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

Posts under General subtopic

Post

Replies

Boosts

Views

Activity

C++ HMAC-SHA256 Signature Works in Python, Fails in C++ — Possible Xcode Runtime Issue?
Hi all, I’m building a macOS-native C++ trading bot, compiled via Xcode. It sends REST API requests to a crypto exchange (Bitvavo) that require HMAC-SHA256 signatures using a pre-sign string (timestamp + method + path + body) and an API secret. Here’s the issue: • The exact same pre-sign string and API secret produce valid responses when signed using Python (hmac.new(secret, msg, hashlib.sha256)), • But when I generate the HMAC signature using C++ (HMAC(EVP_sha256, ...) via OpenSSL), the exchange returns an invalid signature error. Environment: • Xcode 15.3 / macOS 14.x • OpenSSL installed via Homebrew • HMAC test vectors match Python’s output for basic strings (so HMAC lib seems correct) Yet when using the real API keys and dynamic timestamped messages, something differs enough to break verification — possibly due to UTF-8 encoding, memory alignment, or newline handling differences in the Xcode C++ runtime? Has anyone experienced subtle differences between Python and C++ HMAC-SHA256 behavior when compiled in Xcode? I’ve published a GitHub repo for reproducibility: 🔗 https://github.com/vanBaardewijk/bitvavo-cpp-signature-test Thanks in advance for any suggestions or insights. Sascha
2
0
718
Jul ’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?
2
0
114
May ’25
com.apple.developer.web-browser.public-key-credential still leads to com.apple.AuthenticationServices.AuthorizationError Code=1004
Hi, we were recently approved for the com.apple.developer.web-browser.public-key-credential entitlement and have added it to our app. It initially worked as expected for a couple of days, but then it stopped working. We're now seeing the same error as before adding the entitlement: 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)" Do you have any insights into what might be causing this issue? Thank you!
2
0
169
May ’25
ASWebAuthenticationSession password autofill iOS 18.5 broken
I have been implementing an sdk for authenticating a user. I have noticed that on iOS 18.5, whether using SFSafariViewController, or the sdk (built on ASWebAuthenticationSession), password autofill does not work. I have confirmed it works on a different device running iOS 18.0.1. Are there any work arounds for this at this time? Specifically for ASWebAuthenticationSession?
2
0
196
Jul ’25
Mobile apps and consent dialogue when logging in
We are using ASWebAuthenticationSession with apps on IoS to achieve SSO between apps. The IdP for authentication (OIDC) is an on-premise and trusted enterprise IdP based on one of the leading products in the market. Our problem is that the user is prompted for every login (and logouts) with a consent dialogue box: “AppName” wants to use “internal domain-name” to Sign In This allows the app and website to share information about you. Cancel Continue” I have read in various places that Apple has a concept of “Trusted domains” where you can put an “Apple certified” static web-page on the IdP. This page needs to contain specific metadata that iOS can verify. Once a user logs in successfully a few times, and if the IdP is verified as trusted, subsequent logins would not prompt the consent screen. Question: I struggle to find Apple documentation on how to go about a process that ends with this “Apple certified web-page” on our IdP”. Anyone who has experience with this process, or who can point me in some direction to find related documentation?
2
0
493
May ’25
Authorization Plugin View Still Appears After Login on Home Screen for a Few Seconds
I am developing a custom authorization plugin for macOS, and I’ve encountered an issue where the auth plugin view remains visible on the home screen for a few seconds after login. Issue Details: After entering valid credentials, I call setResult(.allow) in my plugin to proceed with login. The authentication succeeds, and macOS starts transitioning to the home screen. However, for a few seconds after login, the authorization plugin view is still visible on the home screen before it disappears. I have observed this issue even when using Apple's sample authorization plugin. Observation: This issue occurs without an external monitor (on a single built-in display). If I manually close the plugin window inside Destroy(AuthPlugin.mechanism), then the auth plugin views do not appear on the home screen, which seems to fix the issue. However, when I do this, a gray screen appears for about a second before the desktop environment fully loads. I suspect that the gray screen appears due to the time macOS takes to fully load the home screen environment after login. Questions: Why does the authorization plugin view persist on the home screen for a few seconds after login? Is manually closing the plugin window in Destroy(AuthPlugin.mechanism) the correct way to prevent this, or is there a better approach? Is my assumption that the gray screen appears due to the home screen not being fully loaded correct? If the gray screen is caused by home screen loading, is there a system notification or event I can listen to in order to know when the home screen has fully loaded?
2
0
382
Mar ’25
Protecting XPC service when called from Authorisation Plugin
