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App Attest Issue in Production - Attestation Object Size Increased
Hi Apple Team and Community, We encountered a sudden and widespread failure related to the App Attest service on Friday, July 25, starting at around 9:22 AM UTC. After an extended investigation, our network engineers noted that the size of the attestation objects received from the attestKey call grew in size notably starting at that time. As a result, our firewall began blocking the requests from our app made to our servers with the Base64-encoded attestation objects in the payload, as these requests began triggering our firewall's max request length rule. Could Apple engineers please confirm whether there was any change rolled out by Apple at or around that time that would cause the attestation object size to increase? Can anyone else confirm seeing this? Any insights from Apple or others would be appreciated to ensure continued stability. Thanks!
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193
Jul ’25
Secure Enclave Cryptokit
I am using the CryptoKit SecureEnclave enum to generate Secure Enclave keys. I've got a couple of questions: What is the lifetime of these keys? When I don't store them somewhere, how does the Secure Enclave know they are gone? Do backups impact these keys? I.e. can I lose access to the key when I restore a backup? Do these keys count to the total storage capacity of the Secure Enclave? If I recall correctly, the Secure Enclave has a limited storage capacity. Do the SecureEnclave key instances count towards this storage capacity? What is the dataRepresentation and how can I use this? I'd like to store the Secure Enclave (preferably not in the Keychain due to its limitations). Is it "okay" to store this elsewhere, for instance in a file or in the UserDefaults? Can the dataRepresentation be used in other apps? If I had the capability of extracting the dataRepresentation as an attacker, could I then rebuild that key in my malicious app, as the key can be rebuilt with the Secure Enclave on the same device, or are there measures in place to prevent this (sandbox, bundle id, etc.)
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237
Jun ’25
Unexpected errSecInteractionNotAllowed (-25308) When Reading Keychain Item with kSecAttrAccessibleAfterFirstUnlock in Background
Hi everyone, I’m encountering an unexpected Keychain behavior in a production environment and would like to confirm whether this is expected or if I’m missing something. In my app, I store a deviceId in the Keychain based on the classic KeychainItemWrapper implementation. I extended it by explicitly setting: kSecAttrAccessible = kSecAttrAccessibleAfterFirstUnlock My understanding is that kSecAttrAccessibleAfterFirstUnlock should allow Keychain access while the app is running in the background, as long as the device has been unlocked at least once after reboot. However, after the app went live, I observed that when the app performs background execution (e.g., triggered by background tasks / silent push), Keychain read attempts intermittently fail with: errSecInteractionNotAllowed (-25308) This seems inconsistent with the documented behavior of kSecAttrAccessibleAfterFirstUnlock. Additional context: The issue never occurs in foreground. The issue does not appear on development devices. User devices are not freshly rebooted when this happens. The Keychain item is created successfully; only background reads fail. Setting the accessibility to kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly produces the same result. Questions: Under what circumstances can kSecAttrAccessibleAfterFirstUnlock still cause a -25308 error? Is there any known restriction when accessing Keychain while the app is running in background execution contexts? Could certain system states (Low Power Mode, Background App Refresh conditions, device lock state, etc.) cause Keychain reads to be blocked unexpectedly? Any insights or similar experiences would be greatly appreciated. Thank you!
