Crypt-CAST5_PP

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CAST5_PP.pm  view on Meta::CPAN

1 # end module
__END__

=head1 NAME

Crypt::CAST5_PP - CAST5 block cipher in pure Perl

=head1 SYNOPSIS

    use Crypt::CBC;

    my $crypt = Crypt::CBC->new({
        key    => "secret key",
        cipher => "CAST5_PP",
    });

    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";

CAST5_PP.pm  view on Meta::CPAN

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_PP can work with Crypt::CBC.

=head2 keysize

Returns the maximum CAST5 key size, 16 bytes.

=head2 new

    $cast5 = Crypt::CAST5_PP->new($key);

Create a new encryption object. If the optional key parameter is given,

CAST5_PP.pm  view on Meta::CPAN

    $cast5->init($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 LIMITATIONS

Always produces untainted output, even if the input is tainted, because
that's what perl's pack() function does.

=head1 SEE ALSO

RFC 2144, "The CAST-128 Encryption Algorithm", C. Adams, May 1997

L<Crypt::CBC>

=head1 AUTHOR

Bob Mathews, <bobmathews@alumni.calpoly.edu>

=head1 COPYRIGHT

Copyright (c) 2006 Bob Mathews. All rights reserved.
This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

Changes  view on Meta::CPAN

Revision history for Perl extension Crypt::CAST5_PP.

1.04  1 Jul 2006
        - removed broken CBC test

1.03  22 May 2005
        - make it work in taintmode

1.02  31 Aug 2002
        - tested with older perls

1.01  4 Aug 2002
        - make it work with strict (is my face red?)

README  view on Meta::CPAN

Crypt::CAST5_PP

The CAST5 block cipher, implemented in pure Perl.


Dependencies:
    Module::Signature is needed to check the signature
    Test::More is needed to run the tests
    Test::Taint is needed for the tainting test
    Crypt::CBC is useful but not required


Installation:
    cpansign -v
    perl Makefile.PL
    make
    make test
    make install

t/2cbc.t  view on Meta::CPAN

# See if we can interoperate with Crypt::CBC
use Test::More;

# prior to 1.22, Crypt::CBC didn't use the Crypt:: prefix to locate ciphers
eval "use Crypt::CBC 1.22";
plan skip_all => "Crypt::CBC required for this test" if $@;
plan tests => 2;

my $cbc = Crypt::CBC->new("0123456789abcdef", "CAST5_PP");

my $msg = "'Twas brillig, and the slithy toves";
my $c = $cbc->encrypt($msg);
is(length($c), 56, "ciphertext length check");
my $d = $cbc->decrypt($c);
is(unpack("H*",$d), unpack("H*",$msg), "encrypt-decrypt");

# end 2cbc.t