General: Forums topic: Privacy & Security Privacy Resources Security Resources Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

Steps to reproduce: register a passkey on device A authenticate on device A, using the prf extension and a constant salt. Note the prf output go to device B. wait for iCloud sync authenticate on device B using the prf extension and the same constant salt. Note the prf output The prf outputs are different. Note: Repeat the authentication on each device. The prf output is identical for a given device, which seems to point towards the inclusion of a device specific component in the prf derivation. In my scenario, I need the prf output to be the same regardless of the device since I use it as the recovery key for my app data. Could you confirm that this is the expected behavior or not? Thanks,

Hi, In the app I’m working on, we rely on SecKeychainUnlock to verify that a password can be used to unlock the login keychain. When macOS 26.4 rolled out, we started getting bug reports that led me to a discovery that makes me think SecKeychainUnlock behavior was changed. I’m going to illustrate my findings with a sample code: #include <pwd.h> #include <stdio.h> #include <string.h> #include <unistd.h> #include <Security/SecKeychain.h> #pragma clang diagnostic ignored "-Wdeprecated-declarations" int main(void) { char password[100]; printf("password: "); scanf("%s", password); struct passwd *home = getpwuid(getuid()); if (!(home && home->pw_dir)) return 1; char path[1024]; strcat(path, home->pw_dir); strcat(path, "/Library/Keychains/login.keychain-db"); SecKeychainRef keychain = NULL; OSStatus result = SecKeychainOpen(path, &keychain); if (result != errSecSuccess) { fprintf(stderr, "SecKeychainOpen failed (error %d)\n", result); return 1; } SecKeychainStatus status = 0; result = SecKeychainGetStatus(keychain, &status); if (result != errSecSuccess) { fprintf(stderr, "SecKeychainGetStatus failed (error %d)\n", result); return 1; } if (status & kSecUnlockStateStatus) { printf("keychain is unlocked, will try to lock first\n"); result = SecKeychainLock(keychain); if (result != errSecSuccess) { fprintf(stderr, "SecKeychainLock failed (error %d)\n", result); return 1; } printf("SecKeychainLock succeeded\n"); } else { printf("keychain is locked\n"); } result = SecKeychainUnlock(keychain, strlen(password), password, TRUE); if (result == errSecSuccess) { printf("SecKeychainUnlock succeeded\n"); printf("password '%s' appears to be valid\n", password); } else { printf("SecKeychainUnlock failed (error %d)\n", result); printf("password '%s' appears to be invalid\n", password); } return 0; } Here are the outputs of this program on a machine running macOS 26.3 when provided with a correct password deadbeef and with an incorrect password foobar: testuser1@tahoe1 kcdebug % ./kcdebug password: deadbeef keychain is unlocked, will try to lock first SecKeychainLock succeeded SecKeychainUnlock succeeded password 'deadbeef' appears to be valid testuser1@tahoe1 kcdebug % ./kcdebug password: foobar keychain is unlocked, will try to lock first SecKeychainLock succeeded SecKeychainUnlock failed (error -25293) password 'foobar' appears to be invalid And here are the outputs of this program on a machine running macOS 26.4: testuser1@tahoe2 kcdebug % ./kcdebug password: deadbeef keychain is unlocked, will try to lock first SecKeychainLock succeeded SecKeychainUnlock succeeded password 'deadbeef' appears to be valid testuser1@tahoe2 kcdebug % ./kcdebug password: foobar keychain is unlocked, will try to lock first SecKeychainLock succeeded SecKeychainUnlock succeeded password 'foobar' appears to be valid I’m prepared to send a feedback with Feedback Assistant, but I would like to get a confirmation that this is indeed a bug and not an intended change in behavior. I would also like to know what are my options now. SecKeychainUnlock is just a means to an end; what I really need is the ability to keep the keychain password in sync with the user password when the latter is changed by our program. Thanks in advance.

