页面登录密码加密传输机制

 为了避免用户密码使用明文传输，在传输前需要进行加密处理，服务端接收之后再进行解密，这样从一定程度上保护了密码安全。

        基本过程如下：

        显然，采用非对称加密更合适，这里我们使用RSA加密算法。

        需要三方面的东东。

        第一样，服务器端RSA加解密工具类及KEY定义。

        第二样，Web端RSA加密工具类，支持根据公钥加密。

        第三样，用户登录时的处理脚本。

        赋代码是直接的

Case one

namespace Tool.Security
{
    /// <summary>
    /// 对公钥的提供和对解密的支持
    /// </summary>
    static class RSAHelper
    {
        private static string ByteToHex(byte[] byteArray)
        {
            string outString = "";
            foreach (Byte b in byteArray)
            {
                outString += b.ToString("X2");
            }
            return outString;
        }

        private static byte[] HexToByte(string hexString)
        {
            byte[] returnBytes = new byte[hexString.Length / 2];
            for (int i = 0; i < returnBytes.Length; i++)
            {
                returnBytes[i] = Convert.ToByte(hexString.Substring(i * 2, 2), 16);
            }
            return returnBytes;
        }

        private static RSACryptoServiceProvider GetRSA()
        {
            CspParameters _cpsParameter = new CspParameters();
            _cpsParameter.Flags = CspProviderFlags.UseMachineKeyStore;

            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(1024, _cpsParameter);

            var keyString = @"<RSAKeyValue><Modulus>ucNbt0w1Epc/Cs7sgUIvz5GH/s6qe5REAQUrAwo3yFZ/ZElY11urTAQ/CctHppJ8dCplxM5yjHUG+XGlYM700IIYPQaylUKNIRUzdP/Ov3wMfakfHFeItwmNhbVDjicfMPlrnQtwv4hlxMMIfDAKD7TbuwzNyLrmACKGfnXclOM=</Modulus><Exponent>AQAB</Exponent><P>+hh9uGmx99hDlYMm9X6s4oxWomKFgIFDWw1gTigL1A21yEF0t0lyd1ehIUvJMg9H1UxOQnLMIXViMjrRajXT8w==</P><Q>viYPHwxXIUCvzq/SU6CcOnizyXpOR+yL6GrYrbxFCVxvlCdI59P9yXeObVWEbLhp4N+tpMNW4nnLtTgU/WunUQ==</Q><DP>LXYQPFpyMFROjLoHde6t7IyIHwJ7tA1LOhznWa2r4MMRPTKwzbR7KzhxoMTO8NuYOiyhuTB27MoSrIDGmmDogw==</DP><DQ>HGVcnrteC6Y4Wvpgw4JZslWyK6VrKUyG/DdwkklqWeKG+y3+sjgzTzHegC9kLkQ/84gTy2YshHfB1xc/8zRvcQ==</DQ><InverseQ>s4UFcRxlke8UZC5wMpaPgBGUR4DjauLdLtPZV/KFaFjquwAS/Mf1Oguz66afLG6AFUsmevuITyT7/Dq9DnurPg==</InverseQ><D>s4EtAm34pxNSDv6vmaQ8kSZ/NOG96hb2s8mrq49XIhc7mMwrtkdVuuorhCpT/Yl2C8bgepJILKP1blu8RFUYSS7SVab/qi1wn6p33hRFb2waxef/QiBPDoLiGDbU6mNsOGGr4fxKcMSrpVhzEJO7fxrZ9yq7ZJ3t2m7N21R9FaE=</D></RSAKeyValue>";
            rsa.FromXmlString(keyString);
            return rsa;
        }

        public static Publickey GetPublickey()
        {
            Publickey publickey = new Publickey();
            RSACryptoServiceProvider rsa = GetRSA();
            RSAParameters rp = rsa.ExportParameters(false);
            publickey.Exponent = ByteToHex(rp.Exponent);
            publickey.Modulus = ByteToHex(rp.Modulus);
            return publickey;
        }

        public static string Decrypt(string s)
        {
            RSACryptoServiceProvider rsa = GetRSA();
            return Encoding.Default.GetString(rsa.Decrypt(HexToByte(s), false));
        }
    }

    class RSAKey
    {
        public string XmlString { get; set; }
    }

    class Publickey
    {
        public string Modulus { get; set; }
        public string Exponent { get; set; }
    }
}

