Crypt::Twofish_PP::Key24 - Twofish with 24 byte (192 bits) keysize

Crypt-Twofish_PP documentation Contained in the Crypt-Twofish_PP distribution.

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NAME

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Crypt::Twofish_PP::Key24 - Twofish with 24 byte (192 bits) keysize

SYNOPSIS

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  use Crypt::CBC;
  my $cipher = Crypt::CBC->new (key => 'my secret key',
                                cipher => 'Twofish_PP::Key24');

DESCRIPTION

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This module is only a helper module and you should never use it directly. Use Crypt::Twofish_PP(3) instead and see there for more documentation.

The standard module for Cipher Block Chaining (CBC) in Perl, Crypt::CBC(3) cannot grok with variable key sizes. However, the Twofish algorithm is defined for key sizes of 24, 24, and 32 bytes, but there is no way to communicate that to Crypt::CBC.

If you want to use Crypt::Twofish_PP(3) in CBC mode with a keysize of 24, simply specify Crypt::Twofish_PP::Key24 as the algorithm. It is eqeuivalent to Crypt::Twofish_PP(3) but it will report a default keysize of 24 bytes back to Crypt::CBC(3).

Note that this is not necessarily the real keysize. The method keysize() of Crypt::Twofish_PP(3) only exists to satisfy Crypt::CBC(3). The module will derive the real keysize from the length of the key you supply.

AUTHOR

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Copyright (C) 2003, Guido Flohr <guido@imperia.net>, all rights reserved. See the source code for details.

This software is contributed to the Perl community by Imperia (http://www.imperia.net/).

SEE ALSO

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Crypt::CBC(3), Crypt::Twofish_PP(3), Crypt::Twofish::Key24(3), Crypt::Twofish_PP::Key32(3), perl(1)

Crypt-Twofish_PP documentation Contained in the Crypt-Twofish_PP distribution. 
#! /bin/false

# vim: tabstop=4
# $Id: Key24.pm,v 1.1.1.1 2003/11/21 21:06:56 guido Exp $

# Twofish in pure Perl.
# Copyright (C) 2003 Guido Flohr <guido@imperia.net>, all rights reserved.

# This program is free software; you can redistribute it and/or modify it
# under the same terms and conditions as Perl itsels (see the Artistic
# license included).

package Crypt::Twofish_PP::Key24;

use strict;

use Crypt::Twofish_PP;
use base qw (Crypt::Twofish_PP);

use vars qw ($KEYSIZE);

# See method keysize() below for an explanation.
$KEYSIZE = 24;

sub keysize
{
	my $self = shift;

	if (ref $self) {
		return $self->{__keylength} * 8;
	} else {
		# When called as a class method, return a constant value.
		return $KEYSIZE;
	}
}

1;

__END__


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