Add private key validation and storage

Yeti/Assets/Localizable.xcstrings

@@ -14,11 +14,11 @@
       "comment" : "Button to create a key."
     },
     "Done" : {
-      "comment" : "Button to go to the next view that adds the user's entered private key."
-    },
-    "Got it!" : {
       "comment" : "Button to go to the next view that adds the user’s entered private key."
     },
+    "Home" : {
+      "comment" : "Navigation title of home view."
+    },
     "Hooo-raaaayyy!" : {
       "comment" : "Title of view that confirms the user’s selection of the signing policy."
     },
@@ -39,6 +39,9 @@
     },
     "Select a signing policy" : {
       "comment" : "Title of view to select a signing policy."
+    },
+    "Should I approve Nostr events automatically or would you like to review them for each app?" : {
+
     },
     "Yeti: Nostr Helper" : {
       "comment" : "Application title."
@@ -46,7 +49,7 @@
     "You’re all set! I’ll take care of most of the approval for you.\nIf I see an event I don’t recognize, I’ll ask you to review it." : {
       "comment" : "Description of what the user should expect after selecting the basic signing policy."
     },
-    "You’re set for now. You’ll need to come back here with every new app and approve some nostr events." : {
+    "You’re set for now. You’ll need to come back here with every new app and approve some Nostr events." : {
       "comment" : "Description of what the user should expect after selecting the manual signing policy."
     },
     "Your private key is stored locally. Only you can see it." : {

Yeti/Item.swift

@@ -1,18 +0,0 @@
-//
-//  Item.swift
-//  Yeti
-//
-//  Created by Terry Yiu on 1/19/25.
-//
-
-import Foundation
-import SwiftData
-
-@Model
-final class Item {
-    var timestamp: Date
-
-    init(timestamp: Date) {
-        self.timestamp = timestamp
-    }
-}

Yeti/Model/SigningPolicyModel.swift

@@ -0,0 +1,60 @@
+//
+//  SigningPolicyModel.swift
+//  Yeti
+//
+//  Created by Terry Yiu on 1/20/25.
+//
+
+import Foundation
+import SwiftData
+
+@Model
+final class SigningPolicyModel {
+    var signingPolicy: SigningPolicy
+
+    init(signingPolicy: SigningPolicy) {
+        self.signingPolicy = signingPolicy
+    }
+}
+
+enum SigningPolicy: Int, Codable, CaseIterable {
+    case basic = 0
+    case manual = 1
+
+    var name: String {
+        switch self {
+        case .basic:
+            return String(
+                localized: "Approve basic actions",
+                comment: "Name of event signing policy that approves basic actions."
+            )
+        case .manual:
+            return String(
+                localized: "Manually approve each app",
+                comment: "Name of event signing policy that requires manual approval to sign each event."
+            )
+        }
+    }
+
+    var description: String {
+        switch self {
+        case .basic:
+            return String(
+                localized:
+"""
+Recommended for most people. This policy will minimize the number of interruptions during your app usage.
+""",
+                comment: "Description of event signing policy that approves basic actions."
+            )
+        case .manual:
+            return String(
+                localized:
+"""
+Recommended for privacy-minded people who would like control over each app.
+Choosing this policy will prompt you to set a preference every time you try a new app.
+""",
+                comment: "Description of event signing policy that requires manual approval to sign each event."
+            )
+        }
+    }
+}

