phpcms v9 sys_auth函数加密原理

$key_length = 4;  $key = md5($key);  $fixedkey = md5($key);  $egiskeys = md5(substr($fixedkey, 16, 16));  $runtokey = $key_length ? ($operation == 'ENCODE' ? substr(md5(microtime(true)), -$key_length) : substr($string, 0, $key_length)) : '';  $keys = md5(substr($runtokey, 0, 16) . substr($fixedkey, 0, 16) . substr($runtokey, 16) . substr($fixedkey, 16));  $key_length = 4;$key = md5($key);$fixedkey = md5($key);$egiskeys = md5(substr($fixedkey, 16, 16));$runtokey = $key_length ? ($operation == 'ENCODE' ? substr(md5(microtime(true)), -$key_length) : substr($string, 0, $key_length)) : '';$keys = md5(substr($runtokey, 0, 16) . substr($fixedkey, 0, 16) . substr($runtokey, 16) . substr($fixedkey, 16));

function sys_auth($string, $operation = 'ENCODE', $key = 'hi', $expiry = 0) {      $key_length = 4;      $key = md5($key);      $fixedkey = md5($key);      $egiskeys = md5(substr($fixedkey, 16, 16));      $runtokey = $key_length ? ($operation == 'ENCODE' ? substr(md5(microtime(true)), -$key_length) : substr($string, 0, $key_length)) : '';      $keys = md5(substr($runtokey, 0, 16) . substr($fixedkey, 0, 16) . substr($runtokey, 16) . substr($fixedkey, 16));            $string = $operation == 'ENCODE' ? sprintf('%010d', $expiry ? $expiry + time() : 0).substr(md5($string.$egiskeys), 0, 16) . $string : base64_decode(substr($string, $key_length));      //10位密文过期信息+16位明文和密钥生成的密文验证信息+明文             $i = 0; $result = '';      $string_length = strlen($string);      for ($i = 0; $i < $string_length; $i++){          $result .= chr(ord($string{$i}) ^ ord($keys{$i % 32}));      }            if($operation == 'ENCODE') {          return $runtokey . str_replace('=', '', base64_encode($result));      } else {          if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$egiskeys), 0, 16)) {              return substr($result, 26);          } else {              return '';          }      }  }  function sys_auth($string, $operation = 'ENCODE', $key = 'hi', $expiry = 0) {$key_length = 4;$key = md5($key);$fixedkey = md5($key);$egiskeys = md5(substr($fixedkey, 16, 16));$runtokey = $key_length ? ($operation == 'ENCODE' ? substr(md5(microtime(true)), -$key_length) : substr($string, 0, $key_length)) : '';$keys = md5(substr($runtokey, 0, 16) . substr($fixedkey, 0, 16) . substr($runtokey, 16) . substr($fixedkey, 16));$string = $operation == 'ENCODE' ? sprintf('%010d', $expiry ? $expiry + time() : 0).substr(md5($string.$egiskeys), 0, 16) . $string : base64_decode(substr($string, $key_length));//10位密文过期信息+16位明文和密钥生成的密文验证信息+明文$i = 0; $result = '';$string_length = strlen($string);for ($i = 0; $i < $string_length; $i++){$result .= chr(ord($string{$i}) ^ ord($keys{$i % 32}));}if($operation == 'ENCODE') {return $runtokey . str_replace('=', '', base64_encode($result));} else {if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$egiskeys), 0, 16)) {return substr($result, 26);} else {return '';}}}