Prioritize user privacy and data security in your app. Discuss best practices for data handling, user consent, and security measures to protect user information.

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Is there a way to hide the 'Save to another device' option during iOS WebAuthn registration?
Hello, I am currently implementing a biometric authentication registration flow using WebAuthn. I am using ASAuthorizationPlatformPublicKeyCredentialRegistrationRequest, and I would like to know if there is a way to hide the "Save to another device" option that appears during the registration process. Specifically, I want to guide users to save the passkey only locally on their device, without prompting them to save it to iCloud Keychain or another device. If there is a way to hide this option or if there is a recommended approach to achieve this, I would greatly appreciate your guidance. Also, if this is not possible due to iOS version or API limitations, I would be grateful if you could share any best practices for limiting user options in this scenario. If anyone has experienced a similar issue, your advice would be very helpful. Thank you in advance.
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1.1k
Oct ’25
App Attest Validation Nonce Not Matched
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.
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1.1k
Sep ’25
Security of userID in Apple passkeys — how exposed is it?
I’m considering storing some sensitive information in the userID field of a passkey, as described in the createCredentialRegistrationRequest method.(link to method). I'm aware of the largeBlob extension introduced in iOS 17+, but it doesn't meet my needs since I want to create a cross-platform passkey that can be used across various devices — and currently, not many devices support the largeBlob extension. According to W3C documentation, the userID field is not considered private information and can be displayed to the user without requiring a verification process. Based on my understanding, it's also not encrypted, which means it might be accessible with physical access to the device. So here are my questions: How do Apple devices (especially iPhones) handle the userID field in their authenticators? Is it possible to access the userID without user verification, as permitted by the W3C specification? Are there any alternative methods to access the userID value stored in a passkey on Apple devices?
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144
Apr ’25
DeviceCheck - Device Validation Endpoint not working
We have been having very high response times in device check device validation service (https://developer.apple.com/documentation/devicecheck/accessing-and-modifying-per-device-data#Create-the-payload-for-a-device-validation-request) since 17 July at 19:10hs GMT. The service information page says the service was running in green status but that isn't the case and we currenly have stop consuming it. Is it being looked at? Are you aware of this issue? Can you give us an estimate of when it should be working correctly?
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797
Jul ’25
Appstore submission rejected - Privacy
Please correct the following issues and upload a new binary to App Store Connect. ITMS-91061: Missing privacy manifest - Your app includes “Frameworks/FirebaseCoreDiagnostics.framework/FirebaseCoreDiagnostics”, which includes FirebaseCoreDiagnostics, an SDK that was identified in the documentation as a commonly used third-party SDK. If a new app includes a commonly used third-party SDK, or an app update adds a new commonly used third-party SDK, the SDK must include a privacy manifest file. Please contact the provider of the SDK that includes this file to get an updated SDK version with a privacy manifest. For more details about this policy, including a list of SDKs that are required to include signatures and manifests, visit: https://developer.apple.com/support/third-party-SDK-requirements. ITMS-91061: Missing privacy manifest - Your app includes “Frameworks/FBLPromises.framework/FBLPromises”, which includes FBLPromises, an SDK that was identified in the documentation as a commonly used third-party SDK. If a new app includes a commonly used third-party SDK, or an app update adds a new commonly used third-party SDK, the SDK must include a privacy manifest file. Please contact the provider of the SDK that includes this file to get an updated SDK version with a privacy manifest. For more details about this policy, including a list of SDKs that are required to include signatures and manifests, visit: https://developer.apple.com/support/third-party-SDK-requirements. ITMS-91061: Missing privacy manifest - Your app includes “Frameworks/GoogleDataTransport.framework/GoogleDataTransport”, which includes GoogleDataTransport, an SDK that was identified in the documentation as a commonly used third-party SDK. If a new app includes a commonly used third-party SDK, or an app update adds a new commonly used third-party SDK, the SDK must include a privacy manifest file. Please contact the provider of the SDK that includes this file to get an updated SDK version with a privacy manifest. For more details about this policy, including a list of SDKs that are required to include signatures and manifests, visit: https://developer.apple.com/support/third-party-SDK-requirements. our app is .NET MAUI app so we already addressed this by adding privacyinfo.xcprivacy privacy manifest under platform/ios/resources but still get flagged for this <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>NSPrivacyTracking</key> <false/> <key>NSPrivacyTrackingDomains</key> <array/> <key>NSPrivacyAccessedAPITypes</key> <array> <dict> <key>NSPrivacyAccessedAPIType</key> <string>NSPrivacyAccessedAPICategoryFileTimestamp</string> <key>NSPrivacyAccessedAPITypeReasons</key> <array> <string>C617.1</string> </array> </dict> <dict> <key>NSPrivacyAccessedAPIType</key> <string>NSPrivacyAccessedAPICategorySystemBootTime</string> <key>NSPrivacyAccessedAPITypeReasons</key> <array> <string>35F9.1</string> </array> </dict> <dict> <key>NSPrivacyAccessedAPIType</key> <string>NSPrivacyAccessedAPICategoryDiskSpace</string> <key>NSPrivacyAccessedAPITypeReasons</key> <array> <string>E174.1</string> </array> </dict> <dict> <key>NSPrivacyAccessedAPIType</key> <string>NSPrivacyAccessedAPICategoryUserDefaults</string> <key>NSPrivacyAccessedAPITypeReasons</key> <array> <string>CA92.1</string> </array> </dict> </array> <key>NSPrivacyCollectedDataTypes</key> <array/> </dict> </plist>
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152
Apr ’25
Fraud prevention using Device Check when publishing multiple apps
I would like to confirm about fraud prevention using Device Check when publishing multiple apps. If the Team ID and Key ID are the same, will the values be shared across all apps with Device Check? With Device Check, only two keys can be created per developer account, and these two are primarily intended for key renewal in case of a leak, rather than for assigning different keys to each app, correct? If both 1 and 2 are correct, does that mean that Device Check should not be used to manage "one-time-only rewards per device" when offering them across multiple apps? Thank you very much for your confirmation.
