# Functional style use Digest::HMAC_SHA1 qw(hmac_sha1 hmac_sha1_hex); $digest = hmac_sha1($data, $key); print hmac_sha1_hex($data, $key); # OO style use Digest::HMAC_SHA1; $hmac = Digest::HMAC_SHA1->new($key); $hmac->add($data); $hmac->addfile(*FILE); $digest = $hmac->digest; $digest = $hmac->hexdigest; $digest = $hmac->b64digest;