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Exporting and re-importing ECC keys with file-based keychain
I'm trying to export and re-import a P-256 private key that was originally generated via SecKeyCreateRandomKey(), but I keep running into roadblocks. The key is simply exported via SecItemExport() with format formatWrappedPKCS8, and I did set a password just to be sure. Do note that I must use the file-based keychain, as the data protection keychain requires a restricted entitlement and I'm not going to pay a yearly fee just to securely store some private keys for a personal project. The 7-day limit for unsigned/self-signed binaries isn't feasible either. Here's pretty much everything I could think of trying: Simply using SecItemImport() does import the key, but I cannot set kSecAttrLabel and more importantly: kSecAttrApplicationTag. There just isn't any way to pass these attributes upfront, so it's always imported as Imported Private Key with an empty comment. Keys don't support many attributes to begin with and I need something that's unique to my program but shared across all the relevant key entries, otherwise it's impossible to query for only my program's keys. kSecAttrLabel is already used for something else and is always unique, which really only leaves kSecAttrApplicationTag. I've already accepted that this can be changed via Keychain Access, as this attribute should end up as the entry's comment. At least, that's how it works with SecKeyCreateRandomKey() and SecItemCopyMatching(). I'm trying to get that same behaviour for imports. Running SecItemUpdate() afterwards to set these 2 attributes doesn't work either, as now the kSecAttrApplicationTag is suddenly used for the entry's label instead of the comment. Even setting kSecAttrComment (just to be certain) doesn't change the comment. I think kSecAttrApplicationTag might be a creation-time attribute only, and since SecItemImport() already created a SecKey I will never be able to set this. It likely falls back to updating the label because it needs to target something that is still mutable? Using SecItemImport() with a nil keychain (i.e. create a transient key), then persisting that with SecItemAdd() via kSecValueRef does allow me to set the 2 attributes, but now the ACL is lost. Or more precise: the ACL does seem to exist as any OS prompts do show the label I originally set for the ACL, but in Keychain Access it shows as Allow all applications to access this item. I'm looking to enable Confirm before allowing access and add my own program to the Always allow access by these applications list. Private keys outright being open to all programs is of course not acceptable, and I can indeed access them from other programs without any prompts. Changing the ACL via SecKeychainItemSetAccess() after SecItemAdd() doesn't seem to do anything. It apparently succeeds but nothing changes. I also reopened Keychain Access to make sure it's not a UI "caching" issue. Creating a transient key first, then getting the raw key via SecKeyCopyExternalRepresentation() and passing that to SecItemAdd() via kSecValueData results in The specified attribute does not exist. This error only disappears if I remove almost all of the attributes. I can pass only kSecValueData, kSecClass and kSecAttrApplicationTag, but then I get The specified item already exists in the keychain errors. I found a doc that explains what determines uniqueness, so here are the rest of the attributes I'm using for SecItemAdd(): kSecClass: not mentioned as part of the primary key but still required, otherwise you'll get One or more parameters passed to a function were not valid. kSecAttrLabel: needed for my use case and not part of the primary key either, but as I said this results in The specified attribute does not exist. kSecAttrApplicationLabel: The specified attribute does not exist. As I understand it this should be the SHA1 hash of the public key, passed as Data. Just omitting it would certainly be an option if the other attributes actually worked, but right now I'm passing it to try and construct a truly unique primary key. kSecAttrApplicationTag: The specified item already exists in the keychain. kSecAttrKeySizeInBits: The specified attribute does not exist. kSecAttrEffectiveKeySize: The specified attribute does not exist. kSecAttrKeyClass: The specified attribute does not exist. kSecAttrKeyType: The specified attribute does not exist. It looks like only kSecAttrApplicationTag is accepted, but still ignored for the primary key. Even entering something that is guaranteed to be unique still results in The specified item already exists in the keychain, so I think might actually be targeting literally any key. I decided to create a completely new keychain and import it there (which does succeed), but the key is completely broken. There's no Kind and Usage at the top of Keychain Access and the table view just below it shows symmetric key instead of private. The kSecAttrApplicationTag I'm passing is still being used as the label instead of the comment and there's no ACL. I can't even delete this key because Keychain Access complains that A missing value was detected. It seems like the key doesn't really contain anything unique for its primary key, so it will always match any existing key. Using SecKeyCreateWithData() and then using that key as the kSecValueRef for SecItemAdd() results in A required entitlement isn't present. I also have to add kSecUseDataProtectionKeychain: false to SecItemAdd() (even though that should already be the default) but then I get The specified item is no longer valid. It may have been deleted from the keychain. This occurs even if I decrypt the PKCS8 manually instead of via SecItemImport(), so it's at least not like it's detecting the transient key somehow. No combination of kSecAttrIsPermanent, kSecUseDataProtectionKeychain and kSecUseKeychain on either SecKeyCreateWithData() or SecItemAdd() changes anything. I also tried PKCS12 despite that it always expects an "identity" (key + cert), while I only have (and need) a private key. Exporting as formatPKCS12 and importing it with itemTypeAggregate (or itemTypeUnknown) does import the key, and now it's only missing the kSecAttrApplicationTag as the original label is automatically included in the PKCS12. The outItems parameter contains an empty list though, which sort of makes sense because I'm not importing a full "identity". I can at least target the key by kSecAttrLabel for SecItemUpdate(), but any attempt to update the comment once again changes the label so it's not really any better than before. SecPKCS12Import() doesn't even import anything at all, even though it does return errSecSuccess while also passing kSecImportExportKeychain explicitly. Is there literally no way?
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2d
Critical iOS Activation Vulnerability
There’s a critical, actively exploited vulnerability in Apple’s iOS activation servers allowing unauthenticated XML payload injection: https://cyberpress.org/apple-ios-activation-vulnerability/ This flaw targets the core activation process, bypassing normal security checks. Despite the severity, it’s barely discussed in public security channels. Why is this not being addressed or publicly acknowledged? Apple developers and security researchers should urgently review and audit activation flows—this is a direct attack vector on device trust integrity. Any insights or official response appreciated.
