问题描述
我正在研究加密.我遇到了这样的问题:
I am studying encryption. And I got a problem like this:
在我用密钥对明文进行异或之后,我得到一个 crypt,010e010c15061b4117030f54060e54040e0642181b17",作为十六进制类型.如果我想从这个 crypt 中获取明文,我应该在 PHP 中做什么?
After I XOR plaintext with a key, I get a crypt, "010e010c15061b4117030f54060e54040e0642181b17", as hex type. If I want to get plaintext from this crypt, what should I do in PHP?
我尝试将其转换为字符串/整数,然后将它们与密钥(三个字母)进行异或.但它不起作用.
I tried convert it to string/int and after that take them to XOR with the key (three letters). But it doesn't work.
这是代码:
function xor_this($string) { // Let's define our key here $key = 'fpt'; // Our plaintext/ciphertext $text = $string; // Our output text $outText = ''; // Iterate through each character for($i=0; $i<strlen($text); ) { for($j=0; $j<strlen($key); $j++,$i++) { $outText .= ($text[$i] ^ $key[$j]); //echo 'i=' . $i . ', ' . 'j=' . $j . ', ' . $outText{$i} . '<br />'; // For debugging } } return $outText; } function strToHex($string) { $hex = ''; for ($i=0; $i < strlen($string); $i++) { $hex .= dechex(ord($string[$i])); } return $hex; } function hexToStr($hex) { $string = ''; for ($i=0; $i < strlen($hex)-1; $i+=2) { $string .= chr(hexdec($hex[$i].$hex[$i+1])); } return $string; } $a = "This is the test"; $b = xor_this($a); echo xor_this($b), '-------------'; // $c = strToHex($b); $e = xor_this($c); echo $e, '++++++++'; // $d = hexToStr($c); $f = xor_this($d); echo $f, '=================';
这是结果:
这是测试-------------
This is the test-------------
PHP 注意:未初始化的字符串偏移量:C: 中的 29Users*****istratorDesktop est.php on line 210 PHP Stack trace: PHP1. {main}() C:Users*****istratorDesktop est.php:0 PHP 2. xor_this() C:Users*****istratorDesktop est.php:239
PHP Notice: Uninitialized string offset: 29 in C: Users*****istratorDesktop est.php on line 210 PHP Stack trace: PHP 1. {main}() C:Users*****istratorDesktop est.php:0 PHP 2. xor_this() C:Users*****istratorDesktop est.php:239
注意:未初始化的字符串偏移量:29 inC:Users*****istratorDesktop est.p hp on line 210
Notice: Uninitialized string offset: 29 in C:Users*****istratorDesktop est.p hp on line 210
调用栈:0.0005 674280 1. {main}() C:Users*****istratorDesktop est.php:00.0022 674848 2. xor_this() C:Users*****istratorDesktop est.php:23 9
Call Stack: 0.0005 674280 1. {main}() C:Users*****istratorDesktop est.php:0 0.0022 674848 2. xor_this() C:Users*****istratorDesktop est.php:23 9
UBE^A?WEAVA?WEAV@?WEARAFWECWB++++++++
UBE^A?WEAVA?WEAV@?WEARAFWECWB++++++++
这是zs$fs?==================
This is zs$fs?=================
为什么?结果是UBE^A?WEAVA?WEAV@?WEARAFWECWB++++++++",我在实际工作中遇到了麻烦.
Why? The "UBE^A?WEAVA?WEAV@?WEARAFWECWB++++++++" is the result, which I got trouble in my real work.
推荐答案
试试这个:
function xor_this($string) { // Let's define our key here $key = ('magic_key'); // Our plaintext/ciphertext $text = $string; // Our output text $outText = ''; // Iterate through each character for($i=0; $i<strlen($text); ) { for($j=0; ($j<strlen($key) && $i<strlen($text)); $j++,$i++) { $outText .= $text{$i} ^ $key{$j}; //echo 'i=' . $i . ', ' . 'j=' . $j . ', ' . $outText{$i} . '<br />'; // For debugging } } return $outText; }
基本上要恢复文本(偶数在),您可以使用相同的功能:
$textToObfuscate = "Some Text 12345"; $obfuscatedText = xor_this($textToObfuscate); $restoredText = xor_this($obfuscatedText);