前言

在需求开发中，为了安全起见，我们都会难免遇到需要对一些敏感参数进行加密或者解密。所以，今天给大家分享的就是使用jsencrypt对请求参数进行RSA加密与解密，发这篇文章其实主要因为近期我的一位朋友问我关于jsencrypt的加密问题，记得在很早之前隐约记得整过一次这玩意，所以今天又给整理了一下，把整个的操作流程当做一篇文章给记录下来，以防急时之需！！！

如何使用？

使用之前，需要给项目引入jsencrypt依赖，如果你是工程项目，请给项目中拉取以下依赖

npm install jsencrypt --save

拉取之后可以通过以下方式引入到项目中进行使用

import JSEncrypt from 'jsencrypt'

如果是传统开发的朋友，请不用着急，本次讲解的demo就是使用的传统方式。
jsencrypt在加密或者解密的时候需要用到密钥，所以需要先生成一对密钥：公钥（加密），私钥（解密）。

生成方法

在终端（基于Unix的操作系统）中输入以下命令

openssl genrsa -out rsa_1024_priv.pem 1024

执行这段命令后会生成一个私钥，可以通过执行以下操作进行查看

cat rsa_1024_priv.pem

然后就可以将其复制并粘贴到需要使用私钥的地方即可。
接下来，可以通过执行以下命令获取公钥

openssl rsa -pubout -in rsa_1024_priv.pem -out rsa_1024_pub.pem

同样，可以通过执行以下操作进行查看

cat rsa_1024_pub.pem

如果已经完成了以上操作，那么恭喜你，你现在可以去给参数进行加密了。

如何给参数加密？

给简单的字符串进行加密与解密，可以使用以下方式

//加密获得签名，key公钥，str加密对字符串内容
function getCode(key, str) {
  var encrypt = new JSEncrypt()
  encrypt.setPublicKey(key)
  var data = encrypt.encrypt(str)
  return data
}

//解密获得明文，key私钥，str加密后的签名
function deCode(key, str) {
  var encrypt = new JSEncrypt()
  encrypt.setPrivateKey(key)
  var data = encrypt.decrypt(str)
  return data
}

如果是给一段较长的字符串加密，这里可能就会有坑了，因为长度问题可能会造成加解密失败，如果你遇到了，请使用下面方式进行分段加解密，这样就解决了该问题的出现

//分段加密算法方法
JSEncrypt.prototype.encryptLong = function (string) {  
  var k = this.getKey(),
  maxLength = (((k.n.bitLength()+7)>>3)-11);

  try {
    var lt = "",
    ct = "";

    if (string.length > maxLength) {
      lt = string.match(/.{1,50}/g);
      lt.forEach(entry => {
        var t1 = k.encrypt(entry);
        ct += t1 ;
      });
      return hex2b64(ct);
    }
    var t = k.encrypt(string),
    y = hex2b64(t);
    return y;
  } catch (ex) {
    return ex;
  }
};

//分段解密算法方法
JSEncrypt.prototype.decryptLong = function (string) {    
  var k = this.getKey(),
  maxLength = (((k.n.bitLength()+7)>>3)-11);

  try {    
    var ct = '';  
    string = b64tohex(string)
    if (string.length > maxLength) {        
      var lt = string.match(/.{1,256}/g);  
      lt.forEach(function(entry) {          
        var t1 = k.decrypt(entry);     
        ct += t1;
      });
      return ct;   
    }      
    var y = k.decrypt(b64tohex(string));      
    return y;
  } catch (ex) {
    return ex;
  }  
};

//分段加密
function getLongCode(key, str) {
  var encrypt = new JSEncrypt()
  encrypt.setPublicKey(key)
  var data = encrypt.encryptLong(str)
  return data
}

//分段解密
function deLongCode(key, str) {
  var decryptLong = new JSEncrypt()
  decryptLong.setPrivateKey(key)
  var data = decryptLong.decryptLong(str)
  return /^{.+}$/g.test(data) && JSON.parse(data) || data
}

