensate")
-    var isCompensatingDaylightTime: Bool = false
-    
-    @AppStorage("deviceId")
-    private var deviceId: Int = 0
-    
-    @EnvironmentObject
-    var keyManager: KeyManagement
-
-    @EnvironmentObject
-    var history: HistoryManager
-    
-    @State
-    var state: ClientState = .noKeyAvailable
-
-    @State
-    var stateResetTimer: Timer?
-    
-    let server = Client()
-
-    private var firstTryIsLocalConnection: Bool {
-        switch connectionType {
-        case .local, .localFirst:
-            return true
-        case .remote, .remoteFirst:
-            return false
-        }
-    }
-
-    private var hasSecondTry: Bool {
-        switch connectionType {
-        case .localFirst, .remoteFirst:
-            return true
-        default:
-            return false
-        }
-    }
-
-    private var secondTryIsLocalConnection: Bool {
-        switch connectionType {
-        case .local, .localFirst:
-            return false
-        case .remote, .remoteFirst:
-            return true
-        }
     }
 
     var buttonBackground: Color {
-        state.allowsAction ?
+        .white.opacity(0.2)
-            .white.opacity(0.2) :
-            .black.opacity(0.2)
     }
 
     var buttonColor: Color {
-        state.allowsAction ? .white : .gray
+        .white
     }
     
     var body: some View {
@@ -85,145 +33,43 @@ struct ContentView: View {
                     .aspectRatio(contentMode: .fit)
                     .fontWeight(.ultraLight)
                     .padding()
-                    .onTapGesture(perform: mainButtonPressed)
+                    .onTapGesture(perform: coordinator.startUnlock)
-                    .disabled(!state.allowsAction)
+                if coordinator.isPerformingRequest {
-                if state == .waitingForResponse {
                     ProgressView()
                         .progressViewStyle(CircularProgressViewStyle())
                         .frame(width: 20, height: 20)
                 } else {
-                    Text(state.actionText)
+                    Text("Unlock")
                         .font(.subheadline)
                 }
             }
             Spacer()
         }
-        .background(state.color)
+        .background(coordinator.state.color)
-        .animation(.easeInOut, value: state.color)
+        .animation(.easeInOut, value: coordinator.state.color)
-        .onAppear {
+        .onChange(of: didLaunchFromComplication) { _, launched in
-            if state == .noKeyAvailable, keyManager.hasAllKeys {
-                state = .ready
-            }
-        }
-        .onChange(of: didLaunchFromComplication) { launched in
             guard launched else {
                 return
             }
             didLaunchFromComplication = false
-            mainButtonPressed()
+            coordinator.startUnlock()
-        }
-    }
-    
-    func mainButtonPressed() {
-        guard let keys = keyManager.getAllKeys(),
-              let deviceId = UInt8(exactly: deviceId) else {
-            return
-        }
-        sendMessage(from: deviceId, using: keys, isFirstTry: true)
-    }
-
-    private func sendMessage(from deviceId: UInt8, using keys: KeySet, isFirstTry: Bool) {
-        preventStateReset()
-        state = .waitingForResponse
-        let localConnection = isFirstTry ? firstTryIsLocalConnection : secondTryIsLocalConnection
-        Task {
-            let response = await send(
-                count: UInt32(nextMessageCounter),
-                from: deviceId,
-                using: keys,
-                to: server,
-                over: localConnection,
-                while: isCompensatingDaylightTime,
-                localAddress: localAddress,
-                remoteAddress: serverPath)
-
-            DispatchQueue.main.async {
-                state = response.response
-                scheduleStateReset()
-                if let counter = response.responseMessage?.id {
-                    nextMessageCounter = Int(counter)
-                }
-            }
-            save(historyItem: response)
-            guard isFirstTry, hasSecondTry else {
-                return
-            }
-            DispatchQueue.main.async {
-                sendMessage(from: deviceId, using: keys, isFirstTry: false)
-            }
-        }
-    }
-
-    private func preventStateReset() {
-        stateResetTimer?.invalidate()
-        stateResetTimer = nil
-    }
-
-    private func scheduleStateReset() {
-        stateResetTimer?.invalidate()
-        stateResetTimer = Timer.scheduledTimer(withTimeInterval: 8.0, repeats: false) { _ in
-            DispatchQueue.main.async {
-                resetState()
-            }
-        }
-    }
-
-    private func resetState() {
-        state = keyManager.hasAllKeys ? .ready : .noKeyAvailable
-        preventStateReset()
-    }
-    
-    private func save(historyItem: HistoryItem) {
-        do {
-            try history.save(item: historyItem)
-        } catch {
-            print("Failed to save item: \(error)")
         }
     }
 }
 
-private func send(count: UInt32, from deviceId: UInt8, using keys: KeySet, to server: Client, over localConnection: Bool, while compensatingTime: Bool, localAddress: String, remoteAddress: String) async -> HistoryItem {
+#Preview {
-    let sentTime = Date()
+    do {
-    // Add time to compensate that the device is using daylight savings time
+        let config = ModelConfiguration(isStoredInMemoryOnly: true)
-    let timeCompensation: UInt32 = compensatingTime ? 3600 : 0
+        let container = try ModelContainer(for: HistoryItem.self, configurations: config)
-    let content = Message.Content(
-        time: sentTime.timestamp + timeCompensation,
-        id: count,
-        device: deviceId)
-    let message = content.authenticate(using: keys.remote)
-    print("Sending message \(count)")
-    let address = localConnection ? localAddress : remoteAddress
-    let (newState, responseMessage) = await send(message, to: server, using: keys.server, local: localConnection, address: address)
-    var historyItem = HistoryItem(
-        sent: message.content,
-        sentDate: sentTime,
-        local: localConnection,
-        response: newState,
-        responseDate: .now,
-        responseMessage: responseMessage?.content)
         
-    guard let responseMessage else {
+        let item = HistoryItem.mock
-        return historyItem
+        container.mainContext.insert(item)
-    }
+        try container.mainContext.save()
-    guard responseMessage.isValid(using: keys.device) else {
+        let coordinator = RequestCoordinator(modelContext: container.mainContext)
-        historyItem.response = .responseRejected(.invalidAuthentication)
+        return ContentView(coordinator: coordinator, didLaunchFromComplication: .constant(false))
-        return historyItem
+            .modelContainer(container)
-    }
+    } catch {
-    return historyItem
+        fatalError("Failed to create model container.")
-}
-
-private func send(_ message: Message, to server: Client, using authToken: Data, local: Bool, address: String) async -> (state: ClientState, response: Message?) {
-    if local {
-        return await server.sendMessageOverLocalNetwork(message, server: address)
-    } else {
-        return await server.send(message, server: address, authToken: authToken)
     }
 }
 
-struct ContentView_Previews: PreviewProvider {
-    static var previews: some View {
-        ContentView(didLaunchFromComplication: .constant(false))
-            .environmentObject(KeyManagement())
-            .environmentObject(HistoryManager())
-    }
-}

Sesame-Watch Watch App/HistoryItemDetail.swift

@@ -1,4 +1,5 @@
 import SwiftUI
+import SwiftData
 import SFSafeSymbols
 
 private let df: DateFormatter = {
@@ -11,26 +12,15 @@ private let df: DateFormatter = {
 
 struct HistoryItemDetail: View {
     
-    let item: HistoryItem
+    @Environment(\.modelContext)
+    private var modelContext
 
-    let history: HistoryManagerProtocol
+    let item: HistoryItem
 
     @Environment(\.dismiss) private var dismiss
     
     private var entryTime: String {
-        df.string(from: item.requestDate)
+        df.string(from: item.startDate)
-    }
-
-    var counterText: String {
-        let sentCounter = item.request.id
-        let startText = "\(sentCounter)"
-        guard let rCounter = item.responseMessage?.id else {
-            return startText
-        }
-        guard sentCounter + 1 != rCounter && sentCounter != rCounter else {
-            return startText
-        }
-        return "\(sentCounter) -> \(rCounter)"
     }
 
     var body: some View {
@@ -43,21 +33,16 @@ struct HistoryItemDetail: View {
                 value: entryTime)
             SettingsListTextItem(
                 title: "Connection",
-                value: item.usedLocalConnection ? "Local" : "Remote")
+                value: item.route.displayName)
-            SettingsListTextItem(
-                title: "Device ID",
-                value: "\(item.request.deviceId!)")
-            SettingsListTextItem(
-                title: "Message Counter",
-                value: counterText)
             SettingsListTextItem(
                     title: "Round Trip Time",
                     value: "\(Int(item.roundTripTime * 1000)) ms")
-            if let offset = item.clockOffset {
+            SettingsListTextItem(
-                SettingsListTextItem(
+                title: "Client challenge",
-                    title: "Clock offset",
+                value: "\(item.message.clientChallenge)")
-                    value: "\(offset) seconds")
+            SettingsListTextItem(
-            }
+                title: "Server challenge",
+                value: "\(item.message.serverChallenge)")
             Button {
                 delete(item: item)
             } label: {
@@ -76,15 +61,22 @@ struct HistoryItemDetail: View {
     }
 
     private func delete(item: HistoryItem) {
-        guard history.delete(item: item) else {
+        modelContext.delete(item)
-            return
-        }
         dismiss()
     }
 }
 
-struct HistoryItemDetail_Previews: PreviewProvider {
+#Preview {
-    static var previews: some View {
+    do {
-        HistoryItemDetail(item: .mock, history: HistoryManagerMock())
+        let config = ModelConfiguration(isStoredInMemoryOnly: true)
+        let container = try ModelContainer(for: HistoryItem.self, configurations: config)
+        
+        let item = HistoryItem.mock
+        container.mainContext.insert(item)
+        try container.mainContext.save()
+        return HistoryItemDetail(item: .mock)
+            .modelContainer(container)
+    } catch {
+        fatalError("Failed to create model container.")
     }
 }

Sesame-Watch Watch App/HistoryListRow.swift

@@ -14,7 +14,7 @@ struct HistoryListRow: View {
     let item: HistoryItem
 
     private var entryTime: String {
-        df.string(from: item.requestDate)
+        df.string(from: item.startDate)
     }
 
     var body: some View {

Sesame-Watch Watch App/HistoryView.swift

@@ -1,21 +1,23 @@
 import SwiftUI
+import SwiftData
 
 struct HistoryView: View {
     
-    @ObservedObject
+    @Environment(\.modelContext)
-    var history: HistoryManager
+    private var modelContext
+
+    @Query(sort: \HistoryItem.startDate, order: .reverse)
+    var history: [HistoryItem] = []
 
     private var unlockCount: Int {
-        history.entries.count {
+        history.count { $0.response == .unlocked }
-            $0.response == .openSesame
-        }
     }
 
     private var percentage: Double {
-        guard history.entries.count > 0 else {
+        guard history.count > 0 else {
             return 0
         }
-        return Double(unlockCount * 100) / Double(history.entries.count)
+        return Double(unlockCount * 100) / Double(history.count)
     }
 
     var body: some View {
@@ -23,7 +25,7 @@ struct HistoryView: View {
             List {
                 HStack {
                     VStack(alignment: .leading) {
-                        Text("\(history.entries.count) requests")
+                        Text("\(history.count) requests")
                             .foregroundColor(.primary)
                             .font(.body)
                         Text(String(format: "%.1f %% success", percentage))
@@ -34,9 +36,9 @@ struct HistoryView: View {
                 }
                 .listRowBackground(Color.clear)
 
-                ForEach(history.entries) { item in
+                ForEach(history) { item in
                     NavigationLink {
-                        HistoryItemDetail(item: item, history: history)
+                        HistoryItemDetail(item: item)
                     } label: {
                         HistoryListRow(item: item)
                     }
@@ -54,14 +56,21 @@ struct HistoryView: View {
     }
 
     private func delete(item: HistoryItem) {
-        guard history.delete(item: item) else {
+        modelContext.delete(item)
-            return
-        }
     }
 }
 
-struct HistoryView_Previews: PreviewProvider {
+#Preview {
-    static var previews: some View {
+    do {
-        HistoryView(history: HistoryManager())
+        let config = ModelConfiguration(isStoredInMemoryOnly: true)
+        let container = try ModelContainer(for: HistoryItem.self, configurations: config)
+        
+        let item = HistoryItem.mock
+        container.mainContext.insert(item)
+        try container.mainContext.save()
+        return HistoryView()
+            .modelContainer(container)
+    } catch {
+        fatalError("Failed to create model container.")
     }
 }

Sesame-Watch Watch App/Sesame_WatchApp.swift

@@ -1,11 +1,16 @@
 import SwiftUI
+import SwiftData
 
 @main
 struct Sesame_Watch_Watch_AppApp: App {
     
-    let keyManagement = KeyManagement()
+    @State
+    var modelContainer: ModelContainer
     
-    let history = HistoryManager()
+    @ObservedObject
+    var coordinator: RequestCoordinator
+    
+    let keyManagement = KeyManagement()
 
     @State
     var selected: Int = 0
@@ -13,17 +18,25 @@ struct Sesame_Watch_Watch_AppApp: App {
     @State
     var didLaunchFromComplication = false
     
+    init() {
+        do {
+            let modelContainer = try ModelContainer(for: HistoryItem.self)
+            self.modelContainer = modelContainer
+            self.coordinator = .init(modelContext: modelContainer.mainContext)
+        } catch {
+            fatalError("Failed to create model container: \(error)")
+        }
+    }
+    
     var body: some Scene {
         WindowGroup {
             TabView(selection: $selected) {
-                ContentView(didLaunchFromComplication: $didLaunchFromComplication)
+                ContentView(coordinator: coordinator, didLaunchFromComplication: $didLaunchFromComplication)
-                    .environmentObject(keyManagement)
-                    .environmentObject(history)
                     .tag(1)
                 SettingsView()
                     .environmentObject(keyManagement)
                     .tag(2)
-                HistoryView(history: history)
+                HistoryView()
                     .tag(3)
             }
             .tabViewStyle(PageTabViewStyle())
@@ -32,5 +45,6 @@ struct Sesame_Watch_Watch_AppApp: App {
                 didLaunchFromComplication = true
             }
         }
+        .modelContainer(modelContainer)
     }
 }

Sesame-Watch Watch App/Settings/SettingsListToggleItem.swift

@@ -1,28 +0,0 @@
-import SwiftUI
-
-struct SettingsListToggleItem: View {
-
-    let title: String
-
-    @Binding
-    var value: Bool
-
-    let subtitle: String
-
-    var body: some View {
-        VStack(alignment: .leading) {
-            Toggle(title, isOn: $value)
-            Text(subtitle)
-                .font(.footnote)
-                .foregroundColor(.secondary)
-        }
-        .padding()
-        .cornerRadius(8)
-    }
-}
-
-struct SettingsListToggleItem_Previews: PreviewProvider {
-    static var previews: some View {
-        SettingsListToggleItem(title: "Toggle", value: .constant(true), subtitle: "Some longer text explaining what the toggle does")
-    }
-}

Sesame-Watch Watch App/SettingsView.swift

@@ -11,29 +11,22 @@ struct SettingsView: View {
     @AppStorage("localIP")
     var localAddress: String = "192.168.178.104/"
 
-    @AppStorage("counter")
-    var nextMessageCounter: Int = 0
-
-    @AppStorage("compensate")
-    var isCompensatingDaylightTime: Bool = false
-
-    @AppStorage("deviceId")
-    private var deviceId: Int = 0
-
     @EnvironmentObject
     var keys: KeyManagement
     
+    var some: String { "some" }
+
     var body: some View {
         NavigationStack {
             List {
                 Picker("Connection", selection: $connectionType) {
-                    Text(ConnectionStrategy.local.rawValue)
+                    Text(display: ConnectionStrategy.local)
                         .tag(ConnectionStrategy.local)
-                    Text(ConnectionStrategy.localFirst.rawValue)
+                    Text(display: ConnectionStrategy.localFirst)
                         .tag(ConnectionStrategy.localFirst)
-                    Text(ConnectionStrategy.remote.rawValue)
+                    Text(display: ConnectionStrategy.remote)
                         .tag(ConnectionStrategy.remote)
-                    Text(ConnectionStrategy.remoteFirst.rawValue)
+                    Text(display: ConnectionStrategy.remoteFirst)
                         .tag(ConnectionStrategy.remoteFirst)
                 }
                 .padding(.leading)
@@ -45,18 +38,6 @@ struct SettingsView: View {
                     title: "Local url",
                     value: $localAddress,
                     footnote: "The url where the device can be reached directly on the local WiFi network.")
-                SettingsNumberItemLink(
-                    title: "Device ID",
-                    value: $deviceId,
-                    footnote: "The device ID is unique for each remote device, and is assigned by the system administrator.")
-                SettingsNumberItemLink(
-                    title: "Message counter",
-                    value: $nextMessageCounter,
-                    footnote: "The message counter is increased after every message to the device, and used to prevent replay attacks.")
-                SettingsListToggleItem(
-                    title: "Daylight savings",
-                    value: $isCompensatingDaylightTime,
-                    subtitle: "Compensate timestamps if the remote has daylight savings time wrongly set.")
                 SettingsKeyItemLink(
                     type: .deviceKey,
                     footnote: "Some text describing the purpose of the key.")

