Java利用RSA进行前台加密然后后台解密案例
程序员文章站
2022-07-15 15:30:22
...
进行加密首先要获取公钥和私钥，本次采用的是公钥进行加密，私钥进行解密，所以首先我把公钥放入session中，然后再前台获取session中的公钥给需要加密的字段进行加密，后台session保存私钥，然后用来解密的。下面是我的案列：
前台页面：
后台：
辅助工具类（参考网上的）RSAUtil.java
package com.lyh.util;
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.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import javax.crypto.Cipher;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.tomcat.util.codec.binary.Base64;
/**
* @author 作者:LYH
* @createDate 创建时间：2018年8月10日 上午11:18:21
*/
public class RSAUtils {
protected static final Log log = LogFactory.getLog(RSAUtils.class);
private static String KEY_RSA_TYPE = "RSA";
private static int KEY_SIZE = 1024;//JDK方式RSA加密最大只有1024位
private static int ENCODE_PART_SIZE = KEY_SIZE/8;
public static final String PUBLIC_KEY_NAME = "public";
public static final String PRIVATE_KEY_NAME = "private";
/**
* 创建公钥秘钥
* @return
*/
public static Map<String,String> createRSAKeys(){
Map<String,String> keyPairMap = new HashMap<>();//里面存放公私秘钥的Base64位加密
try {
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KEY_RSA_TYPE);
keyPairGenerator.initialize(KEY_SIZE,new SecureRandom());
KeyPair keyPair = keyPairGenerator.generateKeyPair();
//获取公钥秘钥
String publicKeyValue = Base64.encodeBase64String(keyPair.getPublic().getEncoded());
String privateKeyValue = Base64.encodeBase64String(keyPair.getPrivate().getEncoded());
//存入公钥秘钥，以便以后获取
keyPairMap.put(PUBLIC_KEY_NAME,publicKeyValue);
keyPairMap.put(PRIVATE_KEY_NAME,privateKeyValue);
} catch (NoSuchAlgorithmException e) {
log.error("当前JDK版本没找到RSA加密算法！");
e.printStackTrace();
}
return keyPairMap;
}
/**
* 公钥加密
* 描述：
* 1字节 = 8位；
* 最大加密长度如 1024位私钥时，最大加密长度为 128-11 = 117字节，不管多长数据，加密出来都是 128 字节长度。
* @param sourceStr
* @param publicKeyBase64Str
* @return
*/
public static String encode(String sourceStr,String publicKeyBase64Str){
byte [] publicBytes = Base64.decodeBase64(publicKeyBase64Str);
//公钥加密
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(publicBytes);
List<byte[]> alreadyEncodeListData = new LinkedList<>();
int maxEncodeSize = ENCODE_PART_SIZE - 11;
String encodeBase64Result = null;
try {
KeyFactory keyFactory = KeyFactory.getInstance(KEY_RSA_TYPE);
PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
Cipher cipher = Cipher.getInstance(KEY_RSA_TYPE);
cipher.init(Cipher.ENCRYPT_MODE,publicKey);
byte[] sourceBytes = sourceStr.getBytes("utf-8");
int sourceLen = sourceBytes.length;
for(int i=0;i<sourceLen;i+=maxEncodeSize){
int curPosition = sourceLen - i;
int tempLen = curPosition;
if(curPosition > maxEncodeSize){
tempLen = maxEncodeSize;
}
byte[] tempBytes = new byte[tempLen];//待加密分段数据
System.arraycopy(sourceBytes,i,tempBytes,0,tempLen);
byte[] tempAlreadyEncodeData = cipher.doFinal(tempBytes);
alreadyEncodeListData.add(tempAlreadyEncodeData);
}
int partLen = alreadyEncodeListData.size();//加密次数
int allEncodeLen = partLen * ENCODE_PART_SIZE;
byte[] encodeData = new byte[allEncodeLen];//存放所有RSA分段加密数据
for (int i = 0; i < partLen; i++) {
byte[] tempByteList = alreadyEncodeListData.get(i);
System.arraycopy(tempByteList,0,encodeData,i*ENCODE_PART_SIZE,ENCODE_PART_SIZE);
}
encodeBase64Result = Base64.encodeBase64String(encodeData);
} catch (Exception e) {
e.printStackTrace();
}
return encodeBase64Result;
}
/**
* 私钥解密
* @param sourceBase64RSA
* @param privateKeyBase64Str
*/
public static String decode(String sourceBase64RSA,String privateKeyBase64Str){
byte[] privateBytes = Base64.decodeBase64(privateKeyBase64Str);
byte[] encodeSource = Base64.decodeBase64(sourceBase64RSA);
int encodePartLen = encodeSource.length/ENCODE_PART_SIZE;
List<byte[]> decodeListData = new LinkedList<>();//所有解密数据
String decodeStrResult = null;
//私钥解密
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(privateBytes);
try {
KeyFactory keyFactory = KeyFactory.getInstance(KEY_RSA_TYPE);
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
Cipher cipher = Cipher.getInstance(KEY_RSA_TYPE);
cipher.init(Cipher.DECRYPT_MODE,privateKey);
int allDecodeByteLen = 0;//初始化所有被解密数据长度
for (int i = 0; i < encodePartLen; i++) {
byte[] tempEncodedData = new byte[ENCODE_PART_SIZE];
System.arraycopy(encodeSource,i*ENCODE_PART_SIZE,tempEncodedData,0,ENCODE_PART_SIZE);
byte[] decodePartData = cipher.doFinal(tempEncodedData);
decodeListData.add(decodePartData);
allDecodeByteLen += decodePartData.length;
}
byte [] decodeResultBytes = new byte[allDecodeByteLen];
for (int i = 0,curPosition = 0; i < encodePartLen; i++) {
byte[] tempSorceBytes = decodeListData.get(i);
int tempSourceBytesLen = tempSorceBytes.length;
System.arraycopy(tempSorceBytes,0,decodeResultBytes,curPosition,tempSourceBytesLen);
curPosition += tempSourceBytesLen;
}
decodeStrResult = new String(decodeResultBytes,"UTF-8");
}catch (Exception e){
e.printStackTrace();
}
return decodeStrResult;
}
}
这样一个完整的项目就大致完成了。
完整案例下载地址https://download.csdn.net/download/qq_36827957/10595782