PHP中的XOR字符串与键

时间:2012-12-14 09:20:45

标签: php

我需要在PHP中对字符串/文本进行XOR运算,base64对其进行编码,但出现了问题:

<?php

$mustget = 'Kw4SCQ==';
$string = 'Josh';

echo("Must get: " . $mustget . "\n");
echo("We got: " . base64_encode(xor_this($string)) . "\n");

function xor_this($text) {
    $key = 'frtkj';
    $i = 0;
    $encrypted = '';
    foreach (str_split($text) as $char) {
        $encrypted .= chr(ord($char) ^ ord($key{$i++ % strlen($key)}));
    }
    return $encrypted;
}

?>

我得到以下结果,但我需要得到“$ mustget”:

Must get: Kw4SCQ==
We got: LB0HAw==

我做错了什么?

1 个答案:

答案 0 :(得分:10)

$mustget = 'Kw4SCQ==';

$key = 'frtkj';
$key_length = strlen($key);

$encoded_data = base64_decode($mustget);

$result = '';

$length = strlen($encoded_data);
for ($i = 0; $i < $length; $i++) {
    $tmp = $encoded_data[$i];

    for ($j = 0; $j < $key_length; $j++) {
        $tmp = chr(ord($tmp) ^ ord($key[$j]));
    }

    $result .= $tmp;
}

echo $result; // Josh

http://ideone.com/NSIe7K

我确信你可以反转它并创建一个“隐藏”数据的函数; - )