1#!/usr/bin/env perl
2
3##
4## Author......: See docs/credits.txt
5## License.....: MIT
6##
7
8use strict;
9use warnings;
10use MIME::Base64 qw (encode_base64 decode_base64);
11
12use Digest::MD5 qw (md5);
13
14sub module_constraints { [[-1, -1], [-1, -1], [0, 55], [-1, -1], [-1, -1]] }
15
16my $itoa62 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
17
18sub module_generate_hash
19{
20  my $word = shift;
21
22  my $digest = md5 ($word);
23
24  my @chksum;
25
26  for (my $i = 0, my $j = 0; $i < 16; $i += 2, $j += 1)
27  {
28    $chksum[$j] = (ord (substr ($digest, $i + 0, 1)) + ord (substr ($digest, $i + 1, 1))) % 62;
29
30    $chksum[$j] = substr ($itoa62, $chksum[$j], 1);
31  }
32
33  my $res = join "", @chksum;
34
35  my $hash = sprintf ("%s", $res);
36
37  return $hash;
38}
39
40sub module_verify_hash
41{
42  my $line = shift;
43
44  my ($hash, $word) = split (':', $line);
45
46  return unless defined $hash;
47  return unless defined $word;
48
49  my $word_packed = pack_if_HEX_notation ($word);
50
51  my $new_hash = module_generate_hash ($word_packed);
52
53  return ($new_hash, $word);
54}
55
561;
57