Question

I have this script, works ok:

#!/usr/bin/perl

$key = pack("H*","3cb37efae7f4f376ebbd76cd");

$str = "&4\=80CHB'";
$dec = decode($str);
print "Decoded string value: $dec\n";

sub decode{ #Sub to decode
    @subvar=@_;
    my $sqlstr = $subvar[0];
    $cipher = unpack("u", $sqlstr);
    $plain = $cipher^$key;
    return substr($plain, 0, length($cipher));
}

If I alter it to get the $str variable from STDIN, it messes up all the result:

#!/usr/bin/perl

$key = pack("H*","3cb37efae7f4f376ebbd76cd");

print "Enter string to decode: ";
$str=<STDIN>;chomp $str;
$dec = decode($str);
print "Decoded string value: $dec\n";

sub decode{ #Sub to decode
    @subvar=@_;
    my $sqlstr = $subvar[0];
    $cipher = unpack("u", $sqlstr);
    $plain = $cipher^$key;
    return substr($plain, 0, length($cipher));
}

First script gets it ok, result is:

Decoded string value: mentos

Second script is bad:

Decoded string value: ot&¸ÝÖóvë½vÍ

Any idea on what I do wrong? Thanks!

Answer 1

You original code has

$str = "&4\=80CHB'";

which for some reason contains an escaped equals sign. It is the same as

$str = "&4=80CHB'";

so you need to enter &4=80CHB' to your modified code.