XOR encoding question

[bbolte]

I'm trying to do some simple XOR encoding and my functions don't seem to be working correctly. I'm not getting the same thing out that I'm putting in. Can anyone see what I'm missing?

Below are my functions:

function hexToStr($hex){
    $string='';
    for ($i=0; $i < strlen($hex)-1; $i+=2){
        $string .= chr(hexdec($hex[$i].$hex[$i+1]));
    }
    return $string;
}

function strToHex($string){
    $hex='';
    for ($i=0; $i < strlen($string); $i++){
        $hex .= dechex(ord($string[$i]));
    }
    return $hex;
}

function doit($key,$text){
    $outText='';
  for($i=0;$i<strlen($text);){
    for($j=0;$j<strlen($key);$j++,$i++){
           @$outText .= $text{$i} ^ $key{$j};
    }
  }
  return $outText;
} 

Basically to encode I run doit() and the strToHex() and to decode I run hexToStr() and then doit().

Thanks...

[logic_earth]

It seems your XOR function is wrong...I've always seen XOR done this way:

function xorSomething ( $key, $text )
{
    $len = strlen( $key );
    for ( $i = 0; isset( $text[ $i ] ); $i++ )
        $text[ $i ] = chr( ord( $text[ $i ] ) ^ ord( $key[ $i % $len ] ) );
    return $text;
} 

[Tarh]

By the way...

function hexToStr($hex){
	return pack('H*', $hex);
}
 
function strToHex($string){
	$res = unpack('H*', $string);
	return $res[1];
}

[bbolte]

sweet! thanks guys, I'll give those a go. truly appreciate it.