用RSA非对称加密方式实现。后台生成rsa密钥对,然后在登陆页面设置rsa公钥,提交时用公钥加密密码,生成的密文传到后台,用私钥解密,获取密码明文。
这样客户端只需要知道rsa加密方式和公钥,前台不知道私钥是无法解密的,此解决方案还是相对比较安全的。
附件是参照网友资料的java+JS的实现,放在这里供大家下载。访问方式/RSA/login.jsp。
需要到http://www.bouncycastle.org下载bcprov-jdk14-123.jar文件。
因为后台要转换成bigint,所以对明文长度有些限制:
总长度不超过126(1汉字长度为9),如下两个字符串:
阿送大法散得阿送大法散得阿送
1232132131231231232131232K1232132131231231232131232K1232132131231231232131232K1232132131231231232131232K1234567890123456789012
RSA速度
* 由于进行的都是大数计算,使得RSA最快的情况也比DES慢上100倍,无论 是软件还是硬件实现。
* 速度一直是RSA的缺陷。一般来说只用于少量数据 加密。
Util.java
- package RSA;
-
- /**
- *
- */
-
- 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 {
-
- private static String RSAKeyStore = "C:/RSAKey.txt";
- /**
- * * 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();
-
- System.out.println(keyPair.getPrivate());
- System.out.println(keyPair.getPublic());
-
- saveKeyPair(keyPair);
- return keyPair;
- } catch (Exception e) {
- throw new Exception(e.getMessage());
- }
- }
-
- public static KeyPair getKeyPair() throws Exception {
- FileInputStream fis = new FileInputStream(RSAKeyStore);
- 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(RSAKeyStore);
- 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));
- }
- }
LoginAction.java
- package RSA;
-
- //login
- /*
- * Generated by MyEclipse Struts
- * Template path: templates/java/JavaClass.vtl
- */
- import java.math.BigInteger;
- import java.net.URLDecoder;
- import java.net.URLEncoder;
-
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
-
- import RSA.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 {
- /*
- * Generated Methods
- */
-
- /**
- * Method execute
- *
- * @param mapping
- * @param form
- * @param request
- * @param response
- * @return ActionForward
- */
- public boolean execute(HttpServletRequest request,
- HttpServletResponse response) throws Exception {
- String pwd ;
- 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));
- pwd = sb.reverse().toString();
- System.out.println(sb);
- System.out.println("=================================");
- pwd = URLDecoder.decode(pwd,"UTF-8");//
- System.out.println(pwd);
- request.setAttribute("pwd", pwd);
- return true;
- }
- }
登陆login.jsp
- <%@ page language="java" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
-
- <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
- <html:html lang="true">
- <head>
- <title>login</title>
-
- <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(){
- var thisPwd = document.getElementById("password").value;
- bodyRSA();
- var result = encryptedString(key, encodeURIComponent(thisPwd));
- //alert(encodeURIComponent(thisPwd)+"\r\n"+result);
- loginForm.action="loginCHK.jsp?result="+result;
- loginForm.submit();
- }
- var key ;
- function bodyRSA(){
- setMaxDigits(130);
- key = new RSAKeyPair("10001","","8246a46f44fc4d961e139fd70f4787d272d374532f4d2d9b7cbaad6a15a8c1301319aa6b3f30413b859351c71938aec516fa7147b69168b195e81df46b6bed7950cf3a1c719d42175f73d7c97a85d7d20a9e83688b92f05b3059bb2ff75cd7190a042cd2db97ebc2ab4da366f2a7085556ed613b5a39c9fdd2bb2595d1dc23b5");
- }
- </script>
- </head>
-
- <body>
- <form method="post" name="loginForm" target=_blank>
- <table border="0">
- <tr>
- <td>
- Password:
- </td>
- <td>
- <input type='text' name="password" id=password style='width:400px' value="my passwd"/>
- </td>
- </tr>
- <tr>
- <td colspan="2" align="center">
- <input type="button" value="SUBMIT" οnclick="rsalogin();" />
- </td>
- </tr>
- </table>
- </form>
- </body>
- </html:html>
登陆校验loginCHK.jsp
- <%@ page language="java" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
-
- <jsp:directive.page import="RSA.LoginAction"/>
-
- <%
- LoginAction la = new LoginAction();
- la.execute(request ,response);
- %>
- pwd is [<%=request.getAttribute("pwd")%>]