Is there a way (in code or on the OAuth2 server/webpage) to specify the desired window size when using ASWebAuthenticationSession on macOS? I haven't found anything, and we would prefer the window to be narrower. For one of our users, the window is even stretched to the full screen width which looks completely broken…

My high-level goal is to add support for Game Mode in a Java game, which launches via a macOS "launcher" app that runs the actual java game as a separate process (e.g. using the java command line tool). I asked this over in the Graphics & Games section and was told this, which is why I'm reposting this here. I'm uncertain how to speak to CLI tools and Java games launched from a macOS app. These sound like security and sandboxing questions which we recommend you ask about in those sections of the forums. The system seems to decide whether to enable Game Mode based on values in the Info.plist (e.g. for LSApplicationCategoryType and GCSupportsGameMode). However, the child process can't seem to see these values. Is there a way to change that? (The rest of this post is copied from my other forums post to provide additional context.) Imagine a native macOS app that acts as a "launcher" for a Java game.** For example, the "launcher" app might use the Swift Process API or a similar method to run the java command line tool (lets assume the user has installed Java themselves) to run the game. I have seen How to Enable Game Mode. If the native launcher app's Info.plist has the following keys set: LSApplicationCategoryType set to public.app-category.games LSSupportsGameMode set to true (for macOS 26+) GCSupportsGameMode set to true The launcher itself can cause Game Mode to activate if the launcher is fullscreened. However, if the launcher opens a Java process that opens a window, then the Java window is fullscreened, Game Mode doesn't seem to activate. In this case activating Game Mode for the launcher itself is unnecessary, but you'd expect Game Mode to activate when the actual game in the Java window is fullscreened. Is there a way to get Game Mode to activate in the latter case? ** The concrete case I'm thinking of is a third-party Minecraft Java Edition launcher, but the issue can also be demonstrated in a sample project (FB13786152). It seems like the official Minecraft launcher is able to do this, though it's not clear how. (Is its bundle identifier hardcoded in the OS to allow for this? Changing a sample app's bundle identifier to be the same as the official Minecraft launcher gets the behavior I want, but obviously this is not a practical solution.)

Hi. We are writing to report a critical issue we've encountered following the recent release of iOS 26 beta 6. After updating our test devices, we discovered that our application is no longer able to establish HTTPS connections to several of our managed FQDNs. This issue was not present in beta 5 and appears to be a direct result of changes introduced in beta 6. The specific FQDNs that are currently unreachable are: d.socdm.com i.socdm.com tg.scodm.com We have reviewed the official iOS & iPadOS 26 Beta 6 Release Notes, particularly the updates related to TLS. While the notes mention changes, we have confirmed that our servers for all affected FQDNs support TLS 1.2, so we believe they should still be compliant. We have also investigated several of Apple's support documents regarding TLS connection requirements (e.g., HT214774, HT214041), but the information does not seem to apply to our situation, and we are currently unable to identify the root cause of this connection failure. https://support.apple.com/en-us/102028 https://support.apple.com/en-us/103214 Although we hope this issue might be resolved in beta 7 or later, the official release is fast approaching, and this has become a critical concern for us. Could you please provide any advice or insight into what might be causing this issue? Any guidance on potential changes in the networking or security frameworks in beta 6 that could affect TLS connections would be greatly appreciated. We have attached the relevant code snippet that triggers the error, along with the corresponding Xcode logs, for your review. Thank you for your time and assistance. #import "ViewController.h" @interface ViewController () @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; NSURL *url = [NSURL URLWithString:@"https://i.socdm.com/sdk/js/adg-script-loader-b-stg.js"]; NSMutableURLRequest *req = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:30.0]; [self sendWithRequest:req completionHandler:^(NSData *_Nullable data, NSHTTPURLResponse *_Nonnull response, NSError *_Nullable error) { if (error){ NSLog(@"Error occurred: %@", error.localizedDescription); return; }else{ NSLog(@"Success! Status Code: %ld", (long)response.statusCode); } }]; } - (void) sendWithRequest:(NSMutableURLRequest *)request completionHandler:(void (^ _Nullable)(NSData *_Nullable data, NSHTTPURLResponse *response, NSError *_Nullable error))completionHandler { NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration]; NSURLSession *session = nil; session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil]; NSURLSessionTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { [session finishTasksAndInvalidate]; NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *) response; if (error) { if (completionHandler) { completionHandler(nil, httpResponse, error); } } else { if (completionHandler) { completionHandler(data, httpResponse, nil); } } }]; [task resume]; } @end error Connection 1: default TLS Trust evaluation failed(-9807) Connection 1: TLS Trust encountered error 3:-9807 Connection 1: encountered error(3:-9807) Task <C50BB081-E1DA-40FF-A1E5-A03A2C4CB733>.<1> HTTP load failed, 0/0 bytes (error code: -1202 [3:-9807]) Task <C50BB081-E1DA-40FF-A1E5-A03A2C4CB733>.<1> finished with error [-1202] Error Domain=NSURLErrorDomain Code=-1202 "The certificate for this server is invalid. You might be connecting to a server that is pretending to be “i.socdm.com” which could put your confidential information at risk." UserInfo={NSLocalizedRecoverySuggestion=Would you like to connect to the server anyway?, _kCFStreamErrorDomainKey=3, NSErrorPeerCertificateChainKey=( "<cert(0x10621ca00) s: *.socdm.com i: GlobalSign RSA OV SSL CA 2018>", "<cert(0x106324e00) s: GlobalSign RSA OV SSL CA 2018 i: GlobalSign>" ), NSErrorClientCertificateStateKey=0, NSErrorFailingURLKey=https://i.socdm.com/sdk/js/adg-script-loader-b-stg.js, NSErrorFailingURLStringKey=https://i.socdm.com/sdk/js/adg-script-loader-b-stg.js, NSUnderlyingError=0x1062bf960 {Error Domain=kCFErrorDomainCFNetwork Code=-1202 "(null)" UserInfo={_kCFStreamPropertySSLClientCertificateState=0, kCFStreamPropertySSLPeerTrust=<SecTrustRef: 0x10609d140>, _kCFNetworkCFStreamSSLErrorOriginalValue=-9807, _kCFStreamErrorDomainKey=3, _kCFStreamErrorCodeKey=-9807, kCFStreamPropertySSLPeerCertificates=( "<cert(0x10621ca00) s: *.socdm.com i: GlobalSign RSA OV SSL CA 2018>", "<cert(0x106324e00) s: GlobalSign RSA OV SSL CA 2018 i: GlobalSign>" )}}, _NSURLErrorRelatedURLSessionTaskErrorKey=( "LocalDataTask <C50BB081-E1DA-40FF-A1E5-A03A2C4CB733>.<1>" ), _kCFStreamErrorCodeKey=-9807, _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask <C50BB081-E1DA-40FF-A1E5-A03A2C4CB733>.<1>, NSURLErrorFailingURLPeerTrustErrorKey=<SecTrustRef: 0x10609d140>, NSLocalizedDescription=The certificate for this server is invalid. You might be connecting to a server that is pretending to be “i.socdm.com” which could put your confidential information at risk.} Error occurred: The certificate for this server is invalid. You might be connecting to a server that is pretending to be “i.socdm.com” which could put your confidential information at risk. 折りたたむ

