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 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.

  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.

LICENSE
    This software is licensed under the GNU Public License. See the included
    COPYING file for details.

