README
1NAME
2 PBKDF2::Tiny - Minimalist PBKDF2 (RFC 2898) with HMAC-SHA1 or HMAC-SHA2
3
4VERSION
5 version 0.005
6
7SYNOPSIS
8 use PBKDF2::Tiny qw/derive verify/;
9
10 my $dk = derive( 'SHA-1', $pass, $salt, $iters );
11
12 if ( verify( $dk, 'SHA-1', $pass, $salt, $iters ) ) {
13 # password is correct
14 }
15
16DESCRIPTION
17 This module provides an RFC 2898 <https://tools.ietf.org/html/rfc2898>
18 compliant PBKDF2 implementation using HMAC-SHA1 or HMAC-SHA2 in under
19 100 lines of code. If you are using Perl 5.10 or later, it uses only
20 core Perl modules. If you are on an earlier version of Perl, you need
21 Digest::SHA or Digest::SHA::PurePerl.
22
23 All documented functions are optionally exported. No functions are
24 exported by default.
25
26FUNCTIONS
27 derive
28 $dk = derive( $type, $password, $salt, $iterations, $dk_length )
29
30 The "derive" function outputs a binary string with the derived key. The
31 first argument indicates the digest function to use. It must be one of:
32 SHA-1, SHA-224, SHA-256, SHA-384, or SHA-512.
33
34 If a password or salt are not provided, they default to the empty
35 string, so don't do that! RFC 2898 recommends
36 <https://tools.ietf.org/html/rfc2898#section-4.1> a random salt of at
37 least 8 octets. If you need a cryptographically strong salt, consider
38 Crypt::URandom.
39
40 The password and salt should encoded as octet strings. If not (i.e. if
41 Perl's internal 'UTF8' flag is on), then an exception will be thrown.
42
43 The number of iterations defaults to 1000 if not provided. If the
44 derived key length is not provided, it defaults to the output size of
45 the digest function.
46
47 derive_hex
48 Works just like "derive" but outputs a hex string.
49
50 verify
51 $bool = verify( $dk, $type, $password, $salt, $iterations, $dk_length );
52
53 The "verify" function checks that a given derived key (in binary form)
54 matches the password and other parameters provided using a constant-time
55 comparison function.
56
57 The first parameter is the derived key to check. The remaining
58 parameters are the same as for "derive".
59
60 verify_hex
61 Works just like "verify" but the derived key must be a hex string
62 (without a leading "0x").
63
64 digest_fcn
65 ($fcn, $block_size, $digest_length) = digest_fcn('SHA-1');
66 $digest = $fcn->($data);
67
68 This function is used internally by PBKDF2::Tiny, but made available in
69 case it's useful to someone.
70
71 Given one of the valid digest types, it returns a function reference
72 that digests a string of data. It also returns block size and digest
73 length for that digest type.
74
75 hmac
76 $key = $digest_fcn->($key) if length($key) > $block_size;
77 $hmac = hmac( $data, $key, $digest_fcn, $block_size );
78
79 This function is used internally by PBKDF2::Tiny, but made available in
80 case it's useful to someone.
81
82 The first two arguments are the data and key inputs to the HMAC
83 function. Both should be encoded as octet strings, as underlying
84 HMAC/digest functions may croak or may give unexpected results if Perl's
85 internal UTF-8 flag is on.
86
87 Note: if the key is longer than the digest block size, it must be
88 preprocessed using the digesting function.
89
90 The third and fourth arguments must be a digesting code reference (from
91 "digest_fcn") and block size.
92
93SEE ALSO
94 * Crypt::PBKDF2
95
96 * Digest::PBDKF2
97
98SUPPORT
99 Bugs / Feature Requests
100 Please report any bugs or feature requests through the issue tracker at
101 <https://github.com/dagolden/PBKDF2-Tiny/issues>. You will be notified
102 automatically of any progress on your issue.
103
104 Source Code
105 This is open source software. The code repository is available for
106 public review and contribution under the terms of the license.
107
108 <https://github.com/dagolden/PBKDF2-Tiny>
109
110 git clone https://github.com/dagolden/PBKDF2-Tiny.git
111
112AUTHOR
113 David Golden <dagolden@cpan.org>
114
115COPYRIGHT AND LICENSE
116 This software is Copyright (c) 2014 by David Golden.
117
118 This is free software, licensed under:
119
120 The Apache License, Version 2.0, January 2004
121
122