We've filed FB22448572 for this, but posting here in case others are hitting the same issue. After upgrading macOS from 26.3.2 to 26.4, SecItemCopyMatching returns errSecAuthFailed (-25293) when reading kSecClassGenericPassword items from the default login keychain. The keychain reports as unlocked, but all authenticated operations fail. The error doesn't self-resolve — we've observed it persisting for 7+ minutes across repeated calls and process restarts. The only workaround we've found is SecKeychainLock(nil) followed by SecKeychainUnlock(nil, 0, nil, false), which prompts the user for their password and clears the stale state. Apple's own security CLI tool also fails while the keychain is in this state: $ security show-keychain-info ~/Library/Keychains/login.keychain-db security: SecKeychainCopySettings .../login.keychain-db: The user name or passphrase you entered is not correct. The trigger seems to be process lifecycle — a new process accessing the keychain early in startup (e.g., from the app delegate) can hit this state after the OS upgrade. It's probabilistic: not every machine and not every restart, but once it happens, it sticks until manual intervention. We're an enterprise app using legacy keychain APIs (SecKeychainCopyDefault, kSecUseKeychain) deployed to thousands of managed devices. We've reproduced this on multiple machines (M1, M2) and have reports from customers in the field after the 26.4 upgrade. I noticed a possibly related thread — Calling SecKeychainUnlock with a locked keychain and an invalid password returns errSecSuccess on macOS 26.4 — where SecKeychainUnlock stopped properly validating passwords after 26.4. Our symptom is different (reads fail on an unlocked keychain rather than unlock succeeding with wrong password), but both appeared after 26.4 and both point to something changing in securityd's authentication handling. Wondering if these could be related. A couple of questions: Is there a known issue with securityd's keychain authentication after 26.4? Could this be related to the CVE-2026-28864 fix ("improved permissions checking" in the Security component)? Would migrating to the data protection keychain (kSecAttrAccessible instead of kSecUseKeychain) avoid this class of issue entirely? Is there a way to detect and clear this stale state programmatically without the user entering their password? Any guidance appreciated.

I've been trying over the past few days to use a PIV-programmed Yubikey to perform mTLS (i.e. mutual client cert auth) in my custom app. My understanding is that I need to feed NSURLSession a SecIdentity to do so. Yubico's instructions state that I need their Yubico Authenticator app for this, but this directly contradicts Apple's own documentation here. I dont need NFC/lightening support, and I only need support for my specific app. When I plug in my key to my iPhone and have TKTokenWatcher active, I DO see "com.apple.pivtoken" appear in the logs. And using Yubico's SDK, I CAN get data from the key (so I'm pretty sure my entitlements and such are correct). But using the below query to get the corresponding (fake? temporary?) keychain item, it returns NULL no matter what I do: let query: [String: Any] = [ kSecClass as String: kSecClassIdentity, kSecReturnRef as String: true, kSecAttrTokenID as String: "apple.com.pivtoken", // Essential for shared iPads kSecMatchLimit as String: kSecMatchLimitOne ] var item: CFTypeRef? let status = SecItemCopyMatching(query as CFDictionary, &item) "status" is always -25300 (which is "not found"). I've also created a CTK extension (as Yubico's authenticator does) and tried to use self.keychainContents.fill(), and then tried to access it with kSecAttrTokenID as ":Yubico YubiKey OTP+FIDO+CCID", as that's what shows via TKTokenWatcher, and this also doesn't work. I've also tried just the app extension ID, and that doesn't work. Both my extension and my main app have the following entitlements: <key>com.apple.developer.default-data-protection</key> <string>NSFileProtectionComplete</string> <key>com.apple.security.application-groups</key> <array/> <key>com.apple.security.smartcard</key> <true/> <key>keychain-access-groups</key> <array> <string>$(AppIdentifierPrefix)com.apple.pivtoken</string> <string>$(AppIdentifierPrefix)myAppExtensionId</string> </array> As one final test, I tried using the yubikey in safari to access my server using mTLS, and it works! I get prompted for a PIN (which is odd because I've programmed it not to require a PIN), but the request succeeds using the key's default PIN. I just cannot get it working with my own app. Can anyone here (or preferably, at Apple) point me in the right direction? I have a feeling that the documentation I've been reading applies to MacOS, and that iOS/ipadOS have their own restrictions that I either need to work around, or which prevent me from doing what I need to do. It's obviously possible (i.e. the Yubico Authenticator sort of does what I need it to), but not in the way that Apple seems to describe in their own documentation.

