General: Forums topic: Privacy & Security Apple Platform Security support document Developer > Security Enabling enhanced security for your app documentation article Creating enhanced security helper extensions documentation article Security Audit Thoughts forums post Cryptography: Forums tags: Security, Apple CryptoKit Security framework documentation Apple CryptoKit framework documentation Common Crypto man pages — For the full list of pages, run: % man -k 3cc For more information about man pages, see Reading UNIX Manual Pages. On Cryptographic Key Formats forums post SecItem attributes for keys forums post CryptoCompatibility sample code Keychain: Forums tags: Security Security > Keychain Items documentation TN3137 On Mac keychain APIs and implementations SecItem Fundamentals forums post SecItem Pitfalls and Best Practices forums post Investigating hard-to-reproduce keychain problems forums post App ID Prefix Change and Keychain Access forums post Smart cards and other secure tokens: Forums tag: CryptoTokenKit CryptoTokenKit framework documentation Mac-specific resources: Forums tags: Security Foundation, Security Interface Security Foundation framework documentation Security Interface framework documentation BSD Privilege Escalation on macOS Related: Networking Resources — This covers high-level network security, including HTTPS and TLS. Network Extension Resources — This covers low-level network security, including VPN and content filters. Code Signing Resources Notarisation Resources Trusted Execution Resources — This includes Gatekeeper. App Sandbox Resources Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

Hi, I have an application that uses SecureEnclave keys to protect secrets. By passing an LAContext object to the Secure Enclave operations, authentication state can be preserved across decrypt operations, and you do not need to re-authenticate for doing different operations. However, for security reasons, I would like to avoid that it is possible to do operations in batch with certain keys generated by the Secure Enclave, by any application. This would avoid malicious binaries to batch-extract all the secrets that are protected by a key from my Secure Enclave, and force to re-authenticate on every operation. Is there a way to prevent batch operations without re-authenticating for Secure Enclave keys? thanks, Remko

We are preparing to implement document signing using USB tokens on iOS and macOS. Several other applications already support this feature. From my testing and development efforts, I've been unable to reliably access or utilize certificates stored on a smartcard through the iOS APIs. Here are the specifics: Environment iOS: 15 and later Xcode: Versions 18 and 26 Smartcard/Token: ePass 2003 (eMudhra), Feitien token (Capricorn) Observed Issue : The token is recognized at the system level, with certificates visible in Keychain Access. However, programmatic access to the private keys on the smartcard from within the app is not working. Signing attempts result in Error 6985 and CACC errors. Approaches Tried: Updated provisioning profiles with the following entitlements: com.apple.developer.smartcard com.apple.security.device.usb TKSmartCard Employed TKSmartCard and TKSmartCardSession for interaction. The token is detected successfully. A session can be established, but there's no straightforward method to leverage it for certificate-based signing. Access to signing functions is unavailable; operations yield Error 6985 or CACC errors. if let smartCard = TKSmartCard(slot: someSlot) { smartCard.openSession { session, error in if let session = session { let command: [UInt8] = [0x00, 0xA4, 0x04, 0x00] session.transmit(Data(command)) { response, error in print("Response: \(String(describing: response))") print("Error: \(String(describing: error))") } } } } TokenKit (macOS/iOS) - Utilized TKTokenWatcher to identify available tokens on macOS (not available on iOS). watcher.setInsertionHandler { tokenID in print("Token detected: \(tokenID)") } CryptoKit / Security Framework - Attempted to retrieve SecCertificate using SecItemCopyMatching queries, which succeeded on macOS but failed on iOS. let query: [CFString: Any] = [ kSecClass: kSecClassCertificate, kSecReturnRef: true, kSecMatchLimit: kSecMatchLimitAll ] var items: CFTypeRef? let status = SecItemCopyMatching(query as CFDictionary, &items) print("Status: \(status)") // macOS succeeds, iOS fails ExternalAccessory Framework (EAAccessory) * Investigated using EAAccessory and EASession for external token communication, but it did not function as expected. This functionality is critical for my project. Has anyone successfully implemented smartcard-based signing on iOS? Any guidance, sample code, or references to relevant Apple documentation would be greatly appreciated.

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.

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

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.)

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

I am writing a MacOS app that uses the Apple crypto libraries to create, save, and use an RSA key pair. I am not using a Secure Enclave so that the private key can later the retrieved through the keychain. The problem I am running into is that on my and multiple other systems the creation and retrieval works fine. On a different system -- running MacOS 15.3 just like the working systems -- the SecKeyCreateRandomKey function appears to work fine and I get a key reference back, but on subsequent runs SecItemCopyMatching results in errSecItemNotFound. Why would it appear to save properly on some systems and not others? var error: Unmanaged<CFError>? let access = SecAccessControlCreateWithFlags(kCFAllocatorDefault, kSecAttrAccessibleWhenUnlockedThisDeviceOnly, .biometryAny, &error)! let tag = TAG.data(using: .utf8)! // com.example.myapp.rsakey let attributes: [String: Any] = [ kSecAttrKeyType as String: KEY_TYPE, // set to kSecAttrKeyTypeRSA kSecAttrKeySizeInBits as String: 3072, kSecPrivateKeyAttrs as String: [ kSecAttrIsPermanent as String: true, kSecAttrApplicationTag as String: tag, kSecAttrAccessControl as String: access, ], ] guard let newKey = SecKeyCreateRandomKey(attributes as CFDictionary, &error) else { throw error!.takeRetainedValue() as Error } return newKey This runs fine on both systems, getting a valid key reference that I can use. But then if I immediately try to pull the key, it works on my system but not the other. let query = [ kSecClass as String: kSecClassKey, kSecAttrApplicationTag as String: tag, kSecReturnRef as String: true, ] var item: CFTypeRef? let status = SecItemCopyMatching(query as CFDictionary, &item) let msg = SecCopyErrorMessageString(status, nil) if status == errSecItemNotFound { print("key not found") } guard status == errSecSuccess else { print("other retrieval error") } return item as! SecKey I've also tried a separate query using the secCall function from here (https://developer.apple.com/forums/thread/710961) that gets ALL kSecClassKey items before and after the "create the key" function and it'll report the same amount of keys before and after on the bugged system. On the other machines where it works, it'll show one more key as expected. In the Signing & Capabilities section of the project config, I have Keychain Sharing set up with a group like com.example.myapp where my key uses a tag like com.example.myapp.rsakey. The entitlements file has an associated entry for Keychain Access Groups with value $(AppIdentifierPrefix)com.example.myapp.