用javascript与java进行RSA加密与解密

这几天一直做安全登录，网上查了好多资料，不尽如意。

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.sunsoft.struts.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 = "hello world";
		byte[] en_test = encrypt(getKeyPair().getPublic(),test.getBytes());
		byte[] de_test = decrypt(getKeyPair().getPrivate(),en_test);
		System.out.println(new String(de_test));
	}
}

 2.测试页面：

IndexAction.java

/*
 * Generated by MyEclipse Struts
 * Template path: templates/java/JavaClass.vtl
 */
package com.sunsoft.struts.action;

import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;

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

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

import com.sunsoft.struts.util.RSAUtil;

/** 
 * MyEclipse Struts
 * Creation date: 06-28-2008
 * 
 * XDoclet definition:
 * @struts.action validate="true"
 */
public class IndexAction extends Action {
	/*
	 * Generated Methods
	 */

	/** 
	 * Method execute
	 * @param mapping
	 * @param form
	 * @param request
	 * @param response
	 * @return ActionForward
	 */
	public ActionForward execute(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)throws Exception {
		
		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);
		request.setAttribute("m", module);
		request.setAttribute("e", empoent);
		return mapping.findForward("login");
	}
}

 通过此action进入登录页面，并传入公钥的　Modulus 与PublicExponent的hex编码形式。

3。登录页面　login.jsp

<%@ page language="java" pageEncoding="GBK"%>

<%@ taglib uri="http://struts.apache.org/tags-bean" prefix="bean" %>
<%@ taglib uri="http://struts.apache.org/tags-html" prefix="html" %>
<%@ taglib uri="http://struts.apache.org/tags-logic" prefix="logic" %>
<%@ taglib uri="http://struts.apache.org/tags-tiles" prefix="tiles" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html:html lang="true">
  <head>
    <html:base />
    
    <title>login</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">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->
<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">
function rsalogin()
{
   bodyRSA();
   var result = encryptedString(key, document.getElementById("pwd").value);
   //alert(result);
   loginForm.action="login.do?result="+result;
   loginForm.submit();
}
var key ;
function bodyRSA()
{
	setMaxDigits(130);
  	key = new RSAKeyPair("10001","","8c1cd09a04ed01aafe70dc84c5f32ae23a16fe8fc8898aba6797c5a9c708720de4f08dbf086af429fc51c0636208f56de20a8ab5686affd9bdfb643ae1e90d5617155c4867eef06b0884ba8ecd187907c7069ae3eed4f0155eeca6573411864035ae803ad8fd91a0cc479f27e41b19c13465ab30f3cfbfd14de56f49cbd09481"); 
  
}

</script>
  </head>
  
  <body >
    <html:form action="login" method="post" focus="username">
      <table border="0">
        <tr>
          <td>Login:</td>
          <td><html:text property="username" /></td>
        </tr>
        <tr>
          <td>Password:</td>
          <td><html:password property="password" styleId="pwd"/></td>
        </tr>
        <tr>
          <td colspan="2" align="center"><input type="button" value="SUBMIT" onclick="rsalogin();"/></td>
        </tr>
      </table>
    </html:form>
  </body>
</html:html>

 3.点击登录后，调用LoginAction.java

/*
 * Generated by MyEclipse Struts
 * Template path: templates/java/JavaClass.vtl
 */
package com.sunsoft.struts.action;

import java.math.BigInteger;

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

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

import com.sunsoft.struts.util.RSAUtil;

/** 
 * MyEclipse Struts
 * Creation date: 06-28-2008
 * 
 * XDoclet definition:
 * @struts.action path="/login" name="loginForm" input="/login.jsp" scope="request" validate="true"
 * @struts.action-forward name="error" path="/error.jsp"
 * @struts.action-forward name="success" path="/success.jsp"
 */
public class LoginAction extends Action {
	/*
	 * Generated Methods
	 */

	/** 
	 * Method execute
	 * @param mapping
	 * @param form
	 * @param request
	 * @param response
	 * @return ActionForward
	 */
	public ActionForward execute(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response) throws Exception{
		//LoginForm loginForm = (LoginForm) form;
		String result = request.getParameter("result");
		System.out.println("原文加密后为：");
		System.out.println(result);
		byte[] en_result = new BigInteger(result, 16).toByteArray();
		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());
		return mapping.findForward("success");
	}
}

 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。

4。login.jsp所调用的js