I set up "Sign in with Apple" via REST API according to the documentation. I can log in on my website and everything looks fine for the user. But I receive an email, that my "Sign in with Apple" account has been rejected by my own website. It states, I will have to re-submit my name and email address the next time I log in to this website. I don't see any error messages, no log entries, no HTTP errors anywhere. I also can't find anything in the docs, the emails seem to not be mentioned there, searching for anything with "rejected" in the forum did not yield any helpful result, because they are always about App entries being rejected etc. Did someone experience something similar yet? What's the reason, I'm getting these emails? I get them every time I go through the "Sign in with Apple" flow on my website again.

Can a macOS Platform SSO extension reliably identify the original app behind a Safari or ASWebAuthenticationSession-mediated request, or does ASAuthorizationProviderExtensionAuthorizationRequest only expose the immediate caller such as Safari ? We are seeing: callerBundleIdentifier = com.apple.Safari callerTeamIdentifier = Apple audit-token-based validation also resolves to Safari So the question is whether this is the expected trust model, and if so, what Apple-recommended mechanism should be used to restrict SSO participation to approved apps when the flow is browser-mediated.

Hello, I’m trying to remove the “Sign in with Apple” for my app via the iOS settings (also tried on a Mac, and on the web via account.apple.com). When I tap “Stop Using”, nothing happens, the dialog disappear but the app remains listed. Someone said on a forum that the issue is linked with the ServiceId that doesn't exist anymore. But how to recover it ? And anyway this behavior is unintended and creates a gap in the process. Has anyone experienced this before? Is there a known fix, or should I contact Apple Support directly for server-side revocation? Thank you!

Xcode 26.x + iOS 26.x MTE Compatibility Feedback Reporter：Third-party App Developer Date：2026 Environments：Xcode 26.2 / 26.4, iOS 26.2 / 26.4 SDK, iPhone 17 Pro, Third-party App (Swift/C++/Python/Boost) Core Issue MTE (Memory Tagging Extension) under Memory Integrity Enforcement generates extensive false positives for valid high-performance memory operations in third-party apps, causing crashes. No official configuration exists to bypass these false positives, severely impacting stability and development costs. Key Problems 1. Widespread False Positives (Valid Code Crashes) After enabling MTE (Soft/Hard Mode), legitimate industrial-standard operations crash: Swift/ C++ containers: Array.append, resize, std::vector reallocation Custom memory pools / Boost lockfree queues:no UAF/corruption Memory reallocation:Legitimate free-reuse patterns are judged as tag mismatches. 2. MTE Hard Mode Incompatibility iOS 26.4 opens MTE Hard Mode for third-party apps, but it immediately crashes apps using standard high-performance memory management. No whitelist/exception mechanism for third-party developers. 3. MTE Soft Mode Limitations Detects far fewer issues than actual memory corruption reports. Only generates 1 simulated report per process, hiding multiple potential issues. Impact Stability: Apps crash in production when MTE is enabled. Cost: Massive code changes required to abandon memory pools/lockfree structures for system malloc. Ecosystem: Popular libraries (Python, Boost) are incompatible. Recommendations Optimize MTE rules: Add system-level exceptions for valid container resizing and memory pool operations. Provide exemptions: Allow per-region/module MTE exceptions for high-performance modules. Support runtimes: Officially support common third-party runtimes (Python/Boost) or provide system-level exemptions. Improve debugging: Increase MTE Soft Mode coverage and allow multiple reports per process.

