File Coverage

blib/lib/Crypt/GOST_PP.pm

Criterion	Covered	Total	%
statement	48	48	100.0
branch	4	4	100.0
condition	1	3	33.3
subroutine	12	12	100.0
pod	0	8	0.0
total	65	75	86.6

#--------------------------------------------------------------------#
# Crypt::GOST_PP
#       Date Written:   10-Dec-2001 12:33:55 PM
#       Last Modified:  26-Feb-2002 10:47:28 AM
#       Author:         Kurt Kincaid ([e-mail])
#       Copyright (c) 2002, Kurt Kincaid
#           All Rights Reserved.
#
#       This is free software and may be modified and/or
#       redistributed under the same terms as Perl itself.
#--------------------------------------------------------------------#

package Crypt::GOST_PP;
use integer;
require Exporter;

@ISA = qw(Exporter);
@EXPORT_OK = qw();

use strict;
no strict 'refs';

use vars qw( @b @t @R @S @h @o @K $VERSION );

$VERSION = "1.10";

sub new {
    my ( $argument, $pp ) = @_;
    Setup( $pp );
    my $class = ref ( $argument ) || $argument;
    my $self = {};
    bless $self, $class;
    return $self;
}

sub encrypt {
    my ( $self, $text ) = @_;
    return GOST( $text );
}

sub decrypt {
    my ( $self, $text ) = @_;
    return GOST( $text, 1 );
}

sub GOST {
    my ( $v, $w, $a, $q, $c, $out, $self );
    my ( $e, $d ) = @_;
    @h = 0 .. 7;
    @o = reverse @h;
    while ( $a < length $e ) {
        $v = N( $e, $a );
        $w = N( $e, ( $a += 8 ) - 4 );
        grep $q++ % 2 ? $v ^= F( $w + $K[ $_ ] ) : ( $w ^= F( $v + $K[ $_ ] ) ), $d ? ( @h, ( @o ) x 3 ) : ( ( @h ) x 3, @o );
        $out .= pack "N2", $w, $v;
    }
    return $out;
}

sub F {
    my $u = 0;
    grep $u |= $S[ $_ ][ $_[ 0 ] >> $_ * 4 & 15 ] << $_ * 4, reverse 0 .. 7;
    return $u << 11 | $u >> 21;
}

sub R {
    return int( rand( shift ) );
}

sub N {
    return vec $_[ 0 ], $_[ 1 ] / 4, 32;
}

sub Setup {
    my $p = shift;
    my ( $s, $i, $c );
    for ( $i = 0; $i < length $p; $i += 4 ) {
        srand( $s ^= N( $p, $i ) );
    }
    @b = @t = 0 .. 15;
    while ( $c < 8 ) {
        grep { push @b, splice @b, R( 9 ), 5 } @t;
        $R[ $c ] = R( 2**32 );
        @{ $S[ $c++ ] } = @b;
    }

}

1;
__END__