#!/usr/bin/perl
# The DMCA says: "a person who has lawfully obtained the right to use a copy of
# a computer program may circumvent a technological measure that effectively
# controls access to a particular portion of that program for the sole purpose
# of identifying and analyzing those elements of the program that are necessary
# to achieve interoperability of an independently created computer program with
# other programs... to the extent that any such acts of identification and
# analysis do not constitute infringement under this title."
#
# This script is, of course, only to ensure interoperability with
# non-javascript-compatible browsers.
#
# by Schnarf (2600, vol. 20, no. 4)
#
# Open the file
open( F, $ARGV[0] ) or die "Could not open $ARGV[0] for reading: $!\n";
  @raw = <F>;
close(F);

$page = join( "\n", @raw );

# Get the data to decrypt
$data = getData($page);

# Now decode that data
$final = decode($data);

# Print it to STDOUT
print $final;

# This just grabs the parameter to _x
sub getData {
    my $page = shift;

    my $start = index( $page, '_x("' );

    if ( $start == -1 ) {
        die("Could not locate start of raw data!\n");
    }

    my $end = index( $page, '");</script>', $start + 4 );

    if ( $end == -1 ) {
        die("Could not locate end of raw data!\n");
    }
    $start += 4;

    return substr( $page, $start, $end - $start );
}

# This is just _x converted to perl
sub decode {
    my $s = shift;
    $s = unescape($s);
    my @t = ();
    my @j = ();
    my $i;

    for ( $i = 0 ; $i < length($s) ; $i++ ) {
        $t[$j] .= chr( ord( substr( $s, $i, 1 ) ) + ( $i % 2 == 0 ? 1 : -1 ) );
        if ( ( $i + 1 ) % 300 == 0 ) {
            $j++;
            $t[$j] = '';
        }
    }

    my $u = '';

    for ( $i = 0 ; $i < $#t ; $i++ ) {
        $u .= $t[$i];
    }

    return $u;
}

sub unescape {
    my $str = shift;

    $str =~ s/%([a-fA-F0-9]{2})/chr(hex($1))/ge;

    return $str;
}