Hello, I am using the prf extension for passkeys that is available since ios 18 and macos15. I am using a fixed, hardcoded prf input when creating or geting the credentials. After creating a passkey, i try to get the credentials and retrieve the prf output, which works great, but i am getting different prf outputs for the same credential and same prf input used in the following scenarios: Logging in directly (platform authenticator) on my macbook/iphone/ipad i get "prf output X" consistently for the 3 devices When i use my iphone/ipad to scan the qr code on my macbook (cross-platform authenticator) i get "prf output Y" consistently with both my ipad and iphone. Is this intended? Is there a way to get deterministic prf output for both platform and cross-platform auth attachements while using the same credential and prf input?

We have utilised the KeyChain Framework for Adding items into KeyChain. We have Generated KeyPair using 'SecKeyGeneratePair' API as below (OSStatus)generateAssymetricKeyPair:(NSUInteger)bitSize{ OSStatus sanityCheck = noErr; SecKeyRef publicKeyRef = NULL; SecKeyRef privateKeyRef = NULL; NSString *appGrpIdentifier = @"group.com.sample.xyz" // Set the private key attributes. NSDictionary *privateKeyAttr = @{(id)kSecAttrIsPermanent: @YES, (id)kSecAttrApplicationTag: [TAG_ASSYMETRIC_PRIVATE_KEY dataUsingEncoding:NSUTF8StringEncoding], (id)kSecAttrCanEncrypt:@NO, (id)kSecAttrCanDecrypt:@YES, (id)kSecAttrAccessGroup: appGrpIdentifier }; // Set the public key attributes. NSDictionary *publicKeyAttr = @{(id)kSecAttrIsPermanent: @YES, (id)kSecAttrApplicationTag: [TAG_ASSYMETRIC_PUBLIC_KEY dataUsingEncoding:NSUTF8StringEncoding], (id)kSecAttrCanEncrypt:@YES, (id)kSecAttrCanDecrypt:@NO, (id)kSecAttrAccessGroup: appGrpIdentifier }; // Set top level attributes for the keypair. NSDictionary *keyPairAttr = @{(id)kSecAttrKeyType: (id)kSecAttrKeyTypeRSA, (id)kSecAttrKeySizeInBits: @(bitSize), (id)kSecClass: (id)kSecClassKey, (id)kSecPrivateKeyAttrs: privateKeyAttr, (id)kSecPublicKeyAttrs: publicKeyAttr, // MOBSF-WARNING-SUPPRESS: (id)kSecAttrAccessible: (id)kSecAttrAccessibleAfterFirstUnlock, // mobsf-ignore: ios_keychain_weak_accessibility_value // MOBSF-SUPPRESS-END (id)kSecAttrAccessGroup: appGrpIdentifier }; // Generate Assymetric keys sanityCheck = SecKeyGeneratePair((CFDictionaryRef)keyPairAttr, &publicKeyRef, &privateKeyRef); if(sanityCheck == errSecSuccess){ NSLog(@"[DB_ENCRYPTION] <ALA_INFO> [OS-CCF] CALLED Assymetric keys are generated"); } else{ NSLog(@"[DB_ENCRYPTION] <ALA_ERROR> [OS-CCF] CALLED Error while generating asymetric keys : %d", (int)sanityCheck); } if (publicKeyRef) { CFRelease(publicKeyRef); } if (privateKeyRef) { CFRelease(privateKeyRef); } return sanityCheck; } KeyPair is added into the KeyChain (BOOL)saveSymetricKeyToKeychain:(NSData *)symmetricKeyData keyIdentifier:(NSString *)keyIdentifier { NSString *appGrpIdentifier = [KeychainGroupManager getAppGroupIdentifier]; NSDictionary *query = @{ (__bridge id)kSecClass: (__bridge id)kSecClassKey, (__bridge id)kSecAttrApplicationTag: keyIdentifier, (__bridge id)kSecValueData: symmetricKeyData, (__bridge id)kSecAttrKeyClass: (__bridge id)kSecAttrKeyClassSymmetric, // MOBSF-WARNING-SUPPRESS: (__bridge id)kSecAttrAccessible: (__bridge id)kSecAttrAccessibleAfterFirstUnlock, // mobsf-ignore: ios_keychain_weak_accessibility_value // MOBSF-SUPPRESS-END (__bridge id)kSecAttrAccessGroup: appGrpIdentifier }; // Now add the key to the Keychain status = SecItemAdd((__bridge CFDictionaryRef)query, NULL); if (status == errSecSuccess) { NSLog(@"[DB_ENCRYPTION] Key successfully stored in the Keychain"); return YES; } else { NSLog(@"<ALA_ERROR> [DB_ENCRYPTION] Error storing key in the Keychain: %d", (int)status); return NO; } } Post App Transfer, we are able to retrieve the Public & Private Key Reference without rebuilding the keychain Query:- Is this attribute "kSecAttrAccessGroup" helping us to retrieve the KeyChain items without having to rebuild on App Transfer to New Apple Account as described in this set of guidelines. Could you please explain in detail on this. https://developer.apple.com/help/app-store-connect/transfer-an-app/overview-of-app-transfer Keychain sharing continues to work only until the app is updated. Therefore, you must rebuild the keychain when submitting updates. If your keychain group is defined in the Xcode project, replace it with a group created by the recipient, incorporating their Team ID for continued keychain sharing. After the update, users must re-login once as the app cannot retrieve the authentication token from the keychain.

