Initial commit

apple-client/Sources/App/PasskeyManager.swift

@@ -0,0 +1,126 @@
+import AuthenticationServices
+import Foundation
+
+#if os(macOS)
+import AppKit
+#else
+import UIKit
+#endif
+
+@MainActor
+final class PasskeyManager: NSObject {
+  private var continuation: CheckedContinuation<ASAuthorization, Error>?
+
+  func register(options: RegistrationOptionsResponse) async throws -> PasskeyRegistrationPayload {
+    guard let challengeData = Data(base64URLEncoded: options.challenge),
+      let userData = Data(base64URLEncoded: options.user.id)
+    else {
+      throw APIErrorResponse(message: "The backend returned malformed access key registration options.")
+    }
+
+    let provider = ASAuthorizationPlatformPublicKeyCredentialProvider(relyingPartyIdentifier: options.rp.id)
+    let clientData = ASPublicKeyCredentialClientData(
+      challenge: challengeData,
+      origin: options.expectedOrigin ?? "http://localhost:4200"
+    )
+    let request = provider.createCredentialRegistrationRequest(
+      clientData: clientData,
+      name: options.user.name,
+      userID: userData
+    )
+
+    let authorization = try await perform(requests: [request])
+
+    guard let registration = authorization.credential as? ASAuthorizationPlatformPublicKeyCredentialRegistration else {
+      throw APIErrorResponse(message: "The platform did not return a valid access key registration.")
+    }
+
+    return PasskeyRegistrationPayload(
+      id: registration.credentialID.base64URLEncodedString(),
+      rawId: registration.credentialID.base64URLEncodedString(),
+      response: .init(
+        clientDataJSON: registration.rawClientDataJSON.base64URLEncodedString(),
+        attestationObject: registration.rawAttestationObject?.base64URLEncodedString() ?? "",
+        transports: nil
+      ),
+      clientExtensionResults: [:],
+      type: "public-key"
+    )
+  }
+
+  func authenticate(options: AuthenticationOptionsResponse) async throws -> PasskeyAuthenticationPayload {
+    guard let challengeData = Data(base64URLEncoded: options.challenge) else {
+      throw APIErrorResponse(message: "The backend returned malformed access key sign-in options.")
+    }
+
+    let rpId = options.rpId
+      ?? URL(string: options.expectedOrigin ?? "")?.host
+      ?? "localhost"
+    let provider = ASAuthorizationPlatformPublicKeyCredentialProvider(relyingPartyIdentifier: rpId)
+    let clientData = ASPublicKeyCredentialClientData(
+      challenge: challengeData,
+      origin: options.expectedOrigin ?? "http://localhost:4200"
+    )
+    let request = provider.createCredentialAssertionRequest(clientData: clientData)
+    let authorization = try await perform(requests: [request])
+
+    guard let assertion = authorization.credential as? ASAuthorizationPlatformPublicKeyCredentialAssertion else {
+      throw APIErrorResponse(message: "The platform did not return a valid access key assertion.")
+    }
+
+    return PasskeyAuthenticationPayload(
+      id: assertion.credentialID.base64URLEncodedString(),
+      rawId: assertion.credentialID.base64URLEncodedString(),
+      response: .init(
+        clientDataJSON: assertion.rawClientDataJSON.base64URLEncodedString(),
+        authenticatorData: assertion.rawAuthenticatorData.base64URLEncodedString(),
+        signature: assertion.signature.base64URLEncodedString(),
+        userHandle: assertion.userID.base64URLEncodedString()
+      ),
+      clientExtensionResults: [:],
+      type: "public-key"
+    )
+  }
+
+  private func perform(requests: [ASAuthorizationRequest]) async throws -> ASAuthorization {
+    try await withCheckedThrowingContinuation { continuation in
+      self.continuation = continuation
+      let controller = ASAuthorizationController(authorizationRequests: requests)
+      controller.delegate = self
+      controller.presentationContextProvider = self
+      controller.performRequests()
+    }
+  }
+}
+
+extension PasskeyManager: ASAuthorizationControllerDelegate {
+  func authorizationController(
+    controller _: ASAuthorizationController,
+    didCompleteWithAuthorization authorization: ASAuthorization
+  ) {
+    continuation?.resume(returning: authorization)
+    continuation = nil
+  }
+
+  func authorizationController(
+    controller _: ASAuthorizationController,
+    didCompleteWithError error: Error
+  ) {
+    continuation?.resume(throwing: error)
+    continuation = nil
+  }
+}
+
+extension PasskeyManager: ASAuthorizationControllerPresentationContextProviding {
+  func presentationAnchor(for controller: ASAuthorizationController) -> ASPresentationAnchor {
+    #if os(macOS)
+    return NSApplication.shared.keyWindow ?? NSApplication.shared.windows.first ?? ASPresentationAnchor()
+    #else
+    return UIApplication.shared.connectedScenes
+      .compactMap { $0 as? UIWindowScene }
+      .flatMap(\.windows)
+      .first(where: \.isKeyWindow) ?? ASPresentationAnchor()
+    #endif
+  }
+}
+