NAME

Digest::Haval256 - A 5-round, 256-bit one-way hash function

ABSTRACT

Digest::Haval256 is a 5-round, 256-bit one-way hash function

SYNOPSIS

    use Digest::Haval256;

    $haval = new Digest::Haval256;
    $haval->add(LIST);
    $haval->addfile(*HANDLE);

    $digest = $haval->digest();
    $digest = $haval->hexdigest();
    $digest = $haval->base64digest();
    
    $digest = $haval->hashsize();
    $digest = $haval->rounds();

DESCRIPTION

Haval is a variable-length, variable-round one-way hash function designed by Yuliang Zheng, Josef Pieprzyk, and Jennifer Seberry. The number of rounds can be 3, 4, or 5, while the hash length can be 128, 160, 192, 224, or 256 bits. Thus, there are a total of 15 different outputs. For better security, however, this module implements the 5-round, 256-bit output.

Functions

hashsize

Returns the size (in bytes) of the hash (32, in this case)

rounds

Returns the number of rounds used (5, in this case)

add(LIST)

Hashes a string or a list of strings

addfile(*HANDLE)

Hashes a file

digest()

Generates a 32-byte binary string

hexdigest()

Generates a hexadecimal representation of the hash output

base64digest()

Generates a base64 representation of the hash output. MIME::Base64 must be installed first for this function to work.

EXAMPLE 1

    #!/usr/local/bin/perl

    use diagnostics;
    use strict;
    use warnings;
    use Digest::Haval256;

    my $string1 = "This is a string.";
    my $string2 = "This is another string.";
    my $string3 = "This is a string.This is another string.";

    my $haval = new Digest::Haval256;
    print "hash size=", $haval->hashsize, "\n";
    print "number of rounds=", $haval->rounds, "\n\n";

    $haval->add($string1);
    my $digest = $haval->hexdigest();
    print "Hash string1 only\n";
    print "$digest\n\n";

    my $haval2 = new Digest::Haval256;
    $haval2->add($string1, $string2);
    my $digest2 = $haval2->hexdigest();
    print "Hash string1 and then hash string2\n";
    print "$digest2\n\n";

    my $haval3 = new Digest::Haval256;
    $haval3->add($string3);
    print "Hash the two concatenated strings\n";
    my $digest3 = $haval3->hexdigest();
    print "$digest3\n";

EXAMPLE 2

    #!/usr/local/bin/perl

    use diagnostics;
    use strict;
    use warnings;
    use MIME::Base64;
    use Digest::Haval256;

    my $file = "strings.pl";
    open INFILE, $file;

    my $haval = new Digest::Haval256;
    $haval->addfile(*INFILE);
    my $hex_output = $haval->hexdigest();
    my $base64_output = $haval->base64digest();
    close INFILE;
    print "$file\n";
    print "$hex_output\n";
    print "$base64_output\n";

MORE EXAMPLES

See the "examples" and "t" directories for more examples.

COPYRIGHT AND LICENSE

Copyright 2003 by Julius C. Duque <jcduque (AT) lycos (DOT) com>

This library is free software; you can redistribute it and/or modify it under the same terms as the GNU General Public License.