Case Two

var dbits;
var canary = 0xdeadbeefcafe;
var j_lm = ((canary & 0xffffff) == 0xefcafe);
function BigInteger(a, b, c) {
    if (a != null)
        if ("number" == typeof a) this.fromNumber(a, b, c);
    else if (b == null && "string" != typeof a) this.fromString(a, 256);
    else this.fromString(a, b);
}
function nbi() { return new BigInteger(null); }
function am1(i, x, w, j, c, n) {
    while (--n >= 0) {
        var v = x * this[i++] + w[j] + c;
        c = Math.floor(v / 0x4000000);
        w[j++] = v & 0x3ffffff;
    }
    return c;
}
function am2(i, x, w, j, c, n) {
    var xl = x & 0x7fff, xh = x >> 15;
    while (--n >= 0) {
        var l = this[i] & 0x7fff;
        var h = this[i++] >> 15;
        var m = xh * l + h * xl;
        l = xl * l + ((m & 0x7fff) << 15) + w[j] + (c & 0x3fffffff);
        c = (l >>> 30) + (m >>> 15) + xh * h + (c >>> 30);
        w[j++] = l & 0x3fffffff;
    }
    return c;
}
function am3(i, x, w, j, c, n) {
    var xl = x & 0x3fff, xh = x >> 14;
    while (--n >= 0) {
        var l = this[i] & 0x3fff;
        var h = this[i++] >> 14;
        var m = xh * l + h * xl;
        l = xl * l + ((m & 0x3fff) << 14) + w[j] + c;
        c = (l >> 28) + (m >> 14) + xh * h;
        w[j++] = l & 0xfffffff;
    }
    return c;
}
if (j_lm && (navigator.appName == "Microsoft Internet Explorer")) {
    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(n) { return BI_RM.charAt(n); }
function intAt(s, i) {
    var c = BI_RC[s.charCodeAt(i)];
    return (c == null) ? -1 : c;
}
function bnpCopyTo(r) {
    for (var i = this.t - 1; i >= 0; --i) r[i] = this[i];
    r.t = this.t;
    r.s = this.s;
}
function bnpFromInt(x) {
    this.t = 1;
    this.s = (x < 0) ? -1 : 0;
    if (x > 0) this[0] = x;
    else if (x < -1) this[0] = x + DV;
    else this.t = 0;
}
function nbv(i) { var r = nbi(); r.fromInt(i); return r; }
function bnpFromString(s, b) {
    var k;
    if (b == 16) k = 4;
    else if (b == 8) k = 3;
    else if (b == 256) k = 8;
    else if (b == 2) k = 1;
    else if (b == 32) k = 5;
    else if (b == 4) k = 2;
    else { this.fromRadix(s, b); return; }
    this.t = 0;
    this.s = 0;
    var i = s.length, mi = false, sh = 0;
    while (--i >= 0) {
        var x = (k == 8) ? s[i] & 0xff : intAt(s, i);
        if (x < 0) {
            if (s.charAt(i) == "-") mi = true;
            continue;
        }
        mi = false;
        if (sh == 0)
            this[this.t++] = x;
        else if (sh + k > this.DB) {
            this[this.t - 1] |= (x & ((1 << (this.DB - sh)) - 1)) << sh;
            this[this.t++] = (x >> (this.DB - sh));
        }
        else
            this[this.t - 1] |= x << sh;
        sh += k;
        if (sh >= this.DB) sh -= this.DB;
    }
    if (k == 8 && (s[0] & 0x80) != 0) {
        this.s = -1;
        if (sh > 0) this[this.t - 1] |= ((1 << (this.DB - sh)) - 1) << sh;
    }
    this.clamp();
    if (mi) BigInteger.ZERO.subTo(this, this);
}
function bnpClamp() {
    var c = this.s & this.DM;
    while (this.t > 0 && this[this.t - 1] == c) --this.t;
}
function bnToString(b) {
    if (this.s < 0) return "-" + this.negate().toString(b);
    var k;
    if (b == 16) k = 4;
    else if (b == 8) k = 3;
    else if (b == 2) k = 1;
    else if (b == 32) k = 5;
    else if (b == 4) k = 2;
    else return this.toRadix(b);
    var km = (1 << k) - 1, d, m = false, r = "", i = this.t;
    var p = this.DB - (i * this.DB) % k;
    if (i-- > 0) {
        if (p < this.DB && (d = this[i] >> p) > 0) { m = true; r = int2char(d); }
        while (i >= 0) {
            if (p < k) {
                d = (this[i] & ((1 << p) - 1)) << (k - p);
                d |= this[--i] >> (p += this.DB - k);
            }
            else {
                d = (this[i] >> (p -= k)) & km;
                if (p <= 0) { p += this.DB; --i; }
            }
            if (d > 0) m = true;
            if (m) r += int2char(d);
        }
    }
    return m ? r : "0";
}
function bnNegate() { var r = nbi(); BigInteger.ZERO.subTo(this, r); return r; }
function bnAbs() { return (this.s < 0) ? this.negate() : this; }
function bnCompareTo(a) {