Hello, I have encountered several challenges related to System Integrity Protection (SIP) state detection and code signing requirements. I would like to seek clarification and guidance on the proper approach to programmatically determine the SIP state. Here are the issues I’ve encountered: XPC Code Signing Check APIs: APIs like setCodeSigningRequirement and setConnectionCodeSigningRequirement do not work when SIP disabled and that's ok given what SIP is. LaunchCodeRequirement API: When using Process.launchRequirement, the LaunchCodeRequirement API does not function anymore when SIP disabled. The IsSIPProtected requirement behaves in a way that is not clearly documented -- it appears to only apply to pre-installed Apple apps. Legacy APIs: Older APIs like SecCodeCheckValidity are likely to be non-functional, though I haven’t had the chance to validate this yet. Private API Concerns: So to mitigate those limitations I prefer my app to not even try to connect to untrusted XPC or launch untrusted Processes when SIP is disabled. The only way to determine SIP state I could find is a low-level C function csr_get_active_config. However, this function is not declared in any publicly available header file, indicating that it is a private API. Since private APIs cannot be used in App Store-distributed apps and are best avoided for Developer ID-signed apps, this does not seem like a viable solution. Given these limitations, what is the recommended and proper approach to programmatically determine the SIP state in a macOS application? Any insights or guidance would be greatly appreciated. Thank you!

Hi Apple Devs, For our app, we utilize passkeys for account creation (not MFA). This is mainly for user privacy, as there is 0 PII associated with passkey account creation, but it additionally also satisfies the 4.8: Login Services requirement for the App Store. However, we're getting blocked in Apple Review. Because the AASA does not get fetched immediately upon app install, the reviewers are not able to create an account immediately via passkeys, and then they reject the build. I'm optimistic I can mitigate the above. But even if we pass Apple Review, this is a pretty catastrophic issue for user security and experience. There are reports that 5% of users cannot create passkeys immediately (https://developer.apple.com/forums/thread/756740). That is a nontrivial amount of users, and this large of an amount distorts how app developers design onboarding and authentication flows towards less secure experiences: App developers are incentivized to not require MFA setup on account creation because requiring it causes significant churn, which is bad for user security. If they continue with it anyways, for mitigation, developers are essentially forced to add in copy into their app saying something along the lines of "We have no ability to force Apple to fetch the config required to continue sign up, so try again in a few minutes, you'll just have to wait." You can't even implement a fallback method. There's no way to check if the AASA is available before launching the ASAuthorizationController so you can't mitigate a portion of users encountering an error!! Any app that wants to use the PRF extension to encrypt core functionality (again, good for user privacy) simply cannot exist because the app simply does not work for an unspecified amount of time for a nontrivial portion of users. It feels like a. Apple should provide a syscall API that we can call to force SWCD to verify the AASA or b. implement a config based on package name for the app store such that the installation will immediately include a verified AASA from Apple's CDN. Flicking the config on would require talking with Apple. If this existed, this entire class of error would go away. It feels pretty shocking that there isn't a mitigation in place for this already given that it incentivizes app developers to pursue strictly less secure and less private authentication practices.