上方代码中出现了几个未定义的方法，hex2b64，b64tohex，这两个方法是base64分段的算法函数，下面是补充的算法封装函数依赖

var dbits;
var canary = 244837814094590;
var j_lm = ((canary & 16777215) == 15715070);
function BigInteger(e, d, f) {
 if (e != null) {
  if ("number" == typeof e) {
   this.fromNumber(e, d, f)
  } else {
   if (d == null && "string" != typeof e) {
    this.fromString(e, 256)
   } else {
    this.fromString(e, d)
   }
  }
 }
}
function nbi() {
 return new BigInteger(null)
}
function am1(f, a, b, e, h, g) {
 while (--g >= 0) {
  var d = a * this[f++] + b[e] + h;
  h = Math.floor(d / 67108864);
  b[e++] = d & 67108863
 }
 return h
}
function am2(f, q, r, e, o, a) {
 var k = q & 32767,
 p = q >> 15;
 while (--a >= 0) {
  var d = this[f] & 32767;
  var g = this[f++] >> 15;
  var b = p * d + g * k;
  d = k * d + ((b & 32767) << 15) + r[e] + (o & 1073741823);
  o = (d >>> 30) + (b >>> 15) + p * g + (o >>> 30);
  r[e++] = d & 1073741823
 }
 return o
}
function am3(f, q, r, e, o, a) {
 var k = q & 16383,
 p = q >> 14;
 while (--a >= 0) {
  var d = this[f] & 16383;
  var g = this[f++] >> 14;
  var b = p * d + g * k;
  d = k * d + ((b & 16383) << 14) + r[e] + o;
  o = (d >> 28) + (b >> 14) + p * g;
  r[e++] = d & 268435455
 }
 return o
}
//if (j_lm && (navigator.appName == "Microsoft Internet Explorer")) { //xpp注释
//    BigInteger.prototype.am = am2;
//    dbits = 30
//} else {
//    if (j_lm && (navigator.appName != "Netscape")) {
//    BigInteger.prototype.am = am1;
//    dbits = 26
//    } else {
  BigInteger.prototype.am = am3;
  dbits = 28
//    }
//}
BigInteger.prototype.DB = dbits;
BigInteger.prototype.DM = ((1 << dbits) - 1);
BigInteger.prototype.DV = (1 << dbits);
var BI_FP = 52;
BigInteger.prototype.FV = Math.pow(2, BI_FP);
BigInteger.prototype.F1 = BI_FP - dbits;
BigInteger.prototype.F2 = 2 * dbits - BI_FP;
var BI_RM = "0123456789abcdefghijklmnopqrstuvwxyz";
var BI_RC = new Array();
var rr, vv;
rr = "0".charCodeAt(0);
for (vv = 0; vv <= 9; ++vv) {
 BI_RC[rr++] = vv
}
rr = "a".charCodeAt(0);
for (vv = 10; vv < 36; ++vv) {
 BI_RC[rr++] = vv
}
rr = "A".charCodeAt(0);
for (vv = 10; vv < 36; ++vv) {
 BI_RC[rr++] = vv
}
function int2char(a) {
 return BI_RM.charAt(a)
}
function intAt(b, a) {
 var d = BI_RC[b.charCodeAt(a)];
 return (d == null) ? -1 : d
}
function bnpToRadix(b) { 
    if (b == null) { 
        b = 10 
    } 
    if (this.signum() == 0 || b < 2 || b > 36) { 
        return "0" 
    } 
    var cs = this.chunkSize(b); 
    var a = Math.pow(b, cs); 
    var d = nbv(a), 
        y = nbi(), 
        z = nbi(), 
        r = ""; 
    this.divRemTo(d, y, z); 
    while (y.signum() > 0) { 
        r = (a + z.intValue()).toString(b).substr(1) + r; 
        y.divRemTo(d, y, z) 
    } 
    return z.intValue().toString(b) + r 
} 
function bnSigNum() { 
    if (this.s < 0) { 
        return -1 
    } else { 
        if (this.t <= 0 || (this.t == 1 && this[0] <= 0)) { 
            return 0 
        } else { 
            return 1 
        } 
    } 
} 
function bnpChunkSize(r) { 
    return Math.floor(Math.LN2 * this.DB / Math.log(r)) 
}
function bnIntValue() { 
    if (this.s < 0) { 
        if (this.t == 1) { 
            return this[0] - this.DV 
        } else { 
            if (this.t == 0) { 
                return -1 
            } 
        } 
    } else { 
        if (this.t == 1) { 
            return this[0] 
        } else { 
            if (this.t == 0) { 
                return 0 
            } 
        } 
    } 
    return ((this[1] & ((1 << (32 - this.DB)) - 1)) << this.DB) | this[0] 
}

