# isValidAuthenticationCode(_:authenticating:using:) Returns a Boolean value indicating whether the given message authentication code is valid for a block of data stored in a buffer. ``` static func isValidAuthenticationCode(_ mac: HMAC.MAC, authenticating bufferPointer: UnsafeRawBufferPointer, using key: SymmetricKey) -> Bool ``` ## Parameters `mac` The authentication code to compare. `bufferPointer` A pointer to the block of data to compare. `key` The symmetric key for the authentication code. ## Return Value A Boolean value that’s `true` if the message authentication code is valid for the data within the specified buffer. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)