javascript加密java解密

具体实现思路如下：

1。服务端生成公钥与私钥，保存。

2。客户端在请求到登录页面后，随机生成一字符串。

3。后此随机字符串作为密钥加密密码，再用从服务端获取到的公钥加密生成的随机字符串。

4。将此两段密文传入服务端，服务端用私钥解出随机字符串，再用此私钥解出加密的密文。

这其中有一个关键是解决服务端的公钥，传入客户端，客户端用此公钥加密字符串后，后又能在服务端用私钥解出。

此文即为实现此步而作。

加密算法为RSA：

1。服务端的RSA  java实现。

package com.java.decode.js.util;
/**
 * 
 */

import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.RSAPrivateKeySpec;
import java.security.spec.RSAPublicKeySpec;

import javax.crypto.Cipher;



/**
 * RSA 工具类。提供加密，解密，生成密钥对等方法。
 * 需要到http://www.bouncycastle.org下载bcprov-jdk14-123.jar。
 * 
 */
public class RSAUtil {
	/**
	 * * 生成密钥对 *
	 * 
	 * @return KeyPair *
	 * @throws EncryptException
	 */
	public static KeyPair generateKeyPair() throws Exception {
		try {
			KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA",
					new org.bouncycastle.jce.provider.BouncyCastleProvider());
			final int KEY_SIZE = 1024;// 没什么好说的了，这个值关系到块加密的大小，可以更改，但是不要太大，否则效率会低
			keyPairGen.initialize(KEY_SIZE, new SecureRandom());
			KeyPair keyPair = keyPairGen.generateKeyPair();
			saveKeyPair(keyPair);
			return keyPair;
		} catch (Exception e) {
			throw new Exception(e.getMessage());
		}
	}
	
	public static KeyPair getKeyPair()throws Exception{
		FileInputStream fis = new FileInputStream("C:\\RSAKey.txt");
		 ObjectInputStream oos = new ObjectInputStream(fis);
		 KeyPair kp= (KeyPair) oos.readObject();
		 oos.close();
		 fis.close();
		 return kp;
	}
	
	public static void saveKeyPair(KeyPair kp)throws Exception{
		
		 FileOutputStream fos = new FileOutputStream("C:\\RSAKey.txt");
         ObjectOutputStream oos = new ObjectOutputStream(fos);
         //生成密钥
         oos.writeObject(kp);
         oos.close();
         fos.close();
	}

	/**
	 * * 生成公钥 *
	 * 
	 * @param modulus *
	 * @param publicExponent *
	 * @return RSAPublicKey *
	 * @throws Exception
	 */
	public static RSAPublicKey generateRSAPublicKey(byte[] modulus,
			byte[] publicExponent) throws Exception {
		KeyFactory keyFac = null;
		try {
			keyFac = KeyFactory.getInstance("RSA",
					new org.bouncycastle.jce.provider.BouncyCastleProvider());
		} catch (NoSuchAlgorithmException ex) {
			throw new Exception(ex.getMessage());
		}

		RSAPublicKeySpec pubKeySpec = new RSAPublicKeySpec(new BigInteger(
				modulus), new BigInteger(publicExponent));
		try {
			return (RSAPublicKey) keyFac.generatePublic(pubKeySpec);
		} catch (InvalidKeySpecException ex) {
			throw new Exception(ex.getMessage());
		}
	}

	/**
	 * * 生成私钥 *
	 * 
	 * @param modulus *
	 * @param privateExponent *
	 * @return RSAPrivateKey *
	 * @throws Exception
	 */
	public static RSAPrivateKey generateRSAPrivateKey(byte[] modulus,
			byte[] privateExponent) throws Exception {
		KeyFactory keyFac = null;
		try {
			keyFac = KeyFactory.getInstance("RSA",
					new org.bouncycastle.jce.provider.BouncyCastleProvider());
		} catch (NoSuchAlgorithmException ex) {
			throw new Exception(ex.getMessage());
		}

		RSAPrivateKeySpec priKeySpec = new RSAPrivateKeySpec(new BigInteger(
				modulus), new BigInteger(privateExponent));
		try {
			return (RSAPrivateKey) keyFac.generatePrivate(priKeySpec);
		} catch (InvalidKeySpecException ex) {
			throw new Exception(ex.getMessage());
		}
	}