function bnpCopyTo(b) {
 for (var a = this.t - 1; a >= 0; --a) {
  b[a] = this[a]
 }
 b.t = this.t;
 b.s = this.s
}
function bnpFromInt(a) {
 this.t = 1;
 this.s = (a < 0) ? -1 : 0;
 if (a > 0) {
  this[0] = a
 } else {
  if (a < -1) {
   this[0] = a + DV
  } else {
   this.t = 0
  }
 }
}
function nbv(a) {
 var b = nbi();
 b.fromInt(a);
 return b
}
function bnpFromString(h, c) {
 var e;
 if (c == 16) {
  e = 4
 } else {
  if (c == 8) {
   e = 3
  } else {
   if (c == 256) {
    e = 8
   } else {
    if (c == 2) {
     e = 1
    } else {
     if (c == 32) {
      e = 5
     } else {
      if (c == 4) {
       e = 2
      } else {
       this.fromRadix(h, c);
       return
      }
     }
    }
   }
  }
 }
 this.t = 0;
 this.s = 0;
 var g = h.length,
 d = false,
 f = 0;
 while (--g >= 0) {
  var a = (e == 8) ? h[g] & 255 : intAt(h, g);
  if (a < 0) {
   if (h.charAt(g) == "-") {
    d = true
   }
   continue
  }
  d = false;
  if (f == 0) {
   this[this.t++] = a
  } else {
   if (f + e > this.DB) {
    this[this.t - 1] |= (a & ((1 << (this.DB - f)) - 1)) << f;
    this[this.t++] = (a >> (this.DB - f))
   } else {
    this[this.t - 1] |= a << f
   }
  }
  f += e;
  if (f >= this.DB) {
   f -= this.DB
  }
 }
 if (e == 8 && (h[0] & 128) != 0) {
  this.s = -1;
  if (f > 0) {
   this[this.t - 1] |= ((1 << (this.DB - f)) - 1) << f
  }
 }
 this.clamp();
 if (d) {
  BigInteger.ZERO.subTo(this, this)
 }
}
function bnpClamp() {
 var a = this.s & this.DM;
 while (this.t > 0 && this[this.t - 1] == a) {
  --this.t
 }
}
function bnToString(c) {
 if (this.s < 0) {
  return "-" + this.negate().toString(c)
 }
 var e;
 if (c == 16) {
  e = 4
 } else {
  if (c == 8) {
   e = 3
  } else {
   if (c == 2) {
    e = 1
   } else {
    if (c == 32) {
     e = 5
    } else {
     if (c == 4) {
      e = 2
     } else {
      return this.toRadix(c)
     }
    }
   }
  }
 }
 var g = (1 << e) - 1,
 l,
 a = false,
 h = "",
 f = this.t;
 var j = this.DB - (f * this.DB) % e;
 if (f-- > 0) {
  if (j < this.DB && (l = this[f] >> j) > 0) {
   a = true;
   h = int2char(l)
  }
  while (f >= 0) {
   if (j < e) {
    l = (this[f] & ((1 << j) - 1)) << (e - j);
    l |= this[--f] >> (j += this.DB - e)
   } else {
    l = (this[f] >> (j -= e)) & g;
    if (j <= 0) {
     j += this.DB;
     --f
    }
   }
   if (l > 0) {
    a = true
   }
   if (a) {
    h += int2char(l)
   }
  }
 }
 return a ? h : "0"
}
function bnNegate() {
 var a = nbi();
 BigInteger.ZERO.subTo(this, a);
 return a
}
function bnAbs() {
 return (this.s < 0) ? this.negate() : this
}
function bnCompareTo(b) {
 var d = this.s - b.s;
 if (d != 0) {
  return d
 }
 var c = this.t;
 d = c - b.t;
 if (d != 0) {
  return (this.s < 0) ? -d : d
 }
 while (--c >= 0) {
  if ((d = this[c] - b[c]) != 0) {
   return d
  }
 }
 return 0
}
function nbits(a) {
 var c = 1,
 b;
 if ((b = a >>> 16) != 0) {
  a = b;
  c += 16
 }
 if ((b = a >> 8) != 0) {
  a = b;
  c += 8
 }
 if ((b = a >> 4) != 0) {
  a = b;
  c += 4
 }
 if ((b = a >> 2) != 0) {
  a = b;
  c += 2
 }
 if ((b = a >> 1) != 0) {
  a = b;
  c += 1
 }
 return c
}
function bnBitLength() {
 if (this.t <= 0) {
  return 0
 }
 return this.DB * (this.t - 1) + nbits(this[this.t - 1] ^ (this.s & this.DM))
}