Sesame.xcodeproj/project.pbxproj

@@ -11,32 +11,61 @@
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 		884A45BB279F48C300D6E650 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 884A45BA279F48C300D6E650 /* Assets.xcassets */; };
 		884A45C5279F4BBE00D6E650 /* KeyManagement.swift in Sources */ = {isa = PBXBuildFile; fileRef = 884A45C4279F4BBE00D6E650 /* KeyManagement.swift */; };
-		884A45C927A43D7900D6E650 /* ClientState.swift in Sources */ = {isa = PBXBuildFile; fileRef = 884A45C827A43D7900D6E650 /* ClientState.swift */; };
 		884A45CB27A464C000D6E650 /* SymmetricKey+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 884A45CA27A464C000D6E650 /* SymmetricKey+Extensions.swift */; };
 		884A45CF27A5402D00D6E650 /* MessageResult.swift in Sources */ = {isa = PBXBuildFile; fileRef = 884A45CE27A5402D00D6E650 /* MessageResult.swift */; };
+		8860D7432B22858600849FAC /* Date+Timestamp.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D7422B22858600849FAC /* Date+Timestamp.swift */; };
+		8860D7462B2328EC00849FAC /* Message+Size.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D7452B2328EC00849FAC /* Message+Size.swift */; };
+		8860D7482B23294600849FAC /* SignedMessage+Crypto.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D7472B23294600849FAC /* SignedMessage+Crypto.swift */; };
+		8860D74A2B2329CE00849FAC /* SignedMessage+Size.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D7492B2329CE00849FAC /* SignedMessage+Size.swift */; };
+		8860D74C2B232A7700849FAC /* SesameHeader.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D74B2B232A7700849FAC /* SesameHeader.swift */; };
+		8860D74E2B232AED00849FAC /* Data+Coding.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D74D2B232AED00849FAC /* Data+Coding.swift */; };
+		8860D7522B233BEA00849FAC /* TransmissionType.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D7512B233BEA00849FAC /* TransmissionType.swift */; };
+		8860D7542B23489300849FAC /* ActiveRequestType.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D7532B23489300849FAC /* ActiveRequestType.swift */; };
+		8860D7552B237F9100849FAC /* TransmissionType.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D7512B233BEA00849FAC /* TransmissionType.swift */; };
+		8860D7562B237F9400849FAC /* ActiveRequestType.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D7532B23489300849FAC /* ActiveRequestType.swift */; };
+		8860D7572B237FAD00849FAC /* MessageType.swift in Sources */ = {isa = PBXBuildFile; fileRef = 88AEE37E2B2217050034EDA9 /* MessageType.swift */; };
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+		8860D7592B237FB200849FAC /* Message+Crypto.swift in Sources */ = {isa = PBXBuildFile; fileRef = 88AEE3852B22376D0034EDA9 /* Message+Crypto.swift */; };
+		8860D75A2B237FB400849FAC /* SignedMessage.swift in Sources */ = {isa = PBXBuildFile; fileRef = 88AEE3832B2236DC0034EDA9 /* SignedMessage.swift */; };
+		8860D75B2B237FB600849FAC /* SignedMessage+Crypto.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D7472B23294600849FAC /* SignedMessage+Crypto.swift */; };
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+		8860D75F2B237FC900849FAC /* SignedMessage+Size.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D7492B2329CE00849FAC /* SignedMessage+Size.swift */; };
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+		8860D76E2B246FC400849FAC /* Text+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D76D2B246FC400849FAC /* Text+Extensions.swift */; };
+		8860D76F2B246FC400849FAC /* Text+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8860D76D2B246FC400849FAC /* Text+Extensions.swift */; };
 		8864664F29E5684C004FE2BE /* CBORCoding in Frameworks */ = {isa = PBXBuildFile; productRef = 8864664E29E5684C004FE2BE /* CBORCoding */; };
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 		888362362A80F4420032BBB2 /* HistoryView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 888362352A80F4420032BBB2 /* HistoryView.swift */; };
+		88AEE37F2B2217050034EDA9 /* MessageType.swift in Sources */ = {isa = PBXBuildFile; fileRef = 88AEE37E2B2217050034EDA9 /* MessageType.swift */; };
+		88AEE3812B22327F0034EDA9 /* UInt32+Random.swift in Sources */ = {isa = PBXBuildFile; fileRef = 88AEE3802B22327F0034EDA9 /* UInt32+Random.swift */; };
+		88AEE3842B2236DC0034EDA9 /* SignedMessage.swift in Sources */ = {isa = PBXBuildFile; fileRef = 88AEE3832B2236DC0034EDA9 /* SignedMessage.swift */; };
+		88AEE3862B22376D0034EDA9 /* Message+Crypto.swift in Sources */ = {isa = PBXBuildFile; fileRef = 88AEE3852B22376D0034EDA9 /* Message+Crypto.swift */; };
+		88AEE3882B226FED0034EDA9 /* MessageResult+UI.swift in Sources */ = {isa = PBXBuildFile; fileRef = 88AEE3872B226FED0034EDA9 /* MessageResult+UI.swift */; };
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 		88E197C729EDCCBD00BF1D19 /* Client.swift in Sources */ = {isa = PBXBuildFile; fileRef = 884A45CC27A465F500D6E650 /* Client.swift */; };
-		88E197C829EDCCCE00BF1D19 /* ClientState.swift in Sources */ = {isa = PBXBuildFile; fileRef = 884A45C827A43D7900D6E650 /* ClientState.swift */; };
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-		88E197D129EDCE5F00BF1D19 /* Data+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = E24EE77127FDCCC00011CFD2 /* Data+Extensions.swift */; };
+		88E197D129EDCE5F00BF1D19 /* Data+Hex.swift in Sources */ = {isa = PBXBuildFile; fileRef = E24EE77127FDCCC00011CFD2 /* Data+Hex.swift */; };
-		88E197D229EDCE6600BF1D19 /* RouteAPI.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2C5C1DA2806FE8900769EF6 /* RouteAPI.swift */; };
+		88E197D229EDCE6600BF1D19 /* SesameRoute.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2C5C1DA2806FE8900769EF6 /* SesameRoute.swift */; };
 		88E197D329EDCE6E00BF1D19 /* MessageResult.swift in Sources */ = {isa = PBXBuildFile; fileRef = 884A45CE27A5402D00D6E650 /* MessageResult.swift */; };
-		88E197D429EDCE7600BF1D19 /* UInt32+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2C5C1DC281B3AC400769EF6 /* UInt32+Extensions.swift */; };
+		88E197D429EDCE7600BF1D19 /* UInt32+Coding.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2C5C1DC281B3AC400769EF6 /* UInt32+Coding.swift */; };
-		88E197D529EDCE8800BF1D19 /* ServerMessage.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2C5C1F7281E769F00769EF6 /* ServerMessage.swift */; };
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 		88E197D829EDD13B00BF1D19 /* SymmetricKey+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 884A45CA27A464C000D6E650 /* SymmetricKey+Extensions.swift */; };
 		E240654B2A8153C6009C1AD8 /* SettingsListTextItem.swift in Sources */ = {isa = PBXBuildFile; fileRef = E240654A2A8153C6009C1AD8 /* SettingsListTextItem.swift */; };
-		E240654D2A8155A3009C1AD8 /* SettingsListToggleItem.swift in Sources */ = {isa = PBXBuildFile; fileRef = E240654C2A8155A3009C1AD8 /* SettingsListToggleItem.swift */; };
 		E240654F2A8159B7009C1AD8 /* SettingsTextInputView.swift in Sources */ = {isa = PBXBuildFile; fileRef = E240654E2A8159B7009C1AD8 /* SettingsTextInputView.swift */; };
 		E24065512A819066009C1AD8 /* SettingsTextItemLink.swift in Sources */ = {isa = PBXBuildFile; fileRef = E24065502A819066009C1AD8 /* SettingsTextItemLink.swift */; };
 		E24065532A819614009C1AD8 /* SettingsNumberItemLink.swift in Sources */ = {isa = PBXBuildFile; fileRef = E24065522A819614009C1AD8 /* SettingsNumberItemLink.swift */; };
@@ -47,8 +76,7 @@
 		E240655C2A822C8E009C1AD8 /* HistoryManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = E28DED36281EC7FB00259690 /* HistoryManager.swift */; };
 		E240655E2A822E97009C1AD8 /* HistoryListRow.swift in Sources */ = {isa = PBXBuildFile; fileRef = E240655D2A822E97009C1AD8 /* HistoryListRow.swift */; };
 		E24065602A822ED9009C1AD8 /* HistoryItemDetail.swift in Sources */ = {isa = PBXBuildFile; fileRef = E240655F2A822ED9009C1AD8 /* HistoryItemDetail.swift */; };
-		E24EE77227FDCCC00011CFD2 /* Data+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = E24EE77127FDCCC00011CFD2 /* Data+Extensions.swift */; };
+		E24EE77227FDCCC00011CFD2 /* Data+Hex.swift in Sources */ = {isa = PBXBuildFile; fileRef = E24EE77127FDCCC00011CFD2 /* Data+Hex.swift */; };
-		E24EE77427FF95920011CFD2 /* DeviceResponse.swift in Sources */ = {isa = PBXBuildFile; fileRef = E24EE77327FF95920011CFD2 /* DeviceResponse.swift */; };
 		E24EE77727FF95C00011CFD2 /* NIOCore in Frameworks */ = {isa = PBXBuildFile; productRef = E24EE77627FF95C00011CFD2 /* NIOCore */; };
 		E24EE77927FF95E00011CFD2 /* Message.swift in Sources */ = {isa = PBXBuildFile; fileRef = E24EE77827FF95E00011CFD2 /* Message.swift */; };
 		E24F6C6E2A89749A0040F8C4 /* ConnectionStrategy.swift in Sources */ = {isa = PBXBuildFile; fileRef = E24F6C6D2A89749A0040F8C4 /* ConnectionStrategy.swift */; };
@@ -66,9 +94,8 @@
 		E28DED33281EB15B00259690 /* HistoryListItem.swift in Sources */ = {isa = PBXBuildFile; fileRef = E28DED32281EB15B00259690 /* HistoryListItem.swift */; };
 		E28DED35281EB17600259690 /* HistoryItem.swift in Sources */ = {isa = PBXBuildFile; fileRef = E28DED34281EB17600259690 /* HistoryItem.swift */; };
 		E28DED37281EC7FB00259690 /* HistoryManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = E28DED36281EC7FB00259690 /* HistoryManager.swift */; };
-		E2C5C1DB2806FE8900769EF6 /* RouteAPI.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2C5C1DA2806FE8900769EF6 /* RouteAPI.swift */; };
+		E2C5C1DB2806FE8900769EF6 /* SesameRoute.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2C5C1DA2806FE8900769EF6 /* SesameRoute.swift */; };
-		E2C5C1DD281B3AC400769EF6 /* UInt32+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2C5C1DC281B3AC400769EF6 /* UInt32+Extensions.swift */; };
+		E2C5C1DD281B3AC400769EF6 /* UInt32+Coding.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2C5C1DC281B3AC400769EF6 /* UInt32+Coding.swift */; };
-		E2C5C1F8281E769F00769EF6 /* ServerMessage.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2C5C1F7281E769F00769EF6 /* ServerMessage.swift */; };
 		E2F5DCCA2A88E913002858B9 /* Array+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2F5DCC92A88E913002858B9 /* Array+Extensions.swift */; };
 		E2F5DCCB2A88E976002858B9 /* Array+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2F5DCC92A88E913002858B9 /* Array+Extensions.swift */; };
 /* End PBXBuildFile section */
@@ -103,19 +130,34 @@
 		884A45B8279F48C100D6E650 /* ContentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentView.swift; sourceTree = "<group>"; };
 		884A45BA279F48C300D6E650 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		884A45C4279F4BBE00D6E650 /* KeyManagement.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = KeyManagement.swift; sourceTree = "<group>"; };
-		884A45C827A43D7900D6E650 /* ClientState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ClientState.swift; sourceTree = "<group>"; };
 		884A45CA27A464C000D6E650 /* SymmetricKey+Extensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "SymmetricKey+Extensions.swift"; sourceTree = "<group>"; };
 		884A45CC27A465F500D6E650 /* Client.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Client.swift; sourceTree = "<group>"; };
 		884A45CE27A5402D00D6E650 /* MessageResult.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MessageResult.swift; sourceTree = "<group>"; };
+		8860D7422B22858600849FAC /* Date+Timestamp.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Date+Timestamp.swift"; sourceTree = "<group>"; };
+		8860D7452B2328EC00849FAC /* Message+Size.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Message+Size.swift"; sourceTree = "<group>"; };
+		8860D7472B23294600849FAC /* SignedMessage+Crypto.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "SignedMessage+Crypto.swift"; sourceTree = "<group>"; };
+		8860D7492B2329CE00849FAC /* SignedMessage+Size.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "SignedMessage+Size.swift"; sourceTree = "<group>"; };
+		8860D74B2B232A7700849FAC /* SesameHeader.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SesameHeader.swift; sourceTree = "<group>"; };
+		8860D74D2B232AED00849FAC /* Data+Coding.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Data+Coding.swift"; sourceTree = "<group>"; };
+		8860D7512B233BEA00849FAC /* TransmissionType.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TransmissionType.swift; sourceTree = "<group>"; };
+		8860D7532B23489300849FAC /* ActiveRequestType.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ActiveRequestType.swift; sourceTree = "<group>"; };
+		8860D7612B23803E00849FAC /* ServerChallenge.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ServerChallenge.swift; sourceTree = "<group>"; };
+		8860D7642B23B5B200849FAC /* RequestCoordinator.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RequestCoordinator.swift; sourceTree = "<group>"; };
+		8860D7672B23D04100849FAC /* PendingOperation.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PendingOperation.swift; sourceTree = "<group>"; };
+		8860D76D2B246FC400849FAC /* Text+Extensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Text+Extensions.swift"; sourceTree = "<group>"; };
 		888362332A80F3F90032BBB2 /* SettingsView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SettingsView.swift; sourceTree = "<group>"; };
 		888362352A80F4420032BBB2 /* HistoryView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HistoryView.swift; sourceTree = "<group>"; };
+		88AEE37E2B2217050034EDA9 /* MessageType.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MessageType.swift; sourceTree = "<group>"; };
+		88AEE3802B22327F0034EDA9 /* UInt32+Random.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UInt32+Random.swift"; sourceTree = "<group>"; };
+		88AEE3832B2236DC0034EDA9 /* SignedMessage.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SignedMessage.swift; sourceTree = "<group>"; };
+		88AEE3852B22376D0034EDA9 /* Message+Crypto.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Message+Crypto.swift"; sourceTree = "<group>"; };
+		88AEE3872B226FED0034EDA9 /* MessageResult+UI.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "MessageResult+UI.swift"; sourceTree = "<group>"; };
 		88E197AC29EDC9BC00BF1D19 /* Sesame-Watch Watch App.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = "Sesame-Watch Watch App.app"; sourceTree = BUILT_PRODUCTS_DIR; };
 		88E197B129EDC9BC00BF1D19 /* Sesame_WatchApp.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Sesame_WatchApp.swift; sourceTree = "<group>"; };
 		88E197B329EDC9BC00BF1D19 /* ContentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentView.swift; sourceTree = "<group>"; };
 		88E197B529EDC9BD00BF1D19 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		88E197D629EDCFE800BF1D19 /* Date+Extensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Date+Extensions.swift"; sourceTree = "<group>"; };
 		E240654A2A8153C6009C1AD8 /* SettingsListTextItem.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SettingsListTextItem.swift; sourceTree = "<group>"; };
-		E240654C2A8155A3009C1AD8 /* SettingsListToggleItem.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SettingsListToggleItem.swift; sourceTree = "<group>"; };
 		E240654E2A8159B7009C1AD8 /* SettingsTextInputView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SettingsTextInputView.swift; sourceTree = "<group>"; };
 		E24065502A819066009C1AD8 /* SettingsTextItemLink.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SettingsTextItemLink.swift; sourceTree = "<group>"; };
 		E24065522A819614009C1AD8 /* SettingsNumberItemLink.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SettingsNumberItemLink.swift; sourceTree = "<group>"; };
@@ -124,8 +166,7 @@
 		E24065592A82218D009C1AD8 /* SettingsKeyInputView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SettingsKeyInputView.swift; sourceTree = "<group>"; };
 		E240655D2A822E97009C1AD8 /* HistoryListRow.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HistoryListRow.swift; sourceTree = "<group>"; };
 		E240655F2A822ED9009C1AD8 /* HistoryItemDetail.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HistoryItemDetail.swift; sourceTree = "<group>"; };
-		E24EE77127FDCCC00011CFD2 /* Data+Extensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Data+Extensions.swift"; sourceTree = "<group>"; };
+		E24EE77127FDCCC00011CFD2 /* Data+Hex.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Data+Hex.swift"; sourceTree = "<group>"; };
-		E24EE77327FF95920011CFD2 /* DeviceResponse.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DeviceResponse.swift; sourceTree = "<group>"; };
