NAME¶
Crypt::Rijndael - Crypt::CBC compliant Rijndael encryption module
SYNOPSIS¶
use Crypt::Rijndael;
# keysize() is 32, but 24 and 16 are also possible
# blocksize() is 16
$cipher = Crypt::Rijndael->new( "a" x 32, Crypt::Rijndael::MODE_CBC() );
$cipher->set_iv($iv);
$crypted = $cipher->encrypt($plaintext);
# - OR -
$plaintext = $cipher->decrypt($crypted);
DESCRIPTION¶
This module implements the Rijndael cipher, which has just been selected as the
Advanced Encryption Standard.
- keysize
- Returns the keysize, which is 32 (bytes). The Rijndael cipher actually
supports keylengths of 16, 24 or 32 bytes, but there is no way to
communicate this to "Crypt::CBC".
- blocksize
- The blocksize for Rijndael is 16 bytes (128 bits), although the algorithm
actually supports any blocksize that is any multiple of our bytes. 128
bits, is however, the AES-specified block size, so this is all we
support.
- $cipher = Crypt::Rijndael->new( $key [, $mode] )
- Create a new "Crypt::Rijndael" cipher object with the given key
(which must be 128, 192 or 256 bits long). The additional $mode argument
is the encryption mode, either "MODE_ECB" (electronic codebook
mode, the default), "MODE_CBC" (cipher block chaining, the same
that "Crypt::CBC" does), "MODE_CFB" (128-bit cipher
feedback), "MODE_OFB" (128-bit output feedback), or
"MODE_CTR" (counter mode).
ECB mode is very insecure (read a book on cryptography if you don't know
why!), so you should probably use CBC mode.
- $cipher->set_iv($iv)
- This allows you to change the initial value vector used by the chaining
modes. It is not relevant for ECB mode.
- $cipher->encrypt($data)
- Encrypt data. The size of $data must be a multiple of
"blocksize" (16 bytes), otherwise this function will croak.
Apart from that, it can be of (almost) any length.
- $cipher->decrypt($data)
- Decrypts $data.
Encryption modes¶
Use these constants to select the cipher type:
- MODE_CBC - Cipher Block Chaining
- MODE_CFB - Cipher feedback
- MODE_CTR - Counter mode
- MODE_ECB - Electronic cookbook mode
- MODE_OFB - Output feedback
- MODE_PCBC - ignore this one for now :)
SEE ALSO¶
Crypt::CBC,
http://www.csrc.nist.gov/encryption/aes/
BUGS¶
Should EXPORT or EXPORT_OK the MODE constants.
AUTHOR¶
Currently maintained by brian d foy, "<bdfoy@cpan.org>".
Original code by Rafael R. Sevilla.
The Rijndael Algorithm was developed by Vincent Rijmen and Joan Daemen, and has
been selected as the US Government's Advanced Encryption Standard.
SOURCE¶
This code is in Github:
git://github.com/briandfoy/crypt-rijndael.git
LICENSE¶
This software is licensed under the Lesser GNU Public License v3 (29 June 2007).
See the included COPYING file for details.