    var r = this.s - a.s;
    if (r != 0) return r;
    var i = this.t;
    r = i - a.t;
    if (r != 0) return r;
    while (--i >= 0) if ((r = this[i] - a[i]) != 0) return r;
    return 0;
}
function nbits(x) {
    var r = 1, t;
    if ((t = x >>> 16) != 0) { x = t; r += 16; }
    if ((t = x >> 8) != 0) { x = t; r += 8; }
    if ((t = x >> 4) != 0) { x = t; r += 4; }
    if ((t = x >> 2) != 0) { x = t; r += 2; }
    if ((t = x >> 1) != 0) { x = t; r += 1; }
    return r;
}
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(n, r) {
    var i;
    for (i = this.t - 1; i >= 0; --i) r[i + n] = this[i];
    for (i = n - 1; i >= 0; --i) r[i] = 0;
    r.t = this.t + n;
    r.s = this.s;
}
function bnpDRShiftTo(n, r) {
    for (var i = n; i < this.t; ++i) r[i - n] = this[i];
    r.t = Math.max(this.t - n, 0);
    r.s = this.s;
}
function bnpLShiftTo(n, r) {
    var bs = n % this.DB;
    var cbs = this.DB - bs;
    var bm = (1 << cbs) - 1;
    var ds = Math.floor(n / this.DB), c = (this.s << bs) & this.DM, i;
    for (i = this.t - 1; i >= 0; --i) {
        r[i + ds + 1] = (this[i] >> cbs) | c;
        c = (this[i] & bm) << bs;
    }
    for (i = ds - 1; i >= 0; --i) r[i] = 0;
    r[ds] = c;
    r.t = this.t + ds + 1;
    r.s = this.s;
    r.clamp();
}
function bnpRShiftTo(n, r) {
    r.s = this.s;
    var ds = Math.floor(n / this.DB);
    if (ds >= this.t) { r.t = 0; return; }
    var bs = n % this.DB;
    var cbs = this.DB - bs;
    var bm = (1 << bs) - 1;
    r[0] = this[ds] >> bs;
    for (var i = ds + 1; i < this.t; ++i) {
        r[i - ds - 1] |= (this[i] & bm) << cbs;
        r[i - ds] = this[i] >> bs;
    }
    if (bs > 0) r[this.t - ds - 1] |= (this.s & bm) << cbs;
    r.t = this.t - ds;
    r.clamp();
}
function bnpSubTo(a, r) {
    var i = 0, c = 0, m = Math.min(a.t, this.t);
    while (i < m) {
        c += this[i] - a[i];
        r[i++] = c & this.DM;
        c >>= this.DB;
    }
    if (a.t < this.t) {
        c -= a.s;
        while (i < this.t) {
            c += this[i];
            r[i++] = c & this.DM;
            c >>= this.DB;
        }
        c += this.s;
    }
    else {
        c += this.s;
        while (i < a.t) {
            c -= a[i];
            r[i++] = c & this.DM;
            c >>= this.DB;
        }
        c -= a.s;
    }
    r.s = (c < 0) ? -1 : 0;
    if (c < -1) r[i++] = this.DV + c;
    else if (c > 0) r[i++] = c;
    r.t = i;
    r.clamp();
}
function bnpMultiplyTo(a, r) {
    var x = this.abs(), y = a.abs();
    var i = x.t;
    r.t = i + y.t;
    while (--i >= 0) r[i] = 0;
    for (i = 0; i < y.t; ++i) r[i + x.t] = x.am(0, y[i], r, i, 0, x.t);
    r.s = 0;
    r.clamp();
    if (this.s != a.s) BigInteger.ZERO.subTo(r, r);
}
function bnpSquareTo(r) {
    var x = this.abs();
    var i = r.t = 2 * x.t;
    while (--i >= 0) r[i] = 0;
    for (i = 0; i < x.t - 1; ++i) {
        var c = x.am(i, x[i], r, 2 * i, 0, 1);
        if ((r[i + x.t] += x.am(i + 1, 2 * x[i], r, 2 * i + 1, c, x.t - i - 1)) >= x.DV) {
            r[i + x.t] -= x.DV;
            r[i + x.t + 1] = 1;
        }
    }
    if (r.t > 0) r[r.t - 1] += x.am(i, x[i], r, 2 * i, 0, 1);
    r.s = 0;
    r.clamp();
}
function bnpDivRemTo(m, q, r) {
    var pm = m.abs();
    if (pm.t <= 0) return;
    var pt = this.abs();
    if (pt.t < pm.t) {
        if (q != null) q.fromInt(0);
        if (r != null) this.copyTo(r);
        return;
    }
    if (r == null) r = nbi();
    var y = nbi(), ts = this.s, ms = m.s;
    var nsh = this.DB - nbits(pm[pm.t - 1]);
    if (nsh > 0) { pm.lShiftTo(nsh, y); pt.lShiftTo(nsh, r); }
    else { pm.copyTo(y); pt.copyTo(r); }
    var ys = y.t;
    var y0 = y[ys - 1];
    if (y0 == 0) return;
    var yt = y0 * (1 << this.F1) + ((ys > 1) ? y[ys - 2] >> this.F2 : 0);
    var d1 = this.FV / yt, d2 = (1 << this.F1) / yt, e = 1 << this.F2;
    var i = r.t, j = i - ys, t = (q == null) ? nbi() : q;
    y.dlShiftTo(j, t);
    if (r.compareTo(t) >= 0) {
        r[r.t++] = 1;
        r.subTo(t, r);
    }
    BigInteger.ONE.dlShiftTo(ys, t);
    t.subTo(y, y);
    while (y.t < ys) y[y.t++] = 0;
    while (--j >= 0) {