function bnpDLShiftTo(c, b) {
 var a;
 for (a = this.t - 1; a >= 0; --a) {
  b[a + c] = this[a]
 }
 for (a = c - 1; a >= 0; --a) {
  b[a] = 0
 }
 b.t = this.t + c;
 b.s = this.s
}
function bnpDRShiftTo(c, b) {
 for (var a = c; a < this.t; ++a) {
  b[a - c] = this[a]
 }
 b.t = Math.max(this.t - c, 0);
 b.s = this.s
}
function bnpLShiftTo(j, e) {
 var b = j % this.DB;
 var a = this.DB - b;
 var g = (1 << a) - 1;
 var f = Math.floor(j / this.DB),
 h = (this.s << b) & this.DM,
 d;
 for (d = this.t - 1; d >= 0; --d) {
  e[d + f + 1] = (this[d] >> a) | h;
  h = (this[d] & g) << b
 }
 for (d = f - 1; d >= 0; --d) {
  e[d] = 0
 }
 e[f] = h;
 e.t = this.t + f + 1;
 e.s = this.s;
 e.clamp()
}
function bnpRShiftTo(g, d) {
 d.s = this.s;
 var e = Math.floor(g / this.DB);
 if (e >= this.t) {
  d.t = 0;
  return
 }
 var b = g % this.DB;
 var a = this.DB - b;
 var f = (1 << b) - 1;
 d[0] = this[e] >> b;
 for (var c = e + 1; c < this.t; ++c) {
  d[c - e - 1] |= (this[c] & f) << a;
  d[c - e] = this[c] >> b
 }
 if (b > 0) {
  d[this.t - e - 1] |= (this.s & f) << a
 }
 d.t = this.t - e;
 d.clamp()
}
function bnpSubTo(d, f) {
 var e = 0,
 g = 0,
 b = Math.min(d.t, this.t);
 while (e < b) {
  g += this[e] - d[e];
  f[e++] = g & this.DM;
  g >>= this.DB
 }
 if (d.t < this.t) {
  g -= d.s;
  while (e < this.t) {
   g += this[e];
   f[e++] = g & this.DM;
   g >>= this.DB
  }
  g += this.s
 } else {
  g += this.s;
  while (e < d.t) {
   g -= d[e];
   f[e++] = g & this.DM;
   g >>= this.DB
  }
  g -= d.s
 }
 f.s = (g < 0) ? -1 : 0;
 if (g < -1) {
  f[e++] = this.DV + g
 } else {
  if (g > 0) {
   f[e++] = g
  }
 }
 f.t = e;
 f.clamp()
}
function bnpMultiplyTo(c, e) {
 var b = this.abs(),
 f = c.abs();
 var d = b.t;
 e.t = d + f.t;
 while (--d >= 0) {
  e[d] = 0
 }
 for (d = 0; d < f.t; ++d) {
  e[d + b.t] = b.am(0, f[d], e, d, 0, b.t)
 }
 e.s = 0;
 e.clamp();
 if (this.s != c.s) {
  BigInteger.ZERO.subTo(e, e)
 }
}
function bnpSquareTo(d) {
 var a = this.abs();
 var b = d.t = 2 * a.t;
 while (--b >= 0) {
  d[b] = 0
 }
 for (b = 0; b < a.t - 1; ++b) {
  var e = a.am(b, a[b], d, 2 * b, 0, 1);