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206
Apr ’25
Biometrics prompt + private key access race condition on since iOS 26.1
We are using SecItemCopyMatching from LocalAuthentication to access the private key to sign a challenge in our native iOS app twice in a few seconds from user interactions. This was working as expected up until about a week ago where we started getting reports of it hanging on the biometrics screen (see screenshot below). From our investigation we've found the following: It impacts newer iPhones using iOS 26.1 and later. We have replicated on these devices: iPhone 17 Pro max iPhone 16 Pro iPhone 15 Pro max iPhone 15 Only reproducible if the app tries to access the private key twice in quick succession after granting access to face ID. Looks like a race condition between the biometrics permission prompt and Keychain private key access We were able to make it work by waiting 10 seconds between private key actions, but this is terrible UX. We tried adding adding retries over the span of 10 seconds which fixed it on some devices, but not all. We checked the release notes for iOS 26.1, but there is nothing related to this. Screenshot:
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581
3w
Control over "\(your_app) wants to open \(another_app)" Dialog
I can't find any information about why this is happening, nor can I reproduce the 'successful' state on this device. My team needs to understand this behavior, so any insight would be greatly appreciated! The expected behavior: If I delete both apps and reinstall them, attempting to open the second app from my app should trigger the system confirmation dialog. The specifics: I'm using the MSAL library. It navigates the user to the Microsoft Authenticator app and then returns to my app. However, even after resetting the phone and reinstalling both apps, the dialog never shows up (it just opens the app directly). Does anyone know the logic behind how iOS handles these prompts or why it might be persistent even after a reset? Thanks in advance!
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158
Jan ’26
Critical Privacy and Security Issue: Spotlight disregards explicit exclusions and exposes user files
Apple has repeatedly ignored my reports about a critical privacy issue in Spotlight on macOS 26, and the problem persists in version 26.3 RC. This is not a minor glitch, it is a fundamental breach of user trust and privacy. Several aspects of Spotlight fail to respect user settings: • Hidden apps still exposed: In the Apps section (Cmd+1), Spotlight continues to display apps marked with the hidden flag, even though they should remain invisible. • Clipboard reactivation: The clipboard feature repeatedly turns itself back on after logout or restart, despite being explicitly disabled by the user. • Excluded files revealed: Most concerning, Spotlight exposes files in Suggestions and Recents (Cmd+3) even when those files are explicitly excluded under System Settings > Spotlight > Search Privacy. This behavior directly violates user expectations and system settings. It is not only a major privacy issue but also a security risk, since sensitive files can be surfaced without consent. Apple must address this immediately. Users rely on Spotlight to respect their privacy configurations, and the current behavior undermines both trust and security.
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444
3w
Errors with Attestation on App
We recently deployed Attestation on our application, and for a majority of the 40,000 users it works well. We have about six customers who are failing attestation. In digging through debug logs, we're seeing this error "iOS assertion verification failed. Unauthorized access attempted." We're assuming that the UUID is blocked somehow on Apple side but we're stumped as to why. We had a customer come in and we could look at the phone, and best we can tell it's just a generic phone with no jailbroken or any malicious apps. How can we determine if the UUID is blocked?
