vapor-docs/3.0/docs/crypto/mac.md

Message authentication

Message authentication is used for verifying message authenticity and validity.

Common use cases are JSON Web Tokens.

For message authentication, Vapor only supports HMAC.

Using HMAC

To use HMAC you first need to select the used hashing algorithm for authentication. This works using generics.

let hash = HMAC<SHA224>.authenticate(message, withKey: authenticationKey)