  if ((d[b + a.t] += a.am(b + 1, 2 * a[b], d, 2 * b + 1, e, a.t - b - 1)) >= a.DV) {
   d[b + a.t] -= a.DV;
   d[b + a.t + 1] = 1
  }
 }
 if (d.t > 0) {
  d[d.t - 1] += a.am(b, a[b], d, 2 * b, 0, 1)
 }
 d.s = 0;
 d.clamp()
}
function bnpDivRemTo(n, h, g) {
 var w = n.abs();
 if (w.t <= 0) {
  return
 }
 var k = this.abs();
 if (k.t < w.t) {
  if (h != null) {
   h.fromInt(0)
  }
  if (g != null) {
   this.copyTo(g)
  }
  return
 }
 if (g == null) {
  g = nbi()
 }
 var d = nbi(),
 a = this.s,
 l = n.s;
 var v = this.DB - nbits(w[w.t - 1]);
 if (v > 0) {
  w.lShiftTo(v, d);
  k.lShiftTo(v, g)
 } else {
  w.copyTo(d);
  k.copyTo(g)
 }
 var p = d.t;
 var b = d[p - 1];
 if (b == 0) {
  return
 }
 var o = b * (1 << this.F1) + ((p > 1) ? d[p - 2] >> this.F2 : 0);
 var A = this.FV / o,
 z = (1 << this.F1) / o,
 x = 1 << this.F2;
 var u = g.t,
 s = u - p,
 f = (h == null) ? nbi() : h;
 d.dlShiftTo(s, f);
 if (g.compareTo(f) >= 0) {
  g[g.t++] = 1;
  g.subTo(f, g)
 }
 BigInteger.ONE.dlShiftTo(p, f);
 f.subTo(d, d);
 while (d.t < p) {
  d[d.t++] = 0
 }
 while (--s >= 0) {
  var c = (g[--u] == b) ? this.DM : Math.floor(g[u] * A + (g[u - 1] + x) * z);
  if ((g[u] += d.am(0, c, g, s, 0, p)) < c) {
   d.dlShiftTo(s, f);
   g.subTo(f, g);
   while (g[u] < --c) {
    g.subTo(f, g)
   }
  }
 }
 if (h != null) {
  g.drShiftTo(p, h);
  if (a != l) {
   BigInteger.ZERO.subTo(h, h)
  }
 }
 g.t = p;
 g.clamp();
 if (v > 0) {
  g.rShiftTo(v, g)
 }
 if (a < 0) {
  BigInteger.ZERO.subTo(g, g)
 }
}
function bnMod(b) {
 var c = nbi();
 this.abs().divRemTo(b, null, c);
 if (this.s < 0 && c.compareTo(BigInteger.ZERO) > 0) {
  b.subTo(c, c)
 }
 return c
}
function Classic(a) {
 this.m = a
}
function cConvert(a) {
 if (a.s < 0 || a.compareTo(this.m) >= 0) {
  return a.mod(this.m)
 } else {
  return a
 }
}
function cRevert(a) {
 return a
}
function cReduce(a) {
 a.divRemTo(this.m, null, a)
}
function cMulTo(a, c, b) {
 a.multiplyTo(c, b);
 this.reduce(b)
}
function cSqrTo(a, b) {
 a.squareTo(b);
 this.reduce(b)
}
Classic.prototype.convert = cConvert;
Classic.prototype.revert = cRevert;
Classic.prototype.reduce = cReduce;
Classic.prototype.mulTo = cMulTo;
Classic.prototype.sqrTo = cSqrTo;
