前言
最近在看，网络安全方面的问题，我们可以使用RSA进行非对称加密防止，获取用户信息。首先我们看下java下操作RSA进行加密解密算法，代码如下：
package com.jb.test;
import java.security.InvalidKeyException;
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 javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import org.apache.commons.codec.binary.Hex;
public class RSAEntry {
public static void main(String[] args) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
// Security.getProviders();//获取所有支持的加密算法
//采用非对称加密解密算法
//生成密钥实例
KeyPairGenerator keygen = KeyPairGenerator.getInstance("RSA");
SecureRandom random = new SecureRandom();
random.setSeed(System.currentTimeMillis());//设置随机种子
keygen.initialize(512, random);//设置密钥长度，应为64的整数倍
//生成密钥公钥对
KeyPair keyPair = keygen.generateKeyPair();
//获取公钥
PublicKey pubkey = keyPair.getPublic();
//获取私钥
PrivateKey prikey = keyPair.getPrivate();
//测试数据
String data = "测试数据";
//使用公钥进行加密
//构建加密解密类
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE, pubkey);//设置为加密模式
byte[] jmdata = cipher.doFinal(data.getBytes());
//打印加密后数据
System.out.println(new String(Hex.encodeHex(jmdata)));
//改为解密模式进行解密
cipher.init(Cipher.DECRYPT_MODE, prikey);//会用私钥解密
jmdata = cipher.doFinal(jmdata);
System.out.println(new String(jmdata));
}
}
在web应用中，我们可以通过js进行前端加密，java进行后台解密，已达到我们的目的。这里需要注意的是，要想实现正确的加密解密算法，需要使用bcprov-ext-jdk15on-147.jar。
首先创建系统的密钥提供者：
package com.jb.test;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import org.apache.commons.codec.binary.Hex;
import org.bouncycastle.jcajce.provider.asymmetric.rsa.BCRSAPublicKey;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
public class RsaInitUtil {
private static KeyPair keyPair;
private static RsaInitUtil util;
private RsaInitUtil(){
try {
if(keyPair == null) {
//如果想要能够解密js的加密文件，使用此提供者是必须的
KeyPairGenerator keygen = KeyPairGenerator.getInstance("RSA", new BouncyCastleProvider());
SecureRandom random = new SecureRandom();
random.setSeed(System.currentTimeMillis());
keygen.initialize(512, random);//设置512位长度
keyPair = keygen.generateKeyPair();
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static RsaInitUtil getInstance(){
synchronized ("rsa") {
if(util == null) {
util = new RsaInitUtil();
}
}
return util;
}
public PublicKey getPublicKey(){
return keyPair.getPublic();
}
public PrivateKey getPrivateKey(){
return keyPair.getPrivate();
}
public String getPublicKeyStr(){
//根据我们的提供者，这里获取的是该类型公钥
BCRSAPublicKey pk = (BCRSAPublicKey) getPublicKey();
String str = new String(Hex.encodeHex(pk.getModulus().toByteArray()));
System.out.println(str);
//获取入口10001一般都为这个
String ss = new String(Hex.encodeHex(pk.getPublicExponent().toByteArray()));
//获取转换字符串
System.out.println(b2Hex(pk.getModulus().toByteArray()));
return ss + str;
}
private String b2Hex(byte[] byteArray) {
StringBuilder sb = new StringBuilder();
for(int i = 0; i < byteArray.length; i++ ) {
int zhz = byteArray[i];
if(zhz < 0) {
zhz += 256;
}
if(zhz < 16) {
sb.append("0");
}
sb.append(Integer.toHexString(zhz));
}
return sb.toString();
}
}
前台引入RSA.js,BigInt.js和Barrett.js并采用如下方法加密：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <%@page import="com.jb.test.RsaInitUtil"%> <% RsaInitUtil rsa = RsaInitUtil.getInstance(); String my = rsa.getPublicKeyStr(); String exp = my.substring(0,6); String mou = my.substring(6); %>RSA测试
后台解密算法为：
package com.jb.test;
import java.net.URLDecoder;
import java.security.NoSuchAlgorithmException;
import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import org.apache.commons.codec.binary.Hex;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller("rsaController")
public class RsaController {
private RsaInitUtil rsaUtil = RsaInitUtil.getInstance();
@RequestMapping("rsaDecTry.do")
public void decodeTry(String res) throws Exception {
Cipher cipher = Cipher.getInstance("RSA",new BouncyCastleProvider());//必须指定此提供者
cipher.init(Cipher.DECRYPT_MODE, rsaUtil.getPrivateKey());
System.out.println(res);
byte[] buff = cipher.doFinal(Hex.decodeHex(res.toCharArray()));
//将字符串转为字符
StringBuilder sb = new StringBuilder(new String(buff,"UTF-8"));
//解密后的内容是倒叙的
sb.reverse();
//进行URL解密，主要是为了中文乱码问题
String result = URLDecoder.decode(sb.toString(), "UTF-8");
System.out.println(result);
}
}
至此可完成，整个加密解密过程，下面大家可以把rsa相关的内容全部整合到一个工具类中，不用想这里处理。
下面为RSA加密解密工具类：
package com.jb.framework.filter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.math.BigInteger;
import java.net.URLDecoder;
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.spec.RSAPrivateKeySpec;
import java.security.spec.RSAPublicKeySpec;
import java.util.Calendar;
import javax.crypto.Cipher;
import org.apache.commons.codec.binary.Hex;
import org.bouncycastle.jcajce.provider.asymmetric.rsa.BCRSAPublicKey;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
public class RSAUtil {
private RSAUtil(){}
public static final String keyPubFile = "rsaPubKey.bin";
public static final String keyPriFile = "rsaPriKey.bin";
private static RSAUtil rsa;
//密钥生成器
private PublicKey publicKey;
//密钥队
private PrivateKey privateKey;
public static RSAUtil getInstance(){
