forked from openkylin/libcrypt-cast5-perl
114 lines
2.7 KiB
Perl
114 lines
2.7 KiB
Perl
|
package Crypt::CAST5;
|
||
|
|
|
||
|
|
require 5.004;
|
||
|
|
use strict;
|
||
|
|
use DynaLoader;
|
||
|
|
|
||
|
|
use vars qw( $VERSION @ISA );
|
||
|
|
|
||
|
|
$VERSION = "0.05";
|
||
|
|
@ISA = qw( DynaLoader );
|
||
|
|
|
||
|
|
bootstrap Crypt::CAST5 $VERSION;
|
||
|
|
|
||
|
|
1 # end Crypt::CAST5
|
||
|
|
__END__
|
||
|
|
|
||
|
|
=head1 NAME
|
||
|
|
|
||
|
|
Crypt::CAST5 - CAST5 block cipher
|
||
|
|
|
||
|
|
=head1 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), "\n";
|
||
|
|
|
||
|
|
my $plaintext = $crypt->decrypt($ciphertext);
|
||
|
|
print $plaintext, "\n";
|
||
|
|
|
||
|
|
=head1 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.
|
||
|
|
|
||
|
|
=head1 FUNCTIONS
|
||
|
|
|
||
|
|
=head2 blocksize
|
||
|
|
|
||
|
|
Returns the CAST5 block size, which is 8 bytes. This function exists
|
||
|
|
so that Crypt::CAST5 can work with Crypt::CBC.
|
||
|
|
|
||
|
|
=head2 keysize
|
||
|
|
|
||
|
|
Returns the maximum CAST5 key size, 16 bytes.
|
||
|
|
|
||
|
|
=head2 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.
|
||
|
|
|
||
|
|
=head2 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 L<Digest::SHA1> or L<Digest::MD5>.
|
||
|
|
Note that Crypt::CBC runs the given "key" through MD5 to get the actual
|
||
|
|
encryption key.
|
||
|
|
|
||
|
|
=head2 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 L<Crypt::CBC>.
|
||
|
|
|
||
|
|
=head2 decrypt
|
||
|
|
|
||
|
|
$plaintext = $cast5->decrypt($ciphertext);
|
||
|
|
|
||
|
|
Decrypt the ciphertext and return the corresponding plaintext.
|
||
|
|
|
||
|
|
=head1 SEE ALSO
|
||
|
|
|
||
|
|
RFC 2144, "The CAST-128 Encryption Algorithm", C. Adams, May 1997
|
||
|
|
|
||
|
|
L<Crypt::CBC>
|
||
|
|
|
||
|
|
=head1 AUTHOR
|
||
|
|
|
||
|
|
Bob Mathews, E<lt>bobmathews@alumni.calpoly.eduE<gt>
|
||
|
|
|
||
|
|
=head1 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.
|
||
|
|
|
||
|
|
=cut
|
||
|
|
|