Crypt::Eksblowfish::BlUsersContributed Perl DocCrypt::Eksblowfish::Blowfish(3)NAMECrypt::Eksblowfish::Blowfish - Blowfish block cipher via Eksblowfish
engine
SYNOPSIS
use Crypt::Eksblowfish::Blowfish;
$block_size = Crypt::Eksblowfish::Blowfish->blocksize;
$key_size = Crypt::Eksblowfish::Blowfish->keysize;
$cipher = Crypt::Eksblowfish::Blowfish->new($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 Blowfish
block cipher, ready to encrypt and decrypt.
Blowfish is a symmetric cipher algorithm designed by Bruce Schneier in
1993. It operates on 64-bit blocks, and takes a variable-length key
from 32 bits (4 octets) to 448 bits (56 octets) in increments of 8 bits
(1 octet).
This implementation of Blowfish uses an encryption engine that was
originally implemented in order to support Eksblowfish, which is a
variant of Blowfish modified to make keying particularly expensive.
See Crypt::Eksblowfish for that variant; this class implements the
original Blowfish.
CLASS METHODS
Crypt::Eksblowfish::Blowfish->blocksize
Returns 8, indicating the Blowfish block size of 8 octets. This
method may be called on either the class or an instance.
Crypt::Eksblowfish::Blowfish->keysize
Returns 0, indicating that the key size is variable. This
situation is handled specially by "Crypt::CBC".
CONSTRUCTOR
Crypt::Eksblowfish::Blowfish->new(KEY)
Performs key setup on a new instance of the Blowfish algorithm,
returning the keyed state. The KEY may be any length from 4 octets
to 56 octets inclusive.
You may occasionally come across an alleged Blowfish key that is
outside this length range, and so is rejected by this constructor.
Blowfish can internally process a key of any octet length up to 72
octets, and some implementations don't enforce the official length
restrictions. If it is necessary for compatibility, a key of out-
of-range length can be processed by
Crypt::Eksblowfish::Uklblowfish.
METHODS
$cipher->blocksize
Returns 8, indicating the Blowfish 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, Crypt::Eksblowfish::Subkeyed,
Crypt::Eksblowfish::Uklblowfish,
<http://www.schneier.com/blowfish.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, 2011 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 v5.18.2 2014-05-13 Crypt::Eksblowfish::Blowfish(3)