DTS regularly receives questions about how to preserve keychain items across an App ID change, and so I thought I’d post a comprehensive answer here for the benefit of all. If you have any questions or comments, please start a new thread here on the forums. Put it in the Privacy & Security > General subtopic and tag it with Security. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" App ID Prefix Change and Keychain Access The list of keychain access groups your app can access is determined by three entitlements. For the details, see Sharing Access to Keychain Items Among a Collection of Apps. If your app changes its App ID prefix, this list changes and you’re likely to lose access to existing keychain items. This situation crops up under two circumstances: When you migrate your app from using a unique App ID prefix to using your Team ID as its App ID prefix. When you transfer your app to another team. In both cases you have to plan carefully for this change. If you only learn about the problem after you’ve made the change, consider undoing the change to give you time to come up with a plan before continuing. Note On macOS, the information in this post only applies to the data protection keychain. For more information about the subtleties of the keychain on macOS, see On Mac Keychains. For more about App ID prefix changes, see Technote 2311 Managing Multiple App ID Prefixes and QA1726 Resolving the Potential Loss of Keychain Access warning. Migrate From a Unique App ID Prefix to Your Team ID Historically each app was assigned its own App ID prefix. This is no longer the case. Best practice is for apps to use their Team ID as their App ID prefix. This enables multiple neat features, including keychain item sharing and pasteboard sharing. If you have an app that uses a unique App ID prefix, consider migrating it to use your Team ID. This is a good thing in general, as long as you manage the migration process carefully. Your app’s keychain access group list is built from three entitlements: keychain-access-groups — For more on this, see Keychain Access Groups Entitlement. application-identifier (com.apple.application-identifier on macOS) com.apple.security.application-groups — For more on this, see App Groups Entitlement. Keycahin access groups from the third bullet are call app group identified keychain access groups, or AGI keychain access groups for short. IMPORTANT A macOS app can only use an AGI keychain access group if all of its entitlement claims are validated by a provisioning profile. See App Groups: macOS vs iOS: Working Towards Harmony for more about this concept. Keychain access groups from the first two bullets depend on the App ID prefix. If that changes, you lose access to any keychain items in those groups. WARNING Think carefully before using the keychain to store secrets that are the only way to access irreplaceable user data. While the keychain is very reliable, there are situations where a keychain item can be lost and it’s bad if it takes the user’s data with it. In some cases losing access to keychain items is not a big deal. For example, if your app uses the keychain to manage a single login credential, losing that is likely to be acceptable. The user can recover by logging in again. In other cases losing access to keychain items is unacceptable. For example, your app might manage access to dozens of different servers, each with unique login credentials. Your users will be grumpy if you require them to log in to all those servers again. In such situations you must carefully plan your migration. The key thing to understand is that an app group is tied to your team, not your App ID prefix, and thus your app retains access to AGI keychain access groups across an App ID prefix change. This suggests the following approach: Release a version of your app that moves keychain items from other keychain access groups to an AGI keychain access group. Give your users time to update to this new version, run it, and so move their keychain items. When you’re confident that the bulk of your users have done this, change your App ID prefix. The approach has one obvious caveat: It’s hard to judge how long to wait at step 2. Transfer Your App to Another Team Historically there was no supported way to maintain access to keychain items across an app transfer. That’s no longer the case, but you must still plan the transfer carefully. The overall approach is: Identify an app group ID to transfer. This could be an existing app group ID, but in many cases you’ll want to register a new app group ID solely for this purpose. Use the old team (the transferor) to release a version of your app that moves keychain items from other keychain access groups to the AGI keychain access group for this app group ID. Give your users time to update to this new version, run it, and so move their keychain items. When you’re confident that the bulk of your users have done this, initiate the app transfer. Once that’s complete, transfer the app group ID you selected in step 1. See App Store Connect Help > Transfer an app > Overview of app transfer > Apps using App Groups. Publish an update to your app from the new team (the transferee). When a user installs this version, it will have access to your app group, and hence your keychain items. WARNING Once you transfer the app group, the old team won’t be able to publish a new version of any app that uses this app group. That makes