Hi there, We're implementing Apple's DeviceCheck App Attest for production iOS authentication. The public documentation defines DCError cases but doesn't specify which errors are expected per API method or recommend retry/remediation strategies. We need Apple's guidance to implement robust, production-aligned error handling before rollout. 1. Error Surface per API Method Question: Can you confirm the complete, officially expected set of DCError values for each method? We understand the following errors are possible across App Attest APIs: invalidKey invalidInput featureUnsupported serverUnavailable unknownSystemFailure Specifically, please confirm which errors can occur for: DCAppAttestService.generateKey() DCAppAttestService.attestKey(_:clientData:) DCAppAttestService.generateAssertion(keyID:clientData:) Are there any additional undocumented or edge-case errors we should handle? 2. Retry Strategy & Remediation Matrix Question: For each API method and error code, please help us with proposal around which errorCode is retriable, whats the remediation pre retry, retry cap and backoff strategy: Kindly also help with errors that are not covered here: Specific sub-questions: invalidKey handling: When this error occurs: Should the app delete the key and call generateKey again? Or should it fail the entire flow? serverUnavailable handling: Should we retry immediately, or wait before retrying? Is exponential backoff recommended? What's the recommended max retry count? Backoff strategy: Which errors (if any) qualify for exponential backoff? Recommended base delay, max delay, and jitter approach? When should we give up and fail the request? unknownSystemFailure: Is this retriable or should we fail? Any known causes or mitigations? 3. Simulator Testing Questions: Simulator API behavior: Can App Attest APIs be called normally on iOS Simulator? If not, is there a way to simulate for testing. Do they complete successfully with simulated attestations, or do they fail? Thanks, Nirekshitha

I need to launch ASWebAuthenticationSession from single sign on extension, but its not launching it might issue with anchoring window, I have create custom windo and passing it in presentanchor(for session) function, custom window is launching but ASWebAuthenticationSession browser is not launching Note - flow is like this Apple PSSO register window lauched OIDC login will happen via ASWebAuthenticationSession to get accesstoken which will use in device registration but ASWebAuthenticationSession is not launching, I am using custom scheme as redirect URI iskeywindow for custom window is always false what is right approach to achieve the goal

I am trying to find a datasheet containing information such as "Key Exchange / Key Agreement / Key Establishment Protocols Used", "Digital Signature Algorithms Used", "Hash Algorithms Used", etc. Any information would greatly appreciated.

I am not able to use Feedback because the app can not reset my password.

We are experiencing an issue with Apple’s Private Email Relay service for Sign in with Apple users. Our setup details are as follows: • Domain: joinalyke.com • Domain successfully added under “Sign in with Apple for Email Communication” • SPF verified • DKIM enabled (2048-bit Easy DKIM via AWS SES) • Emails are being sent from S***@joinalyke.com Amazon SES confirms that emails sent to users’ @privaterelay.appleid.com addresses are successfully delivered (Delivery events recorded in SES and no bounce reported). However, users are not receiving the forwarded emails in their actual inboxes. Since: SES shows successful delivery, SPF and DKIM are properly configured, Domain is registered in the Apple Developer portal, we suspect that the Private Email Relay service may be blocking or not forwarding these emails. Could you please investigate whether: Our domain or IP reputation is being blocked or filtered, There are additional configuration requirements, The relay service is rejecting emails after acceptance, There are content-related filtering policies we should review. We are happy to provide message IDs, timestamps, and sample relay email addresses if required.

Thanks all for reading my post. A bit of context: We just finished an app transfer to our developer account. We successfully signed and generated the new release. We are already able to roll it out in testflight were we found an issue. We store valuable data in the Keychain like Authentication tokens, once the new app is installed over the old one we are experiencing a loss of all data as the keychain become "untrusted". This is worst case scenario for us because all users will immediately lose the access to the app and hence the whole system. Questions: Is there a way to solve this issue, something like migration of the Keychain data? We came to know the standard migration path: Release a version that copies items from the old access groups to a new group based on com.apple.security.application-groups (App Groups). Wait for most users to update and run the migration. Then perform the App ID prefix change. Is this still the best method? Any improvements or new tools available since the 2022 DTS post? The problem with this is that the app is already on our account and that might need to rollback the transfer. Right? How long should we realistically wait for user migration before making the prefix change? Is there a way to measure migration completion? Thank you in advance!