 		E24EE77827FF95E00011CFD2 /* Message.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Message.swift; sourceTree = "<group>"; };
 		E24F6C6D2A89749A0040F8C4 /* ConnectionStrategy.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ConnectionStrategy.swift; sourceTree = "<group>"; };
 		E268E0532A852F8E00185913 /* WidgetKit.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = WidgetKit.framework; path = System/Library/Frameworks/WidgetKit.framework; sourceTree = SDKROOT; };
@@ -141,9 +182,8 @@
 		E28DED34281EB17600259690 /* HistoryItem.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HistoryItem.swift; sourceTree = "<group>"; };
 		E28DED36281EC7FB00259690 /* HistoryManager.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HistoryManager.swift; sourceTree = "<group>"; };
 		E28DED38281EE9CF00259690 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist; path = Info.plist; sourceTree = "<group>"; };
-		E2C5C1DA2806FE8900769EF6 /* RouteAPI.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RouteAPI.swift; sourceTree = "<group>"; };
+		E2C5C1DA2806FE8900769EF6 /* SesameRoute.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SesameRoute.swift; sourceTree = "<group>"; };
-		E2C5C1DC281B3AC400769EF6 /* UInt32+Extensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UInt32+Extensions.swift"; sourceTree = "<group>"; };
+		E2C5C1DC281B3AC400769EF6 /* UInt32+Coding.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UInt32+Coding.swift"; sourceTree = "<group>"; };
-		E2C5C1F7281E769F00769EF6 /* ServerMessage.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ServerMessage.swift; sourceTree = "<group>"; };
 		E2F5DCC92A88E913002858B9 /* Array+Extensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Array+Extensions.swift"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -209,17 +249,51 @@
 				884A45BA279F48C300D6E650 /* Assets.xcassets */,
 				E24F6C6C2A89748B0040F8C4 /* Common */,
 				E2C5C1D92806FE4A00769EF6 /* API */,
+				8860D7442B2328B800849FAC /* API Extensions */,
 				884A45B6279F48C100D6E650 /* SesameApp.swift */,
 				884A45B8279F48C100D6E650 /* ContentView.swift */,
 				E28DED2C281E840B00259690 /* SettingsView.swift */,
 				E28DED2E281E8A0500259690 /* SingleKeyView.swift */,
-				E28DED30281EAE9100259690 /* HistoryView.swift */,
 				E25317542A8A1A07005A537D /* History */,
 				E25317552A8A1A32005A537D /* Extensions */,
 			);
 			path = Sesame;
 			sourceTree = "<group>";
 		};
+		8860D7442B2328B800849FAC /* API Extensions */ = {
+			isa = PBXGroup;
+			children = (
+				88AEE3872B226FED0034EDA9 /* MessageResult+UI.swift */,
+				88AEE37E2B2217050034EDA9 /* MessageType.swift */,
+				E24EE77827FF95E00011CFD2 /* Message.swift */,
+				88AEE3852B22376D0034EDA9 /* Message+Crypto.swift */,
+				88AEE3832B2236DC0034EDA9 /* SignedMessage.swift */,
+				8860D7472B23294600849FAC /* SignedMessage+Crypto.swift */,
+			);
+			path = "API Extensions";
+			sourceTree = "<group>";
+		};
+		8860D76B2B246F5600849FAC /* Extensions */ = {
+			isa = PBXGroup;
+			children = (
+				E2F5DCC92A88E913002858B9 /* Array+Extensions.swift */,
+				884A45CA27A464C000D6E650 /* SymmetricKey+Extensions.swift */,
+				88AEE3802B22327F0034EDA9 /* UInt32+Random.swift */,
+				8860D76D2B246FC400849FAC /* Text+Extensions.swift */,
+			);
+			path = Extensions;
+			sourceTree = "<group>";
+		};
+		88AEE3822B22331E0034EDA9 /* Extensions */ = {
+			isa = PBXGroup;
+			children = (
+				E24EE77127FDCCC00011CFD2 /* Data+Hex.swift */,
+				8860D74D2B232AED00849FAC /* Data+Coding.swift */,
+				E2C5C1DC281B3AC400769EF6 /* UInt32+Coding.swift */,
+			);
+			path = Extensions;
+			sourceTree = "<group>";
+		};
 		88E197B029EDC9BC00BF1D19 /* Sesame-Watch Watch App */ = {
 			isa = PBXGroup;
 			children = (
@@ -253,7 +327,6 @@
 				E24065542A819663009C1AD8 /* SettingsNumberInputView.swift */,
 				E240654E2A8159B7009C1AD8 /* SettingsTextInputView.swift */,
 				E240654A2A8153C6009C1AD8 /* SettingsListTextItem.swift */,
-				E240654C2A8155A3009C1AD8 /* SettingsListToggleItem.swift */,
 				E24065572A819AE3009C1AD8 /* SettingsKeyItemLink.swift */,
 				E24065592A82218D009C1AD8 /* SettingsKeyInputView.swift */,
 			);
@@ -263,11 +336,16 @@
 		E24F6C6C2A89748B0040F8C4 /* Common */ = {
 			isa = PBXGroup;
 			children = (
+				8860D76B2B246F5600849FAC /* Extensions */,
 				884A45CC27A465F500D6E650 /* Client.swift */,
-				884A45C827A43D7900D6E650 /* ClientState.swift */,
 				E24F6C6D2A89749A0040F8C4 /* ConnectionStrategy.swift */,
 				E28DED36281EC7FB00259690 /* HistoryManager.swift */,
 				884A45C4279F4BBE00D6E650 /* KeyManagement.swift */,
+				8860D7512B233BEA00849FAC /* TransmissionType.swift */,
+				8860D7532B23489300849FAC /* ActiveRequestType.swift */,
+				8860D7612B23803E00849FAC /* ServerChallenge.swift */,
+				8860D7642B23B5B200849FAC /* RequestCoordinator.swift */,
+				8860D7672B23D04100849FAC /* PendingOperation.swift */,
 			);
 			path = Common;
 			sourceTree = "<group>";
@@ -275,6 +353,7 @@
 		E25317542A8A1A07005A537D /* History */ = {
 			isa = PBXGroup;
 			children = (
+				E28DED30281EAE9100259690 /* HistoryView.swift */,
 				E28DED32281EB15B00259690 /* HistoryListItem.swift */,
 				E28DED34281EB17600259690 /* HistoryItem.swift */,
 			);
@@ -284,8 +363,7 @@
 		E25317552A8A1A32005A537D /* Extensions */ = {
 			isa = PBXGroup;
 			children = (
-				E2F5DCC92A88E913002858B9 /* Array+Extensions.swift */,
+				8860D7422B22858600849FAC /* Date+Timestamp.swift */,
-				884A45CA27A464C000D6E650 /* SymmetricKey+Extensions.swift */,
 			);
 			path = Extensions;
 			sourceTree = "<group>";
@@ -303,13 +381,12 @@
 		E2C5C1D92806FE4A00769EF6 /* API */ = {
 			isa = PBXGroup;
 			children = (
-				E24EE77127FDCCC00011CFD2 /* Data+Extensions.swift */,
+				88AEE3822B22331E0034EDA9 /* Extensions */,
-				E24EE77327FF95920011CFD2 /* DeviceResponse.swift */,
-				E24EE77827FF95E00011CFD2 /* Message.swift */,
 				884A45CE27A5402D00D6E650 /* MessageResult.swift */,
-				E2C5C1DA2806FE8900769EF6 /* RouteAPI.swift */,
+				E2C5C1DA2806FE8900769EF6 /* SesameRoute.swift */,
-				E2C5C1F7281E769F00769EF6 /* ServerMessage.swift */,
+				8860D7452B2328EC00849FAC /* Message+Size.swift */,
-				E2C5C1DC281B3AC400769EF6 /* UInt32+Extensions.swift */,
+				8860D7492B2329CE00849FAC /* SignedMessage+Size.swift */,
+				8860D74B2B232A7700849FAC /* SesameHeader.swift */,
 			);
 			path = API;
 			sourceTree = "<group>";
@@ -391,7 +468,7 @@
 			attributes = {
 				BuildIndependentTargetsInParallel = 1;
 				LastSwiftUpdateCheck = 1430;
-				LastUpgradeCheck = 1320;
+				LastUpgradeCheck = 1500;
 				TargetAttributes = {
 					884A45B2279F48C100D6E650 = {
 						CreatedOnToolsVersion = 13.2.1;
@@ -464,25 +541,39 @@
 			files = (
 				884A45CF27A5402D00D6E650 /* MessageResult.swift in Sources */,
 				884A45B9279F48C100D6E650 /* ContentView.swift in Sources */,
+				88AEE3882B226FED0034EDA9 /* MessageResult+UI.swift in Sources */,
 				E28DED2F281E8A0500259690 /* SingleKeyView.swift in Sources */,
 				E28DED37281EC7FB00259690 /* HistoryManager.swift in Sources */,
-				E2C5C1DB2806FE8900769EF6 /* RouteAPI.swift in Sources */,
+				E2C5C1DB2806FE8900769EF6 /* SesameRoute.swift in Sources */,
-				E2C5C1DD281B3AC400769EF6 /* UInt32+Extensions.swift in Sources */,
+				E2C5C1DD281B3AC400769EF6 /* UInt32+Coding.swift in Sources */,
-				E24EE77227FDCCC00011CFD2 /* Data+Extensions.swift in Sources */,
+				E24EE77227FDCCC00011CFD2 /* Data+Hex.swift in Sources */,
-				E24EE77427FF95920011CFD2 /* DeviceResponse.swift in Sources */,
+				8860D7482B23294600849FAC /* SignedMessage+Crypto.swift in Sources */,
+				8860D74C2B232A7700849FAC /* SesameHeader.swift in Sources */,
+				8860D7622B23803E00849FAC /* ServerChallenge.swift in Sources */,
+				8860D7432B22858600849FAC /* Date+Timestamp.swift in Sources */,
+				88AEE3862B22376D0034EDA9 /* Message+Crypto.swift in Sources */,
+				8860D7682B23D04100849FAC /* PendingOperation.swift in Sources */,
+				8860D74E2B232AED00849FAC /* Data+Coding.swift in Sources */,
+				8860D7522B233BEA00849FAC /* TransmissionType.swift in Sources */,
 				884A45CB27A464C000D6E650 /* SymmetricKey+Extensions.swift in Sources */,
 				E28DED31281EAE9100259690 /* HistoryView.swift in Sources */,
 				E24EE77927FF95E00011CFD2 /* Message.swift in Sources */,
 				E2F5DCCA2A88E913002858B9 /* Array+Extensions.swift in Sources */,
 				E28DED35281EB17600259690 /* HistoryItem.swift in Sources */,
-				884A45C927A43D7900D6E650 /* ClientState.swift in Sources */,
 				E28DED33281EB15B00259690 /* HistoryListItem.swift in Sources */,
 				E28DED2D281E840B00259690 /* SettingsView.swift in Sources */,
 				884A45B7279F48C100D6E650 /* SesameApp.swift in Sources */,
+				8860D76E2B246FC400849FAC /* Text+Extensions.swift in Sources */,
 				88E197C429EDCC8900BF1D19 /* Client.swift in Sources */,
+				8860D7652B23B5B200849FAC /* RequestCoordinator.swift in Sources */,
+				88AEE3812B22327F0034EDA9 /* UInt32+Random.swift in Sources */,
 				E24F6C6E2A89749A0040F8C4 /* ConnectionStrategy.swift in Sources */,
 				884A45C5279F4BBE00D6E650 /* KeyManagement.swift in Sources */,
-				E2C5C1F8281E769F00769EF6 /* ServerMessage.swift in Sources */,
+				88AEE3842B2236DC0034EDA9 /* SignedMessage.swift in Sources */,
+				8860D74A2B2329CE00849FAC /* SignedMessage+Size.swift in Sources */,
+				8860D7542B23489300849FAC /* ActiveRequestType.swift in Sources */,
+				88AEE37F2B2217050034EDA9 /* MessageType.swift in Sources */,
+				8860D7462B2328EC00849FAC /* Message+Size.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -490,33 +581,46 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				8860D7662B23B5B200849FAC /* RequestCoordinator.swift in Sources */,
+				8860D75D2B237FC000849FAC /* Data+Coding.swift in Sources */,
 				888362342A80F3F90032BBB2 /* SettingsView.swift in Sources */,
 				88E197B429EDC9BC00BF1D19 /* ContentView.swift in Sources */,
 				E2F5DCCB2A88E976002858B9 /* Array+Extensions.swift in Sources */,
 				E24065532A819614009C1AD8 /* SettingsNumberItemLink.swift in Sources */,
 				888362362A80F4420032BBB2 /* HistoryView.swift in Sources */,
+				8860D75B2B237FB600849FAC /* SignedMessage+Crypto.swift in Sources */,
 				E240654F2A8159B7009C1AD8 /* SettingsTextInputView.swift in Sources */,
 				88E197D329EDCE6E00BF1D19 /* MessageResult.swift in Sources */,
-				88E197D529EDCE8800BF1D19 /* ServerMessage.swift in Sources */,
+				88E197D129EDCE5F00BF1D19 /* Data+Hex.swift in Sources */,
-				88E197D129EDCE5F00BF1D19 /* Data+Extensions.swift in Sources */,
+				8860D76C2B246F5E00849FAC /* UInt32+Random.swift in Sources */,
 				E240655A2A82218D009C1AD8 /* SettingsKeyInputView.swift in Sources */,
-				88E197D229EDCE6600BF1D19 /* RouteAPI.swift in Sources */,
+				8860D76F2B246FC400849FAC /* Text+Extensions.swift in Sources */,
+				88E197D229EDCE6600BF1D19 /* SesameRoute.swift in Sources */,
+				8860D75E2B237FC600849FAC /* Message+Size.swift in Sources */,
+				8860D7552B237F9100849FAC /* TransmissionType.swift in Sources */,
+				8860D75C2B237FB900849FAC /* MessageResult+UI.swift in Sources */,
+				8860D7632B23803E00849FAC /* ServerChallenge.swift in Sources */,
 				E24065512A819066009C1AD8 /* SettingsTextItemLink.swift in Sources */,
 				88E197D729EDCFE800BF1D19 /* Date+Extensions.swift in Sources */,
-				88E197C829EDCCCE00BF1D19 /* ClientState.swift in Sources */,
+				8860D75A2B237FB400849FAC /* SignedMessage.swift in Sources */,
 				E24065602A822ED9009C1AD8 /* HistoryItemDetail.swift in Sources */,
+				8860D75F2B237FC900849FAC /* SignedMessage+Size.swift in Sources */,
 				88E197B229EDC9BC00BF1D19 /* Sesame_WatchApp.swift in Sources */,
 				E24065582A819AE3009C1AD8 /* SettingsKeyItemLink.swift in Sources */,
-				88E197C929EDCCE100BF1D19 /* Message.swift in Sources */,
+				8860D7602B237FCC00849FAC /* SesameHeader.swift in Sources */,
+				8860D7592B237FB200849FAC /* Message+Crypto.swift in Sources */,
 				E24F6C6F2A8974C60040F8C4 /* ConnectionStrategy.swift in Sources */,
+				8860D7562B237F9400849FAC /* ActiveRequestType.swift in Sources */,
 				E240654B2A8153C6009C1AD8 /* SettingsListTextItem.swift in Sources */,
+				8860D7692B23D04100849FAC /* PendingOperation.swift in Sources */,
 				88E197C729EDCCBD00BF1D19 /* Client.swift in Sources */,
-				88E197D429EDCE7600BF1D19 /* UInt32+Extensions.swift in Sources */,
+				88E197D429EDCE7600BF1D19 /* UInt32+Coding.swift in Sources */,
 				E240655B2A822397009C1AD8 /* KeyManagement.swift in Sources */,
-				E240654D2A8155A3009C1AD8 /* SettingsListToggleItem.swift in Sources */,
 				E24065552A819663009C1AD8 /* SettingsNumberInputView.swift in Sources */,
+				8860D7572B237FAD00849FAC /* MessageType.swift in Sources */,
 				E240655E2A822E97009C1AD8 /* HistoryListRow.swift in Sources */,
 				E25317562A8A1ABF005A537D /* HistoryItem.swift in Sources */,
+				8860D7582B237FB000849FAC /* Message.swift in Sources */,
 				88E197D829EDD13B00BF1D19 /* SymmetricKey+Extensions.swift in Sources */,
 				E240655C2A822C8E009C1AD8 /* HistoryManager.swift in Sources */,
 			);
@@ -545,6 +649,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
+				ASSETCATALOG_COMPILER_GENERATE_SWIFT_ASSET_SYMBOL_EXTENSIONS = YES;
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
@@ -578,6 +683,7 @@
 				DEBUG_INFORMATION_FORMAT = dwarf;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				ENABLE_TESTABILITY = YES;
+				ENABLE_USER_SCRIPT_SANDBOXING = YES;
 				GCC_C_LANGUAGE_STANDARD = gnu11;
 				GCC_DYNAMIC_NO_PIC = NO;
 				GCC_NO_COMMON_BLOCKS = YES;
@@ -592,7 +698,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 15.2;
+				IPHONEOS_DEPLOYMENT_TARGET = 17.0;
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
 				ONLY_ACTIVE_ARCH = YES;
@@ -606,6 +712,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
+				ASSETCATALOG_COMPILER_GENERATE_SWIFT_ASSET_SYMBOL_EXTENSIONS = YES;
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_ANALYZER_NUMBER_OBJECT_CONVERSION = YES_AGGRESSIVE;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
@@ -639,6 +746,7 @@
 				DEBUG_INFORMATION_FORMAT = "dwarf-with-dsym";
 				ENABLE_NS_ASSERTIONS = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
+				ENABLE_USER_SCRIPT_SANDBOXING = YES;
 				GCC_C_LANGUAGE_STANDARD = gnu11;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
@@ -647,7 +755,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 15.2;
+				IPHONEOS_DEPLOYMENT_TARGET = 17.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				MTL_FAST_MATH = YES;
 				SDKROOT = iphoneos;
@@ -676,7 +784,7 @@
 				INFOPLIST_KEY_UISupportedInterfaceOrientations = UIInterfaceOrientationPortrait;
 				INFOPLIST_KEY_UISupportedInterfaceOrientations_iPad = "UIInterfaceOrientationPortrait UIInterfaceOrientationPortraitUpsideDown UIInterfaceOrientationLandscapeLeft UIInterfaceOrientationLandscapeRight";
 				INFOPLIST_KEY_UISupportedInterfaceOrientations_iPhone = UIInterfaceOrientationPortrait;
-				IPHONEOS_DEPLOYMENT_TARGET = 16.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 17.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -711,7 +819,7 @@
 				INFOPLIST_KEY_UISupportedInterfaceOrientations = UIInterfaceOrientationPortrait;
 				INFOPLIST_KEY_UISupportedInterfaceOrientations_iPad = "UIInterfaceOrientationPortrait UIInterfaceOrientationPortraitUpsideDown UIInterfaceOrientationLandscapeLeft UIInterfaceOrientationLandscapeRight";
 				INFOPLIST_KEY_UISupportedInterfaceOrientations_iPhone = UIInterfaceOrientationPortrait;
-				IPHONEOS_DEPLOYMENT_TARGET = 16.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 17.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -754,7 +862,7 @@
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = 4;
-				WATCHOS_DEPLOYMENT_TARGET = 9.4;
+				WATCHOS_DEPLOYMENT_TARGET = 10.0;
 			};
 			name = Debug;
 		};
@@ -786,7 +894,7 @@
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = 4;
-				WATCHOS_DEPLOYMENT_TARGET = 9.4;
+				WATCHOS_DEPLOYMENT_TARGET = 10.0;
 			};
 			name = Release;
 		};
@@ -817,7 +925,7 @@
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = 4;
-				WATCHOS_DEPLOYMENT_TARGET = 9.4;
+				WATCHOS_DEPLOYMENT_TARGET = 10.0;
 			};
 			name = Debug;
 		};
@@ -848,7 +956,7 @@
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = 4;
-				WATCHOS_DEPLOYMENT_TARGET = 9.4;
+				WATCHOS_DEPLOYMENT_TARGET = 10.0;
 			};
 			name = Release;
 		};

