Meet passkeys

{
    "webcredentials": {
        "apps": [ "A1B2C3D4E5.com.example.Shiny" ]
    }
}

override func viewDidLoad() {
    super.viewDidLoad()
    //Additional setup…

    userNameField.textContentType = .username
}

// AutoFill-assisted passkey request

func signIn() {
    let challenge: Data = … // Fetched from server
    let provider =
        ASAuthorizationPlatformPublicKeyCredentialProvider(
            relyingPartyIdentifier: "example.com")
    let request =
        provider.createCredentialAssertionRequest(
            challenge: challenge)

    let controller =
        ASAuthorizationController(
            authorizationRequests: [request])
    controller.delegate = self
    controller.presentationContextProvider = self

    // Start the request
    controller.performAutoFillAssistedRequests()
}

// Completing a passkey sign in

func authorizationController(controller: ASAuthorizationController,
     didCompleteWithAuthorization authorization: ASAuthorization) {
    
    guard let passkeyAssertion = authorization.credential as?
        ASAuthorizationPlatformPublicKeyCredentialAssertion
    else { … }

    let signature = passkeyAssertion.signature
    let clientDataJSON = passkeyAssertion.rawClientDataJSON

    // Pass these values to your server, and complete the sign in
…
}

// Modal passkey request

func signIn() {
    let challenge: Data = … // Fetched from server
    let provider =      
        ASAuthorizationPlatformPublicKeyCredentialProvider(
            relyingPartyIdentifier: "example.com")
    let request = 
        provider.createCredentialAssertionRequest(
            challenge: challenge)
    
    let controller = 
        ASAuthorizationController(
            authorizationRequests: [request])
    controller.delegate = self
    controller.presentationContextProvider = self

    // Start the request
    controller.performRequests()
}

<input type="text" id="username-field" autocomplete="username webauthn" >

// AutoFill-assisted WebAuthn request (JavaScript)

function signIn() {
    if (!PublicKeyCredential.isConditionalMediationAvailable ||
        !PublicKeyCredential.isConditionalMediationAvailable()) {
        // Browser doesn't support AutoFill-assisted requests.
        return;
    }

    const options = {
        "publicKey": {
            challenge: … // Fetched from server
        },
        mediation: "conditional"
    };

    navigator.credentials.get(options)
        .then(assertion => { 
            // Pass the assertion to your server.
        });
}

// Modal WebAuthn request (JavaScript)

function signIn() {
    var options = {
        "publicKey": {
            challenge: … // Fetched from server
        }
    };

    navigator.credentials.get(options)
        .then(function (assertion) { 
            // Pass the assertion to your server.
    });
}

// Modal request with allow list

func signIn(userName: String) {
    let challenge: Data = … // Fetched from server
    let provider = ASAuthorizationPlatformPublicKeyCredentialProvider(
        relyingPartyIdentifier:"example.com")
    let request = provider.createCredentialAssertionRequest(
        challenge: challenge)

    let credentialIDs: [Data] = … // Fetched from server for provided userName
    request.allowedCredentials = credentialIDs.map(
        ASAuthorizationPlatformPublicKeyCredentialDescriptor.init(credentialID:))

    let controller = ASAuthorizationController(authorizationRequests: [request])
    controller.delegate = self
    controller.presentationContextProvider = self

    // Start the request
    controller.performRequests()
}

// Modal passkey request, silent fallback

func signIn() {
    let challenge: Data = … // Fetched from server
    let provider = ASAuthorizationPlatformPublicKeyCredentialProvider(
        relyingPartyIdentifier:"example.com")
    let request = provider.createCredentialAssertionRequest(
        challenge: challenge)

    let controller = ASAuthorizationController(authorizationRequests: [request])
    controller.delegate = self
    controller.presentationContextProvider = self

    // Start the request
    controller.performRequests(options: .preferImmediatelyAvailableCredentials)
}

// Handling a silent fallback
    
func authorizationController(controller: ASAuthorizationController, 
    didCompleteWithError error: Error) {
    
    guard let error = error as? ASAuthorizationError else { … }

    if error.code == .canceled {
        // Either the user canceled the sheet, or there were no credentials available.
        showSignInForm()
    }
}

// Combined credential modal request

func signIn() {
    let challenge: Data = … // Fetched from server
    let passkeyProvider = ASAuthorizationPlatformPublicKeyCredentialProvider(
        relyingPartyIdentifier:"example.com")
    let passkeyRequest = passkeyProvider.createCredentialAssertionRequest(
        challenge: challenge)

    let passwordRequest = ASAuthorizationPasswordProvider().createRequest()
    let signInWithAppleRequest = ASAuthorizationAppleIDProvider().createRequest()

    let controller = ASAuthorizationController(
        authorizationRequests: [passkeyRequest, passwordRequest, signInWithAppleRequest])
    controller.delegate = self
    controller.presentationContextProvider = self

    // Start the request
    controller.performRequests()
}

// Completing a combined credential request

func authorizationController(controller: ASAuthorizationController, 
     didCompleteWithAuthorization authorization: ASAuthorization) {

    switch authorization.credential {
    case let passkeyAssertion as ASAuthorizationPlatformPublicKeyCredentialAssertion:
        finishSignIn(with: passkeyAssertion)

    case let signInWithAppleCredential as ASAuthorizationAppleIDCredential:
        finishSignIn(with: signInWithAppleCredential)

    case let passwordCredential as ASPasswordCredential:
        finishSignIn(with: passwordCredential)

    default:
        // Handle other credential types
        break
    }
}