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1
218
Jun ’25
Gate Keeper Issue
Hi, I develop a Mac application, initially on Catalina/Xcode12, but I recently upgrade to Monterey/Xcode13. I'm about to publish a new version: on Monterey all works as expected, but when I try the app on Sequoia, as a last step before uploading to the App Store, I encountered some weird security issues: The main symptom is that it's no longer possible to save any file from the app using the Save panel, although the User Select File entitlement is set to Read/Write. I've tried reinstalling different versions of the app, including the most recent downloaded from TestFlight. But, whatever the version, any try to save using the panel (e.g. on the desktop) results in a warning telling that I don't have authorization to record the file to that folder. Moreover, when I type spctl -a -t exec -v /Applications/***.app in the terminal, it returns rejected, even when the application has been installed by TestFlight. An EtreCheck report tells that my app is not signed, while codesign -dv /Applications/***.app returns a valid signature. I'm lost... It suspect a Gate Keeper problem, but I cannot found any info on the web about how this system could be reset. I tried sudo spctl --reset-default, but it returns This operation is no longer supported... I wonder if these symptoms depend on how the app is archived and could be propagated to my final users, or just related to a corrupted install of Sequoia on my local machine. My feeling is that a signature problem should have been detected by the archive validation, but how could we be sure? Any idea would be greatly appreciated, thanks!
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651
Feb ’25
Creating machine identifier to be used by daemon based app
I am developing a daemon-based product that needs a cryptographic, non-spoofable proof of machine identity so a remote management server can grant permissions based on the physical machine. I was thinking to create a signing key in the Secure Enclave and use a certificate signed by that key as the machine identity. The problem is that the Secure Enclave key I can create is only accessible from user context, while my product runs as a system daemon and must not rely on user processes or launchAgents. Could you please advise on the recommended Apple-supported approaches for this use case ? Specifically, Is there a supported way for a system daemon to generate and use an unremovable Secure Enclave key during phases like the pre-logon, that doesn't have non user context (only the my application which created this key/certificate will have permission to use/delete it) If Secure Enclave access from a daemon is not supported, what Apple-recommended alternatives exist for providing a hardware-backed machine identity for system daemons? I'd rather avoid using system keychain, as its contents may be removed or used by root privileged users. The ideal solution would be that each Apple product, would come out with a non removable signing certificate, that represent the machine itself (lets say that the cetificate name use to represent the machine ID), and can be validated by verify that the root signer is "Apple Root CA"
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564
Nov ’25
AES Decryption
Having trouble decrypting a string using an encryption key and an IV. var key: String var iv: String func decryptData(_ encryptedText: String) -> String? { if let textData = Data(base64Encoded: iv + encryptedText) { do { let sealedBox = try AES.GCM.SealedBox(combined: textData) let key = SymmetricKey(data: key.data(using: .utf8)!) let decryptedData = try AES.GCM.open(sealedBox, using: key) return String(data: decryptedData, encoding: .utf8) } catch { print("Decryption failed: \(error)") return nil } } return nil } Proper coding choices aside (I'm just trying anything at this point,) the main problem is opening the SealedBox. If I go to an online decryption site, I can paste in my encrypted text, the encryption key, and the IV as plain text and I can encrypt and decrypt just fine. But I can't seem to get the right combo in my Swift code. I don't have a "tag" even though I'm using the combined option. How can I make this work when all I will be receiving is the encrypted text, the encryption key, and the IV. (the encryption key is 256 bits) Try an AES site with a key of 32 digits and an IV of 16 digits and text of your choice. Use the encrypted version of the text and then the key and IV in my code and you'll see the problem. I can make the SealedBox but I can't open it to get the decrypted data. So I'm not combining the right things the right way. Anyone notice the problem?
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414
Mar ’25
suddenly 'zsh: killed' my Xcode-based console app
I have a small command-line app I've been using for years to process files. I have it run by an Automator script, so that I can drop files onto it. It stopped working this morning. At first, I could still run the app from the command line, without Automator. But then after I recompiled the app, now I cannot even do that. When I run it, it's saying 'zsh: killed' followed by my app's path. What is that? The app does run if I run it from Xcode. How do I fix this?
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591
Feb ’25
Does SecTrustEvaluateWithError validates External Reference Identifiers?
Trying to validate external reference identifiers with SecTrustEvaluateWithError Method by setting reference Ids to SecPolicyCreateSSL() & SecPolicyCreateWithProperties() But two concerns are - Validates for correct reference IDs but gives error for combination of wrong & correct reference Ids 398 days validity works mandatorily before reference Ids check. Is there any other to validate external reference Ids?, which give flexibility To pass multiple combinations of reference IDs string (wrong, correct, IP, DNS) To validate reference ID without days validity of 398. Please suggest. Any help here is highly appreciated.
