docs: public String encrypt(String plainText) {
      // 加密
      String encryptedXml = encrypt(genRandomStr(), plainText);
  
      // 生成安全签名
      String timeStamp = timeStamp = Long.toString(System.currentTimeMillis() / 1000l);
      String nonce = genRandomStr();
  
      try {
        String signature = SHA1.gen(token, timeStamp, nonce, encryptedXml);
        String result = generateXml(encryptedXml, signature, timeStamp, nonce);
        return result;
      } catch (NoSuchAlgorithmException e) {
        throw new RuntimeException(e);
      }
    }