Since Sun 15th Jun 04:30 (UTC+7) we received lots of following error that causes our device test failure. Could Apple please investigate further? ############################# Operations could not be completed. (com.apple.devicecheck.error error 4.) (serverUnavailable)

I have an app (currently not released on App Store) which runs on both iOS and macOS. The app has widgets for both iOS and macOS which uses user preference (set in app) into account while showing data. Before upgrading to macOS 15 (until Sonoma) widgets were working fine and app was launching correctly, but after upgrading to macOS 15 Sequoia, every time I launch the app it give popup saying '“Kontest” would like to access data from other apps. Keeping app data separate makes it easier to manage your privacy and security.' and also widgets do not get user preferences and throw the same type of error on Console application when using logging. My App group for both iOS and macOS is 'group.com.xxxxxx.yyyyy'. I am calling it as 'UserDefaults(suiteName: Constants.userDefaultsGroupID)!.bool(forKey: "shouldFetchAllEventsFromCalendar")'. Can anyone tell, what am I doing wrong here?

Hi all, I’m building a password manager app for iOS. The app implements an ASCredentialProviderExtension and has the entitlement com.apple.developer.authentication-services.autofill-credential-provider. From a UX perspective, I’d like to help users enable my app under: Settings → General → AutoFill & Passwords What I’ve observed: Calling UIApplication.openSettingsURLString only opens my app’s own Settings page, not the AutoFill list. Some apps (e.g. Google Authenticator) appear to redirect users directly into the AutoFill Passwords & Passkeys screen when you tap “Enable AutoFill.” 1Password goes even further: when you tap “Enable” in 1Password App, it shows a system pop-up, prompts for Face ID, and then enables 1Password as the AutoFill provider without the user ever leaving the app. Questions: Is there a public API or entitlement that allows apps to deep-link users directly to the AutoFill Passwords & Passkeys screen? Is there a supported API to programmatically request that my app be enabled as an AutoFill provider (similar to what 1Password seems to achieve)? If not, what is the recommended approach for guiding users through this flow? Thanks in advance!

In my app, I use SecItem to store some data in the Keychain. I’d like to know — when a user sets up a new iPhone and transfers data from the old device, will those Keychain items be migrated or synced to the new device?

Testing my security agent plugin on Tahoe and find that when unlocking the screen, I now get an extra window that pops up over the SFAuthorizationPluginView that says "macOS You must enter a password to unlock the screen" with a Cancel (enabled) and OK button (disabled). See the attached photo. This is new with Tahoe. When unlocking the screen, I see the standard username and password entry view and I enter my password and click OK. That is when this new view appears. I can only click cancel so there is no way to complete authenticating.

Hi, We're in the process of implementing Apple's App Integrity, but am getting stalled due to missing documents. Can anyone assist with this? We've been following https://developer.apple.com/documentation/devicecheck/validating-apps-that-connect-to-your-server to make the necessary updates, but have come up short with where the document references decoding the Attestation Object. Can we get more information here and how the decoding process work?

Hello everyone, I've noticed some unusual behavior while debugging my application on the iOS 26 beta. My standard testing process relies on the App Tracking Transparency (ATT) authorization status being reset whenever I uninstall and reinstall my app. This is crucial for me to test the permission flow. However, on the current beta, I've observed the following: 1 I installed my app on a device running the iOS 26 beta for the first time. The ATTrackingManager.requestTrackingAuthorization dialog appeared as expected. 2 I completely uninstalled the application. 3 I then reinstalled the app. Unexpected Result: The tracking permission dialog did not appear. And more importantly, the device's advertisingIdentifier appears to have remained unchanged. This is highly unusual, as the IDFA is expected to be reset with a fresh app installation. My question: Is this an intentional change, and is there a fundamental shift in how the operating system handles the persistence of the IDFA or the authorization status? Or could this be a bug in the iOS 26 beta? Any information or confirmation on this behavior would be greatly appreciated.