Sesame.xcodeproj/xcshareddata/xcschemes/Sesame Watch App.xcscheme

@@ -0,0 +1,77 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1500"
+   version = "1.7">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "88E197AB29EDC9BC00BF1D19"
+               BuildableName = "Sesame-Watch Watch App.app"
+               BlueprintName = "Sesame-Watch Watch App"
+               ReferencedContainer = "container:Sesame.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      shouldAutocreateTestPlan = "YES">
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "88E197AB29EDC9BC00BF1D19"
+            BuildableName = "Sesame-Watch Watch App.app"
+            BlueprintName = "Sesame-Watch Watch App"
+            ReferencedContainer = "container:Sesame.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "88E197AB29EDC9BC00BF1D19"
+            BuildableName = "Sesame-Watch Watch App.app"
+            BlueprintName = "Sesame-Watch Watch App"
+            ReferencedContainer = "container:Sesame.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

Sesame.xcodeproj/xcshareddata/xcschemes/Sesame-WidgetExtension.xcscheme

@@ -0,0 +1,111 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1500"
+   wasCreatedForAppExtension = "YES"
+   version = "2.0">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "E268E0802A85302000185913"
+               BuildableName = "Sesame-WidgetExtension.appex"
+               BlueprintName = "Sesame-WidgetExtension"
+               ReferencedContainer = "container:Sesame.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "88E197AB29EDC9BC00BF1D19"
+               BuildableName = "Sesame-Watch Watch App.app"
+               BlueprintName = "Sesame-Watch Watch App"
+               ReferencedContainer = "container:Sesame.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      shouldAutocreateTestPlan = "YES">
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = ""
+      selectedLauncherIdentifier = "Xcode.IDEFoundation.Launcher.PosixSpawn"
+      launchStyle = "0"
+      askForAppToLaunch = "Yes"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES"
+      launchAutomaticallySubstyle = "2">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "88E197AB29EDC9BC00BF1D19"
+            BuildableName = "Sesame-Watch Watch App.app"
+            BlueprintName = "Sesame-Watch Watch App"
+            ReferencedContainer = "container:Sesame.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+      <EnvironmentVariables>
+         <EnvironmentVariable
+            key = "_XCWidgetKind"
+            value = ""
+            isEnabled = "YES">
+         </EnvironmentVariable>
+         <EnvironmentVariable
+            key = "_XCWidgetDefaultView"
+            value = "timeline"
+            isEnabled = "YES">
+         </EnvironmentVariable>
+         <EnvironmentVariable
+            key = "_XCWidgetFamily"
+            value = "systemMedium"
+            isEnabled = "YES">
+         </EnvironmentVariable>
+      </EnvironmentVariables>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "E268E0802A85302000185913"
+            BuildableName = "Sesame-WidgetExtension.appex"
+            BlueprintName = "Sesame-WidgetExtension"
+            ReferencedContainer = "container:Sesame.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

Sesame.xcodeproj/xcuserdata/imac.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Bucket
+   uuid = "47155A8E-2113-40C3-89ED-8DEEEFF66A4F"
+   type = "1"
+   version = "2.0">
+</Bucket>

Sesame.xcodeproj/xcuserdata/imac.xcuserdatad/xcschemes/xcschememanagement.plist

@@ -4,16 +4,39 @@
 <dict>
 	<key>SchemeUserState</key>
 	<dict>
+		<key>Sesame Watch App.xcscheme_^#shared#^_</key>
+		<dict>
+			<key>orderHint</key>
+			<integer>2</integer>
+		</dict>
 		<key>Sesame-Watch Watch App.xcscheme_^#shared#^_</key>
 		<dict>
 			<key>orderHint</key>
-			<integer>0</integer>
+			<integer>2</integer>
 		</dict>
-		<key>Sesame.xcscheme_^#shared#^_</key>
+		<key>Sesame-WidgetExtension.xcscheme_^#shared#^_</key>
 		<dict>
 			<key>orderHint</key>
 			<integer>1</integer>
 		</dict>
+		<key>Sesame.xcscheme_^#shared#^_</key>
+		<dict>
+			<key>orderHint</key>
+			<integer>0</integer>
+		</dict>
+	</dict>
+	<key>SuppressBuildableAutocreation</key>
+	<dict>
+		<key>88E197AB29EDC9BC00BF1D19</key>
+		<dict>
+			<key>primary</key>
+			<true/>
+		</dict>
+		<key>E268E0802A85302000185913</key>
+		<dict>
+			<key>primary</key>
+			<true/>
+		</dict>
 	</dict>
 </dict>
 </plist>

Sesame/API Extensions/Message+Crypto.swift

@@ -0,0 +1,26 @@
+import Foundation
+import CryptoKit
+
+extension Message {
+
+    /**
+     Calculate an authentication code for the message content.
+     - Parameter key: The key to use to sign the content.
+     - Returns: The new message signed with the key.
+     */
+    func authenticate(using key: SymmetricKey) -> SignedMessage {
+        let mac = HMAC<SHA256>.authenticationCode(for: encoded, using: key)
+        return .init(mac: Data(mac.map { $0 }), message: self)
+    }
+
+    /**
+     Calculate an authentication code for the message content and convert everything to data.
+     - Parameter key: The key to use to sign the content.
+     - Returns: The new message signed with the key, serialized to bytes.
+     */
+    func authenticateAndSerialize(using key: SymmetricKey) -> Data {
+        let encoded = self.encoded
+        let mac = HMAC<SHA256>.authenticationCode(for: encoded, using: key)
+        return Data(mac.map { $0 }) + encoded
+    }
+}

Sesame/API Extensions/Message.swift

@@ -0,0 +1,123 @@
+import Foundation
+
+/**
+ The message content without authentication.
+ */
+struct Message: Equatable, Hashable {
+    
+    /// The type of message being sent.
+    let messageType: MessageType
+    
+    /**
+     * The random nonce created by the remote
+     *
+     * This nonce is a random number created by the remote, different for each unlock request.
+     * It is set for all message types.
+     */
+    let clientChallenge: UInt32
+    
+    /**
+     * A random number to sign by the remote
+     *
+     * This nonce is set by the server after receiving an initial message.
+     * It is set for the message types `challenge`, `request`, and `response`.
+     */
+    let serverChallenge: UInt32
+    
+    /**
+     * The response status for the previous message.
+     *
+     * It is set only for messages from the server, e.g. the `challenge` and `response` message types.
+     * Must be set to `MessageAccepted` for other messages.
+     */
+    let result: MessageResult
+    
+    init(messageType: MessageType, clientChallenge: UInt32, serverChallenge: UInt32, result: MessageResult) {
+        self.messageType = messageType
+        self.clientChallenge = clientChallenge
+        self.serverChallenge = serverChallenge
+        self.result = result
+    }
+    
+    /**
+     Decode message content from data.
+     
+     The data consists of two `UInt32` encoded in little endian format
+     - Warning: The sequence must contain at least 8 bytes, or the function will crash.
+     - Parameter data: The sequence containing the bytes.
+     */
+    init(decodeFrom data: Data) throws {
+        guard data.count == Message.size else {
+            print("Invalid message size \(data.count)")
+            throw MessageResult.invalidMessageSizeFromDevice
+        }
+        guard let messageType = MessageType(rawValue: data.first!) else {
+            print("Invalid message type \(data.first!)")
+            throw MessageResult.invalidMessageTypeFromDevice
+        }
+        self.messageType = messageType
+        self.clientChallenge = UInt32(data: data.dropFirst().prefix(UInt32.byteSize))
+        self.serverChallenge = UInt32(data: data.dropFirst(UInt32.byteSize+1).prefix(UInt32.byteSize))
+        guard let result = MessageResult(rawValue: data.last!) else {
+            print("Invalid message result \(data.last!)")
+            throw MessageResult.unknownMessageResultFromDevice
+        }
+        self.result = result
+    }
+    
+    /// The message content encoded to data
+    var encoded: Data {
+        messageType.encoded + clientChallenge.encoded + serverChallenge.encoded + result.encoded
+    }
+}
+
+extension Message: Codable {
+
+    enum CodingKeys: Int, CodingKey {
+        case messageType = 1
+        case clientChallenge = 2
+        case serverChallenge = 3
+        case result = 4
+    }
+}
+
+extension Message {
+    
+    init(error: MessageResult, type: MessageType) {
+        self.init(messageType: type, clientChallenge: 0, serverChallenge: 0, result: error)
+    }
+    
+    static func initial() -> Message {
+        .init(
+            messageType: .initial,
+            clientChallenge: .random(),
+            serverChallenge: 0,
+            result: .messageAccepted)
+    }
+    
+    func with(result: MessageResult) -> Message {
+        .init(
+            messageType: messageType.responseType,
+            clientChallenge: clientChallenge,
+            serverChallenge: serverChallenge,
+            result: result)
+    }
+    
+    /**
+     Create the message to respond to this challenge
+     */
+    func requestMessage() -> Message {
+        .init(
+            messageType: .request,
+            clientChallenge: clientChallenge,
+            serverChallenge: serverChallenge,
+            result: .messageAccepted)
+    }
+}
+
+extension Message: CustomStringConvertible {
+    
+    var description: String {
+        "\(messageType)(\(clientChallenge)->\(serverChallenge), \(result))"
+    }
+}

Sesame/API Extensions/MessageResult+UI.swift

@@ -0,0 +1,118 @@
+import Foundation
+import SwiftUI
+import SFSafeSymbols
+
+extension MessageResult {
+    
+    var color: Color {
+        switch self {
+        
+        // Initial state when not configured
+        case .noKeyAvailable:
+            return Color(red: 50/255, green: 50/255, blue: 50/255)
+        
+        // All ready states
+        case .notChecked,
+             .messageAccepted,
+             .deviceAvailable:
+            return Color(red: 115/255, green: 140/255, blue: 90/255)
+            
+        case .unlocked:
+            return Color(red: 65/255, green: 110/255, blue: 60/255)
+        
+        // All implementation errors
+        case .textReceived,
+             .unexpectedSocketEvent,
+             .invalidMessageSizeFromDevice,
+             .invalidMessageSizeFromRemote,
+             .invalidMessageTypeFromDevice,
+             .invalidMessageTypeFromRemote,
+             .unknownMessageResultFromDevice,
+             .invalidUrlParameter,
+             .noOrInvalidBodyDataFromRemote,
+             .invalidMessageResultFromRemote,
+             .unexpectedUrlResponseType,
+             .unexpectedServerResponseCode,
+             .internalServerError,
+             .pathOnServerNotFound,
+             .missingOrInvalidAuthenticationHeaderFromRemote:
+            return Color(red: 30/255, green: 30/255, blue: 160/255)
+            
+        // All security errors
+        case .invalidSignatureFromRemote,
+             .invalidServerChallengeFromDevice,
+             .invalidServerChallengeFromRemote,
+             .invalidClientChallengeFromDevice,
+             .invalidClientChallengeFromRemote,
+             .invalidSignatureFromDevice:
+            return Color(red: 160/255, green: 30/255, blue: 30/255)
+        
+        // Connection errors
+        case .tooManyRequests,
+             .deviceTimedOut,
+             .deviceNotConnected,
+             .serviceBehindProxyUnavailable:
+            return Color(red: 150/255, green: 90/255, blue: 90/255)
+            
+        // Configuration errors
+        case .serverUrlInvalid, .invalidServerAuthenticationFromRemote:
+            return Color(red: 100/255, green: 100/255, blue: 140/255)
+        }
+    }
+    
+    var symbol: SFSymbol {
+        switch self {
+        
+        // Initial state when not configured
+        case .noKeyAvailable:
+            return .questionmarkKeyFilled // .keySlash in 5.0
+        
+        // All ready states
+        case .notChecked,
+             .messageAccepted,
+             .deviceAvailable:
+            return .checkmark
+            
+        case .unlocked:
+            return .lockOpen
+        
+        // All implementation errors
+        case .textReceived,
+             .unexpectedSocketEvent,
+             .invalidMessageSizeFromDevice,
+             .invalidMessageSizeFromRemote,
+             .invalidMessageTypeFromDevice,
+             .invalidMessageTypeFromRemote,
+             .unknownMessageResultFromDevice,
+             .invalidUrlParameter,
+             .noOrInvalidBodyDataFromRemote,
+             .invalidMessageResultFromRemote,
+             .unexpectedUrlResponseType,
+             .unexpectedServerResponseCode,
+             .internalServerError,
+             .pathOnServerNotFound,
+             .missingOrInvalidAuthenticationHeaderFromRemote:
+            return .questionmarkDiamond
+            
+        // All security errors
+        case .invalidSignatureFromRemote,
+             .invalidServerChallengeFromDevice,
+             .invalidServerChallengeFromRemote,
+             .invalidClientChallengeFromDevice,
+             .invalidClientChallengeFromRemote,
+             .invalidSignatureFromDevice:
+            return .lockTrianglebadgeExclamationmark
+        
+        // Connection errors
+        case .tooManyRequests,
+             .deviceTimedOut,
+             .deviceNotConnected,
+             .serviceBehindProxyUnavailable:
+            return .antennaRadiowavesLeftAndRightSlash
+            
+        // Configuration errors
+        case .serverUrlInvalid, .invalidServerAuthenticationFromRemote:
+            return .gearBadgeQuestionmark
+        }
+    }
+}

Sesame/API Extensions/MessageType.swift

@@ -0,0 +1,57 @@
+import Foundation
+
+enum MessageType: UInt8 {
+    
+    /// The initial message from remote to device to request a challenge.
+    case initial = 0
+    
+    /// The second message in an unlock with the challenge from the device to the remote
+    case challenge = 1
+    
+    /// The third message with the signed challenge from the remote to the device
+    case request = 2
+    
+    /// The final message with the unlock result from the device to the remote
+    case response = 3
+}
+
+extension MessageType {
+
+    var encoded: Data {
+        Data([rawValue])
+    }
+}
+
+extension MessageType: Codable {
+    
+}
+
+extension MessageType {
+    
+    var responseType: MessageType {
+        switch self {
+        case .initial:
+            return .challenge
+        case .challenge:
+            return .request
+        case .request, .response:
+            return .response
+        }
+    }
+}
+
+extension MessageType: CustomStringConvertible {
+    
+    var description: String {
+        switch self {
+        case .initial:
+            return "Initial"
+        case .challenge:
+            return "Challenge"
+        case .request:
+            return "Request"
+        case .response:
+            return "Response"
+        }
+    }
+}

Sesame/API Extensions/SignedMessage+Crypto.swift

@@ -0,0 +1,38 @@
+import Foundation
+import CryptoKit
+
+extension SignedMessage {
+
+    /// The message encoded to data
+    var encoded: Data {
+        mac + message.encoded
+    }
+
+    var bytes: [UInt8] {
+        Array(encoded)
+    }
+
+    /**
+     Create a message from received bytes.
+     - Parameter data: The sequence of bytes
+     - Note: The sequence must contain at least `Message.length` bytes, or the function will crash.
+     */
+    init(decodeFrom data: Data) throws {
+        guard data.count == SignedMessage.size else {
+            print("Invalid signed message size \(data.count)")
+            throw MessageResult.invalidMessageSizeFromDevice
+        }
+        let count = SHA256.byteCount
+        self.mac = data.prefix(count)
+        self.message = try Message(decodeFrom: data.dropFirst(count))
+    }
+
+    /**
+     Check if the message contains a valid authentication code
+     - Parameter key: The key used to sign the message.
+     - Returns: `true`, if the message is valid.
+     */
+    func isValid(using key: SymmetricKey) -> Bool {
+         HMAC<SHA256>.isValidAuthenticationCode(mac, authenticating: message.encoded, using: key)
+    }
+}

Sesame/API Extensions/SignedMessage.swift

@@ -0,0 +1,31 @@
+import Foundation
+
+/**
+ An authenticated message to or from the device.
+ */
+struct SignedMessage: Equatable, Hashable {
+    
+    /// The message authentication code for the message (32 bytes)
+    let mac: Data
+
+    /// The message content
+    let message: Message
+
+    /**
+     Create an authenticated message
+     - Parameter mac: The message authentication code
+     - Parameter content: The message content
+     */
+    init(mac: Data, message: Message) {
+        self.mac = mac
+        self.message = message
+    }
+}
+
+extension SignedMessage: Codable {
+    
+    enum CodingKeys: Int, CodingKey {
+        case mac = 1
+        case message = 2
+    }
+}

Sesame/API/DeviceResponse.swift

@@ -1,90 +0,0 @@
-import Foundation
-import NIOCore
-
-/**
- Encapsulates a response from a device.
- */
-struct DeviceResponse {
-
-    /// Shorthand property for a timeout event.
-    static var deviceTimedOut: DeviceResponse {
-        .init(event: .deviceTimedOut)
-    }
-
-    /// Shorthand property for a disconnected event.
-    static var deviceNotConnected: DeviceResponse {
-        .init(event: .deviceNotConnected)
-    }
-
-    /// Shorthand property for a connected event.
-    static var deviceConnected: DeviceResponse {
-        .init(event: .deviceConnected)
-    }
-
-    /// Shorthand property for an unexpected socket event.
-    static var unexpectedSocketEvent: DeviceResponse {
-        .init(event: .unexpectedSocketEvent)
-    }
-
-    /// Shorthand property for an invalid message.
-    static var invalidMessageSize: DeviceResponse {
-        .init(event: .invalidMessageSize)
-    }
-
-    /// Shorthand property for missing body data.
-    static var noBodyData: DeviceResponse {
-        .init(event: .noBodyData)
-    }
-
-    /// Shorthand property for a busy connection
-    static var operationInProgress: DeviceResponse {
-        .init(event: .operationInProgress)
-    }
-
-    /// The response to a key from the server
-    let event: MessageResult
-
-    /// The index of the next key to use
-    let response: Message?
-
-    /**
-     Decode a message from a buffer.
-
-     The buffer must contain `Message.length+1` bytes. The first byte denotes the event type,
-     the remaining bytes contain the message.
-     - Parameter buffer: The buffer where the message bytes are stored
-     */
-    init?(_ buffer: ByteBuffer) {
-        guard let byte = buffer.getBytes(at: 0, length: 1) else {
-            print("No bytes received from device")
-            return nil
-        }
-        guard let event = MessageResult(rawValue: byte[0]) else {
-            print("Unknown response \(byte[0]) received from device")
-            return nil
-        }
-        self.event = event
-        guard let data = buffer.getSlice(at: 1, length: Message.length) else {
-            self.response = nil
-            return
-        }
-        self.response = Message(decodeFrom: data)
-    }
-
-    /**
-     Create a response from an event without a message from the device.
-     - Parameter event: The response from the device.
-     */
-    init(event: MessageResult) {
-        self.event = event
-        self.response = nil
-    }
-
-    /// Get the reponse encoded in bytes.
-    var encoded: Data {
-        guard let message = response else {
-            return event.encoded
-        }
-        return event.encoded + message.encoded
-    }
-}

