Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

crypt::cast5(3pm) [debian man page]

CAST5(3pm)						User Contributed Perl Documentation						CAST5(3pm)

NAME
Crypt::CAST5 - CAST5 block cipher SYNOPSIS
use Crypt::CBC; my $crypt = Crypt::CBC->new({ key => "secret key", cipher => "CAST5", }); my $message = "All mimsy were the borogoves"; my $ciphertext = $crypt->encrypt($message); print unpack("H*", $ciphertext), " "; my $plaintext = $crypt->decrypt($ciphertext); print $plaintext, " "; DESCRIPTION
This module provides an implementation of the CAST5 block cipher using compiled C code for increased speed. CAST5 is also known as CAST-128. It is a product of the CAST design procedure developed by C. Adams and S. Tavares. The CAST5 cipher is available royalty-free. FUNCTIONS
blocksize Returns the CAST5 block size, which is 8 bytes. This function exists so that Crypt::CAST5 can work with Crypt::CBC. keysize Returns the maximum CAST5 key size, 16 bytes. new $cast5 = Crypt::CAST5->new($key); Create a new encryption object. If the optional key parameter is given, it will be passed to the init() function. init $cast5->init($key); Set or change the encryption key to be used. The key must be from 40 bits (5 bytes) to 128 bits (16 bytes) in length. Note that if the key used is 80 bits or less, encryption and decryption will be somewhat faster. It is best for the key to be random binary data, not something printable like a password. A message digest function may be useful for converting a password to an encryption key; see Digest::SHA1 or Digest::MD5. Note that Crypt::CBC runs the given "key" through MD5 to get the actual encryption key. encrypt $ciphertext = $cast5->encrypt($plaintext); Encrypt a block of plaintext using the current encryption key, and return the corresponding ciphertext. The input must be 8 bytes long, and the output has the same length. Note that the encryption is in ECB mode, which means that it encrypts each block independently. That can leave you vulnerable to dictionary attacks, so it is generally best to use some form of chaining between blocks; see Crypt::CBC. decrypt $plaintext = $cast5->decrypt($ciphertext); Decrypt the ciphertext and return the corresponding plaintext. SEE ALSO
RFC 2144, "The CAST-128 Encryption Algorithm", C. Adams, May 1997 Crypt::CBC AUTHOR
Bob Mathews, <bobmathews@alumni.calpoly.edu> COPYRIGHT AND LICENSE
Copyright (C) 2002-2006 Bob Mathews This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. perl v5.14.2 2006-07-01 CAST5(3pm)

Check Out this Related Man Page

Blowfish(3pm)						User Contributed Perl Documentation					     Blowfish(3pm)

NAME
Crypt::Blowfish - Perl Blowfish encryption module SYNOPSIS
use Crypt::Blowfish; my $cipher = new Crypt::Blowfish $key; my $ciphertext = $cipher->encrypt($plaintext); my $plaintext = $cipher->decrypt($ciphertext); You probably want to use this in conjunction with a block chaining module like Crypt::CBC. DESCRIPTION
Blowfish is capable of strong encryption and can use key sizes up to 56 bytes (a 448 bit key). You're encouraged to take advantage of the full key size to ensure the strongest encryption possible from this module. Crypt::Blowfish has the following methods: blocksize() keysize() encrypt() decrypt() FUNCTIONS
blocksize Returns the size (in bytes) of the block cipher. Crypt::Blowfish doesn't return a key size due to its ability to use variable-length keys. More accurately, it shouldn't, but it does anyway to play nicely with others. new my $cipher = new Crypt::Blowfish $key; This creates a new Crypt::Blowfish BlockCipher object, using $key, where $key is a key of "keysize()" bytes (minimum of eight bytes). encrypt my $cipher = new Crypt::Blowfish $key; my $ciphertext = $cipher->encrypt($plaintext); This function encrypts $plaintext and returns the $ciphertext where $plaintext and $ciphertext must be of "blocksize()" bytes. (hint: Blowfish is an 8 byte block cipher) decrypt my $cipher = new Crypt::Blowfish $key; my $plaintext = $cipher->decrypt($ciphertext); This function decrypts $ciphertext and returns the $plaintext where $plaintext and $ciphertext must be of "blocksize()" bytes. (hint: see previous hint) EXAMPLE
my $key = pack("H16", "0123456789ABCDEF"); # min. 8 bytes my $cipher = new Crypt::Blowfish $key; my $ciphertext = $cipher->encrypt("plaintex"); # SEE NOTES print unpack("H16", $ciphertext), " "; PLATFORMS
Please see the README document for platforms and performance tests. NOTES
The module is capable of being used with Crypt::CBC. You're encouraged to read the perldoc for Crypt::CBC if you intend to use this module for Cipher Block Chaining modes. In fact, if you have any intentions of encrypting more than eight bytes of data with this, or any other block cipher, you're going to need some type of block chaining help. Crypt::CBC tends to be very good at this. If you're not going to encrypt more than eight bytes, your data must be exactly eight bytes long. If need be, do your own padding. "" as a null byte is perfectly valid to use for this. SEE ALSO
Crypt::CBC, Crypt::DES, Crypt::IDEA Bruce Schneier, Applied Cryptography, 1995, Second Edition, published by John Wiley & Sons, Inc. COPYRIGHT
The implementation of the Blowfish algorithm was developed by, and is copyright of, A.M. Kuchling. Other parts of the perl extension and module are copyright of Systemics Ltd ( http://www.systemics.com/ ). Code revisions, updates, and standalone release are copyright 1999-2010 W3Works, LLC. AUTHOR
Original algorithm, Bruce Shneier. Original implementation, A.M. Kuchling. Original Perl implementation, Systemics Ltd. Current maintenance by W3Works, LLC. Current revision and maintainer: Dave Paris <amused@pobox.com> perl v5.14.2 2010-03-04 Blowfish(3pm)
Man Page

Featured Tech Videos