1#!/usr/bin/env perl
2
3##
4## Author......: See docs/credits.txt
5## License.....: MIT
6##
7
8use strict;
9use warnings;
10
11use MIME::Base64 qw (decode_base64 encode_base64);
12use Digest::SHA  qw (sha256);
13use Digest::HMAC qw (hmac);
14use Crypt::PBKDF2;
15
16sub module_constraints { [[0, 256], [28, 28], [-1, -1], [-1, -1], [-1, -1]] }
17
18my $ITERATIONS = 15000;
19my $HMAC_SALT  = "Server Key";
20
21sub module_generate_hash
22{
23  my $word = shift;
24  my $salt = shift;
25  my $iter = shift // $ITERATIONS;
26  my $user = shift // random_string (random_number (0, 64));
27
28  my $pbkdf = Crypt::PBKDF2->new
29  (
30    hasher     => Crypt::PBKDF2->hasher_from_algorithm ('HMACSHA2', 256),
31    iterations => $iter,
32    output_len => 32
33  );
34
35  my $pbkdf2_dgst = $pbkdf->PBKDF2 ($salt, $word);
36
37  my $hash_buf = hmac ($HMAC_SALT, $pbkdf2_dgst, \&sha256);
38
39  my $hash = sprintf ('$mongodb-scram$*1*%s*%i*%s*%s', encode_base64 ($user, ""), $iter, encode_base64 ($salt, ""), encode_base64 ($hash_buf, ""));
40
41  return $hash;
42}
43
44sub module_verify_hash
45{
46  my $line = shift;
47
48  my $idx = index ($line, ':');
49
50  return unless $idx >= 0;
51
52  my $hash = substr ($line, 0, $idx);
53  my $word = substr ($line, $idx + 1);
54
55  return unless substr ($hash, 0, 17) eq '$mongodb-scram$*1';
56
57  my (undef, undef, $user, $iter, $salt) = split ('\*', $hash);
58
59  return unless defined ($user);
60  return unless defined ($iter);
61  return unless defined ($salt);
62
63  return unless ($user =~ m/^[A-Za-z0-9+\/=]{0,88}$/);
64
65  $user = decode_base64 ($user);
66
67  return unless (length ($user) <= 64);
68
69  return unless ($iter =~ m/^[1-9][0-9]{0,7}$/);
70
71  $iter = int ($iter);
72
73  return unless ($salt =~ m/^[A-Za-z0-9+\/=]{40}$/);
74
75  $salt = decode_base64 ($salt);
76
77  my $word_packed = pack_if_HEX_notation ($word);
78
79  my $new_hash = module_generate_hash ($word_packed, $salt, $iter, $user);
80
81  return ($new_hash, $word);
82}
83
841;
85