Issue Summary I'm encountering a DCError.invalidInput error when calling DCAppAttestService.shared.generateAssertion() in my App Attest implementation. This issue affects only a small subset of users - the majority of users can successfully complete both attestation and assertion flows without any issues. According to Apple Engineer feedback, there might be a small implementation issue in my code. Key Observations Success Rate: ~95% of users complete the flow successfully Failure Pattern: The remaining ~5% consistently fail at assertion generation Key Length: Logs show key length of 44 characters for both successful and failing cases Consistency: Users who experience the error tend to experience it consistently Platform: Issue observed across different iOS versions and device types Environment iOS App Attest implementation Using DCAppAttestService for both attestation and assertion Custom relying party server communication Issue affects ~5% of users consistently Key Implementation Details 1. Attestation Flow (Working) The attestation process works correctly: // Generate key and attest (successful for all users) self.attestService.generateKey { keyId, keyIdError in guard keyIdError == nil, let keyId = keyId else { return completionHandler(.failure(.dcError(keyIdError as! DCError))) } // Note: keyId length is consistently 44 characters for both successful and failing users // Attest key with Apple servers self.attestKey(keyId, clientData: clientData) { result in // ... verification with RP server // Key is successfully stored for ALL users (including those who later fail at assertion) } } 2. Assertion Flow (Failing for ~5% of Users with invalidInput) The assertion generation fails for a consistent subset of users: // Get assertion data from RP server self.assertRelyingParty.getAssertionData(kid, with: data) { result in switch result { case .success(let receivedData): let session = receivedData.session let clientData = receivedData.clientData let hash = clientData.toSHA256() // SHA256 hash of client data // THIS CALL FAILS WITH invalidInput for ~5% of users // Same keyId (44 chars) that worked for attestation self.attestService.generateAssertion(kid, clientDataHash: hash) { assertion, err in guard err == nil, let assertion = assertion else { // Error: DCError.invalidInput if let err = err as? DCError, err.code == .invalidKey { return reattestAndAssert(.invalidKey, completionHandler) } else { return completionHandler(.failure(.dcError(err as! DCError))) } } // ... verification logic } } } 3. Client Data Structure Client data JSON structure (identical for successful and failing users): // For attestation (works for all users) let clientData = ["challenge": receivedData.challenge] // For assertion (fails for ~5% of users with same structure) var clientData = ["challenge": receivedData.challenge] if let data = data { // Additional data for assertion clientData["account"] = data["account"] clientData["amount"] = data["amount"] } 4. SHA256 Hash Implementation extension Data { public func toSHA256() -> Data { return Data(SHA256.hash(data: self)) } } 5. Key Storage Implementation Using UserDefaults for key storage (works consistently for all users): private let keyStorageTag = "app-attest-keyid" func setKey(_ keyId: String) -> Result<(), KeyStorageError> { UserDefaults.standard.set(keyId, forKey: keyStorageTag) return .success(()) } func getKey() -> Result<String?, KeyStorageError> { let keyId = UserDefaults.standard.string(forKey: keyStorageTag) return .success(keyId) } Questions User-Specific Factors: Since this affects only ~5% of users consistently, could there be device-specific, iOS version-specific, or account-specific factors that cause invalidInput? Key State Validation: Is there any way to validate the state of an attested key before calling generateAssertion()? The key length (44 chars) appears normal for both successful and failing cases. Keychain vs UserDefaults: Could the issue be related to using UserDefaults instead of Keychain for key storage? Though this works for 95% of users. Race Conditions: Could there be subtle race conditions or timing issues that only affect certain users/devices? Error Recovery: Is there a recommended way to handle this error? Should we attempt re-attestation for these users? Additional Context & Debugging Attempts Consistent Failure: Users who experience this error typically experience it on every attempt Key Validation: Both successful and failing users have identical key formats (44 character strings) Device Diversity: Issue observed across different device models and iOS versions Server Logs: Our server successfully provides challenges and processes attestation for all users Re-attestation: Forcing re-attestation sometimes resolves the issue temporarily, but it often recurs The fact that 95% of users succeed with identical code suggests there might be some environmental or device-specific factor that we're not accounting for. Any insights into what could cause invalidInput for a subset of users would be invaluable.

We are facing an issue with Keychain sharing across our apps after our Team ID was updated. Below are the steps we have already tried and the current observations: Steps we have performed so far: After our Team ID changed, we opened and re-saved all the provisioning profiles. We created a Keychain Access Group: xxxx.net.soti.mobicontrol (net.soti.mobicontrol is one bundle id of one of the app) and added it to the entitlements of all related apps. We are saving and reading certificates using this access group only. Below is a sample code snippet we are using for the query: [genericPasswordQuery setObject:(id)kSecClassGenericPassword forKey:(id)kSecClass]; [genericPasswordQuery setObject:identifier forKey:(id)kSecAttrGeneric]; [genericPasswordQuery setObject:accessGroup forKey:(id)kSecAttrAccessGroup]; [genericPasswordQuery setObject:(id)kSecMatchLimitOne forKey:(id)kSecMatchLimit]; [genericPasswordQuery setObject:(id)kCFBooleanTrue forKey:(id)kSecReturnAttributes]; Issues we are facing: Keychain items are not being shared consistently across apps. We receive different errors at different times: Sometimes errSecDuplicateItem (-25299), even when there is no item in the Keychain. Sometimes it works in a debug build but fails in Ad Hoc / TestFlight builds. The behavior is inconsistent and unpredictable. Expectation / Clarification Needed from Apple: Are we missing any additional configuration steps after the Team ID update? Is there a known issue with Keychain Access Groups not working correctly in certain build types (Debug vs AdHoc/TestFlight)? Guidance on why we are intermittently getting -25299 and how to properly reset/re-add items in the Keychain. Any additional entitlement / provisioning profile configuration that we should double-check. Request you to please raise a support ticket with Apple Developer Technical Support including the above details, so that we can get guidance on the correct setup and resolve this issue.