	/**
	 * * 加密 *
	 * 
	 * @param key
	 *            加密的密钥 *
	 * @param data
	 *            待加密的明文数据 *
	 * @return 加密后的数据 *
	 * @throws Exception
	 */
	public static byte[] encrypt(PublicKey pk, byte[] data) throws Exception {
		try {
			Cipher cipher = Cipher.getInstance("RSA",
					new org.bouncycastle.jce.provider.BouncyCastleProvider());
			cipher.init(Cipher.ENCRYPT_MODE, pk);
			int blockSize = cipher.getBlockSize();// 获得加密块大小，如：加密前数据为128个byte，而key_size=1024
			// 加密块大小为127
			// byte,加密后为128个byte;因此共有2个加密块，第一个127
			// byte第二个为1个byte
			int outputSize = cipher.getOutputSize(data.length);// 获得加密块加密后块大小
			int leavedSize = data.length % blockSize;
			int blocksSize = leavedSize != 0 ? data.length / blockSize + 1
					: data.length / blockSize;
			byte[] raw = new byte[outputSize * blocksSize];
			int i = 0;
			while (data.length - i * blockSize > 0) {
				if (data.length - i * blockSize > blockSize)
					cipher.doFinal(data, i * blockSize, blockSize, raw, i
							* outputSize);
				else
					cipher.doFinal(data, i * blockSize, data.length - i
							* blockSize, raw, i * outputSize);
				// 这里面doUpdate方法不可用，查看源代码后发现每次doUpdate后并没有什么实际动作除了把byte[]放到
				// ByteArrayOutputStream中，而最后doFinal的时候才将所有的byte[]进行加密，可是到了此时加密块大小很可能已经超出了
				// OutputSize所以只好用dofinal方法。

				i++;
			}
			return raw;
		} catch (Exception e) {
			throw new Exception(e.getMessage());
		}
	}

	/**
	 * * 解密 *
	 * 
	 * @param key
	 *            解密的密钥 *
	 * @param raw
	 *            已经加密的数据 *
	 * @return 解密后的明文 *
	 * @throws Exception
	 */
	public static byte[] decrypt(PrivateKey pk, byte[] raw) throws Exception {
		try {
			Cipher cipher = Cipher.getInstance("RSA",
					new org.bouncycastle.jce.provider.BouncyCastleProvider());
			cipher.init(cipher.DECRYPT_MODE, pk);
			int blockSize = cipher.getBlockSize();
			ByteArrayOutputStream bout = new ByteArrayOutputStream(64);
			int j = 0;

			while (raw.length - j * blockSize > 0) {
				bout.write(cipher.doFinal(raw, j * blockSize, blockSize));
				j++;
			}
			return bout.toByteArray();
		} catch (Exception e) {
			throw new Exception(e.getMessage());
		}
	}

	/**
	 * * *
	 * 
	 * @param args *
	 * @throws Exception
	 */
	public static void main(String[] args) throws Exception {
		RSAPublicKey rsap = (RSAPublicKey) RSAUtil.generateKeyPair().getPublic();
		String test = "金聪敏";
		byte[] en_test = encrypt(getKeyPair().getPublic(),test.getBytes());
		byte[] de_test = decrypt(getKeyPair().getPrivate(),en_test);
		System.out.println(new String(en_test));
		System.out.println(new String(de_test));
	}
}

2.测试页面：

package com.java.decode.js.servlet;

import java.io.IOException;
import java.security.interfaces.RSAPublicKey;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.java.decode.js.util.RSAUtil;

public class IndexServlet extends HttpServlet {
	@Override
	public void init() throws ServletException {
		super.init();
	}
	
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		doPost(req, resp);
	}
	
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		resp.setContentType("text/html;charset=UTF-8"); 
		resp.setCharacterEncoding("utf-8");
		try {
			RSAPublicKey rsap = (RSAPublicKey) RSAUtil.getKeyPair().getPublic();
			String module = rsap.getModulus().toString(16);
			String empoent = rsap.getPublicExponent().toString(16);
			System.out.println("module");
			System.out.println(module);
			System.out.println("empoent");
			System.out.println(empoent);
			req.setAttribute("m", module);
			req.setAttribute("e", empoent);
			req.getRequestDispatcher("/index.jsp").forward(req, resp);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	@Override
	public void destroy() {
		super.destroy();
	}
}

传入公钥的　Modulus 与PublicExponent的hex编码形式

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
	String path = request.getContextPath();
	String basePath = request.getScheme() + "://"
			+ request.getServerName() + ":" + request.getServerPort()
			+ path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
	<head>
		<base href="<%=basePath%>">

		<title>Java解密javascript加密</title>
		<meta http-equiv="pragma" content="no-cache">
		<meta http-equiv="cache-control" content="no-cache">
		<meta http-equiv="expires" content="0">
		<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
		<meta http-equiv="description" content="This is my page">
		<script type="text/javascript" src="js/RSA.js"></script>  
		<script type="text/javascript" src="js/BigInt.js"></script>  
		<script type="text/javascript" src="js/Barrett.js"></script>  
		<script type="text/javascript">
			var key ;
			function bodyRSA()
			{
				setMaxDigits(130);
			  	key = new RSAKeyPair("10001","","90e5ef845b5bdbed9b7e7a4a893333a135ed7300e85cf5f7ae6db9df07cf96c1f11911abad5c4187725f59422e82af2696168fffffd24ffec26f45e2b35281854170795947b690db8fbb45d8aa34409115941af25d5c1006a1caf396ff9e6fcc1cbbc74e95d13d964af366497783089c6d67772e2594c4e62a367e91490e799f"); 
			  
			}
		
			function submit1() {
				bodyRSA();
				var result = encryptedString(key, document.getElementById("name").value);
				document.getElementById("name").value=result;
				alert(document.getElementById("name").value);
				document.forms[0].action="JavaDecodeJsServlet";
				document.forms[0].submit();
			}
		</script>
	</head>