Sesame/API/Extensions/Data+Coding.swift

@@ -0,0 +1,17 @@
+import Foundation
+
+extension Data {
+
+    func convert<T>(into value: T) -> T {
+        withUnsafeBytes {
+            $0.baseAddress!.load(as: T.self)
+        }
+    }
+
+    init<T>(from value: T) {
+        var target = value
+        self = Swift.withUnsafeBytes(of: &target) {
+            Data($0)
+        }
+    }
+}

Sesame/API/Extensions/Data+Hex.swift

@@ -40,20 +40,3 @@ extension Data {
         }
     }
 }
-
-extension Data {
-
-
-    func convert<T>(into value: T) -> T {
-        withUnsafeBytes {
-            $0.baseAddress!.load(as: T.self)
-        }
-    }
-
-    init<T>(from value: T) {
-        var target = value
-        self = Swift.withUnsafeBytes(of: &target) {
-            Data($0)
-        }
-    }
-}

Sesame/API/Extensions/UInt32+Coding.swift

@@ -15,4 +15,7 @@ extension UInt32 {
     var encoded: Data {
         Data(from: CFSwapInt32HostToLittle(self))
     }
+    
+    /// The size of a `UInt32` when converted to data
+    static let byteSize = MemoryLayout<UInt32>.size
 }

Sesame/API/Message+Size.swift

@@ -0,0 +1,8 @@
+import Foundation
+
+extension Message {
+    
+    /// The byte length of an encoded message content
+    static let size: Int = 2 + 2 * UInt32.byteSize
+    
+}

Sesame/API/Message.swift

@@ -1,179 +0,0 @@
-import Foundation
-import NIOCore
-
-#if canImport(CryptoKit)
-import CryptoKit
-#else
-import Crypto
-#endif
-
-/**
- An authenticated message to or from the device.
- */
-struct Message: Equatable, Hashable {
-
-    /// The message authentication code for the message (32 bytes)
-    let mac: Data
-
-    /// The message content
-    let content: Content
-
-    /**
-     Create an authenticated message
-     - Parameter mac: The message authentication code
-     - Parameter content: The message content
-     */
-    init(mac: Data, content: Content) {
-        self.mac = mac
-        self.content = content
-    }
-}
-
-extension Message: Codable {
-    
-    enum CodingKeys: Int, CodingKey {
-        case mac = 1
-        case content = 2
-    }
-}
-
-extension Message {
-
-    /**
-     The message content without authentication.
-     */
-    struct Content: Equatable, Hashable {
-
-        /// The time of message creation, in UNIX time (seconds since 1970)
-        let time: UInt32
-
-        /// The counter of the message (for freshness)
-        let id: UInt32
-        
-        let deviceId: UInt8?
-
-        /**
-         Create new message content.
-         - Parameter time: The time of message creation,
-         - Parameter id: The counter of the message
-         */
-        init(time: UInt32, id: UInt32, device: UInt8) {
-            self.time = time
-            self.id = id
-            self.deviceId = device
-        }
-
-        /**
-         Decode message content from data.
-
-         The data consists of two `UInt32` encoded in little endian format
-         - Warning: The sequence must contain at least 8 bytes, or the function will crash.
-         - Parameter data: The sequence containing the bytes.
-         */
-        init<T: Sequence>(decodeFrom data: T) where T.Element == UInt8 {
-            self.time = UInt32(data: Data(data.prefix(MemoryLayout<UInt32>.size)))
-            self.id = UInt32(data: Data(data.dropLast().suffix(MemoryLayout<UInt32>.size)))
-            self.deviceId = data.suffix(1).last!
-        }
-
-        /// The byte length of an encoded message content
-        static var length: Int {
-            MemoryLayout<UInt32>.size * 2 + 1
-        }
-
-        /// The message content encoded to data
-        var encoded: Data {
-            time.encoded + id.encoded + Data([deviceId ?? 0])
-        }
-    }
-}
-
-extension Message.Content: Codable {
-
-    enum CodingKeys: Int, CodingKey {
-        case time = 1
-        case id = 2
-        case deviceId = 3
-    }
-}
-
-extension Message {
-
-    /// The length of a message in bytes
-    static var length: Int {
-        SHA256.byteCount + Content.length
-    }
-
-    /**
-     Decode a message from a byte buffer.
-     The buffer must contain at least `Message.length` bytes, or it will return `nil`.
-     - Parameter buffer: The buffer containing the bytes.
-     */
-    init?(decodeFrom buffer: ByteBuffer) {
-        guard let data = buffer.getBytes(at: 0, length: Message.length) else {
-            return nil
-        }
-        self.init(decodeFrom: data)
-    }
-
-    init?(decodeFrom data: Data, index: inout Int) {
-        guard index + Message.length <= data.count else {
-            return nil
-        }
-        self.init(decodeFrom: data.advanced(by: index))
-        index += Message.length
-    }
-
-    /// The message encoded to data
-    var encoded: Data {
-        mac + content.encoded
-    }
-
-    var bytes: [UInt8] {
-        Array(encoded)
-    }
-
-    /**
-     Create a message from received bytes.
-     - Parameter data: The sequence of bytes
-     - Note: The sequence must contain at least `Message.length` bytes, or the function will crash.
-     */
-    init<T: Sequence>(decodeFrom data: T) where T.Element == UInt8 {
-        let count = SHA256.byteCount
-        self.mac = Data(data.prefix(count))
-        self.content = .init(decodeFrom: Array(data.dropFirst(count)))
-    }
-
-    /**
-     Check if the message contains a valid authentication code
-     - Parameter key: The key used to sign the message.
-     - Returns: `true`, if the message is valid.
-     */
-    func isValid(using key: SymmetricKey) -> Bool {
-         HMAC<SHA256>.isValidAuthenticationCode(mac, authenticating: content.encoded, using: key)
-    }
-}
-
-extension Message.Content {
-
-    /**
-     Calculate an authentication code for the message content.
-     - Parameter key: The key to use to sign the content.
-     - Returns: The new message signed with the key.
-     */
-    func authenticate(using key: SymmetricKey) -> Message {
-        let mac = HMAC<SHA256>.authenticationCode(for: encoded, using: key)
-        return .init(mac: Data(mac.map { $0 }), content: self)
-    }
-
-    /**
-     Calculate an authentication code for the message content and convert everything to data.
-     - Parameter key: The key to use to sign the content.
-     - Returns: The new message signed with the key, serialized to bytes.
-     */
-    func authenticateAndSerialize(using key: SymmetricKey) -> Data {
-        let encoded = self.encoded
-        let mac = HMAC<SHA256>.authenticationCode(for: encoded, using: key)
-        return Data(mac.map { $0 }) + encoded
-    }
-}

Sesame/API/MessageResult.swift

@@ -5,92 +5,231 @@ import Foundation
  */
 enum MessageResult: UInt8 {
     
-    /// Text content was received, although binary data was expected
+    // MARK: Device status
+
+    /// The message was accepted.
+    case messageAccepted = 0
+    
+    /// The web socket received text while waiting for binary data.
     case textReceived = 1
 
-    /// A socket event on the device was unexpected (not binary data)
+    /// An unexpected socket event occured while performing the exchange.
     case unexpectedSocketEvent = 2
 
-    /// The size of the payload (i.e. message) was invalid
+    /// The received message size is invalid.
-    case invalidMessageSize = 3
+    case invalidMessageSizeFromRemote = 3
 
-    /// The transmitted message could not be authenticated using the key
+    /// The message signature was incorrect.
-    case messageAuthenticationFailed = 4
+    case invalidSignatureFromRemote = 4
 
-    /// The message time was not within the acceptable bounds
+    /// The server challenge of the message did not match previous messages
-    case messageTimeMismatch = 5
+    case invalidServerChallengeFromRemote = 5
 
-    /// A later key has been used, invalidating this key (to prevent replay attacks after blocked communication)
+    /// The client challenge of the message did not match previous messages
-    case messageCounterInvalid = 6
+    case invalidClientChallengeFromRemote = 6
 
-    /// The key was accepted by the device, and the door will be opened
+    /// An unexpected or unsupported message type was received
-    case messageAccepted = 7
+    case invalidMessageTypeFromRemote = 7
 
-    /// The device id is invalid
+    /// A message is already being processed
-    case messageDeviceInvalid = 8
+    case tooManyRequests = 8
     
+    /// The received message result was not ``messageAccepted``
+    case invalidMessageResultFromRemote = 9
 
-    /// The request did not contain body data with the key
+    /// An invalid Url parameter was set sending a message to the device over a local connection
-    case noBodyData = 10
+    case invalidUrlParameter = 10
     
-    /// The device is not connected
+    // MARK: Server status
-    case deviceNotConnected = 12
     
-    /// The device did not respond within the timeout
+    /// The body data posting a message was missing or of wrong length
-    case deviceTimedOut = 13
+    case noOrInvalidBodyDataFromRemote = 21
     
-    /// Another message is being processed by the device
+    /// The authentication token for the server was invalid
-    case operationInProgress = 14
+    case invalidServerAuthenticationFromRemote = 22
     
-    /// The device is connected
+    /// The request took too long to complete
-    case deviceConnected = 15
+    case deviceTimedOut = 23
     
-    case invalidUrlParameter = 20
+    /// The device is not connected to the server via web socket
+    case deviceNotConnected = 24
+    
+    /// The device sent a response of invalid size
+    case invalidMessageSizeFromDevice = 25
+    
+    /// The header with the authentication token was missing or invalid (not a hex string) from a server request.
+    case missingOrInvalidAuthenticationHeaderFromRemote = 26
+    
+    /// The server produced an internal error (500)
+    case internalServerError = 27
+    
+    // MARK: Remote status
+
+    /// The initial state without information about the connection
+    case notChecked = 30
+    
+    /// The url string is not a valid url
+    case serverUrlInvalid = 31
+    
+    /// The device key or auth token is missing for a request.
+    case noKeyAvailable = 32
+    
+    /// The Sesame server behind the proxy could not be found (502)
+    case serviceBehindProxyUnavailable = 33
+    
+    /// The server url could not be found (404)
+    case pathOnServerNotFound = 34
+    
+    /// The url session request returned an unknown response
+    case unexpectedUrlResponseType = 35
+    
+    /// The request to the server returned an unhandled HTTP code
+    case unexpectedServerResponseCode = 36
+    
+    /// A valid server challenge was received
+    case deviceAvailable = 37
+    
+    case invalidSignatureFromDevice = 38
+    
+    case invalidMessageTypeFromDevice = 39
+    
+    case unknownMessageResultFromDevice = 40
+    
+    /// The device sent a message with an invalid client challenge
+    case invalidClientChallengeFromDevice = 41
+    
+    /// The device used an invalid server challenge in a response
+    case invalidServerChallengeFromDevice = 42
+    
+    /// The unlock process was successfully completed
+    case unlocked = 43
+}
+
+extension MessageResult: Error {
     
-    case invalidResponseAuthentication = 21
 }
 
 extension MessageResult: CustomStringConvertible {
 
     var description: String {
         switch self {
+        case .messageAccepted:
+            return "Message accepted"
         case .textReceived:
             return "The device received unexpected text"
         case .unexpectedSocketEvent:
             return "Unexpected socket event for the device"
-        case .invalidMessageSize:
+        case .invalidMessageSizeFromRemote:
-            return "Invalid message data"
+            return "Invalid message data from remote"
-        case .messageAuthenticationFailed:
+        case .invalidSignatureFromRemote:
             return "Message authentication failed"
-        case .messageTimeMismatch:
+        case .invalidServerChallengeFromRemote:
-            return "Message time invalid"
+            return "Remote used wrong server challenge"
-        case .messageCounterInvalid:
+        case .invalidClientChallengeFromRemote:
-            return "Message counter invalid"
+            return "Wrong client challenge sent"
-        case .messageAccepted:
+        case .invalidMessageTypeFromRemote:
-            return "Message accepted"
+            return "Message type from remote invalid"
-        case .messageDeviceInvalid:
+        case .tooManyRequests:
-            return "Invalid device ID"
+            return "Device busy"
-        case .noBodyData:
+        case .invalidMessageResultFromRemote:
-            return "No body data included in the request"
+            return "Invalid message result"
-        case .deviceNotConnected:
-            return "Device not connected"
-        case .deviceTimedOut:
-            return "The device did not respond"
-        case .operationInProgress:
-            return "Another operation is in progress"
-        case .deviceConnected:
-            return "The device is connected"
         case .invalidUrlParameter:
             return "The url parameter could not be found"
-        case .invalidResponseAuthentication:
+        
-            return "The response could not be authenticated"
+        case .noOrInvalidBodyDataFromRemote:
+            return "Invalid body data in server request"
+        case .invalidServerAuthenticationFromRemote:
+            return "Invalid server token"
+        case .deviceTimedOut:
+            return "The device did not respond"
+        case .deviceNotConnected:
+            return "Device not connected to server"
+        case .invalidMessageSizeFromDevice:
+            return "Invalid device message size"
+        case .missingOrInvalidAuthenticationHeaderFromRemote:
+            return "Invalid server token format"
+        case .internalServerError:
+            return "Internal server error"
+        
+        case .notChecked:
+            return "Not checked"
+        case .serverUrlInvalid:
+            return "Invalid server url"
+        case .noKeyAvailable:
+            return "No key available"
+        case .serviceBehindProxyUnavailable:
+            return "Service behind proxy not found"
+        case .pathOnServerNotFound:
+            return "Invalid server path"
+        case .unexpectedUrlResponseType:
+            return "Unexpected URL response"
+        case .unexpectedServerResponseCode:
+            return "Unexpected server response code"
+        case .deviceAvailable:
+            return "Device available"
+        case .invalidSignatureFromDevice:
+            return "Invalid device signature"
+        case .invalidMessageTypeFromDevice:
+            return "Message type from device invalid"
+        case .unknownMessageResultFromDevice:
+            return "Unknown message result"
+        case .invalidClientChallengeFromDevice:
+            return "Device used wrong client challenge"
+        case .invalidServerChallengeFromDevice:
+            return "Invalid"
+        case .unlocked:
+            return "Unlocked"
         }
     }
 }
 
+extension MessageResult: Codable {
+    
+}
+
 extension MessageResult {
 
     var encoded: Data {
         Data([rawValue])
     }
 }
+
+extension MessageResult {
+    
+    init(httpCode: Int) {
+        switch httpCode {
+        case 200: self = .messageAccepted
+        case 204: self = .noOrInvalidBodyDataFromRemote
+        case 403: self = .invalidServerAuthenticationFromRemote
+        case 404: self = .pathOnServerNotFound
+        case 408: self = .deviceTimedOut
+        case 412: self = .deviceNotConnected
+        case 413: self = .invalidMessageSizeFromDevice
+        case 422: self = .missingOrInvalidAuthenticationHeaderFromRemote
+        case 429: self = .tooManyRequests
+        case 500: self = .internalServerError
+        case 501: self = .unexpectedServerResponseCode
+        case 502: self = .serviceBehindProxyUnavailable
+        default: self = .unexpectedServerResponseCode
+        }
+    }
+    
+    var statusCode: Int {
+        switch self {
+        case .messageAccepted: return 200 // ok
+        case .noOrInvalidBodyDataFromRemote: return 204 // noContent
+        case .invalidServerAuthenticationFromRemote: return 403 // forbidden
+        case .pathOnServerNotFound: return 404 // notFound
+        case .deviceTimedOut: return 408 // requestTimeout
+        case .invalidMessageSizeFromRemote: return 411 // lengthRequired
+        case .deviceNotConnected: return 412 // preconditionFailed
+        case .invalidMessageSizeFromDevice: return 413 // payloadTooLarge
+        case .missingOrInvalidAuthenticationHeaderFromRemote: return 422 // unprocessableEntity
+        case .tooManyRequests: return 429 // tooManyRequests
+        case .internalServerError: return 500 // internalServerError
+        case .unexpectedServerResponseCode: return 501 // notImplemented
+        case .serviceBehindProxyUnavailable: return 502 // badGateway
+        default: return 501 // == unexpectedServerResponseCode
+        }
+    }
+}

Sesame/API/ServerMessage.swift

@@ -1,26 +0,0 @@
-import Foundation
-import NIOCore
-
-#if canImport(CryptoKit)
-import CryptoKit
-#else
-import Crypto
-#endif
-
-struct ServerMessage {
-
-    static let authTokenSize = SHA256.byteCount
-
-    let authToken: Data
-
-    let message: Message
-
-    init(authToken: Data, message: Message) {
-        self.authToken = authToken
-        self.message = message
-    }
-
-    var encoded: Data {
-        authToken + message.encoded
-    }
-}

Sesame/API/SesameHeader.swift

@@ -0,0 +1,14 @@
+import Foundation
+#if canImport(CryptoKit)
+import CryptoKit
+#else
+import Crypto
+#endif
+
+enum SesameHeader {
+    
+    static let authenticationHeader = "Authorization"
+
+    static let serverAuthenticationTokenSize = SHA256.byteCount
+    
+}

Sesame/API/SesameRoute.swift

@@ -3,10 +3,7 @@ import Foundation
 /**
  The active urls on the server, for the device and the remote to connect
  */
-enum RouteAPI: String {
+enum SesameRoute: String {
-
-    /// Check the device status
-    case getDeviceStatus = "status"
 
     /// Send a message to the server, to relay to the device
     case postMessage = "message"

Sesame/API/SignedMessage+Size.swift

@@ -0,0 +1,15 @@
+import Foundation
+
+#if canImport(CryptoKit)
+import CryptoKit
+#else
+import Crypto
+#endif
+
+extension SignedMessage {
+    
+    /// The length of a message in bytes
+    static var size: Int {
+        SHA256.byteCount + Message.size
+    }
+}

