README
1NAME
2 Crypt::Rijndael - Crypt::CBC compliant Rijndael encryption module
3
4SYNOPSIS
5 use Crypt::Rijndael;
6
7 # keysize() is 32, but 24 and 16 are also possible
8 # blocksize() is 16
9
10 $cipher = Crypt::Rijndael->new( "a" x 32, Crypt::Rijndael::MODE_CBC() );
11
12 $cipher->set_iv($iv);
13 $crypted = $cipher->encrypt($plaintext);
14 # - OR -
15 $plaintext = $cipher->decrypt($crypted);
16
17DESCRIPTION
18 This module implements the Rijndael cipher, which has just been selected
19 as the Advanced Encryption Standard.
20
21 keysize
22 Returns the keysize, which is 32 (bytes). The Rijndael cipher
23 actually supports keylengths of 16, 24 or 32 bytes, but there is no
24 way to communicate this to "Crypt::CBC".
25
26 blocksize
27 The blocksize for Rijndael is 16 bytes (128 bits), although the
28 algorithm actually supports any blocksize that is any multiple of
29 our bytes. 128 bits, is however, the AES-specified block size, so
30 this is all we support.
31
32 $cipher = Crypt::Rijndael->new( $key [, $mode] )
33 Create a new "Crypt::Rijndael" cipher object with the given key
34 (which must be 128, 192 or 256 bits long). The additional $mode
35 argument is the encryption mode, either "MODE_ECB" (electronic
36 codebook mode, the default), "MODE_CBC" (cipher block chaining, the
37 same that "Crypt::CBC" does), "MODE_CFB" (128-bit cipher feedback),
38 "MODE_OFB" (128-bit output feedback), or "MODE_CTR" (counter mode).
39
40 ECB mode is very insecure (read a book on cryptography if you dont
41 know why!), so you should probably use CBC mode.
42
43 $cipher->set_iv($iv)
44 This allows you to change the initial value vector used by the
45 chaining modes. It is not relevant for ECB mode.
46
47 $cipher->encrypt($data)
48 Encrypt data. The size of $data must be a multiple of "blocksize"
49 (16 bytes), otherwise this function will croak. Apart from that, it
50 can be of (almost) any length.
51
52 $cipher->decrypt($data)
53 Decrypts $data.
54
55 Encryption modes
56 Use these constants to select the cipher type:
57
58 MODE_CBC - Cipher Block Chaining
59 MODE_CFB - Cipher feedback
60 MODE_CTR - Counter mode
61 MODE_ECB - Electronic cookbook mode
62 MODE_OFB - Output feedback
63 MODE_PCBC - ignore this one for now :)
64
65SEE ALSO
66 Crypt::CBC, http://www.csrc.nist.gov/encryption/aes/
67
68BUGS
69 Should EXPORT or EXPORT_OK the MODE constants.
70
71AUTHOR
72 Currently maintained by brian d foy, "<bdfoy@cpan.org>".
73
74 Original code by Rafael R. Sevilla.
75
76 The Rijndael Algorithm was developed by Vincent Rijmen and Joan Daemen,
77 and has been selected as the US Government's Advanced Encryption
78 Standard.
79
80LICENSE
81 This software is licensed under the GNU Public License. See the included
82 COPYING file for details.
83
84