	<body>
		<form name="form1" action="JavaDecodeJsServlet" method="post">
			请输入：
			<input type="text" id="name" name="name" />
			<input type="button" value="提交" onclick="submit1()" />
		</form>
	</body>
</html>

package com.java.decode.js.servlet;

import java.io.IOException;
import java.math.BigInteger;
import java.security.interfaces.RSAPublicKey;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.java.decode.js.util.HexToBytes;
import com.java.decode.js.util.RSAUtil;

public class JavaDecodeJsServlet extends HttpServlet {
	@Override
	public void init() throws ServletException {
		super.init();
	}
	
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		doPost(req, resp);
	}
	
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		resp.setContentType("text/html;charset=UTF-8"); 
		resp.setCharacterEncoding("utf-8");
		try {
//			String test = "金聪敏";
//			System.out.println("原文加密后为：");
//			System.out.println("result:"+test);
//			byte[] en_test =RSAUtil.encrypt(RSAUtil.getKeyPair().getPublic(),test.getBytes());
//			System.out.println("转成byte[]"+new String(en_test));
//			byte[] de_test =RSAUtil.decrypt(RSAUtil.getKeyPair().getPrivate(),en_test);
//			System.out.println("还原密文：");
//			System.out.println(new String(de_test));
//			StringBuffer sb = new StringBuffer();
//			sb.append(new String(de_test));
//			System.out.println(sb.reverse().toString());
//			String str=sb.reverse().toString();
//			req.setAttribute("name", str);
//			req.getRequestDispatcher("/success.jsp").forward(req, resp);
			
			
			
			
			
			String result = req.getParameter("name");
			System.out.println("原文加密后为：");
			System.out.println("result:"+result);
			byte[] en_result = HexToBytes.HexString2Bytes(result);
			System.out.println("转成byte[]"+new String(en_result));
			byte[] de_result = RSAUtil.decrypt(RSAUtil.getKeyPair().getPrivate(),en_result);
			System.out.println("还原密文：");
			System.out.println(new String(de_result));
			StringBuffer sb = new StringBuffer();
			sb.append(new String(de_result));
			System.out.println(sb.reverse().toString());
//			String str=sb.reverse().toString();
//			req.setAttribute("name", str);
			req.setAttribute("name", sb.toString());
			req.getRequestDispatcher("/success.jsp").forward(req, resp);
		} catch (Exception e) {
			e.printStackTrace();
		}
		
	}
	
	@Override
	public void destroy() {
		super.destroy();
	}
}

// BarrettMu, a class for performing Barrett modular reduction computations in
// JavaScript.
//
// Requires BigInt.js.
//
// Copyright 2004-2005 David Shapiro.
//
// You may use, re-use, abuse, copy, and modify this code to your liking, but
// please keep this header.
//
// Thanks!
// 
// Dave Shapiro
// [email protected] 

function BarrettMu(m)
{
	this.modulus = biCopy(m);
	this.k = biHighIndex(this.modulus) + 1;
	var b2k = new BigInt();
	b2k.digits[2 * this.k] = 1; // b2k = b^(2k)
	this.mu = biDivide(b2k, this.modulus);
	this.bkplus1 = new BigInt();
	this.bkplus1.digits[this.k + 1] = 1; // bkplus1 = b^(k+1)
	this.modulo = BarrettMu_modulo;
	this.multiplyMod = BarrettMu_multiplyMod;
	this.powMod = BarrettMu_powMod;
}

function BarrettMu_modulo(x)
{
	var q1 = biDivideByRadixPower(x, this.k - 1);
	var q2 = biMultiply(q1, this.mu);
	var q3 = biDivideByRadixPower(q2, this.k + 1);
	var r1 = biModuloByRadixPower(x, this.k + 1);
	var r2term = biMultiply(q3, this.modulus);
	var r2 = biModuloByRadixPower(r2term, this.k + 1);
	var r = biSubtract(r1, r2);
	if (r.isNeg) {
		r = biAdd(r, this.bkplus1);
	}
	var rgtem = biCompare(r, this.modulus) >= 0;
	while (rgtem) {
		r = biSubtract(r, this.modulus);
		rgtem = biCompare(r, this.modulus) >= 0;
	}
	return r;
}

function BarrettMu_multiplyMod(x, y)
{
	/*
	x = this.modulo(x);
	y = this.modulo(y);
	*/
	var xy = biMultiply(x, y);
	return this.modulo(xy);
}

function BarrettMu_powMod(x, y)
{
	var result = new BigInt();
	result.digits[0] = 1;
	var a = x;
	var k = y;
	while (true) {
		if ((k.digits[0] & 1) != 0) result = this.multiplyMod(result, a);
		k = biShiftRight(k, 1);
		if (k.digits[0] == 0 && biHighIndex(k) == 0) break;
		a = this.multiplyMod(a, a);
	}
	return result;
}

// BigInt, a suite of routines for performing multiple-precision arithmetic in
// JavaScript.
//
// Copyright 1998-2005 David Shapiro.
//
// You may use, re-use, abuse,
// copy, and modify this code to your liking, but please keep this header.
// Thanks!
//
// Dave Shapiro
// [email protected]