I have Authorisation Plugin which talks using XPC to my Launch Daemon to perform privileged actions. I want to protect my XPC service narrowing it to be called from known trusted clients. Now since I want authorisation plugin code which is from apple to call my service, I cannot use my own team id or app group here. I am currently banking on following properties of client connection. Apple Team ID : EQHXZ8M8AV Bundle ID starting with com.apple. Client signature verified By Apple. This is what I have come up with. func isClientTrusted(connection: NSXPCConnection) -> Bool { let clientPID = connection.processIdentifier logInfo("🔍 Checking XPC Client - PID: \(clientPID)") var secCode: SecCode? var secStaticCode: SecStaticCode? let attributes = [kSecGuestAttributePid: clientPID] as NSDictionary let status = SecCodeCopyGuestWithAttributes(nil, attributes, [], &secCode) guard status == errSecSuccess, let code = secCode else { logInfo("Failed to get SecCode for PID \(clientPID)") return false } let staticStatus = SecCodeCopyStaticCode(code, [], &secStaticCode) guard staticStatus == errSecSuccess, let staticCode = secStaticCode else { logInfo("Failed to get SecStaticCode") return false } var signingInfo: CFDictionary? let signingStatus = SecCodeCopySigningInformation(staticCode, SecCSFlags(rawValue: kSecCSSigningInformation), &signingInfo) guard signingStatus == errSecSuccess, let info = signingInfo as? [String: Any] else { logInfo("Failed to retrieve signing info") return false } // Extract and Verify Team ID if let teamID = info["teamid"] as? String { logInfo("XPC Client Team ID: \(teamID)") if teamID != "EQHXZ8M8AV" { // Apple's official Team ID logInfo("Client is NOT signed by Apple") return false } } else { logInfo("Failed to retrieve Team ID") return false } // Verify Bundle ID Starts with "com.apple." if let bundleID = info["identifier"] as? String { logInfo("XPC Client Bundle ID: \(bundleID)") if !bundleID.hasPrefix("com.apple.") { logInfo("Client is NOT an Apple system process") return false } } else { logInfo("Failed to retrieve Bundle Identifier") return false } // Verify Apple Code Signature Trust var trustRequirement: SecRequirement? let trustStatus = SecRequirementCreateWithString("anchor apple" as CFString, [], &trustRequirement) guard trustStatus == errSecSuccess, let trust = trustRequirement else { logInfo("Failed to create trust requirement") return false } let verifyStatus = SecStaticCodeCheckValidity(staticCode, [], trust) if verifyStatus != errSecSuccess { logInfo("Client's signature is NOT trusted by Apple") return false } logInfo("Client is fully verified as Apple-trusted") return true } Q: Just wanted community feedback, is this correct approach?
2
0
139
Mar ’25
What personal data is included in iOS storage logs
While I was submitting a new feedback today for an iPhone/iPad storage issue, I saw a new log called “iOS storage log”. I could find no reference to this when I searched online. It made me wonder if it was new and if it contained personal data? Most of us only have one device, with all our personal data. Therefore, I’d appreciate any input on what personal data these logs contain.
2
0
144
Jul ’25
Command line app doesn't prompt for a permission when it runs from from a terminal
I've made a simple command line app that requires Screen recording permission. When I ran it from Xcode, it prompts for a permission and once I allowed it from the settings, it runs well. #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <CoreGraphics/CGDisplayStream.h> int main() { printf("# Start #\n"); if (CGPreflightScreenCaptureAccess()) { printf("# Permitted.\n"); } else { printf("# Not permitted.\n"); if (CGRequestScreenCaptureAccess() == false) { printf("# CGRequestScreenCaptureAccess() returning false\n"); } } size_t output_width = 1280; size_t output_height = 720; dispatch_queue_t dq = dispatch_queue_create("com.domain.screengrabber", DISPATCH_QUEUE_SERIAL); CGError err; CGDisplayStreamRef sref = CGDisplayStreamCreateWithDispatchQueue( 1, output_width, output_height, 'BGRA', NULL, dq, ^( CGDisplayStreamFrameStatus status, uint64_t time, IOSurfaceRef frame, CGDisplayStreamUpdateRef ref ) { printf("Got frame: %llu, FrameStatus:%d \n", time, status); } ); err = CGDisplayStreamStart(sref); if (kCGErrorSuccess != err) { printf("Error: failed to start streaming the display. %d\n", err); exit(EXIT_FAILURE); } while (true) { usleep(1e5); } CGDisplayStreamStop(sref); printf("\n\n"); return 0; } Now I want to execute this from terminal, so I went to the build folder and typed the app name. cd /Users/klee/Library/Developer/Xcode/DerivedData/ScreenStreamTest-ezddqbkzhndhakadslymnvpowtig/Build/Products/Debug ./ScreenStreamTest But I am getting following output without any prompt for permission. # Start # # Not permitted. # CGRequestScreenCaptureAccess() returning false Error: failed to start streaming the display. 1001 Is there a something I need to consider for this type of command line app?
2
0
682
Dec ’24
ASPasswordCredential Returns a Blank Password with Apple Password App
Using the simplified sign-in with tvOS and a third party password manager, I receive a complete ASPasswordCredential, and I can easily log into my app. When I do the same thing but with Apple's password manager as the source, I receive an ASPasswordCredential that includes the email address, but the password is an empty string. I have tried deleting the credentials from Apple Passwords and regenerating them with a new login to the app's website. I have tried restarting my iPhone. Is this the expected behavior? How should I be getting a password from Apple's Password app with an ASAuthorizationPasswordRequest?
