Digest::HMAC - Keyed-Hashing for Message Authentication
# Functional style
use Digest::HMAC qw(hmac hmac_hex);
$digest = hmac($data, $key, \&myhash);
print hmac_hex($data, $key, \&myhash);
# OO style
use Digest::HMAC;
$hmac = Digest::HMAC->new($key, "Digest::MyHash");
$hmac->add($data);
$hmac->addfile(*FILE);
$digest = $hmac->digest;
$digest = $hmac->hexdigest;
$digest = $hmac->b64digest;
HMAC is used for message integrity checks between two parties that
share a secret key, and works in combination with some other Digest
algorithm, usually MD5 or SHA-1. The HMAC mechanism is described in
RFC 2104.
HMAC follow the common Digest:: interface, but the constructor
takes the secret key and the name of some other simple Digest::
as argument.
The hmac() and hmac_hex() functions and the Digest::HMAC->new() constructor
takes an optional $blocksize argument as well. The HMAC algorithm assumes the
digester to hash by iterating a basic compression function on blocks of data
and the $blocksize should match the byte-length of such blocks.
The default $blocksize is 64 which is suitable for the MD5 and SHA-1 digest
functions. For stronger algorithms the blocksize probably needs to be
increased.
the Digest::HMAC_MD5 manpage, the Digest::HMAC_SHA1 manpage
RFC 2104
Andrew Rodland <arodland@cpan.org>
Graham Barr <gbarr@ti.com>, Gisle Aas <gisle@aas.no>
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