// IMPORTANT THING: Be sure to set maxDigits according to your precision
// needs. Use the setMaxDigits() function to do this. See comments below.
//
// Tweaked by Ian Bunning
// Alterations:
// Fix bug in function biFromHex(s) to allow
// parsing of strings of length != 0 (mod 4)

// Changes made by Dave Shapiro as of 12/30/2004:
//
// The BigInt() constructor doesn't take a string anymore. If you want to
// create a BigInt from a string, use biFromDecimal() for base-10
// representations, biFromHex() for base-16 representations, or
// biFromString() for base-2-to-36 representations.
//
// biFromArray() has been removed. Use biCopy() instead, passing a BigInt
// instead of an array.
//
// The BigInt() constructor now only constructs a zeroed-out array.
// Alternatively, if you pass <true>, it won't construct any array. See the
// biCopy() method for an example of this.
//
// Be sure to set maxDigits depending on your precision needs. The default
// zeroed-out array ZERO_ARRAY is constructed inside the setMaxDigits()
// function. So use this function to set the variable. DON'T JUST SET THE
// VALUE. USE THE FUNCTION.
//
// ZERO_ARRAY exists to hopefully speed up construction of BigInts(). By
// precalculating the zero array, we can just use slice(0) to make copies of
// it. Presumably this calls faster native code, as opposed to setting the
// elements one at a time. I have not done any timing tests to verify this
// claim.

// Max number = 10^16 - 2 = 9999999999999998;
//               2^53     = 9007199254740992;

var biRadixBase = 2;
var biRadixBits = 16;
var bitsPerDigit = biRadixBits;
var biRadix = 1 << 16; // = 2^16 = 65536
var biHalfRadix = biRadix >>> 1;
var biRadixSquared = biRadix * biRadix;
var maxDigitVal = biRadix - 1;
var maxInteger = 9999999999999998; 

// maxDigits:
// Change this to accommodate your largest number size. Use setMaxDigits()
// to change it!
//
// In general, if you're working with numbers of size N bits, you'll need 2*N
// bits of storage. Each digit holds 16 bits. So, a 1024-bit key will need
//
// 1024 * 2 / 16 = 128 digits of storage.
//

var maxDigits;
var ZERO_ARRAY;
var bigZero, bigOne;

function setMaxDigits(value)
{
	maxDigits = value;
	ZERO_ARRAY = new Array(maxDigits);
	for (var iza = 0; iza < ZERO_ARRAY.length; iza++) ZERO_ARRAY[iza] = 0;
	bigZero = new BigInt();
	bigOne = new BigInt();
	bigOne.digits[0] = 1;
}

setMaxDigits(20);

// The maximum number of digits in base 10 you can convert to an
// integer without JavaScript throwing up on you.
var dpl10 = 15;
// lr10 = 10 ^ dpl10
var lr10 = biFromNumber(1000000000000000);

function BigInt(flag)
{
	if (typeof flag == "boolean" && flag == true) {
		this.digits = null;
	}
	else {
		this.digits = ZERO_ARRAY.slice(0);
	}
	this.isNeg = false;
}

function biFromDecimal(s)
{
	var isNeg = s.charAt(0) == '-';
	var i = isNeg ? 1 : 0;
	var result;
	// Skip leading zeros.
	while (i < s.length && s.charAt(i) == '0') ++i;
	if (i == s.length) {
		result = new BigInt();
	}
	else {
		var digitCount = s.length - i;
		var fgl = digitCount % dpl10;
		if (fgl == 0) fgl = dpl10;
		result = biFromNumber(Number(s.substr(i, fgl)));
		i += fgl;
		while (i < s.length) {
			result = biAdd(biMultiply(result, lr10),
			               biFromNumber(Number(s.substr(i, dpl10))));
			i += dpl10;
		}
		result.isNeg = isNeg;
	}
	return result;
}

function biCopy(bi)
{
	var result = new BigInt(true);
	result.digits = bi.digits.slice(0);
	result.isNeg = bi.isNeg;
	return result;
}

function biFromNumber(i)
{
	var result = new BigInt();
	result.isNeg = i < 0;
	i = Math.abs(i);
	var j = 0;
	while (i > 0) {
		result.digits[j++] = i & maxDigitVal;
		i = Math.floor(i / biRadix);
	}
	return result;
}

function reverseStr(s)
{
	var result = "";
	for (var i = s.length - 1; i > -1; --i) {
		result += s.charAt(i);
	}
	return result;
}

var hexatrigesimalToChar = new Array(
 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
 'u', 'v', 'w', 'x', 'y', 'z'
);

function biToString(x, radix)
	// 2 <= radix <= 36
{
	var b = new BigInt();
	b.digits[0] = radix;
	var qr = biDivideModulo(x, b);
	var result = hexatrigesimalToChar[qr[1].digits[0]];
	while (biCompare(qr[0], bigZero) == 1) {
		qr = biDivideModulo(qr[0], b);
		digit = qr[1].digits[0];
		result += hexatrigesimalToChar[qr[1].digits[0]];
	}
	return (x.isNeg ? "-" : "") + reverseStr(result);
}

