Dear Apple Developer Support, We are currently encountering a recurring issue with the DeviceCheck API across multiple devices in our production environment. The following error is frequently returned: com.apple.devicecheck.error 0 We would like to ask the following: What are the possible underlying causes that could lead to this specific error code (0) in the DeviceCheck API? Is there any known behavior or condition where Wi-Fi network configurations (e.g., DNS filtering, proxy settings, captive portals) could result in this error? Are there known timeouts, connectivity expectations, or TLS-level requirements that the DeviceCheck API enforces which could fail silently under certain network conditions? Is this error ever triggered locally (e.g., client library-level issues) or is it always from a failed communication with Apple’s servers? Any technical clarification, documentation, or internal insight into this error code would be greatly appreciated. This would help us significantly narrow down root causes and better support our users

Hi everyone, I’m working on adapting our app to iOS 26’s new passkey feature, specifically Automatic Passkey Upgrades. https://developer.apple.com/videos/play/wwdc2025/279/ Our app already supports passkey registration and authentication, which have been running reliably in production. We’d like to extend passkey coverage to more users. According to the WWDC session, adding the parameter requestStyle: .conditional to createCredentialRegistrationRequest should allow the system to seamlessly upgrade an account with a passkey. However, in my testing, I consistently receive the following error: Error | Error Domain=com.apple.AuthenticationServices.AuthorizationError Code=1001 "(null)" Test environment: Xcode 26.0 beta 4 (17A5285i) iPhone 11 running iOS 26.0 (23A5297n) Questions: Is the Automatic Passkey Upgrades feature currently available in iOS 26? I understand that the system may perform internal checks and not all upgrade attempts will succeed. However, during development, is there a way to obtain more diagnostic information? At the moment, it’s unclear whether the failure is due to internal validation or an issue with my code or environment. Thanks.

I’m implementing passkey registration and authentication in an iOS 17 app with a credential provider extension, but I’m running into an issue. Setup: I have a credential provider target configured. The app correctly shows the pop-up to register the passkey with my app. My Info.plist is set up properly. Issue: When the following function is triggered: override func prepareInterface(forPasskeyRegistration registrationRequest: ASCredentialRequest) { "code to generate registrationRequest..." let controller = ASAuthorizationController(authorizationRequests: [registrationRequest]) controller.delegate = self controller.presentationContextProvider = self controller.performRequests() } I get the following error: Domain=com.apple.AuthenticationServices.AuthorizationError Code=1004 I do not own the relying party domain (e.g., https://webauthn.io), so I cannot configure an apple-app-site-association file on the website. Question: How can I register and authenticate passkeys on any site that allows passkeys (such as webauthn.io) when I don’t control the webpage? Are there any workarounds or best practices for handling this in iOS 17? Any insights would be greatly appreciated!

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

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

Hi, A user logs in to the file vault, and DisableFDEAutoLogin is false. The file vault login succeeds, but the login to the selected user fails. The user gets the login screen again. If the user puts an invalid password to try and login again, the loginwindow:FDESupport plugin will change the user's password to the invalid one.

My application is supporting hybrid transport on FIDO2 webAuthn specs to create credential and assertion. And it support legacy passkeys which only mean to save to 1 device and not eligible to backup. However In my case, if i set the Backup Eligibility and Backup State flag to false, it fails on the completion of the registrationRequest to save the passkey credential within credential extension, the status is false instead of true. self.extension.completeRegistrationRequest(using: passkeyRegistrationCredential) The attestation and assertion flow only works when both flags set to true. Can advice why its must have to set both to true in this case?

Hi , I have a requirement like, Develop an app for iPad and app uses .net core apis. App will be in kiosk mode, and app doesn't have any type of authentication even OTP also. As the apis will be publishing to all over internet, how can we achieve security to apis? Kindly provide suggestions for this implementation

With Let's Encrypt having completely dropped support for OCSP recently [1], I wanted to ask if macOS has a means of keeping up to date with their CRLs and if so, roughly how often this occurs? I first observed an issue where a revoked-certificate test site, "revoked.badssl.com" (cert signed by Let's Encrypt), was not getting blocked on any browser, when a revocation policy was set up using the SecPolicyCreateRevocation API, in tandem with the kSecRevocationUseAnyAvailableMethod and kSecRevocationPreferCRL flags. After further investigation, I noticed that even on a fresh install of macOS, Safari does not block this test website, while Chrome and Firefox (usually) do, due to its revoked certificate. Chrome and Firefox both have their own means of dealing with CRLs, while I assume Safari uses the system Keychain and APIs. I checked cert info for the site here [2]. It was issued on 2025-07-01 20:00 and revoked an hour later. [1] https://letsencrypt.org/2024/12/05/ending-ocsp/ [2] https://www.ssllabs.com/ssltest/analyze.html?d=revoked.badssl.com

