Crypt::Rijndael - Crypt::CBC compliant Rijndael encryption module

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 = new Crypt::Rijndael "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 = 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 dont 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.

BUGS

Should EXPORT or EXPORT_OK the MODE constants.

AUTHOR

 Rafael R. Sevilla <sevillar@team.ph.inter.net>