I regularly see folks confused by the difference in behaviour of app groups between macOS and iOS. There have been substantial changes in this space recently. While much of this is now covered in the official docs (r. 92322409), I’ve updated this post to go into all the gory details. If you have questions or comments, start a new thread with the details. Put it in the App & System Services > Core OS topic area and tag it with Code Signing and Entitlements. Oh, and if your question is about app group containers, also include Files and Storage. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" App Groups: macOS vs iOS: Working Towards Harmony There are two styles of app group ID: iOS-style app group IDs start with group., for example, group.eskimo1.test. macOS-style app group IDs start with your Team ID, for example, SKMME9E2Y8.eskimo1.test. This difference has been the source of numerous weird problems over the years. Starting in Feb 2025, iOS-style app group IDs are fully supported on macOS for all product types [1]. If you’re writing new code that uses app groups, use an iOS-style app group ID. If you have existing code that uses a macOS-style app group ID, consider how you might transition to the iOS style. IMPORTANT The Feb 2025 changes aren’t tied to an OS release but rather to a Developer website update. For more on this, see Feb 2025 Changes, below. [1] If your product is a standalone executable, like a daemon or agent, wrap it in an app-like structure, as explained in Signing a daemon with a restricted entitlement. iOS-Style App Group IDs An iOS-style app group ID has the following features: It starts with the group. prefix, for example, group.eskimo1.test. You allocate it on the Developer website. This assigns the app group ID to your team. You then claim access to it by listing it in the App Groups entitlement (com.apple.security.application-groups) entitlement. That claim must be authorised by a provisioning profile [1]. The Developer website will only let you include your team’s app group IDs in your profile. For more background on provisioning profiles, see TN3125 Inside Code Signing: Provisioning Profiles. iOS-style app group IDs originated on iOS with iOS 3.0. They’ve always been supported on iOS’s child platforms (iPadOS, tvOS, visionOS, and watchOS). On the Mac: They’ve been supported by Mac Catalyst since that technology was introduced. Likewise for iOS Apps on Mac. Starting in Feb 2025, they’re supported for other Mac products. [1] Strictly speaking macOS does not require that, but if your claim is not authorised by a profile then you might run into other problems. See Entitlements-Validated Flag, below. macOS-Style App Group IDs A macOS-style app group ID has the following features: It should start with your Team ID [1], for example, SKMME9E2Y8.eskimo1.test. It can’t be explicitly allocated on the Developer website. Code that isn’t sandboxed doesn’t need to claim the app group ID in the App Groups entitlement. [2] To use an app group, claim the app group ID in the App Groups entitlement. The App Groups entitlement is not restricted on macOS, meaning that this claim doesn’t need to be authorised by a provisioning profile [3]. However, if you claim an app group ID that’s not authorised in some way, you might run into problems. More on that later in this post. If you submit an app to the Mac App Store, the submission process checks that your app group IDs make sense, that is, they either start with your Team ID (macOS style) or are assigned to your team (iOS style). [1] This is “should” because, historically, macOS has not actually required it. However, that’s now changing, with things like app group container protection. [2] This was true prior to macOS 15. It may still technically be true in macOS 15 and later, but the most important thing, access to the app group container, requires the entitlement because of app group container protection. [3] Technically it’s a validation-required entitlement, something that we’ll come back to in the Entitlements-Validated Flag section. Feb 2025 Changes On 21 Feb 2025 we rolled out a change to the Developer website that completes the support for iOS-style app group IDs on the Mac. Specifically, it’s now possible to create a Mac provisioning profile that authorises the use of an iOS-style app group ID. Note This change doesn’t affect Mac Catalyst or iOS Apps on Mac, which have always been able to use iOS-style app group IDs on the Mac. Prior to this change it was possible to use an iOS-style app group ID on the Mac but that might result in some weird behaviour. Later sections of this post describe some of those problems. Of course, that information is now only of historical interest because, if you’re using an iOS-style app group, you can and should authorise that use with a provisioning profile. We also started seeding Xcode 16.3, which has since been release. This is aware of the Developer website change, and its Signing & Capabilities editor actively encourages you to use iOS-style app groups IDs in all products. Note This Xcode behaviour is the only option for iOS and its child platforms. With Xcode 16.3, it’s now the default for macOS as well. If you have existing project, enable this behaviour using the Register App Groups build setting. Finally, we updated a number of app group documentation pages, including App Groups entitlement and Configuring app groups. Crossing the Streams In some circumstances you might need to have a single app that accesses both an iOS- and a macOS-style app group. For example: You have a macOS app. You want to migrate to an iOS-style app group ID, perhaps because you want to share an app group container with a Mac Catalyst app. But you also need to access existing content in a container identified by a macOS-style app group ID. Historically this caused problems (FB16664827) but, as of Jun 2025, this is fully supported (r. 148552377). When the Developer website generates a Mac provisioning profile for an App ID with the App Groups capability, it automatically adds TEAM_ID.* to the list of app group IDs authorised by that profile (where TEAM_ID is your Team ID). This allows the app to claim access to every iOS-style app group ID associated with the App ID and any macOS-style app group IDs for that team. This helps in two circumstances: It avoids any Mac App Store Connect submission problems, because App Store Connect can see that the app’s profile authorises its use of all the it app group IDs it claims access to. Outside of App Store — for example, when you directly distribute an app using Developer ID signing — you no longer have to rely on macOS granting implicit access to macOS-style app group IDs. Rather, such access is explicitly authorised by your profile. That ensures that your entitlements remain validated, as discussed in the Entitlements-Validated Flag, below. A Historical Interlude These different styles of app group IDs have historical roots: On iOS, third-party apps have always used provisioning profiles, and thus the App Groups entitlement is restricted just like any other entitlement. On macOS, support for app groups was introduced before macOS had general support for provisioning profiles [1], and thus the App Groups entitlement is unrestricted. The unrestricted nature of this entitlement poses two problems. The first is accidental collisions. How do you prevent folks from accidentally using an app group ID that’s in use by some other developer? On iOS this is easy: The Developer website assigns each app group ID to a specific team, which guarantees uniqueness. macOS achieved a similar result by using the Team ID as a prefix. The second problem is malicious reuse. How do you prevent a Mac app from accessing the app group containers of some other team? Again, this isn’t an issue on iOS because the App Groups entitlement is restricted. On macOS the solution was for the Mac App Store to prevent you from publishing an app that used an app group ID that’s used by another team. However, this only works for Mac App Store apps. Directly distributed apps were free to access app group containers of any other app. That was considered acceptable back when the Mac App Store was first introduced. That’s no longer the case, which is why macOS 15 introduced app group container protection. See App Group Container Protection, below. [1] I’m specifically talking about provisioning profiles for directly distributed apps, that is, apps using Developer