synchronized ("rsa") {
if(rsa == null) {
rsa = new RSAUtil();
rsa.init();
}
}
return rsa;
}
private void init() {
//构建RSA算法
try {
KeyPairGenerator kengen = KeyPairGenerator.getInstance("RSA",new BouncyCastleProvider());
//构建随机种子
SecureRandom random = new SecureRandom();
random.setSeed(Calendar.getInstance().getTimeInMillis());
kengen.initialize(512, random);//采用512位加密
KeyPair keyPair = kengen.generateKeyPair();
publicKey = keyPair.getPublic();
privateKey = keyPair.getPrivate();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
}
public PublicKey getPublicKey(){
return this.publicKey;
}
public PrivateKey getPrivateKey(){
return this.privateKey;
}
public String getPublicKeyStr(){
BCRSAPublicKey pk = (BCRSAPublicKey) getPublicKey();
String pubStr = "";
pubStr += b2hex(pk.getPublicExponent().toByteArray());
pubStr += b2hex(pk.getModulus().toByteArray());
return pubStr;
}
public String encryText(String text) {
return encryText(text,getPublicKey());
}
public String encryText(String text, PublicKey pk) {
try {
Cipher cipher = Cipher.getInstance("RSA",new BouncyCastleProvider());
cipher.init(Cipher.ENCRYPT_MODE, pk);
int block = cipher.getBlockSize();//获取最大加密块
int j = 0;
StringBuilder sb = new StringBuilder();
byte[] targetData = text.getBytes("UTF-8");
while (targetData.length - j*block > 0) {
byte[] jmdata = cipher.doFinal(targetData,j*block,Math.min(targetData.length - j*block, block));
sb.append(b2hex(jmdata));
j++;
}
return sb.toString();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public String decryText(String text) {
return decryText(text,getPrivateKey());
}
public String decryText(String text, PrivateKey pk) {
try {
Cipher cipher = Cipher.getInstance("RSA", new BouncyCastleProvider());
cipher.init(Cipher.DECRYPT_MODE, pk);
byte[] targetBuff = Hex.decodeHex(text.replace(" ", "").toCharArray());
int block = cipher.getBlockSize();
int j = 0;
StringBuilder sb = new StringBuilder();
while (targetBuff.length - j * block > 0) {
byte[] jmdata = cipher.doFinal(targetBuff,j*block,block);
sb.append(new String(jmdata,"UTF-8"));
j++;
}
return sb.toString();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public String decryTextByUrl(String text) {
try {
Cipher cipher = Cipher.getInstance("RSA", new BouncyCastleProvider());
cipher.init(Cipher.DECRYPT_MODE, getPrivateKey());
byte[] targetBuff = Hex.decodeHex(text.replace(" ", "").toCharArray());
int block = cipher.getBlockSize();
int j = 0;
StringBuilder sb = new StringBuilder();
while (targetBuff.length - j * block > 0) {//处理大字符串的加密解密处理
byte[] jmdata = cipher.doFinal(targetBuff,j*block,block);
sb.append(new StringBuilder(new String(jmdata,"UTF-8")).reverse());
j++;
}
String res = URLDecoder.decode(sb.toString(), "UTF-8");
return res;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public PublicKey createPubKey(byte[] exponent,byte[]modules) {
try {
KeyFactory keyFactory = KeyFactory.getInstance("RSA", new BouncyCastleProvider());
RSAPublicKeySpec rsaKs = new RSAPublicKeySpec(new BigInteger(modules),new BigInteger(exponent));
return keyFactory.generatePublic(rsaKs);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public PrivateKey createPriKey(byte[] exponent,byte[]modules) {
try {
KeyFactory keyFactory = KeyFactory.getInstance("RSA", new BouncyCastleProvider());
RSAPrivateKeySpec rsaKs = new RSAPrivateKeySpec(new BigInteger(modules),new BigInteger(exponent));
return keyFactory.generatePrivate(rsaKs);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public void saveKeyToFile() {
PublicKey pk = getPublicKey();
PrivateKey prik = getPrivateKey();
String path = RSAUtil.class.getClassLoader().getResource("").getPath();
ObjectOutputStream outPub = null;
ObjectOutputStream outPri = null;
try {
System.out.println(path + keyPubFile);
outPub = new ObjectOutputStream(new FileOutputStream(path + keyPubFile));
outPri = new ObjectOutputStream(new FileOutputStream(path + keyPriFile));
outPub.writeObject(pk);
outPri.writeObject(prik);
} catch (Exception e) {
e.printStackTrace();
}finally {
try {
outPub.close();
outPri.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
public Object readKey(boolean isPub) {
String path = RSAUtil.class.getClassLoader().getResource("").getPath();
ObjectInputStream in = null;
try {
if(isPub) {
path += keyPubFile;
in = new ObjectInputStream(new FileInputStream(path));
PublicKey pk = (PublicKey) in.readObject();
return pk;
}else {
path += keyPriFile;
in = new ObjectInputStream(new FileInputStream(path));
PrivateKey pk = (PrivateKey) in.readObject();
return pk;
}
} catch (Exception e) {
e.printStackTrace();
}finally {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
public String b2hex(byte[] buff) {
StringBuilder sb = new StringBuilder();
for(int i = 0; i < buff.length; i++) {
int z = buff[i];
if(z < 0) {
z+= 256;
}
if(z < 16) {
sb.append("0");
}
sb.append(Integer.toHexString(z));
}
return sb.toString();
}
}
下载：http://xiazai.jb51.net/201808/yuanma/rsajar_jb51.rar
总结
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