        var qd = (r[--i] == y0) ? this.DM : Math.floor(r[i] * d1 + (r[i - 1] + e) * d2);
        if ((r[i] += y.am(0, qd, r, j, 0, ys)) < qd) {
            y.dlShiftTo(j, t);
            r.subTo(t, r);
            while (r[i] < --qd) r.subTo(t, r);
        }
    }
    if (q != null) {
        r.drShiftTo(ys, q);
        if (ts != ms) BigInteger.ZERO.subTo(q, q);
    }
    r.t = ys;
    r.clamp();
    if (nsh > 0) r.rShiftTo(nsh, r);
    if (ts < 0) BigInteger.ZERO.subTo(r, r);
}
function bnMod(a) {
    var r = nbi();
    this.abs().divRemTo(a, null, r);
    if (this.s < 0 && r.compareTo(BigInteger.ZERO) > 0) a.subTo(r, r);
    return r;
}
function Classic(m) { this.m = m; }
function cConvert(x) {
    if (x.s < 0 || x.compareTo(this.m) >= 0) return x.mod(this.m);
    else return x;
}
function cRevert(x) { return x; }
function cReduce(x) { x.divRemTo(this.m, null, x); }
function cMulTo(x, y, r) { x.multiplyTo(y, r); this.reduce(r); }
function cSqrTo(x, r) { x.squareTo(r); this.reduce(r); }
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 x = this[0];
    if ((x & 1) == 0) return 0;
    var y = x & 3;
    y = (y * (2 - (x & 0xf) * y)) & 0xf;
    y = (y * (2 - (x & 0xff) * y)) & 0xff;
    y = (y * (2 - (((x & 0xffff) * y) & 0xffff))) & 0xffff;