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215
May ’25
Intermittent Failures Launching App from Universal Links using ASWebAuthenticationSession
I'm developing an iOS app that utilizes Universal Links and ASWebAuthenticationSession to deep-link from a website to the app itself. This implementation adheres to the recommendations outlined in RFC 8252, ensuring that the app opening the ASWebAuthenticationSession is the same app that is launched via the Universal Link. Problem:  While most users can successfully launch the app via Universal Links,a few percent of users experience instances where the app fails to launch, and the user is redirected to the browser. What I've Tried:  ASWebAuthenticationSession Configuration: I've double-checked the configuration of callbackURLScheme and presentationContextProvider.  Universal Links: Verified the apple-app-site-association file and associated domains entitlement.  Network Conditions: Tested on various network environments (Wi-Fi, cellular) and devices. Questions:  What are the potential causes for this behavior?  Has anyone else encountered a similar issue and found a solution?  Are there any debugging techniques or ways to generate more detailed logs? I haven't been able to determine which device or OS version is causing this problem. Thank you.
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1.1k
Apr ’25
Passkey issue- Unable to verify webcredentials
Recently, we have adapted the passkey function on the Mac, but we always encounter the error message "Unable to verify the web credentials association of xxx with domain aaa. Please try again in a few seconds." We can confirm that https://aaa/.well-known/apple-app-site-association has been configured and is accessible over the public network. Additionally, the entitlements in the app have also been set with webcredentials:aaa. This feature has been experiencing inconsistent performance. When I restart my computer or reinstall the pkg, this feature may work or it may still not work. I believe this is a system issue. Here is feed back ID: FB20876945 In the feedback, I provided the relevant logs. If you have any suggestions or assistance, please contact me. I would be extremely grateful!
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491
Nov ’25
requestTrackingAuthorization stuck in .notDetermined
When developing and testing using my phone I got prompted for allowing app tracking. I later uploaded a build to TestFlight, deleted the old testing app and installed the TestFlight build. I am now stuck in an infinite loop of not getting prompted for allowing app tracking for the app. When entering the app settings the toggle for tracking never appears which leaves me not able to enter the app's content. My guess is that the prompt can only be shown once for the app bundle, but there has to be a way for me to get prompted again without changing the app bundle id. Help is appreciated since this app is scheduled to be published in a week.
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161
May ’25
Empty userID for cross-platform attestation with Android
I've come across strange behavior with the userID property on the returned credential from a passkey attestation. When performing a cross-device passkey assertion between iOS and Android by scanning the generated QR code on my iPhone with an Android device the returned credential object contains an empty userID. This does not happen when performing an on device or cross-device assertion using two iPhones. Is this expected behavior, or is there something I'm missing here? I couldn't find any more information on this in the documentation. iOS Version: 26.0.1, Android Version: 13
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441
Oct ’25
Assistance in Implementing App Attestation
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?
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249
May ’25
Question about revoke the token in 'Sign in with Apple'
News link: https://developer.apple.com/news/?id=12m75xbj If your app offers Sign in with Apple, you’ll need to use the Sign in with Apple REST API to revoke user tokens when deleting an account. I'm not good English. I'm confused about the above sentence Do I have to use REST API unconditionally or can I just delete to the account data?
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185
Mar ’25
Submission Rejected: Guideline 5.1.1 - Legal - Privacy - Data Collection and Storage
Hi, I am in need of your help with publishing my game. I got the following explanation for the negative review of my app/game. Issue Description One or more purpose strings in the app do not sufficiently explain the use of protected resources. Purpose strings must clearly and completely describe the app's use of data and, in most cases, provide an example of how the data will be used. Next Steps Update the local network information purpose string to explain how the app will use the requested information and provide a specific example of how the data will be used. See the attached screenshot. Resources Purpose strings must clearly describe how an app uses the ability, data, or resource. The following are hypothetical examples of unclear purpose strings that would not pass review: "App would like to access your Contacts" "App needs microphone access" See examples of helpful, informative purpose strings. The problem is that they say my app asks to allow my app to find devices on local networks. And that this needs more explanation in the purpose strings. Totally valid to ask, but the problem is my app doesn't need local access to devices, and there shouldn't be code that asks this?? FYI the game is build with Unity. Would love some help on how to turn this off so that my app can get published.
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355
Jan ’26
App Attest – DCAppAttestService.isSupported == false on some devices (~0.23%)
Hi Apple team, For our iPhone app (App Store build), a small subset of devices report DCAppAttestService.isSupported == false, preventing App Attest from being enabled. Approx. impact: 0.23% (352/153,791) iOS observed: Broadly 15.x–18.7 (also saw a few anomalous entries ios/26.0, likely client logging noise) Device models: Multiple generations (iPhone8–iPhone17); a few iPad7 entries present although the app targets iPhone Questions In iPhone main app context, what conditions can make isSupported return false on iOS 14+? Are there known device/iOS cases where temporary false can occur (SEP/TrustChain related)? Any recommended remediation (e.g., DFU restore)? Could you share logging guidance (Console.app subsystem/keywords) to investigate such cases? What fallback policy do you recommend when isSupported == false (e.g., SE-backed signature + DeviceCheck + risk rules), and any limitations? We can provide sysdiagnose/Console logs and more case details upon request. Thank you, —
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232
Oct ’25