Sesame/Common/ActiveRequestType.swift

@@ -0,0 +1,18 @@
+import Foundation
+
+enum RequestType {
+    case challenge
+    case unlock
+}
+
+extension RequestType: CustomStringConvertible {
+    
+    var description: String {
+        switch self {
+        case .challenge:
+            return "Challenge"
+        case .unlock:
+            return "Unlock"
+        }
+    }
+}

Sesame/Common/Client.swift

@@ -3,91 +3,100 @@ import CryptoKit
 
 final class Client {
     
-    // TODO: Use or delete
+    private let localRequestRoute = "message"
-    private let delegate = NeverCacheDelegate()
+    
+    private let urlMessageParameter = "m"
     
     init() {}
     
-    func deviceStatus(authToken: Data, server: String) async -> ClientState {
+    func send(_ message: Message, to url: String, through route: TransmissionType, using keys: KeySet) async -> ServerResponse {
-        await send(path: .getDeviceStatus, server: server, data: authToken).state
+        let sentTime = Date.now
+        let signedMessage = message.authenticate(using: keys.remote)
+        let response: Message
+        switch route {
+        case .throughServer:
+            response = await send(signedMessage, toServerUrl: url, authenticateWith: keys.server, verifyUsing: keys.device)
+            
+        case .overLocalWifi:
+            response = await send(signedMessage, toLocalDeviceUrl: url, verifyUsing: keys.device)
+        }
+        let receivedTime = Date.now
+        // Create best guess for creation of challenge.
+        let roundTripTime = receivedTime.timeIntervalSince(sentTime)
+        let serverChallenge = ServerChallenge(
+            creationDate: sentTime.addingTimeInterval(roundTripTime / 2),
+            message: response)
+        
+        // Validate message content
+        guard response.result == .messageAccepted else {
+            print("Failure: \(response)")
+            return (response, nil)
+        }
+        
+        guard response.clientChallenge == message.clientChallenge else {
+            print("Invalid client challenge: \(response)")
+            return (response.with(result: .invalidClientChallengeFromDevice), nil)
+        }
+        return (response, serverChallenge)
     }
 
-    func sendMessageOverLocalNetwork(_ message: Message, server: String) async -> (state: ClientState, response: Message?) {
+    
+    private func send(_ message: SignedMessage, toLocalDeviceUrl server: String, verifyUsing deviceKey: SymmetricKey) async -> Message {
         let data = message.encoded.hexEncoded
-        guard let url = URL(string: server + "message?m=\(data)") else {
+        guard let url = URL(string: server)?.appendingPathComponent("\(localRequestRoute)?\(urlMessageParameter)=\(data)") else {
-            return (.internalError("Invalid server url"), nil)
+            return message.message.with(result: .serverUrlInvalid)
         }
         
         var request = URLRequest(url: url)
         request.httpMethod = "POST"
-        return await requestAndDecode(request)
-    }
-    
-    func send(_ message: Message, server: String, authToken: Data) async -> (state: ClientState, response: Message?) {
-        let serverMessage = ServerMessage(authToken: authToken, message: message)
-        return await send(path: .postMessage, server: server, data: serverMessage.encoded)
-    }
-    
-    private func send(path: RouteAPI, server: String, data: Data) async -> (state: ClientState, response: Message?) {
-        guard let url = URL(string: server) else {
-            return (.internalError("Invalid server url"), nil)
-        }
-        let fullUrl = url.appendingPathComponent(path.rawValue)
-        return await send(to: fullUrl, data: data)
-    }
-
-    private func send(to url: URL, data: Data) async -> (state: ClientState, response: Message?) {
-        var request = URLRequest(url: url)
-        request.httpBody = data
-        request.httpMethod = "POST"
         request.timeoutInterval = 10
-        return await requestAndDecode(request)
+        return await perform(request, inResponseTo: message.message, verifyUsing: deviceKey)
     }
     
-    private func requestAndDecode(_ request: URLRequest) async -> (state: ClientState, response: Message?) {
+    private func send(_ message: SignedMessage, toServerUrl server: String, authenticateWith authToken: Data, verifyUsing deviceKey: SymmetricKey) async -> Message {
-        guard let data = await fulfill(request) else {
+        guard let url = URL(string: server)?.appendingPathComponent(SesameRoute.postMessage.rawValue) else {
-            return (.deviceNotAvailable(.serverNotReached), nil)
+            return message.message.with(result: .serverUrlInvalid)
         }
-        guard let byte = data.first else {
+        
-            return (.internalError("Empty response"), nil)
+        var request = URLRequest(url: url)
-        }
+        request.httpBody = message.encoded
-        guard let status = MessageResult(rawValue: byte) else {
+        request.httpMethod = "POST"
-            return (.internalError("Invalid message response: \(byte)"), nil)
+        request.timeoutInterval = 10
-        }
+        request.addValue(authToken.hexEncoded, forHTTPHeaderField: SesameHeader.authenticationHeader)
-        let result = ClientState(keyResult: status)
+        return await perform(request, inResponseTo: message.message, verifyUsing: deviceKey)
-        guard data.count == Message.length + 1 else {
-            if data.count != 1 {
-                print("Device response with only \(data.count) bytes")
-            }
-            return (result, nil)
-        }
-        let messageData = Array(data.advanced(by: 1))
-        let message = Message(decodeFrom: messageData)
-        return (result, message)
     }
     
-    private func fulfill(_ request: URLRequest) async -> Data? {
+    private func perform(_ request: URLRequest, inResponseTo message: Message, verifyUsing deviceKey: SymmetricKey) async -> Message {
+        let (response, responseData) = await fulfill(request)
+        guard response == .messageAccepted, let data = responseData else {
+            return message.with(result: response)
+        }
+        guard data.count == SignedMessage.size else {
+            print("[WARN] Received message with \(data.count) bytes (\(Array(data)))")
+            return message.with(result: .invalidMessageSizeFromDevice)
+        }
+        let decodedMessage: SignedMessage
+        do {
+            decodedMessage = try SignedMessage(decodeFrom: data)
+        } catch {
+            return message.with(result: error as! MessageResult)
+        }
+        guard decodedMessage.isValid(using: deviceKey) else {
+            return message.with(result: .invalidSignatureFromDevice)
+        }
+        return decodedMessage.message
+    }
+    
+    private func fulfill(_ request: URLRequest) async -> (response: MessageResult, data: Data?) {
         do {
             let (data, response) = try await URLSession.shared.data(for: request)
             guard let code = (response as? HTTPURLResponse)?.statusCode else {
-                print("No response from server")
+                return (.unexpectedUrlResponseType, nil)
-                return nil
             }
-            guard code == 200 else {
+            return (.init(httpCode: code), data)
-                print("Invalid server response \(code)")
-                return nil
-            }
-            return data
         } catch {
             print("Request failed: \(error)")
-            return nil
+            return (.deviceTimedOut, nil)
         }
     }
 }
-
-class NeverCacheDelegate: NSObject, NSURLConnectionDataDelegate {
-    
-    func connection(_ connection: NSURLConnection, willCacheResponse cachedResponse: CachedURLResponse) -> CachedURLResponse? {
-        return nil
-    }
-}

Sesame/Common/ClientState.swift

@@ -1,371 +0,0 @@
-import Foundation
-import SwiftUI
-import SFSafeSymbols
-
-enum ConnectionError {
-    case serverNotReached
-    case deviceDisconnected
-}
-
-extension ConnectionError: CustomStringConvertible {
-
-    var description: String {
-        switch self {
-        case .serverNotReached:
-            return "Server unavailable"
-        case .deviceDisconnected:
-            return "Device disconnected"
-        }
-    }
-}
-
-enum RejectionCause {
-    case invalidDeviceId
-    case invalidCounter
-    case invalidTime
-    case invalidAuthentication
-    case timeout
-    case missingKey
-}
-
-extension RejectionCause: CustomStringConvertible {
-
-    var description: String {
-        switch self {
-        case .invalidDeviceId:
-            return "Invalid device ID"
-        case .invalidCounter:
-            return "Invalid counter"
-        case .invalidTime:
-            return "Invalid time"
-        case .invalidAuthentication:
-            return "Invalid authentication"
-        case .timeout:
-            return "Device not responding"
-        case .missingKey:
-            return "No key to verify message"
-        }
-    }
-}
-
-enum ClientState {
-
-    /// There is no key stored locally on the client. A new key must be generated before use.
-    case noKeyAvailable
-
-    /// The device status is being requested
-    case requestingStatus
-
-    /// The remote device is not connected (no socket opened)
-    case deviceNotAvailable(ConnectionError)
-
-    /// The device is connected and ready to receive a message
-    case ready
-    
-    /// The message is being transmitted and a response is awaited
-    case waitingForResponse
-    
-    /// The transmitted message was rejected (multiple possible reasons)
-    case messageRejected(RejectionCause)
-
-    case responseRejected(RejectionCause)
-
-    /// The device responded that the opening action was started
-    case openSesame
-
-    case internalError(String)
-    
-    var canSendKey: Bool {
-        switch self {
-        case .ready, .openSesame, .messageRejected:
-            return true
-        default:
-            return false
-        }
-    }
-    
-    init(keyResult: MessageResult) {
-        switch keyResult {
-        case .messageAuthenticationFailed:
-            self = .messageRejected(.invalidAuthentication)
-        case .messageTimeMismatch:
-            self = .messageRejected(.invalidTime)
-        case .messageCounterInvalid:
-            self = .messageRejected(.invalidCounter)
-        case .deviceTimedOut:
-            self = .messageRejected(.timeout)
-        case .messageAccepted:
-            self = .openSesame
-        case .messageDeviceInvalid:
-            self = .messageRejected(.invalidDeviceId)
-        case .noBodyData, .invalidMessageSize, .textReceived, .unexpectedSocketEvent, .invalidUrlParameter, .invalidResponseAuthentication:
-            print("Unexpected internal error: \(keyResult)")
-            self = .internalError(keyResult.description)
-        case .deviceNotConnected:
-            self = .deviceNotAvailable(.deviceDisconnected)
-        case .operationInProgress:
-            self = .waitingForResponse
-        case .deviceConnected:
-            self = .ready
-        }
-    }
-
-    var actionText: String {
-        switch self {
-        case .noKeyAvailable:
-            return "No key"
-        case .requestingStatus:
-            return "Checking..."
-        case .deviceNotAvailable(let connectionError):
-            switch connectionError {
-            case .serverNotReached:
-                return "Server not found"
-            case .deviceDisconnected:
-                return "Device disconnected"
-            }
-        case .ready:
-            return "Unlock"
-        case .waitingForResponse:
-            return "Unlocking..."
-        case .messageRejected(let rejectionCause):
-            switch rejectionCause {
-            case .invalidDeviceId:
-                return "Invalid device ID"
-            case .invalidCounter:
-                return "Invalid counter"
-            case .invalidTime:
-                return "Invalid timestamp"
-            case .invalidAuthentication:
-                return "Invalid signature"
-            case .timeout:
-                return "Device not responding"
-            case .missingKey:
-                return "Device key missing"
-            }
-        case .responseRejected(let rejectionCause):
-            switch rejectionCause {
-            case .invalidDeviceId:
-                return "Invalid device id (response)"
-            case .invalidCounter:
-                return "Invalid counter (response)"
-            case .invalidTime:
-                return "Invalid time (response)"
-            case .invalidAuthentication:
-                return "Invalid signature (response)"
-            case .timeout:
-                return "Timed out (response)"
-            case .missingKey:
-                return "Missing key (response)"
-            }
-        case .openSesame:
-            return "Unlocked"
-        case .internalError(let string):
-            return string
-        }
-    }
-
-    var requiresDescription: Bool {
-        switch self {
-        case .deviceNotAvailable, .messageRejected, .internalError, .responseRejected:
-            return true
-        default:
-            return false
-        }
-    }
-    
-    var color: Color {
-        switch self {
-        case .noKeyAvailable:
-            return Color(red: 50/255, green: 50/255, blue: 50/255)
-        case .deviceNotAvailable:
-            return Color(red: 150/255, green: 90/255, blue: 90/255)
-        case .messageRejected, .responseRejected:
-            return Color(red: 160/255, green: 30/255, blue: 30/255)
-        case .internalError:
-            return Color(red: 100/255, green: 0/255, blue: 0/255)
-        case .ready:
-            return Color(red: 115/255, green: 140/255, blue: 90/255)
-        case .requestingStatus, .waitingForResponse:
-            return Color(red: 160/255, green: 170/255, blue: 110/255)
-        case .openSesame:
-            return Color(red: 65/255, green: 110/255, blue: 60/255)
-        }
-    }
-    
-    var allowsAction: Bool {
-        switch self {
-        case .noKeyAvailable, .waitingForResponse:
-            return false
-        default:
-            return true
-        }
-    }
-}
-
-extension ClientState: Equatable {
-    
-}
-
-extension ClientState: CustomStringConvertible {
-
-    var description: String {
-        switch self {
-        case .noKeyAvailable:
-            return "No key set."
-        case .requestingStatus:
-            return "Checking device status"
-        case .deviceNotAvailable(let status):
-            return status.description
-        case .ready:
-            return "Ready"
-        case .waitingForResponse:
-            return "Unlocking..."
-        case .messageRejected(let cause):
-            return cause.description
-        case .openSesame:
-            return "Unlocked"
-        case .internalError(let e):
-            return "Error: \(e)"
-        case .responseRejected(let cause):
-            switch cause {
-            case .invalidAuthentication:
-                return "Device message not authenticated"
-            default:
-                return cause.description
-            }
-        }
-    }
-}
-
-// MARK: Coding
-
-extension ClientState {
-
-    var encoded: Data {
-        Data([code])
-    }
-
-    var code: UInt8 {
-        switch self {
-        case .noKeyAvailable:
-            return 1
-        case .requestingStatus:
-            return 2
-        case .deviceNotAvailable(let connectionError):
-            switch connectionError {
-            case .serverNotReached:
-                return 3
-            case .deviceDisconnected:
-                return 4
-            }
-        case .ready:
-            return 5
-        case .waitingForResponse:
-            return 6
-        case .messageRejected(let rejectionCause):
-            switch rejectionCause {
-            case .invalidDeviceId:
-                return 19
-            case .invalidCounter:
-                return 7
-            case .invalidTime:
-                return 8
-            case .invalidAuthentication:
-                return 9
-            case .timeout:
-                return 10
-            case .missingKey:
-                return 11
-            }
-        case .responseRejected(let rejectionCause):
-            switch rejectionCause {
-            case .invalidCounter:
-                return 12
-            case .invalidTime:
-                return 13
-            case .invalidAuthentication:
-                return 14
-            case .timeout:
-                return 15
-            case .missingKey:
-                return 16
-            case .invalidDeviceId:
-                return 20
-            }
-        case .openSesame:
-            return 17
-        case .internalError:
-            return 18
-        }
-    }
-
-    init(code: UInt8) {
-        switch code {
-        case 1:
-            self = .noKeyAvailable
-        case 2:
-            self = .requestingStatus
-        case 3:
-            self = .deviceNotAvailable(.serverNotReached)
-        case 4:
-            self = .deviceNotAvailable(.deviceDisconnected)
-        case 5:
-            self = .ready
-        case 6:
-            self = .waitingForResponse
-        case 7:
-            self = .messageRejected(.invalidCounter)
-        case 8:
-            self = .messageRejected(.invalidTime)
-        case 9:
-            self = .messageRejected(.invalidAuthentication)
-        case 10:
-            self = .messageRejected(.timeout)
-        case 11:
-            self = .messageRejected(.missingKey)
-        case 12:
-            self = .responseRejected(.invalidCounter)
-        case 13:
-            self = .responseRejected(.invalidTime)
-        case 14:
-            self = .responseRejected(.invalidAuthentication)
-        case 15:
-            self = .responseRejected(.timeout)
-        case 16:
-            self = .responseRejected(.missingKey)
-        case 17:
-            self = .openSesame
-        case 18:
-            self = .internalError("")
-        case 19:
-            self = .messageRejected(.invalidDeviceId)
-        case 20:
-            self = .responseRejected(.invalidDeviceId)
-        default:
-            self = .internalError("Unknown code \(code)")
-        }
-    }
-}
-
-extension ClientState {
-
-    @available(iOS 16, *)
-    var symbol: SFSymbol {
-        switch self {
-        case .deviceNotAvailable:
-            return .wifiExclamationmark
-        case .internalError:
-            return .applewatchSlash
-        case .noKeyAvailable:
-            return .lockTrianglebadgeExclamationmark
-        case .openSesame:
-            return .lockOpen
-        case .messageRejected:
-            return .nosign
-        case .responseRejected:
-            return .exclamationmarkTriangle
-        case .requestingStatus, .ready, .waitingForResponse:
-            return .wifiExclamationmark
-        }
-    }
-}

Sesame/Common/ConnectionStrategy.swift

@@ -1,10 +1,27 @@
 import Foundation
+import CryptoKit
 
-enum ConnectionStrategy: String, CaseIterable, Identifiable {
+enum ConnectionStrategy: Int, CaseIterable, Identifiable {
-    case local = "Local"
+    case local = 0
-    case localFirst = "Local first"
+    case remote = 1
-    case remote = "Remote"
+    case localFirst = 2
-    case remoteFirst = "Remote first"
+    case remoteFirst = 3
 
-    var id: Self { self }
+    var id: Int { rawValue }
+    
+    var transmissionTypes: [TransmissionType] {
+        switch self {
+        case .local: return [.overLocalWifi]
+        case .localFirst: return [.overLocalWifi, .throughServer]
+        case .remote: return [.throughServer]
+        case .remoteFirst: return [.throughServer, .overLocalWifi]
+        }
+    }
+}
+
+extension ConnectionStrategy: CustomStringConvertible {
+    
+    var description: String {
+        transmissionTypes.map { $0.displayName }.joined(separator: "+")
+    }
 }

Sesame/Common/Extensions/Text+Extensions.swift

@@ -0,0 +1,9 @@
+import Foundation
+import SwiftUI
+
+extension Text {
+    
+    init(display: CustomStringConvertible) {
+        self.init(display.description)
+    }
+}

Sesame/Common/Extensions/UInt32+Random.swift

@@ -0,0 +1,8 @@
+import Foundation
+
+extension UInt32 {
+    
+    static func random() -> UInt32 {
+        random(in: UInt32.min...UInt32.max)
+    }
+}