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367
Mar ’25
How to use an Intune-delivered SCEP certificate for mTLS in iOS app using URLSessionDelegate?
I am working on implementing mTLS authentication in my iOS app (Apple Inhouse & intune MAM managed app). The SCEP client certificate is deployed on the device via Intune MDM. When I try accessing the protected endpoint via SFSafariViewController/ASWebAuthenticationSession, the certificate picker appears and the request succeeds. However, from within my app (using URLSessionDelegate), the certificate is not found (errSecItemNotFound). The didReceive challenge method is called, but my SCEP certificate is not found in the app. The certificate is visible under Settings > Device Management > SCEP Certificate. How can I make my iOS app access and use the SCEP certificate (installed via Intune MDM) for mTLS requests? Do I need a special entitlement, keychain access group, or configuration in Intune or Developer account to allow my app to use the certificate? Here is the sample code I am using: final class KeychainCertificateDelegate: NSObject, URLSessionDelegate { func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) { guard challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodClientCertificate else { completionHandler(.performDefaultHandling, nil) return } // Get the DNs the server will accept guard let expectedDNs = challenge.protectionSpace.distinguishedNames else { completionHandler(.cancelAuthenticationChallenge, nil) return } var identityRefs: CFTypeRef? = nil let err = SecItemCopyMatching([ kSecClass: kSecClassIdentity, kSecMatchLimit: kSecMatchLimitAll, kSecMatchIssuers: expectedDNs, kSecReturnRef: true, ] as NSDictionary, &identityRefs) if err != errSecSuccess { completionHandler(.cancelAuthenticationChallenge, nil) return } guard let identities = identityRefs as? [SecIdentity], let identity = identities.first else { print("Identity list is empty") completionHandler(.cancelAuthenticationChallenge, nil) return } let credential = URLCredential(identity: identity, certificates: nil, persistence: .forSession) completionHandler(.useCredential, credential) } } func perform_mTLSRequest() { guard let url = URL(string: "https://sample.com/api/endpoint") else { return } var request = URLRequest(url: url) request.httpMethod = "POST" request.setValue("application/json", forHTTPHeaderField: "Accept") request.setValue("Bearer \(bearerToken)", forHTTPHeaderField: "Authorization") let delegate = KeychainCertificateDelegate() let session = URLSession(configuration: .ephemeral, delegate: delegate, delegateQueue: nil) let task = session.dataTask(with: request) { data, response, error in guard let httpResponse = response as? HTTPURLResponse, (200...299).contains(httpResponse.statusCode) else { print("Bad response") return } if let data = data { print(String(data: data, encoding: .utf8)!) } } task.resume() }
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834
Sep ’25
macOS App Keychain errSecAuthFailed after long run, restart fixes
I'm writing an app on macOS that stores passwords in the Keychain and later retrieves them using SecItemCopyMatching(). This works fine 90% of the time. However, occasionally, the call to SecItemCopyMatching() fails with errSecAuthFailed (-25293). When this occurs, simply restarting the app resolves the issue; otherwise, it will consistently fail with errSecAuthFailed. What I suspect is that the Keychain access permission has a time limitation for a process. This issue always seems to arise when I keep my app running for an extended period.