step 1 in the process critical. If you have an existing app group that’s used solely by the app being transferred — for example, an app group that you use to share state between the app and its app extensions — then choosing that app group ID makes sense. On the other hand, choosing the ID of an app group that’s share between this app and some unrelated app, one that’s not being transferred, would be bad, because any updates to that other app will lose access to the app group. There are some other significant caveats: The process doesn’t work for Mac apps because Mac apps that have ever used an app group can’t be transferred. See App Store Connect Help > Transfer an app > App transfer criteria. If and when that changes, you’ll need to choose an iOS-style app group ID for your AGI keychain access group. For more about the difference between iOS- and macOS-style app group IDs, see App Groups: macOS vs iOS: Working Towards Harmony. The current transfer process of app groups exposes a small window where some other team can ‘steal’ your app group ID. We have a bug on file to improve that process (r. 171616887). The process works best when transferring between two teams that are both under the control of the same entity. If that’s not the case, take steps to ensure that the old team transfers the app group in step 5. When you submit the app from the new team (step 6), App Store Connect will warn you about a potential loss of keychain access. That warning is talking about keychain items in normal keychain access groups. Items in an AGI keychain access group will still be accessible as long as you transfer the app group. Alternative Approaches for App Transfer In addition to the technique described in the previous section, there are a some alternative approaches you should at consider: Do nothing Do not transfer your app Get creative Do Nothing In this case the user loses all the secrets that your app stored in the keychain. This may be acceptable for certain apps. For example, if your app uses the keychain to manage a single login credential, losing that is likely to be acceptable. The user can recover by logging in again. Do Not Transfer Another option is to not transfer your app. Instead, ship a new version of the app from the new team and have the old app recommend that the user upgrade. There are a number of advantages to this approach. The first is that there’s absolutely no risk of losing any user data. The two apps are completely independent. The second advantage is that the user can install both apps on their device at the same time. This opens up a variety of potential migration paths. For example, you might ship an update to the old app with an export feature that saves the user’s state, including their secrets, to a suitably encrypted file, and then match that with an import facility on the new app. Finally, this approach offers flexible timing. The user can complete their migration at their leisure. However, there are a bunch of clouds to go with these silver linings: Your users might never migrate to the new app. If this is a paid app, or an app with in-app purchase, the user will have to buy things again. You lose the original app’s history, ratings, reviews, and so on. Get Creative Finally, you could attempt something creative. For example, you might: Publish a new version of the app that supports exporting the user’s state, including the secrets. Tell your users to do this, with a deadline. Transfer the app and then, when the deadline expires, publish the new version with an import feature. Frankly, this isn’t very practical. The problem is with step 2: There’s no good way to get all your users to do the export, and if they don’t do it before the deadline there’s no way to do it after. Test Before You Ship Once you have a new version of your app, with the new App ID prefix, it’s time to test. To run a day-to-day test: On a test device, install the existing version of the app from the App Store. Use the app to generate keychain items as a normal user would. For example, if you store login credentials in the keychain, use the app to save such a credential. In Xcode, run the new version of your app. Check that the keychain items you created in step 2 still work. After you upload this new version to App Store Connect, use TestFlight to run an internal test: On a test device, install the existing version of the app from the App Store. Use the app to generate keychain items as a normal user. For example, if you store login credentials in the keychain, use the app to save such a credential. Use TestFlight to update the app to your new version. Check that the keychain items you created in step 2 still work. Do this before you release the app to your beta testers and then again before releasing it to customers. WARNING These TestFlight test are your last chance to ensure that everything works. If you detect an error at this stage, you still have a chance to fix it. Revision History 2026-04-07 Added the Test Before You Ship section. 2026-03-31 Rewrote the Transfer Your App to Another Team section to describe a new approach for preserving access to keychain items across app transfers. Moved the previous discussion into a new Alternative Approaches for App Transfer section. Clarified that a macOS program can now use an app group as a keychain access group as long as its entitlements are validated. Made numerous editorial changes. 2022-05-17 First posted.

