Merge 9b1c3fdc88 into c63d87cbec

Sources/Packages/Sources/SmartCardSecretKit/PersistentAuthenticationHandler.swift

@@ -0,0 +1,68 @@
+import LocalAuthentication
+import SecretKit
+
+extension SmartCard {
+
+    /// A context describing a persisted authentication.
+    final class PersistentAuthenticationContext: PersistedAuthenticationContext {
+
+        /// The Secret to persist authentication for.
+        let secret: Secret
+        /// The LAContext used to authorize the persistent context.
+        nonisolated(unsafe) let context: LAContext
+        /// An expiration date for the context.
+        /// - Note -  Monotonic time instead of Date() to prevent people setting the clock back.
+        let monotonicExpiration: UInt64
+
+        /// Initializes a context.
+        /// - Parameters:
+        ///   - secret: The Secret to persist authentication for.
+        ///   - context: The LAContext used to authorize the persistent context.
+        ///   - duration: The duration of the authorization context, in seconds.
+        init(secret: Secret, context: LAContext, duration: TimeInterval) {
+            self.secret = secret
+            unsafe self.context = context
+            let durationInNanoSeconds = Measurement(value: duration, unit: UnitDuration.seconds).converted(to: .nanoseconds).value
+            self.monotonicExpiration = clock_gettime_nsec_np(CLOCK_MONOTONIC) + UInt64(durationInNanoSeconds)
+        }
+
+        /// A boolean describing whether or not the context is still valid.
+        var valid: Bool {
+            clock_gettime_nsec_np(CLOCK_MONOTONIC) < monotonicExpiration
+        }
+
+        var expiration: Date {
+            let remainingNanoseconds = monotonicExpiration - clock_gettime_nsec_np(CLOCK_MONOTONIC)
+            let remainingInSeconds = Measurement(value: Double(remainingNanoseconds), unit: UnitDuration.nanoseconds).converted(to: .seconds).value
+            return Date(timeIntervalSinceNow: remainingInSeconds)
+        }
+    }
+
+    actor PersistentAuthenticationHandler: Sendable {
+
+        private var persistedAuthenticationContexts: [Secret: PersistentAuthenticationContext] = [:]
+
+        func existingPersistedAuthenticationContext(secret: Secret) -> PersistentAuthenticationContext? {
+            guard let persisted = persistedAuthenticationContexts[secret], persisted.valid else { return nil }
+            return persisted
+        }
+
+        func persistAuthentication(secret: Secret, forDuration duration: TimeInterval) async throws {
+            let newContext = LAContext()
+            newContext.touchIDAuthenticationAllowableReuseDuration = duration
+            newContext.localizedCancelTitle = String(localized: .authContextRequestDenyButton)
+
+            let formatter = DateComponentsFormatter()
+            formatter.unitsStyle = .spellOut
+            formatter.allowedUnits = [.hour, .minute, .day]
+
+            
+            let durationString = formatter.string(from: duration)!
+            newContext.localizedReason = String(localized: .authContextPersistForDuration(secretName: secret.name, duration: durationString))
+            let success = try await newContext.evaluatePolicy(.deviceOwnerAuthentication, localizedReason: newContext.localizedReason)
+            guard success else { return }
+            let context = PersistentAuthenticationContext(secret: secret, context: newContext, duration: duration)
+            persistedAuthenticationContexts[secret] = context
+        }
+    }
+}

Sources/Packages/Sources/SmartCardSecretKit/SmartCardStore.swift

@@ -34,6 +34,7 @@ extension SmartCard {
         public var secrets: [Secret] {
             state.secrets
         }
+        private let persistentAuthenticationHandler = PersistentAuthenticationHandler()
 
         /// Initializes a Store.
         public init() {
@@ -58,9 +59,15 @@ extension SmartCard {
 
         public func sign(data: Data, with secret: Secret, for provenance: SigningRequestProvenance) async throws -> Data {
             guard let tokenID = await state.tokenID else { fatalError() }
-            let context = LAContext()
-            context.localizedReason = String(localized: .authContextRequestSignatureDescription(appName: provenance.origin.displayName, secretName: secret.name))
-            context.localizedCancelTitle = String(localized: .authContextRequestDenyButton)
+            var context: LAContext
+            if let existing = await persistentAuthenticationHandler.existingPersistedAuthenticationContext(secret: secret) {
+                context = unsafe existing.context
+            } else {
+                let newContext = LAContext()
+                newContext.localizedReason = String(localized: .authContextRequestSignatureDescription(appName: provenance.origin.displayName, secretName: secret.name))
+                newContext.localizedCancelTitle = String(localized: .authContextRequestDenyButton)
+                context = newContext
+            }
             let attributes = KeychainDictionary([
                 kSecClass: kSecClassKey,
                 kSecAttrKeyClass: kSecAttrKeyClassPrivate,
@@ -86,11 +93,12 @@ extension SmartCard {
             return signature as Data
         }
         
-        public func existingPersistedAuthenticationContext(secret: Secret) -> PersistedAuthenticationContext? {
-            nil
+        public func existingPersistedAuthenticationContext(secret: Secret) async -> PersistedAuthenticationContext? {
+            await persistentAuthenticationHandler.existingPersistedAuthenticationContext(secret: secret)
         }
 
-        public func persistAuthentication(secret: Secret, forDuration: TimeInterval) throws {
+        public func persistAuthentication(secret: Secret, forDuration duration: TimeInterval) async throws {
+            try await persistentAuthenticationHandler.persistAuthentication(secret: secret, forDuration: duration)
         }
 
         /// Reloads all secrets from the store.
@@ -163,7 +171,7 @@ extension SmartCard.Store {
             let publicKeySecRef = SecKeyCopyPublicKey(publicKeyRef)!
             let publicKeyAttributes = SecKeyCopyAttributes(publicKeySecRef) as! [CFString: Any]
             let publicKey = publicKeyAttributes[kSecValueData] as! Data
-            let attributes = Attributes(keyType: KeyType(secAttr: algorithmSecAttr, size: keySize)!, authentication: .unknown)
+            let attributes = Attributes(keyType: KeyType(secAttr: algorithmSecAttr, size: keySize)!, authentication: .presenceRequired)
             let secret = SmartCard.Secret(id: tokenID, name: name, publicKey: publicKey, attributes: attributes)
             guard signatureAlgorithm(for: secret) != nil else { return nil }
             return secret