Crypt::Rijndael − Crypt::CBC compliant Rijndael encryption module


 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() );
 $crypted = $cipher−>encrypt($plaintext);
        # − OR −
 $plaintext = $cipher−>decrypt($crypted);


This module implements the Rijndael cipher, which has just been selected as the Advanced Encryption Standard.

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".


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.


This allows you to change the initial value vector used by the chaining modes. It is not relevant for ECB mode.


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.


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 :)


Crypt::CBC, http://www.csrc.nist.gov/encryption/aes/


Should EXPORT or EXPORT_OK the MODE constants.


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.


This code is in Github:



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


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.