RSA加密长字符串，而且直接加密中文(不encode)会有问题，这里用别人提供的方法尝试可以了，这里我直接新增一个方法复用别人分段加密的算法代码

[wisejin]

/**

• 分段加密长字符串-支持中文的
• @param {string} str the string to encrypt
• @return {string} the encrypted string encoded in base64
• @public
  */
  JSEncrypt.prototype.encryptLongSupportCh = function (string) {
  var k = this.getKey();
  try {
  var lt = '';
  var ct = '';
  //RSA每次加密117bytes，需要辅助方法判断字符串截取位置
  //1.获取字符串截取点
  var bytes = new Array();
  bytes.push(0);
  var byteNo = 0;
  var len, c;
  len = string.length;
  var temp = 0;
  for (var i = 0; i < len; i++) {
  c = string.charCodeAt(i);
  if (c >= 0x010000 && c <= 0x10ffff) {
  byteNo += 4;
  } else if (c >= 0x000800 && c <= 0x00ffff) {
  byteNo += 3;
  } else if (c >= 0x000080 && c <= 0x0007ff) {
  byteNo += 2;
  } else {
  byteNo += 1;
  }
  if (byteNo % 117 >= 114 || byteNo % 117 == 0) {
  if (byteNo - temp >= 114) {
  bytes.push(i);
  temp = byteNo;
  }
  }
  }
  //2.截取字符串并分段加密
  if (bytes.length > 1) {
  for (var i = 0; i < bytes.length - 1; i++) {
  var str;
  if (i == 0) {
  str = string.substring(0, bytes[i + 1] + 1);
  } else {
  str = string.substring(bytes[i] + 1, bytes[i + 1] + 1);
  }
  var t1 = k.encrypt(str);
  ct += t1;
  }
  if (bytes[bytes.length - 1] != string.length - 1) {
  var lastStr = string.substring(bytes[bytes.length - 1] + 1);
  ct += k.encrypt(lastStr);
  }
  return hex2b64(ct);
  }
  var t = k.encrypt(string);
  var y = hex2b64(t);
  return y;
  } catch (ex) {
  return false;
  }
  };