crypt::blowfish(3) [suse man page]
Blowfish(3) User Contributed Perl Documentation Blowfish(3) 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 v5.12.1 2010-03-04 Blowfish(3)
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Crypt::Eksblowfish(3pm) User Contributed Perl Documentation Crypt::Eksblowfish(3pm) NAME
Crypt::Eksblowfish - the Eksblowfish block cipher SYNOPSIS
use Crypt::Eksblowfish; $block_size = Crypt::Eksblowfish->blocksize; $cipher = Crypt::Eksblowfish->new(8, $salt, $key); $block_size = $cipher->blocksize; $ciphertext = $cipher->encrypt($plaintext); $plaintext = $cipher->decrypt($ciphertext); $p_array = $cipher->p_array; $s_boxes = $cipher->s_boxes; if($cipher->is_weak) { ... DESCRIPTION
An object of this type encapsulates a keyed instance of the Eksblowfish block cipher, ready to encrypt and decrypt. Eksblowfish is a variant of the Blowfish cipher, modified to make the key setup very expensive. ("Eks" stands for "expensive key schedule".) This doesn't make it significantly cryptographically stronger, but is intended to hinder brute-force attacks. It also makes it unsuitable for any application requiring key agility. It was designed by Niels Provos and David Mazieres for password hashing in OpenBSD. See Crypt::Eksblowfish::Bcrypt for the hash algorithm. See Crypt::Eksblowfish::Blowfish for the unmodified Blowfish cipher. Eksblowfish is a parameterised (family-keyed) cipher. It takes a cost parameter that controls how expensive the key scheduling is. It also takes a family key, known as the "salt". Cost and salt parameters together define a cipher family. Within each family, a key determines an encryption function in the usual way. See Crypt::Eksblowfish::Family for a way to encapsulate an Eksblowfish cipher family. CLASS METHODS
Crypt::Eksblowfish->blocksize Returns 8, indicating the Eksblowfish block size of 8 octets. This method may be called on either the class or an instance. CONSTRUCTOR
Crypt::Eksblowfish->new(COST, SALT, KEY) Performs key setup on a new instance of the Eksblowfish algorithm, returning the keyed state. The KEY may be any length from 1 octet to 72 octets inclusive. The SALT is a family key, and must be exactly 16 octets. COST is an integer parameter controlling the expense of keying: the number of operations in key setup is proportional to 2^COST. All three parameters influence all the subkeys; changing any of them produces a different encryption function. Due to the mandatory family-keying parameters (COST and SALT), this constructor does not match the interface expected by "Crypt::CBC" and similar crypto plumbing modules. To use Eksblowfish with them it is necessary to have an object that encapsulates a cipher family and provides a constructor that takes only a key argument. That facility is supplied by "Crypt::Eksblowfish::Family". METHODS
$cipher->blocksize Returns 8, indicating the Eksblowfish block size of 8 octets. This method may be called on either the class or an instance. $cipher->encrypt(PLAINTEXT) PLAINTEXT must be exactly eight octets. The block is encrypted, and the ciphertext is returned. $cipher->decrypt(CIPHERTEXT) CIPHERTEXT must be exactly eight octets. The block is decrypted, and the plaintext is returned. $cipher->p_array $cipher->s_boxes These methods extract the subkeys from the keyed cipher. This is not required in ordinary operation. See the superclass Crypt::Eksblowfish::Subkeyed for details. $cipher->is_weak This method checks whether the cipher has been keyed with a weak key. It may be desired to avoid using weak keys. See the superclass Crypt::Eksblowfish::Subkeyed for details. SEE ALSO
Crypt::Eksblowfish::Bcrypt, Crypt::Eksblowfish::Blowfish, Crypt::Eksblowfish::Family, Crypt::Eksblowfish::Subkeyed, <http://www.usenix.org/events/usenix99/provos/provos_html/node4.html> AUTHOR
Eksblowfish guts originally by Solar Designer (solar at openwall.com). Modifications and Perl interface by Andrew Main (Zefram) <zefram@fysh.org>. COPYRIGHT
Copyright (C) 2006, 2007, 2008, 2009, 2010 Andrew Main (Zefram) <zefram@fysh.org> The original Eksblowfish code (in the form of crypt()) from which this module is derived is in the public domain. It may be found at <http://www.openwall.com/crypt/>. LICENSE
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. perl v5.14.2 2011-11-15 Crypt::Eksblowfish(3pm)