Hi Forum, We’re building a security-focused SDK for iOS that includes SIM Binding and SIM Swap detection to help prevent fraud and unauthorised device access, particularly in the context of banking and fintech apps. We understand that iOS limits access to SIM-level data, and that previously available APIs (such as those in CoreTelephony, now deprecated from iOS 16 onwards) provide only limited support for these use cases. We have a few questions and would appreciate any guidance from the community or Apple engineers: Q1. Are there any best practices or Apple-recommended approaches for binding a SIM to a device or user account? Q2. Is there a reliable way to detect a SIM swap when the app is not running (e.g., via system callback, entitlement, or background mechanism)? Q3. Are fields like GID1, GID2, or ICCID accessible through any public APIs or entitlements (such as com.apple.coretelephony.IdentityAccess)? If so, what is the process to request access? Q4. For dual SIM and eSIM scenarios, is there a documented approach to identify which SIM is active or whether a SIM slot has changed? Q5. In a banking or regulated environment, is it possible for an app vendor (e.g., a bank) to acquire certain entitlements from Apple and securely expose that information to a security SDK like ours? What would be the compliant or recommended way to structure such a partnership? Thanks in advance for any insights!

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.

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!

Hi team, is there a native way to detect if a change has been made to biometrics using FaceID or TouchID? Thanks in advance.

Hi, I have a set of plugins which are registered for login. One of them is a custom ui view for the login screen. The scenario: 1.DisableFDEAutoLogin is false. 2.The User logs in to the file vault login screen. 3.The security plugins are activated, and working. 4.We get any kind of an error from the plugins, and therefore the login fails. 5.We get a native login screen, after the denial of authorization. 6.In case that DisableFDEAutoLogin is true, I do get the custom login screen, after the file vault login. My question: Why dont I see the custom login screen, after the auto login fails? Cheers Sivan

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.

Hi Team, We are trying to understand deep sleep behaviour, can you please help us clarifying on the below questions: When will we configure Hibernate 25, is it valid for M series MacBooks? Is Hibernate 25 called deep sleep mode? What are the settings I need to do on Mac, to make my Mac go in to deep sleep? When awakening from deep sleep , what would be macOS system behaviour? If we have custom SFAuthorization plug in at system.login.screensaver, what would be the behaviour with deep sleep?

For testing purposes we have code that calls SecTrustEvaluateAsyncWithError() with a trust object containing a hardcoded leaf certificate and the corresponding intermediate certificate required to form a valid chain. Because the leaf certificate has since expired we pass a date in the past via SecTrustSetVerifyDate() at wich the certificate was still valid, but trust evaluation fails: Error Domain=NSOSStatusErrorDomain Code=-67825 "“<redacted>” certificate is not standards compliant" UserInfo={NSLocalizedDescription=“<redacted>” certificate is not standards compliant, NSUnderlyingError=0x600000c282a0 {Error Domain=NSOSStatusErrorDomain Code=-67825 "Certificate 0 “<redacted>” has errors: Certificate Transparency validation required for this use;" UserInfo={NSLocalizedDescription=Certificate 0 “<redacted>” has errors: Certificate Transparency validation required for this use;}}} I know that App Transport Security enforces Certificate Transparency by default, but is there a way around that here?

I’m developing an iOS application and aiming to install a PKCS#12 (.p12) certificate into the com.apple.token keychain access group so that Microsoft Edge for iOS, managed via MDM/Intune, can read and use it for client certificate authentication. I’m attempting to save to the com.apple.token keychain access group, but I’m getting error -34018 (errSecMissingEntitlement) and the item isn’t saved. This occurs on both a physical device and the simulator. I’m using SecItemAdd from the Security framework to store it. Is this the correct approach? https://developer.apple.com/documentation/security/secitemadd(::) I have added com.apple.token to Keychain Sharing. I have also added com.apple.token to the app’s entitlements. Here is the code I’m using to observe this behavior: public static func installToTokenGroup(p12Data: Data, password: String) throws -> SecIdentity { // First, import the P12 to get the identity let options: [String: Any] = [ kSecImportExportPassphrase as String: password ] var items: CFArray? let importStatus = SecPKCS12Import(p12Data as CFData, options as CFDictionary, &items) guard importStatus == errSecSuccess, let array = items as? [[String: Any]], let dict = array.first else { throw NSError(domain: NSOSStatusErrorDomain, code: Int(importStatus), userInfo: [NSLocalizedDescriptionKey: "Failed to import P12: \(importStatus)"]) } let identity = dict[kSecImportItemIdentity as String] as! SecIdentity let addQuery: [String: Any] = [ kSecClass as String: kSecClassIdentity, kSecValueRef as String: identity, kSecAttrLabel as String: kSecAttrAccessGroupToken, kSecAttrAccessible as String: kSecAttrAccessibleAfterFirstUnlock, kSecAttrAccessGroup as String: kSecAttrAccessGroupToken ] let status = SecItemAdd(addQuery as CFDictionary, nil) if status != errSecSuccess && status != errSecDuplicateItem { throw NSError(domain: NSOSStatusErrorDomain, code: Int(status), userInfo: [NSLocalizedDescriptionKey: "Failed to add to token group: \(status)"]) } return identity }

First, I do not publish my application to the AppStore, but I need to customize a sandbox environment. It seems that sandbox-exec cannot configure entitlements, so I have used some other APIs, such as sandbox_compile_entitlements and sandbox_apply_container. When encountering the entitlement "com.apple.security.files.user-selected.read-only", I am unsure how to correctly write sandbox profile to implement this. Can anyone help me?