I lived with knowledge that one needs to provide his login password to unlock the login keychain. This does not seem to be entirely true after upgrading Tahoe to 26.4. For example, on 26.3: Go to ~/Library/Keychains Copy login.keychain-db to different name, say test.keychain-db. Double-click on test.keychain-db -> this should open Keychain Access with test in Custom keychains section, it will appear locked. Select test keychain and press Cmd+L to unlock it. When prompted, provide your login password. Result: the keychain is unlocked. When I preform above sequence of steps on 26.4 I am not able to unlock the copied keychain (the original login keychain appears implicitly unlocked).

Hi everyone, I’ve been working on an experimental prototype called FaceBridge that explores whether Secure Enclave–backed biometric authorization can be delegated between macOS and iPhone using only public Apple APIs. The goal of the project was to better understand the architectural boundaries of cross-device trust and approval flows that resemble Apple’s built-in Touch ID / Continuity authorization experiences. FaceBridge implements a local authorization pipeline where: macOS generates a signed authorization request the request is delivered to a trusted nearby iPhone over BLE / Network framework the iPhone verifies sender identity Face ID approval is requested using LocalAuthentication the iPhone signs the approval response using Secure Enclave–backed keys macOS validates the response and unlocks a protected action Security properties currently implemented: • Secure Enclave–backed signing identities per device • cryptographic device pairing and trust persistence • replay protection using nonce + timestamp binding • structured authorization request/response envelopes • signed responder identity verification • trusted-device registry model • local encrypted transport over BLE and local network This is intentionally not attempting to intercept or replace system-level Touch ID dialogs (App Store installs, Keychain prompts, loginwindow, etc.), but instead explores what is possible within application-level authorization boundaries using public APIs only. The project is open source: https://github.com/wesleysfavarin/facebridge Technical architecture write-up: https://medium.com/@wesleysfavarin/facebridge I’m particularly interested in feedback around: • recommended Secure Enclave identity lifecycle patterns • best practices for cross-device trust persistence • LocalAuthentication usage in delegated approval scenarios • whether similar authorization models are expected to become more formally supported across Apple platforms in the future Thanks in advance for any guidance or suggestions.

I can't find any information about why this is happening, nor can I reproduce the 'successful' state on this device. My team needs to understand this behavior, so any insight would be greatly appreciated! The expected behavior: If I delete both apps and reinstall them, attempting to open the second app from my app should trigger the system confirmation dialog. The specifics: I'm using the MSAL library. It navigates the user to the Microsoft Authenticator app and then returns to my app. However, even after resetting the phone and reinstalling both apps, the dialog never shows up (it just opens the app directly). Does anyone know the logic behind how iOS handles these prompts or why it might be persistent even after a reset? Thanks in advance!