    y = (y * (2 - x * y % this.DV)) % this.DV;

    return (y > 0) ? this.DV - y : -y;
}
function Montgomery(m) {
    this.m = m;
    this.mp = m.invDigit();
    this.mpl = this.mp & 0x7fff;
    this.mph = this.mp >> 15;
    this.um = (1 << (m.DB - 15)) - 1;
    this.mt2 = 2 * m.t;
}
function montConvert(x) {
    var r = nbi();
    x.abs().dlShiftTo(this.m.t, r);
    r.divRemTo(this.m, null, r);
    if (x.s < 0 && r.compareTo(BigInteger.ZERO) > 0) this.m.subTo(r, r);
    return r;
}
function montRevert(x) {
    var r = nbi();
    x.copyTo(r);
    this.reduce(r);
    return r;
}
function montReduce(x) {
    while (x.t <= this.mt2)
        x[x.t++] = 0;
    for (var i = 0; i < this.m.t; ++i) {

        var j = x[i] & 0x7fff;
        var u0 = (j * this.mpl + (((j * this.mph + (x[i] >> 15) * this.mpl) & this.um) << 15)) & x.DM;

        j = i + this.m.t;
        x[j] += this.m.am(0, u0, x, i, 0, this.m.t);

        while (x[j] >= x.DV) { x[j] -= x.DV; x[++j]++; }
    }
    x.clamp();
    x.drShiftTo(this.m.t, x);
    if (x.compareTo(this.m) >= 0) x.subTo(this.m, x);
}
function montSqrTo(x, r) { x.squareTo(r); this.reduce(r); }
function montMulTo(x, y, r) { x.multiplyTo(y, r); this.reduce(r); }
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(e, z) {
    if (e > 0xffffffff || e < 1) return BigInteger.ONE;
    var r = nbi(), r2 = nbi(), g = z.convert(this), i = nbits(e) - 1;
    g.copyTo(r);
    while (--i >= 0) {
        z.sqrTo(r, r2);
        if ((e & (1 << i)) > 0) z.mulTo(r2, g, r);
        else { var t = r; r = r2; r2 = t; }
    }
    return z.revert(r);
}
function bnModPowInt(e, m) {
    var z;
    if (e < 256 || m.isEven()) z = new Classic(m); else z = new Montgomery(m);
    return this.exp(e, z);
}
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(key) {
    var i, j, t;
    for (i = 0; i < 256; ++i)
        this.S[i] = i;
    j = 0;
    for (i = 0; i < 256; ++i) {
        j = (j + this.S[i] + key[i % key.length]) & 255;
        t = this.S[i];
        this.S[i] = this.S[j];
        this.S[j] = t;
    }
    this.i = 0;
    this.j = 0;
}
function ARC4next() {
    var t;
    this.i = (this.i + 1) & 255;
    this.j = (this.j + this.S[this.i]) & 255;
    t = this.S[this.i];
    this.S[this.i] = this.S[this.j];
    this.S[this.j] = t;
    return this.S[(t + 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(x) {
    rng_pool[rng_pptr++] ^= x & 255;
    rng_pool[rng_pptr++] ^= (x >> 8) & 255;
    rng_pool[rng_pptr++] ^= (x >> 16) & 255;
    rng_pool[rng_pptr++] ^= (x >> 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) {
    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(ba) {
    var i;
    for (i = 0; i < ba.length; ++i) ba[i] = rng_get_byte();
}
function SecureRandom() { }
SecureRandom.prototype.nextBytes = rng_get_bytes;
function parseBigInt(str, r) {
    return new BigInteger(str, r);
}
function linebrk(s, n) {
    var ret = "";
    var i = 0;
    while (i + n < s.length) {
        ret += s.substring(i, i + n) + "
";
        i += n;
    }
    return ret + s.substring(i, s.length);
}
function byte2Hex(b) {
    if (b < 0x10)
        return "0" + b.toString(16);
    else
        return b.toString(16);
}
function pkcs1pad2(s, n) {
    if (n < s.length + 11) {
        alert("Message too long for RSA");
        return null;
    }
