代码是直接在kjur-jsrsasign-d282c71库里面的jsrsasign-all-min.js添加的。所以要了解具体情况需要先下载该库。

//输入d是需要加密的字符串
RSAKey.prototype.privEncrypt = function(d) {
//关键是pkcs1pad1函数，实现了PKCS1Padding，
//PKCS1Padding的实现原理可以参照下面的超链接[PKCS1Padding分析](https://www.cnblogs.com/spencerN/archive/2012/10/18/2729602.html)
//n是啥意思，看看下面的超链接[RSA公钥私钥加密](https://www.cnblogs.com/zhaoxingjun/articles/6139127.html)就知道了
//n的大概意思就是两个素数的乘积累
  var a = pkcs1pad1(d, (this.n.bitLength() + 7) >> 3);
  if (a == null) {
    return null
  var e = this.doPrivate(a);
  if (e == null) {
    return null
  //转成16进制的字符串
  var b = e.toString(16);
  if ((b.length & 1) == 0) {
    return b
  } else {
    return "0" + b
RSA加密参照网页链接：
 RSA公钥私钥加密
 PKCS1Padding分析
 
pkcs1pad1的实现
 
去PKCS1Padding分析页面，看看具体原理
 
// An highlighted block
function pkcs1pad1(e, h) {
  //EB = 00 + BT+ PS + 00 +D
  // BT | PS             PS.length = 1024/8 - 3 - D.length
  // 00 | 00
  // 01 | FF             for private
  // 02 | ramdom value   for public
  // D is the  plaintext
  if (h < e.length + 11) {
    throw "Message too long for RSA";
    return null
  var g = new Array();
  var d = e.length - 1;
  while (d >= 0 && h > 0) {
    var f = e.charCodeAt(d--);
    g[--h] = f;
  g[--h] = 0;
  while (h > 2) {
    g[--h] = 255;
  g[--h] = 1;
  g[--h] = 0;
  return new BigInteger(g)
//私钥传入是hex的格式，我这里是特殊需要。
        let priHex = "";
        let rsa = new RSAKey();
        rsa.readPKCS8PrvKeyHex(priHex);
	//输入是字符串，输入是hex的字串
        let hSig = rsa.privEncrypt(content);
        //转成Base64的字符串
        let hipherText = hex2b64(hSig);
如果是PKCS#1的pem格式的Base64私钥可以用下面的接口读入
 
        let prvKey = "";
        let rsa = new RSAKey();
        rsa.readPrivateKeyFromPEMString(prvKey);
        //输入是字符串，输入是hex的字串
        let hSig = rsa.privEncrypt(content);
        let hipherText = hex2b64(hSig);
//公钥（注意包括头（-----BEGIN PUBLIC KEY-----）尾（-----END PUBLIC KEY-----）标志）
-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDbdq5NjtUEkAQ6wucPuhC0aRvSMsaX3GrhkwsLLdWZnVNVpkJRw
yPFq9HJNuntRw7P9Sb3Tk.
            $privateKeyFilePath = '-----BEGIN RSA PRIVATE KEY-----
MIICdgIBADANBgkqhkiG9w0BAQEFAASCAmAwggJcAgEAAoGBAJDArkki2k3+xhze
v5emztqFtUhOzVlSveQ5dOLC4nNlLg8r81I9xBaXB7m4rb6lVjLgUuAXKUJ8y7yH
eE02s695cR/ZD0fierrMKMkmTFZIqOVYchn15N8E
var encrypt = new JSEncrypt();
encrypt.setPublicKey(PUBLIC_KEY);
var encrypted = encrypt.encryptLong("results");
console.log('加密后数据:%o', encrypted);
var decrypt = new JSEncrypt();
decrypt.setPrivateKey(PRIVATE_KEY);
let un = decrypt.decryptLong(encrypted);
console.log('解密后数据:%o', un);