php encryption class

key = $key; } } //加密函数 public function passport_encrypt($txt) { srand((double)microtime() * 1000000); $encrypt_key = md5(rand(0, 32000)); $ctr = 0; $tmp = ''; for ($i = 0; $i < strlen($txt); $i++) { $ctr = $ctr == strlen($encrypt_key) ? 0 : $ctr; $tmp .= $encrypt_key[$ctr] . ($txt[$i] ^ $encrypt_key[$ctr++]); } return urlencode(base64_encode($this->passport_key($tmp, $this->key))); } //解密函数 public function passport_decrypt($txt) { $txt = $this->passport_key(base64_decode(urldecode($txt)), $this->key); $tmp = ''; for ($i = 0; $i < strlen($txt); $i++) { $md5 = $txt[$i]; $tmp .= $txt[++$i] ^ $md5; } return $tmp; } private function passport_key($txt, $encrypt_key) { $encrypt_key = md5($encrypt_key); $ctr = 0; $tmp = ''; for ($i = 0; $i < strlen($txt); $i++) { $ctr = $ctr == strlen($encrypt_key) ? 0 : $ctr; $tmp .= $txt[$i] ^ $encrypt_key[$ctr++]; } return $tmp; } }