function biToDecimal(x)
{
	var b = new BigInt();
	b.digits[0] = 10;
	var qr = biDivideModulo(x, b);
	var result = String(qr[1].digits[0]);
	while (biCompare(qr[0], bigZero) == 1) {
		qr = biDivideModulo(qr[0], b);
		result += String(qr[1].digits[0]);
	}
	return (x.isNeg ? "-" : "") + reverseStr(result);
}

var hexToChar = new Array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                          'a', 'b', 'c', 'd', 'e', 'f');

function digitToHex(n)
{
	var mask = 0xf;
	var result = "";
	for (i = 0; i < 4; ++i) {
		result += hexToChar[n & mask];
		n >>>= 4;
	}
	return reverseStr(result);
}

function biToHex(x)
{
	var result = "";
	var n = biHighIndex(x);
	for (var i = biHighIndex(x); i > -1; --i) {
		result += digitToHex(x.digits[i]);
	}
	return result;
}

function charToHex(c)
{
	var ZERO = 48;
	var NINE = ZERO + 9;
	var littleA = 97;
	var littleZ = littleA + 25;
	var bigA = 65;
	var bigZ = 65 + 25;
	var result;

	if (c >= ZERO && c <= NINE) {
		result = c - ZERO;
	} else if (c >= bigA && c <= bigZ) {
		result = 10 + c - bigA;
	} else if (c >= littleA && c <= littleZ) {
		result = 10 + c - littleA;
	} else {
		result = 0;
	}
	return result;
}

function hexToDigit(s)
{
	var result = 0;
	var sl = Math.min(s.length, 4);
	for (var i = 0; i < sl; ++i) {
		result <<= 4;
		result |= charToHex(s.charCodeAt(i))
	}
	return result;
}

function biFromHex(s)
{
	var result = new BigInt();
	var sl = s.length;
	for (var i = sl, j = 0; i > 0; i -= 4, ++j) {
		result.digits[j] = hexToDigit(s.substr(Math.max(i - 4, 0), Math.min(i, 4)));
	}
	return result;
}

function biFromString(s, radix)
{
	var isNeg = s.charAt(0) == '-';
	var istop = isNeg ? 1 : 0;
	var result = new BigInt();
	var place = new BigInt();
	place.digits[0] = 1; // radix^0
	for (var i = s.length - 1; i >= istop; i--) {
		var c = s.charCodeAt(i);
		var digit = charToHex(c);
		var biDigit = biMultiplyDigit(place, digit);
		result = biAdd(result, biDigit);
		place = biMultiplyDigit(place, radix);
	}
	result.isNeg = isNeg;
	return result;
}

function biDump(b)
{
	return (b.isNeg ? "-" : "") + b.digits.join(" ");
}

function biAdd(x, y)
{
	var result;

	if (x.isNeg != y.isNeg) {
		y.isNeg = !y.isNeg;
		result = biSubtract(x, y);
		y.isNeg = !y.isNeg;
	}
	else {
		result = new BigInt();
		var c = 0;
		var n;
		for (var i = 0; i < x.digits.length; ++i) {
			n = x.digits[i] + y.digits[i] + c;
			result.digits[i] = n % biRadix;
			c = Number(n >= biRadix);
		}
		result.isNeg = x.isNeg;
	}
	return result;
}

function biSubtract(x, y)
{
	var result;
	if (x.isNeg != y.isNeg) {
		y.isNeg = !y.isNeg;
		result = biAdd(x, y);
		y.isNeg = !y.isNeg;
	} else {
		result = new BigInt();
		var n, c;
		c = 0;
		for (var i = 0; i < x.digits.length; ++i) {
			n = x.digits[i] - y.digits[i] + c;
			result.digits[i] = n % biRadix;
			// Stupid non-conforming modulus operation.
			if (result.digits[i] < 0) result.digits[i] += biRadix;
			c = 0 - Number(n < 0);
		}
		// Fix up the negative sign, if any.
		if (c == -1) {
			c = 0;
			for (var i = 0; i < x.digits.length; ++i) {
				n = 0 - result.digits[i] + c;
				result.digits[i] = n % biRadix;
				// Stupid non-conforming modulus operation.
				if (result.digits[i] < 0) result.digits[i] += biRadix;
				c = 0 - Number(n < 0);
			}
			// Result is opposite sign of arguments.
			result.isNeg = !x.isNeg;
		} else {
			// Result is same sign.
			result.isNeg = x.isNeg;
		}
	}
	return result;
}


function biHighIndex(x)
{
	var result = x.digits.length - 1;
	while (result > 0 && x.digits[result] == 0) --result;
	return result;
}

function biNumBits(x)
{
	var n = biHighIndex(x);
	var d = x.digits[n];
	var m = (n + 1) * bitsPerDigit;
	var result;
	for (result = m; result > m - bitsPerDigit; --result) {
		if ((d & 0x8000) != 0) break;
		d <<= 1;
	}
	return result;
}