Sesame/Common/HistoryManager.swift

@@ -1,6 +1,7 @@
 import Foundation
 import CBORCoding
 
+/*
 class HistoryManagerBase: ObservableObject {
 
     @Published
@@ -141,3 +142,4 @@ final class HistoryManagerMock: HistoryManagerBase, HistoryManagerProtocol {
         return true
     }
 }
+*/

Sesame/Common/KeyManagement.swift

@@ -129,9 +129,8 @@ final class KeyManagement: ObservableObject {
     @Published
     private(set) var hasAuthToken = false
 
-    var hasAllKeys: Bool {
+    @Published
-        hasRemoteKey && hasDeviceKey && hasAuthToken
+    private(set) var hasAllKeys = false
-    }
 
     init() {
         self.keyChain = KeyChain(domain: "christophhagen.de")
@@ -189,5 +188,6 @@ final class KeyManagement: ObservableObject {
         self.hasRemoteKey = keyChain.has(.remoteKey)
         self.hasDeviceKey = keyChain.has(.deviceKey)
         self.hasAuthToken = keyChain.has(.authToken)
+        self.hasAllKeys = hasRemoteKey && hasDeviceKey && hasAuthToken
     }
 }

Sesame/Common/PendingOperation.swift

@@ -0,0 +1,12 @@
+import Foundation
+
+struct PendingOperation {
+    
+    let route: TransmissionType
+    
+    let operation: RequestType
+}
+
+extension PendingOperation: Equatable {
+    
+}

Sesame/Common/RequestCoordinator.swift

@@ -0,0 +1,229 @@
+import Foundation
+import SwiftUI
+import SwiftData
+
+final class RequestCoordinator: ObservableObject {
+    
+    @Published
+    var serverChallenge: ServerChallenge? = nil
+    
+    @Published
+    var state: MessageResult = .noKeyAvailable
+    
+    @Published
+    private var timer: Timer?
+    
+    @Published
+    var pendingRequests: [PendingOperation] = []
+    
+    @Published
+    var activeRequest: PendingOperation?
+    
+    @Published
+    var keyManager = KeyManagement()
+    
+    @AppStorage("server")
+    var serverPath: String = "https://christophhagen.de/sesame/"
+    
+    @AppStorage("localIP")
+    var localAddress: String = "192.168.178.104/"
+    
+    @AppStorage("connectionType")
+    var connectionType: ConnectionStrategy = .remoteFirst
+    
+    let modelContext: ModelContext
+    
+    init(modelContext: ModelContext) {
+        self.modelContext = modelContext
+        if keyManager.hasAllKeys {
+            self.state = .notChecked
+        }
+    }
+    
+    let client = Client()
+    
+    var needsNewServerChallenge: Bool {
+        serverChallenge?.isExpired ?? true
+    }
+    
+    @Published
+    var isPerformingRequest: Bool = false
+    
+    func startUnlock() {
+        addOperations(.challenge, .unlock)
+    }
+    
+    func startChallenge() {
+        addOperations(.challenge)
+    }
+    
+    private func addOperations(_ operations: RequestType...) {
+        #warning("Only perform challenge when doing unlock? Remove code complexity")
+        // Just add all operations for an unlock
+        // For every completed operation, the unnecessary ones will be removed without executing them
+        let operations = connectionType.transmissionTypes.map { route in
+            operations.map { PendingOperation(route: route, operation: $0) }
+        }.joined()
+        
+        pendingRequests.append(contentsOf: operations)
+        continueRequests()
+    }
+    
+    private func continueRequests() {
+        guard activeRequest == nil else {
+            return
+        }
+        guard !pendingRequests.isEmpty else {
+            self.isPerformingRequest = false
+            return
+        }
+        let activeRequest = pendingRequests.removeFirst()
+        self.activeRequest = activeRequest
+        self.isPerformingRequest = true
+        Task {
+            await process(request: activeRequest)
+        }
+    }
+    
+    private func process(request: PendingOperation) async {
+        let startTime = Date.now
+        let (success, response, challenge) = await self.start(request)
+        let endTime = Date.now
+        let roundTripTime = endTime.timeIntervalSince(startTime)
+        
+        if let s = challenge?.message {
+            print("\(s) took \(Int(roundTripTime * 1000)) ms")
+        } else {
+            print("\(request.operation.description) took \(Int(roundTripTime * 1000)) ms")
+        }
+        
+        if request.operation == .unlock, let response {
+            print("Saving history item")
+            let item = HistoryItem(message: response, startDate: startTime, route: request.route, finishDate: endTime)
+            modelContext.insert(item)
+        }
+
+        DispatchQueue.main.async {
+            self.filterPendingRequests(after: request, success: success, hasChallenge: challenge != nil)
+            if let response {
+                self.state = response.result
+            }
+            if let challenge {
+                self.serverChallenge = challenge
+            }
+            self.activeRequest = nil
+            self.continueRequests()
+        }
+    }
+    
+    private func filterPendingRequests(after operation: PendingOperation, success: Bool, hasChallenge: Bool) {
+        if success {
+            // Filter all unlocks
+            if operation.operation == .unlock {
+                // Successful unlock means no need for next challenge or unlocks, so remove all
+                self.pendingRequests = []
+            } else {
+                // Successful challenge means no need for additional challenges, but keep unlocks
+                self.pendingRequests = pendingRequests.filter { $0.operation != .challenge }
+            }
+        } else {
+            // Filter all operations with the same route for connection errors
+            // And with type, depending on error?
+        }
+    }
+    
+    private func start(_ operation: PendingOperation) async -> OptionalServerResponse {
+        switch operation.operation {
+        case .challenge:
+            if let serverChallenge, !serverChallenge.isExpired {
+                return (true, serverChallenge.message, serverChallenge)
+            }
+            return await performChallenge(route: operation.route)
+            
+        case .unlock:
+            guard let serverChallenge, !serverChallenge.isExpired else {
+                return (false, nil, nil)
+            }
+            return await performUnlock(with: serverChallenge.message, route: operation.route)
+        }
+    }
+    
+    private func performChallenge(route: TransmissionType) async -> OptionalServerResponse {
+        let initialMessage = Message.initial()
+        let (result, challenge) = await send(initialMessage, route: route)
+        guard let message = challenge?.message else {
+            return (false, result, nil)
+        }
+        // Can't get here without the message being accepted
+        guard message.messageType == .challenge else {
+            print("Invalid message type for challenge: \(message)")
+            return (false, result.with(result: .invalidMessageTypeFromDevice), nil)
+        }
+        return (true, result.with(result: .deviceAvailable), challenge)
+    }
+    
+    private func performUnlock(with challenge: Message, route: TransmissionType) async -> OptionalServerResponse {
+        let request = challenge.requestMessage()
+        let (unlockState, responseData) = await send(request, route: route)
+        
+        guard let response = responseData?.message else {
+            return (false, unlockState, nil)
+        }
+        switch response.messageType {
+        case .initial, .request:
+            print("Invalid message type for response: \(response)")
+            return (false, response.with(result: .invalidMessageTypeFromDevice), nil)
+        case .challenge:
+            // New challenge received, challenge was expired
+            return (true, unlockState, responseData)
+        case .response:
+            break
+        }
+        
+        guard response.serverChallenge == request.serverChallenge else {
+            print("Invalid server challenge for unlock: \(response)")
+            return (false, response.with(result: .invalidServerChallengeFromDevice), nil)
+        }
+        return (true, response.with(result: .unlocked), nil)
+    }
+    
+    private func url(for route: TransmissionType) -> String {
+        switch route {
+        case .throughServer:
+            return serverPath
+        case .overLocalWifi:
+            return localAddress
+        }
+    }
+    
+    private func send(_ message: Message, route: TransmissionType) async -> ServerResponse {
+        guard let keys = keyManager.getAllKeys() else {
+            return (message.with(result: .noKeyAvailable), nil)
+        }
+        let url = url(for: route)
+        return await client.send(message, to: url, through: route, using: keys)
+    }
+
+    func startUpdatingServerChallenge() {
+        guard timer == nil else {
+            return
+        }
+        DispatchQueue.main.async {
+            self.timer = Timer.scheduledTimer(withTimeInterval: 3, repeats: true) { [weak self] timer in
+                guard let self else {
+                    timer.invalidate()
+                    return
+                }
+                DispatchQueue.main.async {
+                    self.startChallenge()
+                }
+            }
+            self.timer!.fire()
+        }
+    }
+
+    func endUpdatingServerChallenge() {
+        timer?.invalidate()
+        timer = nil
+    }
+}

Sesame/Common/ServerChallenge.swift

@@ -0,0 +1,17 @@
+import Foundation
+
+struct ServerChallenge {
+    
+    private static let challengeExpiryTime: TimeInterval = 25.0
+    
+    let creationDate: Date
+    
+    let message: Message
+    
+    var isExpired: Bool {
+        creationDate.addingTimeInterval(ServerChallenge.challengeExpiryTime) < Date.now
+    }
+}
+
+typealias ServerResponse = (result: Message, challenge: ServerChallenge?)
+typealias OptionalServerResponse = (success: Bool, result: Message?, challenge: ServerChallenge?)

Sesame/Common/TransmissionType.swift

@@ -0,0 +1,42 @@
+import Foundation
+import SFSafeSymbols
+
+enum TransmissionType: Int {
+    case throughServer = 0
+    case overLocalWifi = 1
+}
+
+extension TransmissionType: Codable {
+    
+}
+
+extension TransmissionType {
+    
+    var symbol: SFSymbol {
+        switch self {
+        case .throughServer: return .network
+        case .overLocalWifi: return .wifi
+        }
+    }
+}
+
+extension TransmissionType: CaseIterable {
+    
+}
+
+extension TransmissionType: CustomStringConvertible {
+    
+    var description: String {
+        displayName
+    }
+}
+
+extension TransmissionType {
+    
+    var displayName: String {
+        switch self {
+        case .throughServer: return "Mobile"
+        case .overLocalWifi: return "WiFi"
+        }
+    }
+}

Sesame/ContentView.swift

@@ -1,288 +1,98 @@
 import SwiftUI
+import SwiftData
 import CryptoKit
 
 struct ContentView: View {
     
-    @AppStorage("server")
+    private let unlockButtonSize: CGFloat = 250
-    var serverPath: String = "https://christophhagen.de/sesame/"
+    private let smallButtonSize: CGFloat = 50
-    
+    private let buttonBackground: Color = .white.opacity(0.2)
-    @AppStorage("localIP")
+    private let buttonColor: Color = .white
-    var localAddress: String = "192.168.178.104/"
-
-    @AppStorage("counter")
-    var nextMessageCounter: Int = 0
-
-    @AppStorage("compensate")
-    var isCompensatingDaylightTime: Bool = false
-    
-    @AppStorage("local")
-    private var useLocalConnection = false
-    
-    @AppStorage("deviceID")
-    private var deviceID: Int = 0
     
     @ObservedObject
-    var keyManager = KeyManagement()
+    var coordinator: RequestCoordinator
     
-    let history = HistoryManager()
+    @State private var showSettingsSheet = false
+    @State private var showHistorySheet = false
+    @State private var didShowKeySheetOnce = false
     
-    @State
+    init(modelContext: ModelContext) {
-    var state: ClientState = .noKeyAvailable
+        self.coordinator = .init(modelContext: modelContext)
-
-    @State
-    private var timer: Timer?
-
-    @State
-    private var hasActiveRequest = false
-
-    @State
-    private var responseTime: Date? = nil
-
-    @State
-    private var showSettingsSheet = false
-
-    @State
-    private var showHistorySheet = false
-    
-    @State
-    private var didShowKeySheetOnce = false
-    
-    let server = Client()
-
-    var compensationTime: UInt32 {
-        isCompensatingDaylightTime ? 3600 : 0
     }
     
-    var isPerformingRequests: Bool {
-        hasActiveRequest ||
-        state == .waitingForResponse
-    }
-
-    var buttonBackground: Color {
-        state.allowsAction ?
-            .white.opacity(0.2) :
-            .black.opacity(0.2)
-    }
-
-    let buttonBorderWidth: CGFloat = 3
-
-    var buttonColor: Color {
-        state.allowsAction ? .white : .gray
-    }
-
-    private let buttonWidth: CGFloat = 250
-
-    private let smallButtonHeight: CGFloat = 50
-
-    private let smallButtonWidth: CGFloat = 120
-
-    private let smallButtonBorderWidth: CGFloat = 1
-
     var body: some View {
-        GeometryReader { geo in
+        VStack(spacing: 20) {
-            VStack(spacing: 20) {
+            HStack {
-                HStack {
-                    Button("History", action: { showHistorySheet = true })
-                        .frame(width: smallButtonWidth,
-                               height: smallButtonHeight)
-                        .background(.white.opacity(0.2))
-                        .cornerRadius(smallButtonHeight / 2)
-                        .overlay(RoundedRectangle(cornerRadius: smallButtonHeight / 2).stroke(lineWidth: smallButtonBorderWidth).foregroundColor(.white))
-                        .foregroundColor(.white)
-                        .font(.title2)
-                        .padding()
-                    Spacer()
-                    Button("Settings", action: { showSettingsSheet = true })
-                        .frame(width: smallButtonWidth,
-                               height: smallButtonHeight)
-                        .background(.white.opacity(0.2))
-                        .cornerRadius(smallButtonHeight / 2)
-                        .overlay(RoundedRectangle(cornerRadius: smallButtonHeight / 2).stroke(lineWidth: smallButtonBorderWidth).foregroundColor(.white))
-                        .foregroundColor(.white)
-                        .font(.title2)
-                        .padding()
-                }
                 Spacer()
-                if state.requiresDescription {
+                Text("Sesame")
-                    Text(state.description)
+                    .font(.title)
-                        .padding()
+                Spacer()
+            }
+            Text(coordinator.state.description)
+            Spacer()
+            HStack(alignment: .bottom, spacing: 0) {
+                Button(action: { showHistorySheet = true }) {
+                    Image(systemSymbol: .clockArrowCirclepath)
+                        .foregroundColor(.white)
+                        .frame(width: smallButtonSize, height: smallButtonSize)
+                        .background(.white.opacity(0.2))
+                        .cornerRadius(smallButtonSize / 2)
+                        .font(.title2)
+                    
                 }
-                Button(state.actionText, action: mainButtonPressed)
+                Button("Unlock", action: coordinator.startUnlock)
-                    .frame(width: buttonWidth,
+                    .frame(width: unlockButtonSize, height: unlockButtonSize)
-                           height: buttonWidth)
                     .background(buttonBackground)
-                    .cornerRadius(buttonWidth / 2)
+                    .cornerRadius(unlockButtonSize / 2)
-                    .overlay(RoundedRectangle(cornerRadius: buttonWidth / 2)
-                        .stroke(lineWidth: buttonBorderWidth).foregroundColor(buttonColor))
                     .foregroundColor(buttonColor)
                     .font(.title)
-                    .disabled(!state.allowsAction)
+                Button(action: { showSettingsSheet = true }) {
-                    .padding(.bottom, (geo.size.width-buttonWidth) / 2)
+                    Image(systemSymbol: .gearshape)
-            }
+                        .foregroundColor(.white)
-            .background(state.color)
+                        .frame(width: smallButtonSize, height: smallButtonSize)
-            .onAppear {
+                        .background(.white.opacity(0.2))
-                if keyManager.hasAllKeys {
+                        .cornerRadius(smallButtonSize / 2)
-                    state = .requestingStatus
+                        .font(.title2)
                 }
-                startRegularStatusUpdates()
             }
-            .onDisappear {
+            
-                endRegularStatusUpdates()
+            Picker("Connection type", selection: $coordinator.connectionType) {
-            }
+                ForEach(ConnectionStrategy.allCases, id: \.rawValue) { connection in
-            .frame(width: geo.size.width, height: geo.size.height)
+                    Text(connection.description).tag(connection)
-            .animation(.easeInOut, value: state.color)
+                }
-            .sheet(isPresented: $showSettingsSheet) {
-                SettingsView(
-                    keyManager: keyManager,
-                    serverAddress: $serverPath,
-                    localAddress: $localAddress,
-                    deviceID: $deviceID,
-                    nextMessageCounter: $nextMessageCounter,
-                    isCompensatingDaylightTime: $isCompensatingDaylightTime,
-                    useLocalConnection: $useLocalConnection)
-            }
-            .sheet(isPresented: $showHistorySheet) {
-                HistoryView(history: history)
             }
+            .pickerStyle(.segmented)
+            .padding(.horizontal, 30)
         }
+        .background(coordinator.state.color)
+        .onAppear(perform: coordinator.startUpdatingServerChallenge)
+        .onDisappear(perform: coordinator.endUpdatingServerChallenge)
+        .animation(.easeInOut, value: coordinator.state.color)
+        .sheet(isPresented: $showSettingsSheet) {
+            SettingsView(
+                keyManager: coordinator.keyManager,
+                serverAddress: $coordinator.serverPath,
+                localAddress: $coordinator.localAddress)
+        }
+        .sheet(isPresented: $showHistorySheet) { HistoryView() }
         .preferredColorScheme(.dark)
     }
     
-    func mainButtonPressed() {
-        guard let key = keyManager.get(.remoteKey),
-              let token = keyManager.get(.authToken)?.data,
-              let deviceId = UInt8(exactly: deviceID) else {
-            return
-        }
-
-        let count = UInt32(nextMessageCounter)
-        let sentTime = Date()
-        // Add time to compensate that the device is using daylight savings time
-        let content = Message.Content(
-            time: sentTime.timestamp + compensationTime,
-            id: count,
-            device: deviceId)
-        let message = content.authenticate(using: key)
-        let historyItem = HistoryItem(sent: message.content, date: sentTime, local: useLocalConnection)
-        state = .waitingForResponse
-        print("Sending message \(count)")
-        Task {
-            let (newState, responseMessage) = await send(message, authToken: token)
-            let receivedTime = Date.now
-            responseTime = receivedTime
-            state = newState
-            let finishedItem = historyItem.didReceive(response: newState, date: receivedTime, message: responseMessage?.content)
-            guard let key = keyManager.get(.deviceKey) else {
-                save(historyItem: finishedItem.notAuthenticated())
-                return
-            }
-            guard let responseMessage else {
-                save(historyItem: finishedItem)
-                return
-            }
-            guard responseMessage.isValid(using: key) else {
-                save(historyItem: finishedItem.invalidated())
-                return
-            }
-            
-            nextMessageCounter = Int(responseMessage.content.id)
-            save(historyItem: finishedItem)
-        }
-    }
-    
-    private func send(_ message: Message, authToken: Data) async -> (state: ClientState, response: Message?) {
-        if useLocalConnection {
-            return await server.sendMessageOverLocalNetwork(message, server: localAddress)
-        } else {
-            return await server.send(message, server: serverPath, authToken: authToken)
-        }
-    }
-
-    private func save(historyItem: HistoryItem) {
-        do {
-            try history.save(item: historyItem)
-        } catch {
-            print("Failed to save item: \(error)")
-        }
-    }
     