We are using the CryptoTokenKit framework, specifically the classes TKSmartCardSlotManager, TKSmartCardSlot, and TKSmartCard, to communicate with smart cards through external USB readers on iOS and iPadOS. In most cases, we are able to detect readers via TKSmartCardSlotManager, and send APDU commands using transmitRequest method, with the following code (where self->_slot and self->_card are previously created TkSmartCardSlot and TkSmartCard, respectively): #import <CryptoTokenKit/CryptoTokenKit.h> - (NSData *)sendCardCommand:(NSData *)command { if (!self->_card || !self->_card.valid || self->_slot.state != TKSmartCardSlotStateValidCard) return nil; NSMutableData *res = [[NSMutableData alloc] init]; NSError *sessionError = nil; [self->_card inSessionWithError:&sessionError executeBlock:^BOOL(NSError **error) { dispatch_semaphore_t semaphore = dispatch_semaphore_create(0); try { [self->_card transmitRequest:command reply:^(NSData * _Nullable response, NSError* _Nullable apduError) { if (apduError != nil) self->_error = apduError; else [res appendData: response]; dispatch_semaphore_signal(semaphore); }]; } catch (NSException *exception) { dispatch_semaphore_signal(semaphore); } dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER); if (res.length == 0) return NO; return YES; }]; return res; } However, with certain other USB smart card readers, we occasionally encounter APDU communication failures when calling transmitRequest (for instance, with a HID Global OMNIKEY 5422), which returns the following error: "Domain: CryptoTokenKit Code: -2". Once a failure occurs and transmitRequest starts returning this error, all subsequent calls to transmitRequest fail with the same error. This persists even when: A different smart card is inserted The same card is reinserted A different USB reader (previously working correctly) is connected The TKSmartCard object is recreated via makeSmartCard The slot state changes (observed via KVO) All internal objects (TKSmartCard, TKSmartCardSlot) are reset in the application At this point, the system appears to be stuck in a non-recoverable state which affects all readers and cards, including those that were previously functioning correctly. The only way to recover from this state is terminating and restarting the application which is running the code. After restarting the app, everything works normally again. We have created a bug report: FB22339746. The issue has been reproduced on iOS 26.4 and 18.5. Also on iPadOS 18.1. Anyone has already faced a similar issue? Could it be related to some internal state of TKSmartCardSlotManager?

Hi, I’m building a macOS tool that analyzes process behavior to detect autonomous / AI-like activity locally (process trees, file access patterns, and network usage). The system is fully user-space and runs locally in real time. I’m planning to use the Endpoint Security Framework for process and file event monitoring. This is an open-source project (non-enterprise), developed by a solo developer. My question: What are the realistic chances of getting Endpoint Security entitlements approved for this type of project? Are there specific requirements or common reasons for rejection I should be aware of? Thanks, sivan-rnd

Hi , I did The MFA(2FA) of Email OTP For MacOS Login Screen using, Authorization Plugin, Using This git hub project. It is working For Login Screen , Im trying to Add The Same plugin for LockScreen but it is not working at lock Screen , Below is the reffrense theard For The issue , https://developer.apple.com/forums/thread/127614, please Share The Code that should Present the NSwindow at Screen Saver (Lock Screen) MacOS .

Hello, sorry for the awkward text formatting but I kept getting prevented from positing due to "sensitive language"... Help.txt

I'm currently reviewing the various DCError cases defined in Apple’s DeviceCheck framework (reference: https://developer.apple.com/documentation/devicecheck/dcerror-swift.struct). To better understand how to handle these in production, I’m looking for a clear breakdown of: Which specific DCError values can occur during service.generateKey, service.attestKey, and service.generateAssertion The realworld scenarios or conditions that typically cause each error for each method. If anyone has insight on how these errors arise and what conditions trigger them, I’d appreciate your input.

I have a question regarding Platform SSO and the use of Secure Enclave–backed keys with biometric policies. If we configure userSecureEnclaveKeyBiometricPolicy with userSecureEnclaveKey, my understanding is that the Secure Enclave key is protected by biometric authentication (e.g., Face ID / Touch ID). In this setup, during a login request that also refreshes the id_token and refresh_token, the assertion is signed using the userSecureEnclaveKey. My question is: Will this signing operation trigger a biometric prompt every time the assertion is generated (i.e., during login/token refresh) ?