Hi, we are experiencing a specific issue with the Private Email Relay service. Our domain e.glassesdirect.co.uk consistently fails SPF verification while our other domains pass. The Pattern: We've noticed that domains with SPF records fitting in 1-2 TXT strings pass, but this specific domain (~750 chars, 3 TXT strings) fails. Technical Details: Team ID: SM2J7LWD33 Domain: e.glassesdirect.co.uk SPF Record length: ~750 characters Third-party tools (MxToolbox) confirm the record is valid. We suspect Apple's verification parser might be failing to handle concatenated TXT strings or hitting a size limit. Could any Apple engineers confirm if there is a character limit or a bug in handling multi-part TXT records?

We are currently experiencing an unexpected issue with the DeviceCheck query_two_bits endpoint. According to the official documentation (Accessing and Modifying Per-Device Data), the last_update_time field should represent the month and year when the bits were last modified. The Issue: For several specific device tokens, our server is receiving a last_update_time value that is set in the future. Current Date: April 2026 Returned last_update_time: 2026-12 (December 2026) Here is a response: { "body": "{\"bit0\":false,\"bit1\":true,\"last_update_time\":\"2026-12\"}", "headers": { "Server": ["Apple"], "Date": ["Thu, 02 Apr 2026 06:05:23 GMT"], "Content-Type": ["application/json; charset=UTF-8"], "Transfer-Encoding": ["chunked"], "Connection": ["keep-alive"], "X-Apple-Request-UUID": ["53e16c38-d9f7-4d58-a354-ce07a4eaa35b"], "X-Responding-Instance": ["af-bit-store-56b5b6b478-k8hnh"], "Strict-Transport-Security": ["max-age=31536000; includeSubdomains"], "X-Frame-Options": ["SAMEORIGIN"], "X-Content-Type-Options": ["nosniff"], "X-XSS-Protection": ["1; mode=block"] }, "statusCode": "OK", "statusCodeValue": 200 } Technical Details: Endpoint: https://api.development.devicecheck.apple.com/v1/query_two_bits (also occurring in Production) Response Body Example: JSON { "bit0": true, "bit1": false, "last_update_time": "2026-12" } Observations: This occurs even when our server has not sent an update_two_bits request for that specific device in the current month. Questions: Is there a known issue with the timestamp synchronization or regional database propagation for DeviceCheck? Does the last_update_time field ever represent an expiration date or any value other than the "last modified" month? Best regards,

For my api I have a domain scheme of env.service.example.com. I am trying to setup sign in with apple, however, when trying to set my return urls, the env subdomain is stripped, making the return url incorrect. For example, when I try to set https://env.service.example.com/ it is changed to https://service.example.com/ when submitted. Is there any way around this issue?