     
-    private func startRegularStatusUpdates() {
-        guard timer == nil else {
-            return
-        }
-        DispatchQueue.main.async {
-            timer = Timer.scheduledTimer(withTimeInterval: 5, repeats: true, block: checkDeviceStatus)
-            timer!.fire()
-        }
-    }
-
-    private func endRegularStatusUpdates() {
-        timer?.invalidate()
-        timer = nil
-    }
-    
-    func checkDeviceStatus(_ timer: Timer) {
-        guard !useLocalConnection else {
-            return
-        }
-        guard let authToken = keyManager.get(.authToken) else {
-            if !didShowKeySheetOnce {
-                didShowKeySheetOnce = true
-                //showSettingsSheet = true
-            }
-            return
-        }
-        guard !hasActiveRequest else {
-            return
-        }
-        hasActiveRequest = true
-        Task {
-            let newState = await server.deviceStatus(authToken: authToken.data, server: serverPath)
-            hasActiveRequest = false
-            switch state {
-            case .noKeyAvailable:
-                return
-            case .requestingStatus, .deviceNotAvailable, .ready:
-                state = newState
-            case .waitingForResponse:
-                return
-            case .messageRejected, .openSesame, .internalError, .responseRejected:
-                guard let time = responseTime else {
-                    state = newState
-                    return
-                }
-                responseTime = nil
-                // Wait at least 5 seconds after these states have been reached before changing the
-                // interface to allow sufficient time to see the result
-                let elapsed = Date.now.timeIntervalSince(time)
-                guard elapsed < 5 else {
-                    state = newState
-                    return
-                }
-                let secondsToWait = Int(elapsed.rounded(.up))
-                DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(secondsToWait)) {
-                    state = newState
-                }
-            }
-        }
-    }
 }
 
-struct ContentView_Previews: PreviewProvider {
+#Preview {
-    static var previews: some View {
+    do {
-        ContentView()
+        let config = ModelConfiguration(isStoredInMemoryOnly: true)
-            .previewDevice("iPhone 8")
+        let container = try ModelContainer(for: HistoryItem.self, configurations: config)
-    }
+        
-}
+        let item = HistoryItem.mock
-
+        container.mainContext.insert(item)
-extension Date {
+        try container.mainContext.save()
-
+        return ContentView(modelContext: container.mainContext)
-    var timestamp: UInt32 {
+            .modelContainer(container)
-        UInt32(timeIntervalSince1970.rounded())
+    } catch {
-    }
+        fatalError("Failed to create model container.")
-
-    init(timestamp: UInt32) {
-        self.init(timeIntervalSince1970: TimeInterval(timestamp))
     }
 }

Sesame/Extensions/Date+Timestamp.swift

@@ -0,0 +1,12 @@
+import Foundation
+
+extension Date {
+
+    var timestamp: UInt32 {
+        UInt32(timeIntervalSince1970.rounded())
+    }
+
+    init(timestamp: UInt32) {
+        self.init(timeIntervalSince1970: TimeInterval(timestamp))
+    }
+}

Sesame/History/HistoryItem.swift

@@ -1,114 +1,55 @@
 import Foundation
+import SwiftData
 
+@Model
+final class HistoryItem {
     
-struct HistoryItem {
+    let startDate: Date
     
-    /// The sent/received date (local time, not including compensation offset)
+    let message: Message
-    let requestDate: Date
     
-    let request: Message.Content
+    let route: TransmissionType
     
-    let usedLocalConnection: Bool
+    let finishDate: Date
     
-    var response: ClientState
+    init(message: Message, startDate: Date, route: TransmissionType, finishDate: Date) {
-    
+        self.startDate = startDate
-    let responseMessage: Message.Content?
+        self.message = message
-    
+        self.finishDate = finishDate
-    let responseDate: Date
+        self.route = route
-
-    init(sent message: Message.Content, sentDate: Date, local: Bool, response: ClientState, responseDate: Date, responseMessage: Message.Content?) {
-        self.requestDate = sentDate
-        self.request = message
-        self.responseMessage = responseMessage
-        self.response = response
-        self.responseDate = responseDate
-        self.usedLocalConnection = local
     }
     
-    // MARK: Statistics
-
     var roundTripTime: TimeInterval {
-        responseDate.timeIntervalSince(requestDate)
+        finishDate.timeIntervalSince(startDate)
     }
     
-    var deviceTime: Date? {
+    var response: MessageResult {
-        guard let timestamp = responseMessage?.time else {
+        message.result
-            return nil
-        }
-        return Date(timestamp: timestamp)
-    }
-
-    var requestLatency: TimeInterval? {
-        deviceTime?.timeIntervalSince(requestDate)
-    }
-
-    var responseLatency: TimeInterval? {
-        guard let deviceTime = deviceTime else {
-            return nil
-        }
-        return responseDate.timeIntervalSince(deviceTime)
-    }
-
-    var clockOffset: Int? {
-        guard let deviceTime = deviceTime else {
-            return nil
-        }
-        let estimatedArrival = requestDate.advanced(by: roundTripTime / 2)
-        return Int(deviceTime.timeIntervalSince(estimatedArrival))
-    }
-
-}
-
-extension HistoryItem: Codable {
-    
-    enum CodingKeys: Int, CodingKey {
-        case requestDate = 1
-        case request = 2
-        case usedLocalConnection = 3
-        case response = 4
-        case responseMessage = 5
-        case responseDate = 6
-    }
-}
-
-extension ClientState: Codable {
-    
-    init(from decoder: Decoder) throws {
-        let code = try decoder.singleValueContainer().decode(UInt8.self)
-        self.init(code: code)
-    }
-    
-    func encode(to encoder: Encoder) throws {
-        var container = encoder.singleValueContainer()
-        try container.encode(code)
     }
 }
 
 extension HistoryItem: Identifiable {
     
-    var id: UInt32 {
+    var id: Double {
-        requestDate.timestamp
+        startDate.timeIntervalSince1970
     }
 }
 
 extension HistoryItem: Comparable {
     
     static func < (lhs: HistoryItem, rhs: HistoryItem) -> Bool {
-        lhs.requestDate < rhs.requestDate
+        lhs.startDate < rhs.startDate
     }
 }
 
 extension HistoryItem {
     
     static var mock: HistoryItem {
-        let content = Message.Content(time: Date.now.timestamp, id: 123, device: 0)
+        let message = Message(messageType: .request, clientChallenge: 123, serverChallenge: 234, result: .unlocked)
-        let content2 = Message.Content(time: (Date.now + 1).timestamp, id: 124, device: 0)
         return .init(
-            sent: content,
+            message: message,
-            sentDate: .now,
+            startDate: Date.now.addingTimeInterval(-5),
-            local: false,
+            route: .throughServer,
-            response: .openSesame,
+            finishDate: Date.now)
-            responseDate: .now + 2,
-            responseMessage: content2)
     }
 }

Sesame/History/HistoryListItem.swift

@@ -1,6 +1,8 @@
 import SwiftUI
+import SwiftData
 import SFSafeSymbols
 
+
 private let df: DateFormatter = {
     let df = DateFormatter()
     df.dateStyle = .short
@@ -13,60 +15,55 @@ struct HistoryListItem: View {
     let entry: HistoryItem
 
     var entryTime: String {
-        df.string(from: entry.requestDate)
+        df.string(from: entry.startDate)
     }
 
     var roundTripText: String {
         "\(Int(entry.roundTripTime * 1000)) ms"
     }
     
-    var counterText: String {
+    var clientNonceText: String {
-        let sentCounter = entry.request.id
+        "\(entry.message.clientChallenge)"
-        let startText = "\(sentCounter)"
-        guard let rCounter = entry.responseMessage?.id else {
-            return startText
-        }
-        let diff = Int(rCounter) - Int(sentCounter)
-        guard diff != 1 && diff != 0 else {
-            return startText
-        }
-        return startText + " (\(diff))"
     }
     
-    var timeOffsetText: String? {
+    var serverNonceText: String {
-        guard let offset = entry.clockOffset else {
+        "\(entry.message.serverChallenge)"
-            return nil
-        }
-        return "\(offset) s"
     }
     
     var body: some View {
         VStack(alignment: .leading) {
             HStack {
+                Image(systemSymbol: entry.route.symbol)
                 Text(entry.response.description)
                     .font(.headline)
                 Spacer()
                 Text(entryTime)
-            }.padding(.bottom, 1)
+            }
             HStack {
-                Image(systemSymbol: entry.usedLocalConnection ? .wifi : .network)
+                Image(systemSymbol: .arrowUpArrowDownCircle)
-                Text(roundTripText)
+                Text(roundTripText).padding(.trailing)
-                    .font(.subheadline)
+                Image(systemSymbol: .lockIphone)
-                Image(systemSymbol: .personalhotspot)
+                Text(clientNonceText).padding(.trailing)
-                Text(counterText)
+                Image(systemSymbol: .doorRightHandClosed)
-                    .font(.subheadline)
+                Text(serverNonceText).padding(.trailing)
-                if let timeOffsetText {
+            }
-                    Image(systemSymbol: .stopwatch)
+            .foregroundColor(.secondary)
-                    Text(timeOffsetText)
+            .font(.footnote)
-                        .font(.subheadline)
-                }
-            }.foregroundColor(.secondary)
         }
     }
 }
 
-struct HistoryListItem_Previews: PreviewProvider {
+#Preview {
-    static var previews: some View {
+    do {
-        HistoryListItem(entry: .mock)
+        let config = ModelConfiguration(isStoredInMemoryOnly: true)
+        let container = try ModelContainer(for: HistoryItem.self, configurations: config)
+        
+        let item = HistoryItem.mock
+        container.mainContext.insert(item)
+        try container.mainContext.save()
+        return HistoryListItem(entry: item)
+            .modelContainer(container)
+    } catch {
+        fatalError("Failed to create model container.")
     }
 }

Sesame/History/HistoryView.swift

@@ -1,14 +1,14 @@
 import SwiftUI
+import SwiftData
 
 struct HistoryView: View {
 
-    let history: HistoryManagerProtocol
+    @Query
-
-    @State
     private var items: [HistoryItem] = []
 
-    @State
+    private var unlockCount: Int {
-    private var unlockCount = 0
+        items.count { $0.response == .unlocked }
+    }
 
     private var percentage: Double {
         guard items.count > 0 else {
@@ -17,11 +17,18 @@ struct HistoryView: View {
         return Double(unlockCount * 100) / Double(items.count)
     }
     
+    private var requestNumberText: String {
+        guard items.count != 1 else {
+            return "1 Request"
+        }
+        return "\(items.count) Requests"
+    }
+
     var body: some View {
         NavigationView {
             List {
                 HStack {
-                    Text("\(items.count) requests")
+                    Text(requestNumberText)
                         .foregroundColor(.primary)
                         .font(.body)
                     Spacer()
@@ -35,26 +42,20 @@ struct HistoryView: View {
             }
             .navigationTitle("History")
         }
-        .onAppear {
-            load()
-        }
-    }
-
-    private func load() {
-        Task {
-            let entries = history.loadEntries()
-            DispatchQueue.main.async {
-                items = entries
-                unlockCount = items.count {
-                    $0.response == .openSesame
-                }
-            }
-        }
     }
 }
 
-struct HistoryView_Previews: PreviewProvider {
+#Preview {
-    static var previews: some View {
+    do {
-        HistoryView(history: HistoryManagerMock())
+        let config = ModelConfiguration(isStoredInMemoryOnly: true)
+        let container = try ModelContainer(for: HistoryItem.self, configurations: config)
+        
+        let item = HistoryItem.mock
+        container.mainContext.insert(item)
+        try container.mainContext.save()
+        return HistoryView()
+            .modelContainer(container)
+    } catch {
+        fatalError("Failed to create model container.")
     }
 }

Sesame/SesameApp.swift

@@ -1,10 +1,24 @@
 import SwiftUI
+import SwiftData
 
 @main
 struct SesameApp: App {
-    var body: some Scene {
+    
-        WindowGroup {
+    @State
-            ContentView()
+    var modelContainer: ModelContainer
+    
+    init() {
+        do {
+            self.modelContainer = try ModelContainer(for: HistoryItem.self)
+        } catch {
+            fatalError("Failed to create model container: \(error)")
         }
     }
+    
+    var body: some Scene {
+        WindowGroup {
+            ContentView(modelContext: modelContainer.mainContext)
+        }
+        .modelContainer(modelContainer)
+    }
 }

Sesame/SettingsView.swift

@@ -10,31 +10,6 @@ struct SettingsView: View {
     @Binding
     var localAddress: String
     
-    @Binding
-    var deviceID: Int
-    
-    @Binding
-    var nextMessageCounter: Int
-
-    @Binding
-    var isCompensatingDaylightTime: Bool
-    
-    @Binding
-    var useLocalConnection: Bool
-    
-    @State
-    private var showDeviceIdInput = false
-    
-    @State
-    private var deviceIdText = ""
-    
-    @State
-    private var showCounterInput = false
-    
-    @State
-    private var counterText = ""
-    
-    
     var body: some View {
         NavigationView {
             ScrollView {
@@ -53,49 +28,11 @@ struct SettingsView: View {
                             .foregroundColor(.secondary)
                             .padding(.leading, 8)
                     }.padding(.vertical, 8)
-                    Toggle(isOn: $useLocalConnection) {
-                        Text("Use direct connection to device")
-                    }
-                    Text("Attempt to communicate directly with the device. This is useful if the server is unavailable. Requires a WiFi connection on the same network as the device.")
-                        .font(.caption)
-                        .foregroundColor(.secondary)
-                    VStack(alignment: .leading) {
-                        Text("Device id")
-                            .bold()
-                        HStack(alignment: .bottom) {
-                            Text("\(deviceID)")
-                                .font(.system(.body, design: .monospaced))
-                                .foregroundColor(.secondary)
-                                .padding([.trailing, .bottom])
-                            Button("Edit", action: showAlertToChangeDeviceID)
-                                .padding([.horizontal, .bottom])
-                                .padding(.top, 4)
-                        }
-                    }.padding(.vertical, 8)
-                    VStack(alignment: .leading) {
-                        Text("Message counter")
-                            .bold()
-                        HStack(alignment: .bottom) {
-                            Text("\(nextMessageCounter)")
-                                .font(.system(.body, design: .monospaced))
-                                .foregroundColor(.secondary)
-                                .padding([.trailing, .bottom])
-                            Button("Edit", action: showAlertToChangeCounter)
-                                .padding([.horizontal, .bottom])
-                                .padding(.top, 4)
-                        }
-                    }.padding(.vertical, 8)
                     ForEach(KeyManagement.KeyType.allCases) { keyType in
                         SingleKeyView(
                             keyManager: keyManager,
                             type: keyType)
                     }
-                    Toggle(isOn: $isCompensatingDaylightTime) {
-                        Text("Compensate daylight savings time")
-                    }
-                    Text("If the remote has daylight savings time wrongly set, then the time validation will fail. Use this option to send messages with adjusted timestamps. Warning: Incorrect use of this option will allow replay attacks.")
-                        .font(.caption)
-                        .foregroundColor(.secondary)
                 }.padding()
             }.onDisappear {
                 if !localAddress.hasSuffix("/") {
@@ -103,54 +40,8 @@ struct SettingsView: View {
                 }
             }
             .navigationTitle("Settings")
-            .alert("Update device ID", isPresented: $showDeviceIdInput, actions: {
-                TextField("Device ID", text: $deviceIdText)
-                    .keyboardType(.decimalPad)
-                    .font(.system(.body, design: .monospaced))
-                    .foregroundColor(.black)
-                Button("Save", action: saveDeviceID)
-                Button("Cancel", role: .cancel, action: {})
-            }, message: {
-                Text("Enter the device ID")
-            })
-            .alert("Update message counter", isPresented: $showCounterInput, actions: {
-                TextField("Message counter", text: $counterText)
-                    .keyboardType(.decimalPad)
-                    .font(.system(.body, design: .monospaced))
-                    .foregroundColor(.black)
-                Button("Save", action: saveCounter)
-                Button("Cancel", role: .cancel, action: {})
-            }, message: {
-                Text("Enter the message counter")
-            })
         }
     }
-    
-    private func showAlertToChangeDeviceID() {
-        deviceIdText = "\(deviceID)"
-        showDeviceIdInput = true
-    }
-    
-    private func saveDeviceID() {
-        guard let id = UInt8(deviceIdText) else {
-            print("Invalid device id '\(deviceIdText)'")
-            return
-        }
-        self.deviceID = Int(id)
-    }
-    
-    private func showAlertToChangeCounter() {
-        counterText = "\(nextMessageCounter)"
-        showCounterInput = true
-    }
-    
-    private func saveCounter() {
-        guard let id = UInt32(counterText) else {
-            print("Invalid message counter '\(counterText)'")
-            return
-        }
-        self.nextMessageCounter = Int(id)
-    }
 }
 
 struct SettingsView_Previews: PreviewProvider {
@@ -158,10 +49,6 @@ struct SettingsView_Previews: PreviewProvider {
         SettingsView(
             keyManager: KeyManagement(),
             serverAddress: .constant("https://example.com"),
-            localAddress: .constant("192.168.178.42"),
+            localAddress: .constant("192.168.178.42"))
-            deviceID: .constant(0),
-            nextMessageCounter: .constant(12345678),
-            isCompensatingDaylightTime: .constant(true),
-            useLocalConnection: .constant(false))
     }
 }