function bnpInvDigit() {
 if (this.t < 1) {
  return 0
 }
 var a = this[0];
 if ((a & 1) == 0) {
  return 0
 }
 var b = a & 3;
 b = (b * (2 - (a & 15) * b)) & 15;
 b = (b * (2 - (a & 255) * b)) & 255;
 b = (b * (2 - (((a & 65535) * b) & 65535))) & 65535;
 b = (b * (2 - a * b % this.DV)) % this.DV;
 return (b > 0) ? this.DV - b : -b
}
function Montgomery(a) {
 this.m = a;
 this.mp = a.invDigit();
 this.mpl = this.mp & 32767;
 this.mph = this.mp >> 15;
 this.um = (1 << (a.DB - 15)) - 1;
 this.mt2 = 2 * a.t
}
function montConvert(a) {
 var b = nbi();
 a.abs().dlShiftTo(this.m.t, b);
 b.divRemTo(this.m, null, b);
 if (a.s < 0 && b.compareTo(BigInteger.ZERO) > 0) {
  this.m.subTo(b, b)
 }
 return b
}
function montRevert(a) {
 var b = nbi();
 a.copyTo(b);
 this.reduce(b);
 return b
}
function montReduce(a) {
 while (a.t <= this.mt2) {
  a[a.t++] = 0
 }
 for (var c = 0; c < this.m.t; ++c) {
  var b = a[c] & 32767;
  var d = (b * this.mpl + (((b * this.mph + (a[c] >> 15) * this.mpl) & this.um) << 15)) & a.DM;
  b = c + this.m.t;
  a[b] += this.m.am(0, d, a, c, 0, this.m.t);
  while (a[b] >= a.DV) {
   a[b] -= a.DV;
   a[++b]++
  }
 }
 a.clamp();
 a.drShiftTo(this.m.t, a);
 if (a.compareTo(this.m) >= 0) {
  a.subTo(this.m, a)
 }
}
function montSqrTo(a, b) {
 a.squareTo(b);
 this.reduce(b)
}
function montMulTo(a, c, b) {
 a.multiplyTo(c, b);
 this.reduce(b)
}
Montgomery.prototype.convert = montConvert;
Montgomery.prototype.revert = montRevert;
Montgomery.prototype.reduce = montReduce;
Montgomery.prototype.mulTo = montMulTo;
Montgomery.prototype.sqrTo = montSqrTo;
function bnpIsEven() {
 return ((this.t > 0) ? (this[0] & 1) : this.s) == 0
}
function bnpExp(h, j) {
 if (h > 4294967295 || h < 1) {
  return BigInteger.ONE
 }
 var f = nbi(),
 a = nbi(),
 d = j.convert(this),
 c = nbits(h) - 1;
 d.copyTo(f);
 while (--c >= 0) {
  j.sqrTo(f, a);
  if ((h & (1 << c)) > 0) {
   j.mulTo(a, d, f)
  } else {
   var b = f;
   f = a;
   a = b
  }
 }
 return j.revert(f)
}
function bnModPowInt(b, a) {
 var c;
 if (b < 256 || a.isEven()) {
  c = new Classic(a)
 } else {
  c = new Montgomery(a)
 }
 return this.exp(b, c)
}