Hi everyone, I'm integrating Apple's DeviceCheck API into my app and have run into a strange issue that I can't find documented anywhere. The Problem When I call Apple's DeviceCheck query endpoint (POST https://api.devicecheck.apple.com/v1/query_two_bits), the response occasionally returns a last_update_time value that is in the future — ahead of the current server time. Example response: { "bit0": true, "bit1": false, "last_update_time": "2026-05" // future month, not yet reached } What I've Checked My server's system clock is correctly synced via NTP The JWT token I generate uses the current timestamp for the iat field This doesn't happen on every device — only on some specific devices The issue is reproducible on the same device across multiple calls Questions Is last_update_time sourced from the device's local clock at the time update_two_bits was called? Or is it stamped server-side by Apple? Could a device with an incorrectly set system clock (set to the future) cause Apple's servers to record a future last_update_time? Is there a recommended way to validate or sanitize last_update_time on the server side to handle this edge case? Has anyone else encountered this behavior? Any known workarounds? Any insight would be greatly appreciated. Thanks!

Hello everyone, We are currently preparing for an App Transfer to a new Apple Developer account due to a corporate merger. We are trying to figure out the best way to handle Apple Sign-In user migration and would love to get some advice on our proposed fallback plan. 📌 Current Situation We need to transfer our app's ownership to a new corporate entity. The app heavily relies on Apple Sign-In. The Issue: We did not collect the transfer_sub values during our initial development phase. Although we started collecting them recently, we will not have them for all existing users by the time the transfer happens. 🚨 The Risk (The 60-Day Rule) Based on Apple's documentation, even if we provide the transfer_sub, users must log into the app within 60 days of the transfer to successfully migrate their accounts. This means that users who log in after 60 days, or those whose transfer_sub is missing, will fail the Apple migration process. They will be treated as "new users" and will lose access to their existing account data. 💡 Our Proposed Custom Recovery Flow Since we cannot rely entirely on Apple's automated migration, we are planning to build a custom internal account recovery process to prevent user drop-off: A user (who failed the migration or logged in after 60 days) attempts to use Apple Sign-In on the transferred app. Since the existing account isn't linked, Apple generates a new identifier (sub), and the user enters the new sign-up flow. During the sign-up process, we enforce a mandatory identity verification step (e.g., SMS phone number verification). We query our existing user database using this verified information. If a matching existing user is found: We interrupt the sign-up process and display a prompt: "An existing account was found. We will link your account." We then update our database by mapping the new Apple sub value to their existing account record, allowing them to log in seamlessly. ❓ My Questions App Review Risk: Could this manual mapping approach—overwriting the Apple sub on an existing account based on internal identity verification—violate any Apple guidelines or result in an App Store rejection? Shared Experiences: Has anyone dealt with missing transfer_sub values or the 60-day migration limit during an App Transfer? How did you mitigate user loss? Best Practices: Are there any alternative, safer, or more recommended workarounds for this scenario?

Hi, We are implementing Platform SSO and using attestKey during registration via ASAuthorizationProviderExtensionLoginManager. Could you clarify whether the attestKey flow involves sending attestation data to an Apple server for verification (similar to App Attest in the DeviceCheck framework), or if the attestation certificate chain is generated and signed entirely on-device without any Apple server interaction? The App Attest flow is clearly documented as using Apple’s attestation service, but the Platform SSO process is less clearly described. Thank you.

I’m implementing a macOS Platform SSO extension using ASAuthorizationProviderExtensionAuthorizationRequest. In beginAuthorization, I intercept an OAuth authorize request and call: request.complete(httpAuthorizationHeaders: [ "x-psso-attestation": signedJWT ]) I also tested: request.complete(httpAuthorizationHeaders: [ "Authorization": "Bearer test-value" ]) From extension logs, I can confirm the request is intercepted correctly and the header dictionary passed into complete(httpAuthorizationHeaders:) contains the expected values. However: the header is not visible in browser devtools the header does not appear at the server / reverse proxy So the question is: Does complete(httpAuthorizationHeaders:) support arbitrary custom headers, or only a restricted set of authorization-related headers ? Is there something that I might be missing ? And if custom headers are not supported, is there any supported way for a Platform SSO extension to attach a normal HTTP header to the continued outbound request ?