Fork from @retupmoca's original fixing some installation errors.

use Digest::HMAC;
use Digest;

my Buf $hmac = hmac($key, $data, &md5);
my Str $hmac = hmac-hex($key, $data, &md5);

• sub hmac-hex($key, $data, Callable &hash, $blocksize = 64 --> Str)

  Returns the hex stringified output of hmac.

• sub hmac($key, $data, Callable &hash, $blocksize = 64 --> Buf)

  Computes the HMAC of the passed information.

  $key and $data can either be Str or Blob objects; if they are Str they will be encoded as ascii.

  &hash needs to be a hash function that takes and returns a Blob or Buf. If it operates on or returns a Str, it will not work. (The md5, sha1, sha256 functions from Digest work well, as in the example above)

  $blocksize is the block size of the hash function. 64 is the default, and is correct for at least md5, sha1, sha256.

Since version 0.28, Digest also implements the HMAC algorithm, along with many others. You can use that one for a more complete range of digest methods.