BigInteger.prototype.toRadix = bnpToRadix; 
BigInteger.prototype.signum = bnSigNum; 
BigInteger.prototype.chunkSize = bnpChunkSize;
BigInteger.prototype.intValue = bnIntValue; 

BigInteger.prototype.copyTo = bnpCopyTo;
BigInteger.prototype.fromInt = bnpFromInt;
BigInteger.prototype.fromString = bnpFromString;
BigInteger.prototype.clamp = bnpClamp;
BigInteger.prototype.dlShiftTo = bnpDLShiftTo;
BigInteger.prototype.drShiftTo = bnpDRShiftTo;
BigInteger.prototype.lShiftTo = bnpLShiftTo;
BigInteger.prototype.rShiftTo = bnpRShiftTo;
BigInteger.prototype.subTo = bnpSubTo;
BigInteger.prototype.multiplyTo = bnpMultiplyTo;
BigInteger.prototype.squareTo = bnpSquareTo;
BigInteger.prototype.divRemTo = bnpDivRemTo;
BigInteger.prototype.invDigit = bnpInvDigit;
BigInteger.prototype.isEven = bnpIsEven;
BigInteger.prototype.exp = bnpExp;
BigInteger.prototype.toString = bnToString;
BigInteger.prototype.negate = bnNegate;
BigInteger.prototype.abs = bnAbs;
BigInteger.prototype.compareTo = bnCompareTo;
BigInteger.prototype.bitLength = bnBitLength; 
BigInteger.prototype.mod = bnMod;
BigInteger.prototype.modPowInt = bnModPowInt;
BigInteger.ZERO = nbv(0);
BigInteger.ONE = nbv(1);
function Arcfour() {
 this.i = 0;
 this.j = 0;
 this.S = new Array()
}
function ARC4init(d) {
 var c,
 a,
 b;
 for (c = 0; c < 256; ++c) {
  this.S[c] = c
 }
 a = 0;
 for (c = 0; c < 256; ++c) {
  a = (a + this.S[c] + d[c % d.length]) & 255;
  b = this.S[c];
  this.S[c] = this.S[a];
  this.S[a] = b
 }
 this.i = 0;
 this.j = 0
}
function ARC4next() {
 var a;
 this.i = (this.i + 1) & 255;
 this.j = (this.j + this.S[this.i]) & 255;
 a = this.S[this.i];
 this.S[this.i] = this.S[this.j];
 this.S[this.j] = a;
 return this.S[(a + this.S[this.i]) & 255]
}
Arcfour.prototype.init = ARC4init;
Arcfour.prototype.next = ARC4next;
function prng_newstate() {
 return new Arcfour()
}
var rng_psize = 256;
var rng_state;
var rng_pool;
var rng_pptr;
function rng_seed_int(a) {
 rng_pool[rng_pptr++] ^= a & 255;
 rng_pool[rng_pptr++] ^= (a >> 8) & 255;
 rng_pool[rng_pptr++] ^= (a >> 16) & 255;
 rng_pool[rng_pptr++] ^= (a >> 24) & 255;
 if (rng_pptr >= rng_psize) {
  rng_pptr -= rng_psize
 }
}
function rng_seed_time() {
 rng_seed_int(new Date().getTime())
}
 if (rng_pool == null) { //注释
  rng_pool = new Array();
  rng_pptr = 0;
  var t;
 // if (navigator.appName == "Netscape" && navigator.appVersion < "5" && window.crypto) {
 //    var z = window.crypto.random(32);
 //    for (t = 0; t < z.length; ++t) {
 //    rng_pool[rng_pptr++] = z.charCodeAt(t) & 255
 //    }
 // }
 // while (rng_pptr < rng_psize) {
 //    t = Math.floor(65536 * Math.random());
 //    rng_pool[rng_pptr++] = t >>> 8;
 //    rng_pool[rng_pptr++] = t & 255
 // }
 // rng_pptr = 0;
 // rng_seed_time()
 }
function rng_get_byte() {
 if (rng_state == null) {
  rng_seed_time();
  rng_state = prng_newstate();
  rng_state.init(rng_pool);
  for (rng_pptr = 0; rng_pptr < rng_pool.length; ++rng_pptr) {
   rng_pool[rng_pptr] = 0
  }
  rng_pptr = 0
 }
 return rng_state.next()
}
function rng_get_bytes(b) {
 var a;
 for (a = 0; a < b.length; ++a) {
  b[a] = rng_get_byte()
 }
}
function SecureRandom() {}
SecureRandom.prototype.nextBytes = rng_get_bytes;
function parseBigInt(b, a) {
