docs: public String decryptEcho(String msgSignature, String timeStamp, String nonce, String echoStr) throws AesException {
          String signature = SHA1.getSHA1(token, timeStamp, nonce, echoStr);
  
          if (!signature.equals(msgSignature)) {
              throw new AesException(AesException.ValidateSignatureError);
          }
  
          return decrypt(echoStr);
      }