PHP source code analysis of DZX1.5 encryption and decryption function authcode usage, dzx1.5authcode_PHP tutorial

PHP source code analysis of DZX1.5 encryption and decryption function authcode usage, dzx1.5authcode

This article describes the use of DZX1.5 encryption and decryption function authcode of PHP source code analysis. Share it with everyone for your reference. The specific analysis is as follows:

<&#63;php
$authkey = '';
/**
 * @param string $string: 输入的需要加密（或解密）的明文（或密文）
 * @param string $operation: 'DECODE'或其它，其中默认表示解密，输入其它表示加密
 * @param string $key: 加解密密钥
 * @param int $expiry: 有效期
 */
function authcode($string, $operation = 'DECODE', $key = '', $expiry = 0) {
  global $authkey;
  $ckey_length = 4;
  $key = md5($key != '' &#63; $key : $authkey);
  $keya = md5(substr($key, 0, 16));
  $keyb = md5(substr($key, 16, 16));
  $keyc = $ckey_length &#63; ($operation == 'DECODE' &#63; substr($string, 0, $ckey_length): substr(md5(microtime()), -$ckey_length)) : '';
  $cryptkey = $keya.md5($keya.$keyc);
  $key_length = strlen($cryptkey);
  $string = $operation == 'DECODE' &#63; base64_decode(substr($string, $ckey_length)) : sprintf('%010d', $expiry &#63; $expiry + time() : 0).substr(md5($string.$keyb), 0, 16).$string;
  $string_length = strlen($string);
  $result = '';
  $box = range(0, 255);
  $rndkey = array();
  for($i = 0; $i <= 255; $i++) {
    $rndkey[$i] = ord($cryptkey[$i % $key_length]);
  }
  for($j = $i = 0; $i < 256; $i++) {
    $j = ($j + $box[$i] + $rndkey[$i]) % 256;
    $tmp = $box[$i];
    $box[$i] = $box[$j];
    $box[$j] = $tmp;
  }
  for($a = $j = $i = 0; $i < $string_length; $i++) {
    $a = ($a + 1) % 256;
    $j = ($j + $box[$a]) % 256;
    $tmp = $box[$a];
    $box[$a] = $box[$j];
    $box[$j] = $tmp;
    $result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
  }
  if($operation == 'DECODE') {
    if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$keyb), 0, 16)) {
      return substr($result, 26);
    } else {
      return '';
    }
  } else {
    return $keyc.str_replace('=', '', base64_encode($result));
  }
}
$str = '1234';
$key = '1234';
echo "明文:".$str;
echo "<br />";
echo "密钥:".$key;
$encode = authcode($str,'11',$key);
echo "<br />";
echo "加密后的密文:".$encode;
echo "<br />";
$decode = authcode($encode,'DECODE',$key);
echo "解密后的明文:".$decode;
/*End of php*/

The running results are as follows:

Clear text:1234
Key:1234
Encrypted ciphertext: a52f67eXZGVy0HtQBo4vOREhq3WxnL6E2zlx75JGfoJW
Decrypted plaintext: 1234

I hope this article will be helpful to everyone’s PHP programming design.

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