package Secure;

use strict;
use vars qw(@ISA @EXPORT $Q);

use CGI; my $q= new CGI; $Q= $q;
use Digest::MD5 qw(md5_hex);

use Exporter; @ISA= qw(Exporter);
@EXPORT= qw($Q);

#################################### êîäîâîå ñëîâî

my $code= 'Masha';	#òîëüêî öèôðû, àíãëèéñêèå áóêâû è ñïåöñèìâîëû êëàâèàòóðû; äëèíà êîäîâîãî ñëîâà íåîãðàíè÷åíà

####################################

my $chars= "	\n !\"#\$%&'()*+,-./0123456789:;<=>?\@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~¹ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ¨¥²¯ª¡¸´³¿º¢–—«»°…";	#íàáîð äîïóñòèìûõ ñèìâîëîâ
my @charM= split"", $chars;
my $p= $q->param("Q");

if( $p=~ /^[0-9a-f]+$/i )
{
	$p=~ s/^([a-f0-9]{16})//i;
	my @txt= split"", $p;
	my( $rnd, $i, $ii, $strO, $str, @md5 )=( $1, 0, 0, "", "" );

	for( @txt )		#äåøèôðîâàíèå
	{
		if( $ii%32==0 )
		{
			@md5= split"", md5_hex($rnd.$code.$i);
			$i++;
		}

		$strO.= _sumRev($_, $md5[$ii%32]);

		if( $ii%2==1 ){
			$str.= $charM[hex($strO)];
			$strO= "";
		}

		$ii++;
	}

	for( split/&/, $str )	#çàïèñü â ïàðàìåòðû
	{
		my @sp= split"=", $_;
		$sp[1]=~ s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg;
		$Q->append( -name=> $sp[0], -values=> $sp[1] );
	}

	if( $Q->param("test") ne "test" )	#äåéñòâèå, åñëè êîäîâîå ñëîâî íåïðàâèëüíîå
	{
		print $q->header( -charset=> "windows-1251" );
		print "<a href='javascript:history.back()'>Ââåäèòå ïðàâèëüíîå êîäîâîå ñëîâî åù¸ ðàç!</a>";
		print "<script type='text/javascript'>localStorage.removeItem('codeword')</script>";
		exit(0);
	}
}

sub _sumRev		#äåìàñêèðîâàíèå
{
	my( $ap, $bp )=( hex($_[0]), hex($_[1]) );
	my $s= $ap<$bp ? 16+$ap-$bp : $ap-$bp;
	return sprintf("%x", $s);
}

1;