function biMultiply(x, y)
{
	var result = new BigInt();
	var c;
	var n = biHighIndex(x);
	var t = biHighIndex(y);
	var u, uv, k;

	for (var i = 0; i <= t; ++i) {
		c = 0;
		k = i;
		for (j = 0; j <= n; ++j, ++k) {
			uv = result.digits[k] + x.digits[j] * y.digits[i] + c;
			result.digits[k] = uv & maxDigitVal;
			c = uv >>> biRadixBits;
			//c = Math.floor(uv / biRadix);
		}
		result.digits[i + n + 1] = c;
	}
	// Someone give me a logical xor, please.
	result.isNeg = x.isNeg != y.isNeg;
	return result;
}

function biMultiplyDigit(x, y)
{
	var n, c, uv;

	result = new BigInt();
	n = biHighIndex(x);
	c = 0;
	for (var j = 0; j <= n; ++j) {
		uv = result.digits[j] + x.digits[j] * y + c;
		result.digits[j] = uv & maxDigitVal;
		c = uv >>> biRadixBits;
		//c = Math.floor(uv / biRadix);
	}
	result.digits[1 + n] = c;
	return result;
}

function arrayCopy(src, srcStart, dest, destStart, n)
{
	var m = Math.min(srcStart + n, src.length);
	for (var i = srcStart, j = destStart; i < m; ++i, ++j) {
		dest[j] = src[i];
	}
}

var highBitMasks = new Array(0x0000, 0x8000, 0xC000, 0xE000, 0xF000, 0xF800,
                             0xFC00, 0xFE00, 0xFF00, 0xFF80, 0xFFC0, 0xFFE0,
                             0xFFF0, 0xFFF8, 0xFFFC, 0xFFFE, 0xFFFF);

function biShiftLeft(x, n)
{
	var digitCount = Math.floor(n / bitsPerDigit);
	var result = new BigInt();
	arrayCopy(x.digits, 0, result.digits, digitCount,
	          result.digits.length - digitCount);
	var bits = n % bitsPerDigit;
	var rightBits = bitsPerDigit - bits;
	for (var i = result.digits.length - 1, i1 = i - 1; i > 0; --i, --i1) {
		result.digits[i] = ((result.digits[i] << bits) & maxDigitVal) |
		                   ((result.digits[i1] & highBitMasks[bits]) >>>
		                    (rightBits));
	}
	result.digits[0] = ((result.digits[i] << bits) & maxDigitVal);
	result.isNeg = x.isNeg;
	return result;
}

var lowBitMasks = new Array(0x0000, 0x0001, 0x0003, 0x0007, 0x000F, 0x001F,
                            0x003F, 0x007F, 0x00FF, 0x01FF, 0x03FF, 0x07FF,
                            0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF);

function biShiftRight(x, n)
{
	var digitCount = Math.floor(n / bitsPerDigit);
	var result = new BigInt();
	arrayCopy(x.digits, digitCount, result.digits, 0,
	          x.digits.length - digitCount);
	var bits = n % bitsPerDigit;
	var leftBits = bitsPerDigit - bits;
	for (var i = 0, i1 = i + 1; i < result.digits.length - 1; ++i, ++i1) {
		result.digits[i] = (result.digits[i] >>> bits) |
		                   ((result.digits[i1] & lowBitMasks[bits]) << leftBits);
	}
	result.digits[result.digits.length - 1] >>>= bits;
	result.isNeg = x.isNeg;
	return result;
}

function biMultiplyByRadixPower(x, n)
{
	var result = new BigInt();
	arrayCopy(x.digits, 0, result.digits, n, result.digits.length - n);
	return result;
}

function biDivideByRadixPower(x, n)
{
	var result = new BigInt();
	arrayCopy(x.digits, n, result.digits, 0, result.digits.length - n);
	return result;
}

function biModuloByRadixPower(x, n)
{
	var result = new BigInt();
	arrayCopy(x.digits, 0, result.digits, 0, n);
	return result;
}

function biCompare(x, y)
{
	if (x.isNeg != y.isNeg) {
		return 1 - 2 * Number(x.isNeg);
	}
	for (var i = x.digits.length - 1; i >= 0; --i) {
		if (x.digits[i] != y.digits[i]) {
			if (x.isNeg) {
				return 1 - 2 * Number(x.digits[i] > y.digits[i]);
			} else {
				return 1 - 2 * Number(x.digits[i] < y.digits[i]);
			}
		}
	}
	return 0;
}

function biDivideModulo(x, y)
{
	var nb = biNumBits(x);
	var tb = biNumBits(y);
	var origYIsNeg = y.isNeg;
	var q, r;
	if (nb < tb) {
		// |x| < |y|
		if (x.isNeg) {
			q = biCopy(bigOne);
			q.isNeg = !y.isNeg;
			x.isNeg = false;
			y.isNeg = false;
			r = biSubtract(y, x);
			// Restore signs, 'cause they're references.
			x.isNeg = true;
			y.isNeg = origYIsNeg;
		} else {
			q = new BigInt();
			r = biCopy(x);
		}
		return new Array(q, r);
	}

	q = new BigInt();
	r = x;

