package Crypt::Loki97;

use strict;
use warnings;
require Exporter;

our @EXPORT_OK = qw(keysize blocksize new encrypt decrypt);
our $VERSION = '1.0.1';
our @ISA = qw(Exporter);

require XSLoader;
XSLoader::load('Crypt::Loki97', $VERSION);

# Preloaded methods go here.

1;

__END__

=head1 NAME

Crypt::Loki97 - Crypt::CBC compliant block cipher

=head1 SYNOPSIS

    use Crypt::Loki97;

    $cipher = new Crypt::Loki97 $key;
    $ciphertext = $cipher->encrypt($plaintext);
    $plaintext  = $cipher->decrypt($ciphertext);

=head1 DESCRIPTION

Loki97 is 128-bit block cipher that accepts a variable-length key. It
was designed by Lawrie Brown, Josef Pieprzyk, and Jennifer Seberry.

The default key length in this implementation is 128 bits.

Loki97 was one of the 15 candidates for the AES.

This module supports the Crypt::CBC interface, with the following
functions.

=head2 Functions

=over

=item B<blocksize>

Returns the size (in bytes) of the block (16, in this case).

=item B<keysize>

Returns the size (in bytes) of the key (16, in this case).

=item B<encrypt($data)>

Encrypts 16 bytes of $data and returns the corresponding ciphertext.

=item B<decrypt($data)>

Decrypts 16 bytes of $data and returns the corresponding plaintext.

=back

=head1 EXAMPLE 1

    #!/usr/local/bin/perl

    use diagnostics;
    use strict;
    use warnings;
    use Crypt::Loki97;

    # key must be 16 bytes long
    my $key = "0123456789abcdef";

    my $cipher = new Crypt::Loki97 $key;

    print "blocksize = ", $cipher->blocksize, " bytes \n";
    print "keysize = ", $cipher->keysize, " bytes \n";

    # block must be 16 bytes long
    my $plaintext1 = "0123456789abcdef";

    my $ciphertext = $cipher->encrypt($plaintext1);
    my $plaintext2 = $cipher->decrypt($ciphertext);

    print "Decryption OK\n" if ($plaintext1 eq $plaintext2);

=head1 EXAMPLE 2

    #!/usr/local/bin/perl

    use diagnostics;
    use strict;
    use warnings;
    use Crypt::CBC;  # CBC automatically loads Loki97 for us

    # when using Crypt::CBC, key may be of ANY length
    my $key = "0123456789abcdef";

    # IV must be exactly 16 bytes long
    my $IV = pack "H32", 0;

    my $cipher = Crypt::CBC->new({'key' => $key,
                                  'cipher' => 'Loki97',
                                  'iv' => $IV,
                                  'regenerate_key' => 1,
                                  'padding' => 'standard',
                                  'prepend_iv' => 0
                                });

    # when using Crypt::CBC, plaintext may be of ANY length
    my $plaintext1 = "This is a test";

    my $ciphertext = $cipher->encrypt($plaintext1);
    my $plaintext2 = $cipher->decrypt($ciphertext);

    print "Decryption OK\n" if ($plaintext1 eq $plaintext2);

=head1 MORE EXAMPLES

See B<Crypt::CBC> for more examples using CBC mode. See also the
"examples" and "t" directories for some more examples.

=head1 SEE ALSO

B<Crypt::Khazad>, B<Crypt::Misty1>, B<Crypt::Anubis>,
B<Crypt::Noekeon>, B<Crypt::Skipjack>, B<Crypt::Camellia>,
B<Crypt::Square>, B<Crypt::Rainbow>, and B<Crypt::Shark>.

=head1 COPYRIGHT AND LICENSE

Copyright 2003 by Julius C. Duque. Please read B<contact.html> that
comes with this distribution for details on how to contact the author.

This library is free software; you can redistribute it and/or modify
it under the same terms as the GNU General Public License.

=cut