Yeti/Utilities/PrivateKeySecureStorage.swift

@@ -0,0 +1,72 @@
+//
+//  PrivateKeySecureStorage.swift
+//  Yeti
+//
+//  Created by Terry Yiu on 1/20/25.
+//
+
+import Foundation
+import NostrSDK
+
+class PrivateKeySecureStorage {
+
+    static let shared = PrivateKeySecureStorage()
+
+    private let service = "yeti-private-keys"
+
+    func keypair(for publicKey: PublicKey) -> Keypair? {
+        let query = [
+            kSecAttrService: service,
+            kSecAttrAccount: publicKey.hex,
+            kSecClass: kSecClassGenericPassword,
+            kSecReturnData: true,
+            kSecMatchLimit: kSecMatchLimitOne
+        ] as [CFString: Any] as CFDictionary
+
+        var result: AnyObject?
+        let status = SecItemCopyMatching(query, &result)
+
+        if status == errSecSuccess,
+           let data = result as? Data,
+           let privateKeyHex = String(data: data, encoding: .utf8) {
+            return Keypair(hex: privateKeyHex)
+        } else {
+            return nil
+        }
+    }
+
+    func store(for keypair: Keypair) {
+        let query = [
+            kSecAttrService: service,
+            kSecAttrAccount: keypair.publicKey.hex,
+            kSecClass: kSecClassGenericPassword,
+            kSecValueData: keypair.privateKey.hex.data(using: .utf8) as Any
+        ] as [CFString: Any] as CFDictionary
+
+        var status = SecItemAdd(query, nil)
+
+        if status == errSecDuplicateItem {
+            let query = [
+                kSecAttrService: service,
+                kSecAttrAccount: keypair.publicKey.hex,
+                kSecClass: kSecClassGenericPassword
+            ] as [CFString: Any] as CFDictionary
+
+            let updates = [
+                kSecValueData: keypair.privateKey.hex.data(using: .utf8) as Any
+            ] as CFDictionary
+
+            status = SecItemUpdate(query, updates)
+        }
+    }
+
+    func delete(for publicKey: PublicKey) {
+        let query = [
+            kSecAttrService: service,
+            kSecAttrAccount: publicKey.hex,
+            kSecClass: kSecClassGenericPassword
+        ] as [CFString: Any] as CFDictionary
+
+        _ = SecItemDelete(query)
+    }
+}

Yeti/Views/AddKeyView.swift

@@ -5,10 +5,15 @@
 //  Created by Terry Yiu on 1/19/25.
 //
 
+import Combine
+import NostrSDK
 import SwiftUI
 
 struct AddKeyView: View {
-    @State private var key: String = ""
+    @State private var keypair: Keypair?
+    @State private var nostrIdentifier: String = ""
+
+    @State private var navigationDestinationPresented: Bool = false
 
     var body: some View {
         NavigationStack {
@@ -26,8 +31,17 @@ struct AddKeyView: View {
                                 localized: "nsec / private key",
                                 comment: "Prompt asking user to enter in a Nostr private key."
                             ),
-                            text: $key
+                            text: $nostrIdentifier
                         )
+                        .autocorrectionDisabled(false)
+                        .textContentType(.password)
+                        .textInputAutocapitalization(.never)
+                        .onReceive(Just(nostrIdentifier)) { newValue in
+                            let filtered = newValue.trimmingCharacters(in: .whitespacesAndNewlines)
+                            nostrIdentifier = filtered
+
+                            self.keypair = Keypair(nsec: filtered)
+                        }
                     },
                     footer: {
                         Text(
@@ -40,12 +54,26 @@ Footer text explaining that the private key is stored locally and only the user
                     }
                 )
 
-                NavigationLink(destination: SigningPolicySelectionView()) {
+                Button("Next", action: {
-                    Text("Next", comment: "Button to go to the next view that adds the user’s entered private key.")
+                    navigationDestinationPresented = true
+                })
+                .disabled(!validPrivateKey)
+                .buttonStyle(.borderedProminent)
+                .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .center)
+                .listRowInsets(EdgeInsets())
+                .background(Color(UIColor.systemGroupedBackground))
+            }
+            .navigationDestination(isPresented: $navigationDestinationPresented) {
+                if let keypair {
+                    SigningPolicySelectionView(keypair: keypair)
                 }
             }
         }
     }
+
+    private var validPrivateKey: Bool {
+        keypair != nil
+    }
 }
 
 #Preview {

Yeti/Views/ContentView.swift

@@ -37,10 +37,12 @@ struct ContentView: View {
                 .buttonStyle(.borderedProminent)
             }
         }
+        .navigationTitle(String(localized: "Home", comment: "Navigation title of home view."))
+        .toolbar(removing: .title)
     }
 }
 