	// Normalize Y.
	var t = Math.ceil(tb / bitsPerDigit) - 1;
	var lambda = 0;
	while (y.digits[t] < biHalfRadix) {
		y = biShiftLeft(y, 1);
		++lambda;
		++tb;
		t = Math.ceil(tb / bitsPerDigit) - 1;
	}
	// Shift r over to keep the quotient constant. We'll shift the
	// remainder back at the end.
	r = biShiftLeft(r, lambda);
	nb += lambda; // Update the bit count for x.
	var n = Math.ceil(nb / bitsPerDigit) - 1;

	var b = biMultiplyByRadixPower(y, n - t);
	while (biCompare(r, b) != -1) {
		++q.digits[n - t];
		r = biSubtract(r, b);
	}
	for (var i = n; i > t; --i) {
    var ri = (i >= r.digits.length) ? 0 : r.digits[i];
    var ri1 = (i - 1 >= r.digits.length) ? 0 : r.digits[i - 1];
    var ri2 = (i - 2 >= r.digits.length) ? 0 : r.digits[i - 2];
    var yt = (t >= y.digits.length) ? 0 : y.digits[t];
    var yt1 = (t - 1 >= y.digits.length) ? 0 : y.digits[t - 1];
		if (ri == yt) {
			q.digits[i - t - 1] = maxDigitVal;
		} else {
			q.digits[i - t - 1] = Math.floor((ri * biRadix + ri1) / yt);
		}

		var c1 = q.digits[i - t - 1] * ((yt * biRadix) + yt1);
		var c2 = (ri * biRadixSquared) + ((ri1 * biRadix) + ri2);
		while (c1 > c2) {
			--q.digits[i - t - 1];
			c1 = q.digits[i - t - 1] * ((yt * biRadix) | yt1);
			c2 = (ri * biRadix * biRadix) + ((ri1 * biRadix) + ri2);
		}

		b = biMultiplyByRadixPower(y, i - t - 1);
		r = biSubtract(r, biMultiplyDigit(b, q.digits[i - t - 1]));
		if (r.isNeg) {
			r = biAdd(r, b);
			--q.digits[i - t - 1];
		}
	}
	r = biShiftRight(r, lambda);
	// Fiddle with the signs and stuff to make sure that 0 <= r < y.
	q.isNeg = x.isNeg != origYIsNeg;
	if (x.isNeg) {
		if (origYIsNeg) {
			q = biAdd(q, bigOne);
		} else {
			q = biSubtract(q, bigOne);
		}
		y = biShiftRight(y, lambda);
		r = biSubtract(y, r);
	}
	// Check for the unbelievably stupid degenerate case of r == -0.
	if (r.digits[0] == 0 && biHighIndex(r) == 0) r.isNeg = false;

	return new Array(q, r);
}

function biDivide(x, y)
{
	return biDivideModulo(x, y)[0];
}

function biModulo(x, y)
{
	return biDivideModulo(x, y)[1];
}

function biMultiplyMod(x, y, m)
{
	return biModulo(biMultiply(x, y), m);
}

function biPow(x, y)
{
	var result = bigOne;
	var a = x;
	while (true) {
		if ((y & 1) != 0) result = biMultiply(result, a);
		y >>= 1;
		if (y == 0) break;
		a = biMultiply(a, a);
	}
	return result;
}

function biPowMod(x, y, m)
{
	var result = bigOne;
	var a = x;
	var k = y;
	while (true) {
		if ((k.digits[0] & 1) != 0) result = biMultiplyMod(result, a, m);
		k = biShiftRight(k, 1);
		if (k.digits[0] == 0 && biHighIndex(k) == 0) break;
		a = biMultiplyMod(a, a, m);
	}
	return result;
}

// RSA, a suite of routines for performing RSA public-key computations in
// JavaScript.
//
// Requires BigInt.js and Barrett.js.
//
// Copyright 1998-2005 David Shapiro.
//
// You may use, re-use, abuse, copy, and modify this code to your liking, but
// please keep this header.
//
// Thanks!
// 
// Dave Shapiro
// [email protected] 

function RSAKeyPair(encryptionExponent, decryptionExponent, modulus)
{
	this.e = biFromHex(encryptionExponent);
	this.d = biFromHex(decryptionExponent);
	this.m = biFromHex(modulus);
	// We can do two bytes per digit, so
	// chunkSize = 2 * (number of digits in modulus - 1).
	// Since biHighIndex returns the high index, not the number of digits, 1 has
	// already been subtracted.
	this.chunkSize = 2 * biHighIndex(this.m);
	this.radix = 16;
	this.barrett = new BarrettMu(this.m);
}

function twoDigit(n)
{
	return (n < 10 ? "0" : "") + String(n);
}

function encryptedString(key, s)
	// Altered by Rob Saunders ([email protected]). New routine pads the
	// string after it has been converted to an array. This fixes an
	// incompatibility with Flash MX's ActionScript.
{
	var a = new Array();
	var sl = s.length;
	var i = 0;
	while (i < sl) {
		a[i] = s.charCodeAt(i);
		i++;
	}