The header documentation for the (deprecated) LAContext.evaluatedPolicyDomainState property contains the following: @warning Please note that the value returned by this property can change exceptionally between major OS versions even if the state of biometry has not changed. I noticed that the documentation for the new LAContext.domainState property does not contain a similar warning. I also found this related thread from 2016/17. Is the domainState property not susceptible to changes between major OS versions? Or is this generally not an issue anymore?

I want iOS device identifier for a framework that is used in multiple vendor's apps. I'm developing a framework to control a peripheral. The framework has to send unique information to register the device with the peripheral. My naive idea was to use IdentifierForVendor. But this API provides the device identifier for the same vendor's apps, not the framework. (The framework will be used by multiple vendors.) Is there a usable device identifier for the framework, regardless of app vendor? Please tell me any solution.

Hello everyone, We recently transferred our iOS app from one Apple Developer account to another, and after the transfer, we encountered a serious issue where all previously stored Keychain data and the local database became inaccessible. As a result, all users are automatically logged out and lose access to their locally stored data (such as chat history) once they update to the new version signed with the new Team ID. We understand that Keychain items are tied to the App ID prefix (Team ID), which changes during an app transfer. However, we’re looking for possible workarounds or best practices to avoid user data loss. Questions: Is there any reliable method to maintain or migrate access to old Keychain data after an app transfer? Would reverting the app back to the original developer account and releasing an update from there (to persist or migrate data) before transferring it again be a viable solution? Has anyone faced a similar issue and found a practical way to handle data persistence during an app transfer? Any guidance, technical suggestions, or shared experiences would be highly appreciated. This issue is causing major impact for our users, so we’re hoping to find a safe and supported approach. Thank you, Mohammed Hassan

We’re investigating a Platform SSO registration issue on macOS and wanted to check whether others have seen similar behavior or know whether this is expected system behavior. Scenario: Our extension implements ASAuthorizationProviderExtensionRegistrationHandler for device and user registration. On failure we complete with ASAuthorizationProviderExtensionRegistrationResult.failed, and on success we complete with .success. What we’re seeing: If registration fails multiple times, macOS shows multiple system dialogs saying: Registration failed and will automatically retry in a few minutes. If we do not close those earlier failure dialogs and then start another registration that succeeds, the old failure dialogs remain visible and do not dismiss automatically. They have to be closed manually one by one. From our side, these appear to be system-owned Platform SSO dialogs, not app-owned windows. We only return the registration result via the handler completion. Any guidance on whether macOS is expected to reconcile/dismiss earlier failure dialogs after a later success would also be helpful.

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).

I downloaded a P12 file (containing a private key) from the company server, and retrieved the private key from this P12 file using a password : private func loadPrivateKeyFromPKCS12(path: String, password: String) throws -> SecKey? { let p12Data: Data do { p12Data = try Data(contentsOf: fileURL) } catch let readError { ... } let options: [CFString: Any] = [ kSecImportExportPassphrase: password as CFString ] var items: CFArray? let status = SecPKCS12Import(p12Data as CFData, options as CFDictionary, &items) guard status == errSecSuccess else { throw exception } var privateKey: SecKey? let idd = identity as! SecIdentity let _ = SecIdentityCopyPrivateKey(idd, &privateKey) return privateKey } However, when I use this private key to call SecKeyCreateSignature for data signing, a dialog box always pops up to ask user to input the Mac admin password. What confuses me is that this private key is clearly stored in the local P12 file, and there should be no access to the keychain involved in this process. Why does the system still require the user's login password for signing? Is it possible to perform silent signing (without the system dialog popping up) in this scenario?

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 .

Since October 3rd, I've stopped receiving responses to the Private Access Tokens challenge. I'm using this link: https://demo-issuer.private-access-tokens.fastly.com/.well-known/token-issuer-directory. I receive tokens from Fastly and return a header to the iOS app, but then I don't receive another authentication request from iOS. The user has automatic verification enabled on their phone. The problem is global and affects all my mobile app users. Has anyone encountered a similar problem and found a solution?

I've contacted Apple support about this topic, and they've directed me to this forum. I regularly perform Pentests of iOS applications. To properly assess the security of iOS apps, I must bypass given security precaution taken by our customers, such as certificate pinning. According to a number of blog articles, this appears to only be viable on jailbroken devices. If a target application requires a modern version of iOS, the security assessment can't be properly performed. As it should be in Apple's best interest, to offer secure applications on the App Store, what's the recommended approach to allow intrusive pentesting of iOS apps?

I have reached out to support and they simply tell me they are unable to help me, first redirecting me to generic Apple support, after following up they provided the explanation that they only handle administrative tasks and to post on the forums. I am unable to change my App Tracking Transparency it provides no real error, though network traffic shows a 409 HTTP response from the backend API when trying to save. Here is a screenshot of the result when trying to save. Does anyone have any suggestions on how to get this resolved? I've commented back to the reviewers and they simply provided help documentation. I have a technical issue and am unable to get anyone to help resolve this.