ID signing. Entitlements-Validated Flag The fact that the App Groups entitlement is unrestricted on macOS is, when you think about it, a little odd. The purpose of entitlements is to gate access to functionality. If an entitlement isn’t restricted, it’s not much of a gate! For most unrestricted entitlements that’s not a problem. Specifically, for both the App Sandbox and Hardened Runtime entitlements, those are things you opt in to, so macOS is happy to accept the entitlement at face value. After all, if you want to cheat you can just not opt in [1]. However, this isn’t the case for the App Groups entitlement, which actually gates access to functionality. Dealing with this requires macOS to walk a fine line between security and compatibility. Part of that solution is the entitlements-validated flag. When a process runs an executable, macOS checks its entitlements. There are two categories: Restricted entitlements must be authorised by a provisioning profile. If your process runs an executable that claims a restricted entitlement that’s not authorised by a profile, the system traps. Unrestricted entitlements don’t have to be authorised by a provisioning profile; they can be used by any code at any time. However, the App Groups entitlement is a special type of unrestricted entitlement called a validation-required entitlement. If a process runs an executable that claims a validation-required entitlement and that claim is not authorised by a profile, the system allows the process to continue running but clears its entitlements-validated flag. Some subsystems gate functionality on the entitlements-validated flag. For example, the data protection keychain uses entitlements as part of its access control model, but refuses to honour those entitlements if the entitlement-validated flag has been cleared. Note If you’re curious about this flag, use the procinfo subcommand of launchctl to view it. For example: % sudo launchctl procinfo `pgrep Test20230126` … code signing info = valid … entitlements validated … If the flag has been cleared, this line will be missing from the code signing info section. Historically this was a serious problem because it prevented you from creating an app that uses both app groups and the data protection keychain [2] (r. 104859788). Fortunately that’s no longer an issue because the Developer website now lets you include the App Groups entitlement in macOS provisioning profiles. [1] From the perspective of macOS checking entitlements at runtime. There are other checks: The App Sandbox is mandatory for Mac App Store apps, but that’s checked when you upload the app to App Store Connect. Directly distributed apps must be notarised to pass Gatekeeper, and the notary service requires that all executables enable the hardened runtime. [2] See TN3137 On Mac keychain APIs and implementations for more about the data protection keychain. App Groups and the Keychain The differences described above explain a historical oddity associated with keychain access. The Sharing access to keychain items among a collection of apps article says: Application groups When you collect related apps into an application group using the App Groups entitlement, they share access to a group container, and gain the ability to message each other in certain ways. You can use app group names as keychain access group names, without adding them to the Keychain Access Groups entitlement. On iOS this makes a lot of sense: The App Groups entitlement is a restricted entitlement on iOS. The Developer website assigns each iOS-style app group ID to a specific team, which guarantees uniqueness. The required group. prefix means that these keychain access groups can’t collide with other keychain access groups, which all start with an App ID prefix (there’s also Apple-only keychain access groups that start with other prefixes, like apple). However, this didn’t work on macOS [1] because the App Groups entitlement is unrestricted there. However, with the Feb 2025 changes it should now be possible to use an iOS-style app group ID as a keychain access group on macOS. Note I say “should” because I’ve not actually tried it (-: Keep in mind that standard keychain access groups are protected the same way on all platforms, using the restricted Keychain Access Groups entitlement (keychain-access-groups). [1] Except for Mac Catalyst apps and iOS Apps on Mac. Not Entirely Unsatisfied When you launch a Mac app that uses app groups you might see this log entry: type: error time: 10:41:35.858009+0000 process: taskgated-helper subsystem: com.apple.ManagedClient category: ProvisioningProfiles message: com.example.apple-samplecode.Test92322409: Unsatisfied entitlements: com.apple.security.application-groups Note The exact format of that log entry, and the circumstances under which it’s generated, varies by platform. On macOS 13.0.1 I was able to generate it by running a sandboxed app that claims a macOS-style app group ID in the App Groups entitlement and also claims some other restricted entitlement. This looks kinda worrying and can be the source of problems. It means that the App Groups entitlement claims an entitlement that’s not authorised by a provisioning profile. On iOS this would trap, but on macOS the system allows the process to continue running. It does, however, clear the entitlements-validate flag. See Entitlements-Validated Flag for an in-depth discussion of this. The easiest way to avoid this problem is to authorise your app group ID claims with a provisioning profile. If there’s some reason you can’t do that, watch out for potential problems with: The data protection keychain — See the discussion of that in the Entitlements-Validated Flag and App Groups and the Keychain sections, both above. App group container protection — See App Group Container Protection, below. App Group Container Protection macOS 15 introduced app group container protection. To access an app group container without user intervention: Claim access to the app group by listing its ID in the App Groups entitlement. Locate the container by calling the containerURL(forSecurityApplicationGroupIdentifier:) method. Ensure that at least one of the following criteria are met: Your app is deployed via the Mac App Store (A). Or via TestFlight when running on macOS 15.1 or later (B). Or the app group ID starts with your app’s Team ID (C). Or your app’s claim to the app group is authorised by a provisioning profile embedded in the app (D) [1]. If your app doesn’t follow these rules, the system prompts the user to approve its access to the container. If granted, that consent applies only for the duration of that app instance. For more on this, see: The System Integrity Protection section of the macOS Sequoia 15 Release Notes The System Integrity Protection section of the macOS Sequoia 15.1 Release Notes WWDC 2024 Session 10123 What’s new in privacy, starting at 12:23 The above criteria mean that you rarely run into the app group authorisation prompt. If you encounter a case where that happens, feel free to start a thread here on DevForums. See the top of this post for info on the topic and tags to use. Note Prior to the Feb 2025 change, things generally worked out fine when you app was deployed but you might’ve run into problems during development. That’s no longer the case. [1] This is what allows Mac Catalyst and iOS Apps on Mac to work. Revision History 2025-08-12 Added a reference to the Register App Groups build setting. 2025-07-28 Updated the Crossing the Streams section for the Jun 2025 change. Made other minor editorial changes. 2025-04-16 Rewrote the document now that iOS-style app group IDs are fully supported on the Mac. Changed the title from App Groups: macOS vs iOS: Fight! to App Groups: macOS vs iOS: Working Towards Harmony 2025-02-25 Fixed the Xcode version number mentioned in yesterday’s update. 2025-02-24 Added a quick update about the iOS-style app group IDs on macOS issue. 2024-11-05 Further clarified app group container protection. Reworked some other sections to account for this new reality. 2024-10-29 Clarified the points in App Group Container Protection. 2024-10-23 Fleshed out the discussion of app group container protection on macOS 15. 2024-09-04 Added information about app group container protection on macOS 15. 2023-01-31 Renamed the Not Entirely Unsatisfactory section to Not Entirely Unsatisfied. Updated it to describe the real impact of that log message. 2022-12-12 First posted.

