1Digest::HMAC(3)       User Contributed Perl Documentation      Digest::HMAC(3)
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NAME

6       Digest::HMAC - Keyed-Hashing for Message Authentication
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SYNOPSIS

9        # Functional style
10        use Digest::HMAC qw(hmac hmac_hex);
11        $digest = hmac($data, $key, \&myhash);
12        print hmac_hex($data, $key, \&myhash);
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14        # OO style
15        use Digest::HMAC;
16        $hmac = Digest::HMAC->new($key, "Digest::MyHash");
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18        $hmac->add($data);
19        $hmac->addfile(*FILE);
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21        $digest = $hmac->digest;
22        $digest = $hmac->hexdigest;
23        $digest = $hmac->b64digest;
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DESCRIPTION

26       HMAC is used for message integrity checks between two parties that
27       share a secret key, and works in combination with some other Digest
28       algorithm, usually MD5 or SHA-1.  The HMAC mechanism is described in
29       RFC 2104.
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31       HMAC follow the common "Digest::" interface, but the constructor takes
32       the secret key and the name of some other simple "Digest::" as
33       argument.
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35       The hmac() and hmac_hex() functions and the Digest::HMAC->new()
36       constructor takes an optional $blocksize argument as well.  The HMAC
37       algorithm assumes the digester to hash by iterating a basic compression
38       function on blocks of data and the $blocksize should match the byte-
39       length of such blocks.
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41       The default $blocksize is 64 which is suitable for the MD5 and SHA-1
42       digest functions.  For stronger algorithms the blocksize probably needs
43       to be increased.
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SEE ALSO

46       Digest::HMAC_MD5, Digest::HMAC_SHA1
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48       RFC 2104
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AUTHORS

51       Graham Barr <gbarr@ti.com>, Gisle Aas <gisle@aas.no>
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55perl v5.16.3                      2011-07-25                   Digest::HMAC(3)