I am developing a Flutter iOS application and encountering a crash when using biometric authentication (Face ID) via the local_auth plugin. ■ Environment Flutter: 3.x local_auth: 2.2.0 (also tested with 2.1.6) iOS: real device (Face ID is working normally for device unlock) Firebase Authentication (email/password) Xcode build ■ Issue When calling biometric authentication, the app crashes immediately. Code: final didAuthenticate = await auth.authenticate( localizedReason: 'Authenticate to login', options: const AuthenticationOptions( biometricOnly: false, useErrorDialogs: false, ), ); ■ Error Thread 1: signal SIGABRT Crash occurs in libsystem_kernel.dylib (__pthread_kill) Happens immediately when authenticate() is called No exception is caught in Dart (native crash) ■ Verified NSFaceIDUsageDescription is correctly included in Info.plist Confirmed it exists in the built Runner.app Info.plist localizedReason is non-empty and in English Flutter clean / pod install executed App reinstalled on device Face ID works normally outside the app ■ Question Under what conditions does LAContext.evaluatePolicy trigger SIGABRT instead of returning an error? Are there known issues with presenting biometric authentication UI in certain UI states (e.g., view controller hierarchy, scene lifecycle)? Could this be related to UIScene / rootViewController issues? What is the correct timing and context to call biometric authentication safely in iOS apps? I suspect this is related to native iOS behavior rather than Flutter logic. Any guidance would be appreciated.

Hello, I’m working on a security agent plugin for Mac. The plugin provides a mechanism with custom UI via SFAuthorizationPluginView and a privileged mechanism with the business logic. The plugin needs to support unlocking the device, so I changed the authorize right to invoke my agent: <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>class</key> <string>evaluate-mechanisms</string> <key>created</key> <real>731355374.33196402</real> <key>mechanisms</key> <array> <string>FooBar:loginUI</string> <string>builtin:reset-password,privileged</string> <string>FooBar:authenticate,privileged</string> <string>builtin:authenticate,privileged</string> </array> <key>modified</key> <real>795624943.31730103</real> <key>shared</key> <true/> <key>tries</key> <integer>10000</integer> <key>version</key> <integer>1</integer> </dict> </plist> I also changed the system.login.screensaver right to use authorize-session-owner: <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>class</key> <string>rule</string> <key>comment</key> <string>The owner or any administrator can unlock the screensaver, set rule to "authenticate-session-owner-or-admin" to enable SecurityAgent.</string> <key>created</key> <real>731355374.33196402</real> <key>modified</key> <real>795624943.32567298</real> <key>rule</key> <array> <string>authenticate-session-owner</string> </array> <key>version</key> <integer>1</integer> </dict> </plist> I also set screenUnlockMode to 2, as was suggested in this thread: macOS Sonoma Lock Screen with SFAutorizationPluginView is not hiding the macOS desktop. In the Display Authorization plugin at screensaver unlock thread, Quinn said that authorization plugins are not able to use Touch ID. However, on a MacBook with at touch bar, when I lock the screen, close the lid, and then open it, the touch bar invites me to unlock with Touch ID. If I choose to do so, the screen unlocks and I can interact with the computer, but the plugin UI stays on screen and never goes away, and after about 30 seconds the screen locks back. I can reliably reproduce it on a MacBook Pro with M1 chip running Tahoe 26.1. Is this a known macOS bug? What can I do about it? Ideally, I would like to be able to integrate Touch ID into my plugin, but since that seems to be impossible, the next best thing would be to reliably turn it off completely. Thanks in advance.

Our proposed solution to identify an app user when opening a website operated by app developer is: Apps sends a request to backed with app users auth header Backend fetches a generated authenticated url from website backend, based on users auth header App opens it in browser The browser journey is self contained within domain of the business. Would this interaction require an ATT request given that the users identity cannot be tracked back to the app user ? Thanks

On Tahoe and earlier, ScreenCapture permissions can disappear and not return. Customers are having an issue with this disappearing and when our code executes CGRequestScreenCaptureAccess() nothing happens, the prompt does not appear. I can reproduce this by using the "-" button and removing the entry in the settings, then adding it back with the "+" button. CGPreflightScreenCaptureAccess() always returns the correct value but once the entry has been removed, CGRequestScreenCaptureAccess() requires a reboot before it will work again.