Greetings, We are struggling to implement device binding according to your documentation. We are generation a nonce value in backend like this: public static String generateNonce(int byteLength) { byte[] randomBytes = new byte[byteLength]; new SecureRandom().nextBytes(randomBytes); return Base64.getUrlEncoder().withoutPadding().encodeToString(randomBytes); } And our mobile client implement the attestation flow like this: @implementation AppAttestModule - (NSData *)sha256FromString:(NSString *)input { const char *str = [input UTF8String]; unsigned char result[CC_SHA256_DIGEST_LENGTH]; CC_SHA256(str, (CC_LONG)strlen(str), result); return [NSData dataWithBytes:result length:CC_SHA256_DIGEST_LENGTH]; } RCT_EXPORT_MODULE(); RCT_EXPORT_METHOD(generateAttestation:(NSString *)nonce resolver:(RCTPromiseResolveBlock)resolve rejecter:(RCTPromiseRejectBlock)reject) { if (@available(iOS 14.0, *)) { DCAppAttestService *service = [DCAppAttestService sharedService]; if (![service isSupported]) { reject(@"not_supported", @"App Attest is not supported on this device.", nil); return; } NSData *nonceData = [self sha256FromString:nonce]; NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; NSString *savedKeyId = [defaults stringForKey:@"AppAttestKeyId"]; NSString *savedAttestation = [defaults stringForKey:@"AppAttestAttestationData"]; void (^resolveWithValues)(NSString *keyId, NSData *assertion, NSString *attestationB64) = ^(NSString *keyId, NSData *assertion, NSString *attestationB64) { NSString *assertionB64 = [assertion base64EncodedStringWithOptions:0]; resolve(@{ @"nonce": nonce, @"signature": assertionB64, @"deviceType": @"IOS", @"attestationData": attestationB64 ?: @"", @"keyId": keyId }); }; void (^handleAssertion)(NSString *keyId, NSString *attestationB64) = ^(NSString *keyId, NSString *attestationB64) { [service generateAssertion:keyId clientDataHash:nonceData completionHandler:^(NSData *assertion, NSError *assertError) { if (!assertion) { reject(@"assertion_error", @"Failed to generate assertion", assertError); return; } resolveWithValues(keyId, assertion, attestationB64); }]; }; if (savedKeyId && savedAttestation) { handleAssertion(savedKeyId, savedAttestation); } else { [service generateKeyWithCompletionHandler:^(NSString *keyId, NSError *keyError) { if (!keyId) { reject(@"keygen_error", @"Failed to generate key", keyError); return; } [service attestKey:keyId clientDataHash:nonceData completionHandler:^(NSData *attestation, NSError *attestError) { if (!attestation) { reject(@"attestation_error", @"Failed to generate attestation", attestError); return; } NSString *attestationB64 = [attestation base64EncodedStringWithOptions:0]; [defaults setObject:keyId forKey:@"AppAttestKeyId"]; [defaults setObject:attestationB64 forKey:@"AppAttestAttestationData"]; [defaults synchronize]; handleAssertion(keyId, attestationB64); }]; }]; } } else { reject(@"ios_version", @"App Attest requires iOS 14+", nil); } } @end For validation we are extracting the nonce from the certificate like this: private static byte[] extractNonceFromAttestationCert(X509Certificate certificate) throws IOException { byte[] extensionValue = certificate.getExtensionValue("1.2.840.113635.100.8.2"); if (Objects.isNull(extensionValue)) { throw new IllegalArgumentException("Apple App Attest nonce extension not found in certificate."); } ASN1Primitive extensionPrimitive = ASN1Primitive.fromByteArray(extensionValue); ASN1OctetString outerOctet = ASN1OctetString.getInstance(extensionPrimitive); ASN1Sequence sequence = (ASN1Sequence) ASN1Primitive.fromByteArray(outerOctet.getOctets()); ASN1TaggedObject taggedObject = (ASN1TaggedObject) sequence.getObjectAt(0); ASN1OctetString nonceOctet = ASN1OctetString.getInstance(taggedObject.getObject()); return nonceOctet.getOctets(); } And for the verification we are using this method: private OptionalMethodResult<Void> verifyNonce(X509Certificate certificate, String expectedNonce, byte[] authData) { byte[] expectedNonceHash; try { byte[] nonceBytes = MessageDigest.getInstance("SHA-256").digest(expectedNonce.getBytes()); byte[] combined = ByteBuffer.allocate(authData.length + nonceBytes.length).put(authData).put(nonceBytes).array(); expectedNonceHash = MessageDigest.getInstance("SHA-256").digest(combined); } catch (NoSuchAlgorithmException e) { log.error("Error while validations iOS attestation: {}", e.getMessage(), e); return OptionalMethodResult.ofError(deviceBindError.getChallengeNotMatchedError()); } byte[] actualNonceFromCert; try { actualNonceFromCert = extractNonceFromAttestationCert(certificate); } catch (Exception e) { log.error("Error while extracting nonce from certificate: {}", e.getMessage(), e); return OptionalMethodResult.ofError(deviceBindError.getChallengeNotMatchedError()); } if (!Arrays.equals(expectedNonceHash, actualNonceFromCert)) { return OptionalMethodResult.ofError(deviceBindError.getChallengeNotMatchedError()); } return OptionalMethodResult.empty(); } But the values did not matched. What are we doing wrong here? Thanks.