2
0
242
Aug ’25
Permission requirements for LAContext's canEvaluatePolicy
Hi, I am developing an app that checks if biometric authentication capabilities (Face ID and Touch ID) are available on a device. I have a few questions: Do I need to include a privacy string in my app to use the LAContext's canEvaluatePolicy function? This function checks if biometric authentication is available on the device, but does not actually trigger the authentication. From my testing, it seems like a privacy declaration is only required when using LAContext's evaluatePolicy function, which would trigger the biometric authentication. Can you confirm if this is the expected behavior across all iOS versions and iPhone models? When exactly does the biometric authentication permission pop-up appear for users - is it when calling canEvaluatePolicy or evaluatePolicy? I want to ensure my users have a seamless experience. Please let me know if you have any insights on these questions. I want to make sure I'm handling the biometric authentication functionality correctly in my app. Thank you!
2
0
121
Jun ’25
Custom Authorization Plugin in Login Flow
What Has Been Implemented Replaced the default loginwindow:login with a custom authorization plugin. The plugin: Performs primary OTP authentication. Displays a custom password prompt. Validates the password using Open Directory (OD) APIs. Next Scenario was handling password change Password change is simulated via: sudo pwpolicy -u robo -setpolicy "newPasswordRequired=1" On next login: Plugin retrieves the old password. OD API returns kODErrorCredentialsPasswordChangeRequired. Triggers a custom change password window to collect and set new password. Issue Observed : After changing password: The user’s login keychain resets. Custom entries under the login keychain are removed. We have tried few solutions Using API, SecKeychainChangePassword(...) Using CLI, security set-keychain-password -o oldpwd -p newpwd ~/Library/Keychains/login.keychain-db These approaches appear to successfully change the keychain password, but: On launching Keychain Access, two password prompts appear, after authentication, Keychain Access window doesn't appear (no app visibility). Question: Is there a reliable way (API or CLI) to reset or update the user’s login keychain password from within the custom authorization plugin, so: The keychain is not reset or lost. Keychain Access works normally post-login. The password update experience is seamless. Thank you for your help and I appreciate your time and consideration
2
0
139
Jun ’25
Determining if a block of data was signed on the Secure Enclave
Hello, I'm exploring the Secure Enclave APIs, and I'm wondering if it's possible to "cryptographically" determine if a block of data was signed on the Secure Enclave. When I sign a block of data using the Secure Enclave (which implies using a key pair automatically generated by the enclave) and distribute the public key to others, is there any way to verify if the message was encrypted on it / its private key was generated by it? In other words, what I'm trying to achieve is to make sure that the public key hasn't been tampered with until it reaches its destination (including on-device threats, since otherwise I could've used a normal keychain item, perhaps?). For the purpose of this example, I'm not necessarily interested in figuring out if the key was signed on a certain device's enclave, but rather on any Secure Enclave. So, using something derived from the enclave's GID Key (described in the Apple Platform Security guide) would work for this.
2
0
597
Jan ’25
DCError.invalidInput on generateAssertion() - Affecting Small Subset of Users
Issue Summary I'm encountering a DCError.invalidInput error when calling DCAppAttestService.shared.generateAssertion() in my App Attest implementation. This issue affects only a small subset of users - the majority of users can successfully complete both attestation and assertion flows without any issues. According to Apple Engineer feedback, there might be a small implementation issue in my code. Key Observations Success Rate: ~95% of users complete the flow successfully Failure Pattern: The remaining ~5% consistently fail at assertion generation Key Length: Logs show key length of 44 characters for both successful and failing cases Consistency: Users who experience the error tend to experience it consistently Platform: Issue observed across different iOS versions and device types Environment iOS App Attest implementation Using DCAppAttestService for both attestation and assertion Custom relying party server communication Issue affects ~5% of users consistently Key Implementation Details 1. Attestation Flow (Working) The attestation process works correctly: // Generate key and attest (successful for all users) self.attestService.generateKey { keyId, keyIdError in guard keyIdError == nil, let keyId = keyId else { return completionHandler(.failure(.dcError(keyIdError as! DCError))) } // Note: keyId length is consistently 44 characters for both successful and failing users // Attest key with Apple servers self.attestKey(keyId, clientData: clientData) { result in // ... verification with RP server // Key is successfully stored for ALL users (including those who later fail at assertion) } } 2. Assertion Flow (Failing for ~5% of Users with invalidInput) The assertion generation fails for a consistent subset of users: // Get assertion data from RP server self.assertRelyingParty.getAssertionData(kid, with: data) { result in switch result { case .success(let receivedData): let session = receivedData.session let clientData = receivedData.clientData let hash = clientData.toSHA256() // SHA256 hash of client data // THIS CALL FAILS WITH invalidInput for ~5% of users // Same keyId (44 chars) that worked for attestation self.attestService.generateAssertion(kid, clientDataHash: hash) { assertion, err in guard err == nil, let assertion = assertion else { // Error: DCError.invalidInput if let err = err as? DCError, err.code == .invalidKey { return reattestAndAssert(.invalidKey, completionHandler) } else { return completionHandler(.failure(.dcError(err as! DCError))) } } // ... verification logic } } } 3. Client Data Structure Client data JSON structure (identical for successful and failing users): // For attestation (works for all users) let clientData = ["challenge": receivedData.challenge] // For assertion (fails for ~5% of users with same structure) var clientData = ["challenge": receivedData.challenge] if let data = data { // Additional data for assertion clientData["account"] = data["account"] clientData["amount"] = data["amount"] } 4. SHA256 Hash Implementation extension Data { public func toSHA256() -> Data { return Data(SHA256.hash(data: self)) } } 5. Key Storage Implementation Using UserDefaults for key storage (works consistently for all users): private let keyStorageTag = "app-attest-keyid" func setKey(_ keyId: String) -> Result<(), KeyStorageError> { UserDefaults.standard.set(keyId, forKey: keyStorageTag) return .success(()) } func getKey() -> Result<String?, KeyStorageError> { let keyId = UserDefaults.standard.string(forKey: keyStorageTag) return .success(keyId) } Questions User-Specific Factors: Since this affects only ~5% of users consistently, could there be device-specific, iOS version-specific, or account-specific factors that cause invalidInput? Key State Validation: Is there any way to validate the state of an attested key before calling generateAssertion()? The key length (44 chars) appears normal for both successful and failing cases. Keychain vs UserDefaults: Could the issue be related to using UserDefaults instead of Keychain for key storage? Though this works for 95% of users. Race Conditions: Could there be subtle race conditions or timing issues that only affect certain users/devices? Error Recovery: Is there a recommended way to handle this error? Should we attempt re-attestation for these users? Additional Context & Debugging Attempts Consistent Failure: Users who experience this error typically experience it on every attempt Key Validation: Both successful and failing users have identical key formats (44 character strings) Device Diversity: Issue observed across different device models and iOS versions Server Logs: Our server successfully provides challenges and processes attestation for all users Re-attestation: Forcing re-attestation sometimes resolves the issue temporarily, but it often recurs The fact that 95% of users succeed with identical code suggests there might be some environmental or device-specific factor that we're not accounting for. Any insights into what could cause invalidInput for a subset of users would be invaluable.
2
0
192
Jun ’25
Adding a sandboxed v2ray precompiled binary to my application
Greetings! I want to add my pre-compiled binary of v2ray to my application so I can activate it in background as a proxy and run stuff through it. I've codesigned it via: codesign -s - -i production.myproject.v2ray -o runtime --entitlements v2ray.entitlements -f v2ray Contents of entitlements file: <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>com.apple.security.app-sandbox</key> <true/> <key>com.apple.security.files.downloads.read-write</key> <true/> <key>com.apple.security.files.user-selected.read-write</key> <true/> <key>com.apple.security.network.client</key> <true/> <key>com.apple.security.network.server</key> <true/> </dict> </plist> Originally I ran it like this without sandboxing from my main target app: guard let v2rayPath = Bundle.main.path(forResource: "v2ray", ofType: nil) else { throw NSError(domain: "ProxyController", code: 1, userInfo: [NSLocalizedDescriptionKey: "V2Ray binary not found in bundle"]) } let task = Process() task.executableURL = URL(fileURLWithPath: v2rayPath) task.arguments = ["-config", configURL.path] // Redirect output for debugging let pipe = Pipe() task.standardOutput = pipe task.standardError = pipe``` And it ran flawlessly. Now it refuses to start. Any help, pointers or examples of such usage will be greatly appreciated
2
0
648
Dec ’24
ASWebAuthenticationSession Async/Await API
Is there any particular reason why ASWebAuthenticationSession doesn't have support for async/await? (example below) do { let callbackURL = try await webAuthSession.start() } catch { // handle error } I'm curious if this style of integration doesn't exist for architectural reasons? Or is the legacy completion handler style preserved in order to prevent existing integrations from breaking?
2
1
635
3w