	while (a.length % key.chunkSize != 0) {
		a[i++] = 0;
	}

	var al = a.length;
	var result = "";
	var j, k, block;
	for (i = 0; i < al; i += key.chunkSize) {
		block = new BigInt();
		j = 0;
		for (k = i; k < i + key.chunkSize; ++j) {
			block.digits[j] = a[k++];
			block.digits[j] += a[k++] << 8;
		}
		var crypt = key.barrett.powMod(block, key.e);
		var text = key.radix == 16 ? biToHex(crypt) : biToString(crypt, key.radix);
		result += text + " ";
	}
	return result.substring(0, result.length - 1); // Remove last space.
}

function decryptedString(key, s)
{
	var blocks = s.split(" ");
	var result = "";
	var i, j, block;
	for (i = 0; i < blocks.length; ++i) {
		var bi;
		if (key.radix == 16) {
			bi = biFromHex(blocks[i]);
		}
		else {
			bi = biFromString(blocks[i], key.radix);
		}
		block = key.barrett.powMod(bi, key.d);
		for (j = 0; j <= biHighIndex(block); ++j) {
			result += String.fromCharCode(block.digits[j] & 255,
			                              block.digits[j] >> 8);
		}
	}
	// Remove trailing null, if any.
	if (result.charCodeAt(result.length - 1) == 0) {
		result = result.substring(0, result.length - 1);
	}
	return result;
}

17 楼 yangy608 2012-11-15   引用 
有个bug，单独加密1或5是解不出来的
16 楼 awerty3450p 2012-05-14   引用 
我按六楼的方法 已经解决JAVA解密不正确的问题 但是JAVA加密得到的代码不正确　　求破的方法
15 楼 awerty3450p 2012-05-11   引用 
博主你好，我有一个字符js加密 和 JAVA加密以后不一致  除了最后一位其他都差1 而另外的字符加密正常，百思不得其解
14 楼 Mov_webhobo 2012-04-19   引用 
引用
因为发现解出的明文是倒序的，后面就用StringBuffer的reverse()来转换了一下。

没有看懂JS源码，不知道这个的原因是什么？


引用

3 楼 hdown 2009-07-21   引用
已经在用了，谢谢啦

不过加密个别中英文字符串的时候会抛异常的


真的假的？搞得不敢用了！
13 楼 a47313198 2011-12-26   引用 
guzhixiong 写道
楼主，js 加密中文后，解密的是乱码，需要怎么解决呢，，试了好多方法没有解决，请问你有碰到过吗？是怎么解决的，请赐教


先使用 encodeURIComponent() 函数对中文进行编码，再加密试试。
解密后，使用 java.net.Decoder.decode(str, "UTF-8") 进行中文还原。
12 楼 hannibal005 2011-11-06   引用 
还是觉得JS里面的加密方法有问题。。因为我java里面的源程序加密解密字符串13579都没问题
11 楼 hannibal005 2011-11-05   引用 
这个方法很多字符都不能正常解密，比如13579 等等
10 楼 hannibal005 2011-11-05   引用 
楼主，我问下 request.setAttribute("m", module);  
        request.setAttribute("e", empoent);  
这个的作用是把公钥的　Modulus 与PublicExponent传入login.jsp么？我在login.jsp没有看到接受函数，请问JS加密的时候需要这2个参数么？
9 楼 guzhixiong 2011-09-07   引用 
楼主，js 加密中文后，解密的是乱码，需要怎么解决呢，，试了好多方法没有解决，请问你有碰到过吗？是怎么解决的，请赐教
8 楼 jjiangxixihahaitcyc 2011-06-03   引用 
JS加密过，不能正常解密，是怎么回事啊？
7 楼 lein07 2011-02-26   引用 
我觉得，每个Session新建一对密钥，这样Javascript就不需要随机码了，并且更安全。
6 楼 hxskwk 2011-01-14   引用 
4楼所说情况确实存在，问题出现在那呢？
这里:byte[] en_result = new BigInteger(result, 16).toByteArray();  
有的时候你会发现数组长度129，第一个元素为0，这肯定是不正确的！
解决办法:自己写一个16进制转字节数组的方法，很简单，在网上一搜一大堆！
至于加密中文我到没试过......

5 楼 chris_strive 2010-05-05   引用 
C:/RSAKey.txt 是什么文件啊？
4 楼 basakasky 2010-04-05   引用 
楼主，我只在Action中调用generateKeyPair方法产生一个KeyPair对象存入session中，
登陆时从session中取出该KeyPair对象，这样做的话不知是否可行？

我的试验结果是有时候输入:
"//","%","?"时会报异常Bad arguments，有时候输入这几个字符却不会报异常
不知你是否碰到过？

持续关 注中!
3 楼 hdown 2009-07-21   引用 
已经在用了，谢谢啦

不过加密个别中英文字符串的时候会抛异常的
2 楼 yanghong21240 2008-11-05   引用 
 
1 楼 wv1124 2008-09-04   引用 
好强啊，谢谢了

以上网友的问题在js加密java解密完美版项目中已经解决

引用

http://sunxboy.iteye.com/blog/209156