Can someone please guide me on the entire process of integrating ads in an IOS application using google's admob sdk? Not related to code but things related to Apple's privacy policy. Which options do need to select or specify in my app profile's privacy policy (identifier) section?

We are interested in using a hardware-bound key in a launch daemon. In a previous post, Quinn explicitly told me this is not possible to use an SE keypair outside of the system context and my reading of the Apple documentation also supports that. That said, we have gotten the following key-creation and persistence flow to work, so we have some questions as to how this fits in with the above. (1) In a launch daemon (running thus as root), we do: let key = SecureEnclave.P256.Signing.PrivateKey() (2) We then use key.dataRepresentation to store a reference to the key in the system keychain as a kSecClassGenericPassword. (3) When we want to use the key, we fetch the data representation from system keychain and we "rehydrate" the key using: SecureEnclave.P256.Signing.PrivateKey(dataRepresentation: data) (4) We then use the output of the above to sign whatever we want. My questions: in the above flow, are we actually getting a hardware-bound key from the Secure Enclave or is this working because it's actually defaulting to a non-hardware-backed key? if it is an SE key, is it that the Apple documentation stating that you can only use the SE with the Data Protection Keychain in the user context is outdated (or wrong)? does the above work, but is not an approach sanctioned by Apple? Any feedback on this would be greatly appreciated.

For security reasons, my application needs to prohibit external devices. If it is determined that the current phone is connected to any external devices, including non MFI authenticated devices, the app will exit. Please tell me how to do it? Thanks for your help.