hmac

Computes an HMAC (Hash-based Message Authentication Code).

hmac(x:any, key:string, [algorithm=string]) -> string

Description

The hmac function computes an HMAC for the given value x using the provided key. HMAC combines a cryptographic hash function with a secret key to produce a message authentication code, useful for verifying both data integrity and authenticity.

`x: any`

The value to authenticate. Strings and blobs are hashed directly; other types are first converted to their string representation.

`key: string`

The secret key for the HMAC computation. Currently a plain string; secret support is planned for the future.

`algorithm = string (optional)`

The hash algorithm to use. Defaults to "sha256".

Supported algorithms: sha256, sha512, sha384, sha1, md5.

Examples

Compute an HMAC with the default algorithm (SHA-256)

from {
  digest: hmac("The quick brown fox jumps over the lazy dog", "key"),
}

{
  digest: "f7bc83f430538424b13298e6aa6fb143ef4d59a14946175997479dbc2d1a3cd8",
}

Compute an HMAC with SHA-512

from {
  digest: hmac("The quick brown fox jumps over the lazy dog", "key", algorithm="sha512"),
}

{
  digest: "b42af09057bac1e2d41708e48a902e09b5ff7f12ab428a4fe86653c73dd248fb82f948a549f7b791a5b41915ee4d1ec3935357e4e2317250d0372afa2ebeeb3a",
}

Authenticate field values in a pipeline

from {message: "login_attempt", user: "alice"}
digest = hmac(message, "my-secret-key")

{
  message: "login_attempt",
  user: "alice",
  digest: "a52e561875744cb115f279f496517fd63e53df997a1e3f98a70dd3d7d51748b5",
}