    var ba = new Array();
    var i = s.length - 1;
    while (i >= 0 && n > 0) ba[--n] = s.charCodeAt(i--);
    ba[--n] = 0;
    var rng = new SecureRandom();
    var x = new Array();
    while (n > 2) {
        x[0] = 0;
        while (x[0] == 0) rng.nextBytes(x);
        ba[--n] = x[0];
    }
    ba[--n] = 2;
    ba[--n] = 0;
    return new BigInteger(ba);
}
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(N, E) {
    if (N != null && E != null && N.length > 0 && E.length > 0) {
        this.n = parseBigInt(N, 16);
        this.e = parseInt(E, 16);
    }
    else
        alert("Invalid RSA public key");
}
function RSADoPublic(x) {
    return x.modPowInt(this.e, this.n);
}
function RSAEncrypt(text) {
    var m = pkcs1pad2(text, (this.n.bitLength() + 7) >> 3);
    if (m == null) return null;
    var c = this.doPublic(m);
    if (c == null) return null;
    var h = c.toString(16);
    if ((h.length & 1) == 0) return h; else return "0" + h;
}
RSAKey.prototype.doPublic = RSADoPublic;
RSAKey.prototype.setPublic = RSASetPublic;
RSAKey.prototype.encrypt = RSAEncrypt;
var b64map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var b64pad = "=";
function hex2b64(h) {
    var i;
    var c;
    var ret = "";
    for (i = 0; i + 3 <= h.length; i += 3) {
        c = parseInt(h.substring(i, i + 3), 16);
        ret += b64map.charAt(c >> 6) + b64map.charAt(c & 63);
    }
    if (i + 1 == h.length) {
        c = parseInt(h.substring(i, i + 1), 16);
        ret += b64map.charAt(c << 2);
    }
    else if (i + 2 == h.length) {
        c = parseInt(h.substring(i, i + 2), 16);
        ret += b64map.charAt(c >> 2) + b64map.charAt((c & 3) << 4);
    }
    while ((ret.length & 3) > 0) ret += b64pad;
    return ret;
}
function b64tohex(s) {
    var ret = ""
    var i;
    var k = 0;
    var slop;
    for (i = 0; i < s.length; ++i) {
        if (s.charAt(i) == b64pad) break;
        v = b64map.indexOf(s.charAt(i));
        if (v < 0) continue;
        if (k == 0) {
            ret += int2char(v >> 2);
            slop = v & 3;
            k = 1;
        }
        else if (k == 1) {
            ret += int2char((slop << 2) | (v >> 4));
            slop = v & 0xf;
            k = 2;
        }
        else if (k == 2) {
            ret += int2char(slop);
            ret += int2char(v >> 2);
            slop = v & 3;
            k = 3;
        }
        else {
            ret += int2char((slop << 2) | (v >> 4));
            ret += int2char(v & 0xf);
            k = 0;
        }
    }
    if (k == 1)
        ret += int2char(slop << 2);
    return ret;
}
function b64toBA(s) {

    var h = b64tohex(s);
    var i;
    var a = new Array();
    for (i = 0; 2 * i < h.length; ++i) {
        a[i] = parseInt(h.substring(2 * i, 2 * i + 2), 16);
    }
    return a;
}

Case Three

        function OnBeforeLoginClick() {

            var pwd = $("PlainPass").value; 

            var maskValue = "xxxxxxxxxxxxxxxxxxxxx".substring(0, pwd.length);
            $("PlainPass").value = maskValue;

            var modulus = '公钥modulus';
            var exponent = '公钥exponent';

            var rsa = new RSAKey();
            rsa.setPublic(modulus, exponent);

            var res = rsa.encrypt(pwd);
            if (res) {
                $("hfPassword").value = res;
            }

            return true;
        }