 return new BigInteger(b, a)
}
function linebrk(c, d) {
 var a = "";
 var b = 0;
 while (b + d < c.length) {
  a += c.substring(b, b + d) + "\n";
  b += d
 }
 return a + c.substring(b, c.length)
}
function byte2Hex(a) {
 if (a < 16) {
  return "0" + a.toString(16)
 } else {
  return a.toString(16)
 }
}
function pkcs1pad2(e, h) {
 if (h < e.length + 11) {
//    alert("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--);
  if (f < 128) {
   g[--h] = f
  } else {
   if ((f > 127) && (f < 2048)) {
    g[--h] = (f & 63) | 128;
    g[--h] = (f >> 6) | 192
   } else {
    g[--h] = (f & 63) | 128;
    g[--h] = ((f >> 6) & 63) | 128;
    g[--h] = (f >> 12) | 224
   }
  }
 }
 g[--h] = 0;
 var b = new SecureRandom();
 var a = new Array();
 while (h > 2) {
  a[0] = 0;
  while (a[0] == 0) {
   b.nextBytes(a)
  }
  g[--h] = a[0]
 }
 g[--h] = 2;
 g[--h] = 0;
 return new BigInteger(g)
}
function RSAKey() {
 this.n = null;
 this.e = 0;
 this.d = null;
 this.p = null;
 this.q = null;
 this.dmp1 = null;
 this.dmq1 = null;
 this.coeff = null
}
function RSASetPublic(b, a) {
 if (b != null && a != null && b.length > 0 && a.length > 0) {
  this.n = parseBigInt(b, 16);
  this.e = parseInt(a, 16);
  return this.n.toString();
 } else {
//    alert("Invalid RSA public key")
  return 0;
 }
}
function RSADoPublic(a) {
 return a.modPowInt(this.e, this.n)
}
function RSAEncrypt(d) {
 var a = pkcs1pad2(d, (this.n.bitLength() + 7) >> 3);
 if (a == null) {
  return null
 }
 var e = this.doPublic(a);
 if (e == null) {
  return null
 }
 var b = e.toString(16);
 if ((b.length & 1) == 0) {
  return b
 } else {
  return "0" + b
 }
 return a;
}
RSAKey.prototype.doPublic = RSADoPublic;
RSAKey.prototype.setPublic = RSASetPublic;
RSAKey.prototype.encrypt = RSAEncrypt;
var b64map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var b64pad = "=";
function hex2b64(d) {
 var b;
 var e;
 var a = "";
 for (b = 0; b + 3 <= d.length; b += 3) {
  e = parseInt(d.substring(b, b + 3), 16);
  a += b64map.charAt(e >> 6) + b64map.charAt(e & 63)
 }
 if (b + 1 == d.length) {
  e = parseInt(d.substring(b, b + 1), 16);
  a += b64map.charAt(e << 2)
 } else {
  if (b + 2 == d.length) {
   e = parseInt(d.substring(b, b + 2), 16);
   a += b64map.charAt(e >> 2) + b64map.charAt((e & 3) << 4)
  }
 }
 while ((a.length & 3) > 0) {
  a += b64pad
 }
 return a
}
function b64tohex(e) {
 var c = "";
 var d;
 var a = 0;
 var b;
 var v;
 for (d = 0; d < e.length; ++d) {
  if (e.charAt(d) == b64pad) {
   break
  }
  v = b64map.indexOf(e.charAt(d));
  if (v < 0) {
   continue
  }
  if (a == 0) {
   c += int2char(v >> 2);
   b = v & 3;
   a = 1
  } else {
   if (a == 1) {
    c += int2char((b << 2) | (v >> 4));
    b = v & 15;
    a = 2
   } else {
    if (a == 2) {
     c += int2char(b);
     c += int2char(v >> 2);
     b = v & 3;
     a = 3
    } else {
     c += int2char((b << 2) | (v >> 4));
     c += int2char(v & 15);
     a = 0
    }
   }
  }
 }
 if (a == 1) {
  c += int2char(b << 2)
 }
 return c
}
function b64toBA(e) {
 var d = b64tohex(e);
 var c;
 var b = new Array();
 for (c = 0; 2 * c < d.length; ++c) {
  b[c] = parseInt(d.substring(2 * c, 2 * c + 2), 16)
 }
 return b
};

至此，关于使用jsencrypt对参数进行RSA加密的内容就讲解完了，如果各位有什么问题可以在评论区域给我留言。
具体使用请移步 jsencrypt demo