 #Preview {
     ContentView()
-        .modelContainer(for: Item.self, inMemory: true)
+        .modelContainer(for: SigningPolicyModel.self, inMemory: true)
 }

Yeti/Views/SigningPolicyConfirmationView.swift

@@ -24,15 +24,18 @@ If I see an event I don’t recognize, I’ll ask you to review it.
 """,
                     comment: "Description of what the user should expect after selecting the basic signing policy."
                 )
+                .font(.caption)
             case .manual:
                 Text(
 """
-You’re set for now. You’ll need to come back here with every new app and approve some nostr events.
+You’re set for now. You’ll need to come back here with every new app and approve some Nostr events.
 """,
                     comment: "Description of what the user should expect after selecting the manual signing policy."
                 )
+                .font(.caption)
             }
         }
+        .toolbar(.hidden)
     }
 }
 

Yeti/Views/SigningPolicySelectionView.swift

@@ -5,11 +5,16 @@
 //  Created by Terry Yiu on 1/20/25.
 //
 
+import NostrSDK
 import SwiftUI
 
 struct SigningPolicySelectionView: View {
+    let keypair: Keypair
+
     @State var signingPolicy: SigningPolicy = .basic
 
+    @State private var navigationDestinationPresented: Bool = false
+
     var body: some View {
         NavigationStack {
             Form {
@@ -19,6 +24,12 @@ struct SigningPolicySelectionView: View {
                     .listRowInsets(EdgeInsets())
                     .background(Color(UIColor.systemGroupedBackground))
 
+                Text("Should I approve Nostr events automatically or would you like to review them for each app?")
+                    .font(.caption)
+                    .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .center)
+                    .listRowInsets(EdgeInsets())
+                    .background(Color(UIColor.systemGroupedBackground))
+
                 Section(
                     content: {
                         Picker(
@@ -40,56 +51,22 @@ struct SigningPolicySelectionView: View {
                     }
                 )
 
-                NavigationLink(destination: SigningPolicyConfirmationView(signingPolicy: signingPolicy)) {
+                Button("Done", action: {
-                    Text("Done", comment: "Button to go to the next view that adds the user’s entered private key.")
+                    PrivateKeySecureStorage.shared.store(for: keypair)
-                }
+                    navigationDestinationPresented = true
+                })
+                .buttonStyle(.borderedProminent)
+                .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .center)
+                .listRowInsets(EdgeInsets())
+                .background(Color(UIColor.systemGroupedBackground))
+            }
+            .navigationDestination(isPresented: $navigationDestinationPresented) {
+                SigningPolicyConfirmationView(signingPolicy: signingPolicy)
             }
         }
     }
 }
 
-enum SigningPolicy: CaseIterable {
-    case basic
-    case manual
-
-    var name: String {
-        switch self {
-        case .basic:
-            return String(
-                localized: "Approve basic actions",
-                comment: "Name of event signing policy that approves basic actions."
-            )
-        case .manual:
-            return String(
-                localized: "Manually approve each app",
-                comment: "Name of event signing policy that requires manual approval to sign each event."
-            )
-        }
-    }
-
-    var description: String {
-        switch self {
-        case .basic:
-            return String(
-                localized:
-"""
-Recommended for most people. This policy will minimize the number of interruptions during your app usage.
-""",
-                comment: "Description of event signing policy that approves basic actions."
-            )
-        case .manual:
-            return String(
-                localized:
-"""
-Recommended for privacy-minded people who would like control over each app.
-Choosing this policy will prompt you to set a preference every time you try a new app.
-""",
-                comment: "Description of event signing policy that requires manual approval to sign each event."
-            )
-        }
-    }
-}
-
 #Preview {
-    SigningPolicySelectionView()
+    SigningPolicySelectionView(keypair: Keypair()!)
 }

Yeti/YetiApp.swift

@@ -14,7 +14,7 @@ struct YetiApp: App {
 
     var sharedModelContainer: ModelContainer = {
         let schema = Schema([
-            Item.self
+            SigningPolicyModel.self
         ])
         let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false)