Hi, We are using the MSAL library to authenticate users, with SSO authentication implemented through the Microsoft Authenticator app. The problem is that once or twice a day, a prompt for forced authentication appears, indicating that silent token acquisition is failing and resulting in a requirement for forced authentication. Below are some of the logs: ================================================= 2025-08-28 11:00:05.034 [Info] [AppDelegate.swift:121] application(:didFinishLaunchingWithOptions:) > MSAL message: TID=751353 MSAL 1.8.1 iOS 18.5 [2025-08-28 10:00:05 - EC9D1457-2D70-4878-926F-553391EBC9D3] [MSAL] Silent flow finished. Result (null), error: -51115 error domain: MSIDErrorDomain 2025-08-28 11:00:05.034 [Info] [AppDelegate.swift:121] application(:didFinishLaunchingWithOptions:) > MSAL message: TID=751353 MSAL 1.8.1 iOS 18.5 [2025-08-28 10:00:05 - EC9D1457-2D70-4878-926F-553391EBC9D3] [MSAL] acquireTokenSilent returning with error: (MSALErrorDomain, -50002) Masked(not-null) ==================================================== We initially raised this issue with Microsoft, but according to them: In the app's logs, the single one failure it contains, was when the SSO extension returned the error com.apple.AuthenticationServices.AuthorizationError, -6000 during a silent call. This error code is generated by the system framework (Apple), not by our code. It indicates that the framework encountered an unexpected internal issue before or after calling the SSO extension. MSAL returning interaction_required to the client app is the most effective way to recover from this error (as you mention, after the user selects the account the app continues working as expected). Additionally, as you also mention, the interactive call is made by switching to Authenticator (not displaying a "window" without leaving Eva Lite app), which means MSAL is not able to use the SSO extension and is using the fallback to legacy authentication. The recommended next step is for the customer to request support directly from Apple as this is an issue on their side. Additionally, the customer can also try to update to the latest iOS, in case Apple has already fixed this issue. ============================================= STEPS TO REPRODUCE There is no such steps its just that this is an enterprise application which is getting used on managed devices[iPhone 14]. The device are managed using some intune policy. Platform and Version: iOS Development Environment: Xcode 15, macOS 13.6.1 Run-time Configuration: iOS 18 Please let me know if there are any solutions to resolve this problem. Thank you.

I keep getting the following error when trying to run Passkey sign in on macOS. Told not to present authorization sheet: Error Domain=com.apple.AuthenticationServicesCore.AuthorizationError Code=1 "(null)" ASAuthorizationController credential request failed with error: Error Domain=com.apple.AuthenticationServices.AuthorizationError Code=1004 "(null)" This is the specific error. Application with identifier a is not associated with domain b I have config the apple-app-site-association link and use ?mode=developer Could there be any reason for this?

I am working on implementing mTLS authentication in my iOS app (Apple Inhouse &amp; 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 &gt; Device Management &gt; 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?) -&gt; 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, &amp;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() }

Hello Apple Team We are integrating App Attest with our backend and seeing a 400 Bad Request response when calling the attestation endpoint. The issue is that the response does not include an X-Request-ID or JSON error payload with id and code, which makes it hard to diagnose. Instead, it only returns a receipt blob. Request Details URL: https://data-development.appattest.apple.com/v1/attestationData Request Headers: Authorization: eyJraWQiOiI0RjVLSzRGV1JaIiwidHlwIjoiSldUIiwiYWxnIjoiRVMyNTYifQ.eyJpc3MiOiJOOVNVR1pNNjdRIiwiZXhwIjoxNzU3MDUxNTYwLCJpYXQiOjE3NTcwNDc5NjB9.MEQCIF236MqPCl6Vexg7RcPUMK8XQeACXogldnpuiNnGQnzgAiBQqASdbJ64g58xfWGpbzY3iohvxBSO5U5ZE3l87JjfmQ Content-Type: application/octet-stream Request Body: (Binary data, logged as [B@59fd7d35) Response Status: 400 Bad Request Response Headers: Date: Fri, 05 Sep 2025 04:52:40 GMT x-b3-traceid: 4c42e18094022424 x-b3-spanid: 4c42e18094022424 Response Body (truncated): "receipt": h'308006092A864886F70D01070... Problem The response does not include X-Request-ID. The response does not include JSON with id or code. Only a receipt blob is returned. Questions Can the x-b3-traceid be used by Apple to trace this failed request internally? Is it expected for some failures to return only a receipt blob without X-Request-ID? How should we interpret this error so we can handle it properly in production? Thanks in advance for your guidance.

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.

Hello I'm using Auth0 for handling auth in my app When the user wants to sign in, it will show the auth system pop-up And when the user wants to log out it shows the same pop-up My issue is how to replace the Sign In text in this pop-up to show Sign Out instead of Sign In when the user wants to sign out?

Hello everyone, I'm developing a FIDO2 service using the AuthenticationServices framework. I've run into an issue when a user manually deletes a passkey from their password manager. When this happens, the ASAuthorizationError I get doesn't clearly indicate that the passkey is missing. The error code is 1001, and the localizedDescription is "The operation couldn't be completed. No credentials available for login." The userInfo also contains "NSLocalizedFailureReason": "No credentials available for login." My concern is that these localized strings will change depending on the user's device language, making it unreliable for me to programmatically check for a "no credentials" scenario. Is there a more precise way to determine that the user has no passkey, without relying on localized string values? Thank you for your help.

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.

We are using SecPKCS12Import C API in our application to import a self seigned public key certificate. We tried to run the application for the first time on Tahoe and it failed with OSStatus -26275 error. The release notes didn't mention any deprecation or change in the API as per https://developer.apple.com/documentation/macos-release-notes/macos-26-release-notes. Are we missing anything? There are no other changes done to our application.

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.

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.