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100
Apr ’25
SystemExtension approve failed on mac15.x
Hello, I'm an application developer related to Apple system extensions. I developed an endpoint security system extension that can run normally before the 14.x system. However, after I upgraded to 15.x, I found that when I uninstalled and reinstalled my system extension, although the system extension was installed successfully, a system warning box would pop up when I clicked enable in the Settings, indicating a failure. I conducted the following test. I reinstalled a brand-new MAC 15.x system. When I installed my applications, the system extensions could be installed successfully and enabled normally. However, when I uninstalled and reinstalled, my system extension couldn't be enabled properly and a system warning popped up as well. I tried disabling SIP and enabling System Extension Developers, but it still didn't work. When the system warning box pops up, I can see some error log information through the console application, including an error related to Failed to authorize right 'com.apple.system-extensions.admin' by client '/System/Library/ExtensionKit/Extensions/SettingsSystemExtensionController.appex' [2256] for authorization created by '/System/Library/ExtensionKit/Extensions/SettingsSystemExtensionController.appex' [2256] (3,0) (-60005) (engine 179) as shown in the screenshot. The same problem, mentioned in Cannot approve some extensions in MacOS Sequoia , but there is no solution
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786
Oct ’25
TKTokenSession not used
Hi, I'm working on developing my own CryptoTokenKit (CTK) extension to enable codesign with HSM-backed keys. Here's what I’ve done so far: The container app sets up the tokenConfiguration with TKTokenKeychainCertificate and TKTokenKeychainKey. The extension registers successfully and is visible via pluginkit when launching the container app. The virtual smartcard appears when running security list-smartcards. The certificate, key, and identity are all visible using security export-smartcard -i [card]. However, nothing appears in the Keychain. After adding logging and reviewing output in the Console, I’ve observed the following behavior when running codesign: My TKTokenSession is instantiated correctly, using my custom TKToken implementation — so far, so good. However, none of the following TKTokenSession methods are ever called: func tokenSession(_ session: TKTokenSession, beginAuthFor operation: TKTokenOperation, constraint: Any) throws -> TKTokenAuthOperation func tokenSession(_ session: TKTokenSession, supports operation: TKTokenOperation, keyObjectID: TKToken.ObjectID, algorithm: TKTokenKeyAlgorithm) -> Bool func tokenSession(_ session: TKTokenSession, sign dataToSign: Data, keyObjectID: Any, algorithm: TKTokenKeyAlgorithm) throws -> Data func tokenSession(_ session: TKTokenSession, decrypt ciphertext: Data, keyObjectID: Any, algorithm: TKTokenKeyAlgorithm) throws -> Data func tokenSession(_ session: TKTokenSession, performKeyExchange otherPartyPublicKeyData: Data, keyObjectID objectID: Any, algorithm: TKTokenKeyAlgorithm, parameters: TKTokenKeyExchangeParameters) throws -> Data The only relevant Console log is: default 11:31:15.453969+0200 PersistentToken [0x154d04850] invalidated because the client process (pid 4899) either cancelled the connection or exited There’s no crash report related to the extension, so my assumption is that ctkd is closing the connection for some unknown reason. Is there any way to debug this further? Thank you for your help.
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103
Apr ’25
LocalAuthentication (Alternative) in Autofill Credential Provider extension
Hi, how can you authenticate a User through Biometrics with iPhone Passcode as Fallback in the Autofill Credential Provider Extension? In the App it works without a problem. In the Extension I get "Caller is not running foreground" Yeah, it isn't, as it's just a sheet above e.g. Safari. I'd like to avoid having the user setup a Passcode dedicated to my App, especially because FaceID is way faster. Does anybody know how to achieve iOS native Auth in the extension? Please let me know, a code sample would be appreciated. Regards, Mia
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293
Mar ’25
Something odd with Endpoint Security & was_mapped_writable
I'm seeing some odd behavior which may be a bug. I've broken it down to a least common denominator to reproduce it. But maybe I'm doing something wrong. I am opening a file read-write. I'm then mapping the file read-only and private: void* pointer = mmap(NULL, 17, PROT_READ, MAP_FILE | MAP_PRIVATE, fd, 0); I then unmap the memory and close the file. After the close, eslogger shows me this: {"close":{"modified":false,[...],"was_mapped_writable":false}} Which makes sense. I then change the mmap statement to: void* pointer = mmap(NULL, 17, PROT_READ, MAP_FILE | MAP_SHARED, fd, 0); I run the new code and and the close looks like: {"close":{"modified":false, [....], "was_mapped_writable":true}} Which also makes sense. I then run the original again (ie, with MAP_PRIVATE vs. MAP_SHARED) and the close looks like: {"close":{"modified":false,"was_mapped_writable":true,[...]} Which doesn't appear to be correct. Now if I just open and close the file (again, read-write) and don't mmap anything the close still shows: {"close":{ [...], "was_mapped_writable":true,"modified":false}} And the same is true if I open the file read-only. It will remain that way until I delete the file. If I recreate the file and try again, everything is good until I map it MAP_SHARED. I tried this with macOS 13.6.7 and macOS 15.0.1.
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709
Oct ’25
Understanding deep sleep
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?
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601
Sep ’25
CryptoKitError
Hi, I am using CryptoKit in my app. I am getting an error sometimes with some users. I log the description to Firebase but I am not sure what is it exactly about.  CryptoKit.CryptoKitError error 2  CryptoKit.CryptoKitError error 3 I receive both of these errors. I also save debug prints to a log file and let users share them with me. Logs are line-by-line encrypted but after getting these errors in the app also decryption of log files doesn't work and it throws these errors too. I couldn't reproduce the same error by myself, and I can't reach the user's logs so I am a little blind about what triggers this. It would be helpful to understand what these errors mean. Thanks
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1.6k
May ’25