1.RSA简介
RSA是目前使用最广泛的公钥密码体制之一,可以实现非对称加密。它是1977年由罗纳德·李维斯特（Ron Rivest）、阿迪·萨莫尔（Adi Shamir）和伦纳德·阿德曼（Leonard Adleman）一起提出的。当时他们三人都在麻省理工学院工作。RSA就是他们三人姓氏开头字母拼在一起组成的。RSA算法的安全性基于RSA问题的困难性，也就是基于大整数因子分解的困难性上。但是RSA问题不会比因子分解问题更加困难，也就是说，在没有解决因子分解问题的情况下可能解决RSA问题，因此RSA算法并不是完全基于大整数因子分解的困难性上的。
2.代码样例
a.RSAHelper.java工具类
import java.io.ByteArrayOutputStream;
import java.io.IOException;
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.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import org.apache.commons.codec.binary.Base64;
import org.springframework.util.Base64Utils;
/**
* RSA加解密工具类
* @author shixiangcheng
* 2020-04-29
*/
public final class RSAHelper {
public static final String PUBLIC_KEY_VALUES = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA0bb7yxuvRIWOUxlTbTXE\n" +
"cKX5f4Q6+BBOf1fYJKic9l6Wf1QPmyt6ML7PywaPH861D7eYoQl0bGNK2fKsgcAG\n" +
"ZzObG5CpmP8ESnSzqcjltdAgx+neCZQy7yUmXUIhpBEQMN80CNYoasOxeZTdPh2w\n" +
"zhlmwa27ubkvpINtKUfZbg8sQ5wiDGbLM32ej8z2Rl8DNY4vrusJaNXB7LWaRQm7\n" +
"4lPhLN2B/hMv/Ktif4iNxUCYDY97Xws2kVVu7ffWkn4rnhiCrTw2XMZRjIJq3a4o\n" +
"4zGWUhYm0usVOLz+yG22cLSCIDhM8tBXL2f3960l4OIQbSObfQkGnqlmi0Fe686p\n" +
"gwIDAQAB";
public static final String PRIVATE_KEY_VALUES = "MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQDRtvvLG69EhY5T\n" +
"GVNtNcRwpfl/hDr4EE5/V9gkqJz2XpZ/VA+bK3owvs/LBo8fzrUPt5ihCXRsY0rZ\n" +
"8qyBwAZnM5sbkKmY/wRKdLOpyOW10CDH6d4JlDLvJSZdQiGkERAw3zQI1ihqw7F5\n" +
"lN0+HbDOGWbBrbu5uS+kg20pR9luDyxDnCIMZsszfZ6PzPZGXwM1ji+u6wlo1cHs\n" +
"tZpFCbviU+Es3YH+Ey/8q2J/iI3FQJgNj3tfCzaRVW7t99aSfiueGIKtPDZcxlGM\n" +
"gmrdrijjMZZSFibS6xU4vP7IbbZwtIIgOEzy0FcvZ/f3rSXg4hBtI5t9CQaeqWaL\n" +
"QV7rzqmDAgMBAAECggEBAIpVZ5Y8tso+RvmttQhO9TtRYFirArLrHryFV4Am8RLa\n" +
"pe9rpbe3YCyTUUIdG3/hvDGX68geEnwEqzVFDGGyJwcgVWpDbHwNi+kJPhH7APuD\n" +
"RHxaWip7ZXW2Ta4ql0JANyvlr888ZQC4AXOvrJjywNPSkaOkVDZYX4LnZrRaPqSH\n" +
"j9iVGuKK4nbqbXP1tuLyto6bsn3L2KuwrBthtiDPaZ1cRm3aSu/XND030iSGloW/\n" +
"/f6vHI3U//cPFPdi8p54nbpGTB0E66D2xbfK5+z9dZYoFDZUdMsloR1JgS4vQErr\n" +
"17165RS7cpWx2HejiKat6qmNFXkHbREpcLDT+lq91LECgYEA7wqm+mIFIYyXEARc\n" +
"lKKabCKaufKE+7kyBGpAEyon1lYZHw62dCYkGmuXULam4IAz7TesWsbG5SEgDx/A\n" +
"jeFSoC6NTyyTzSh1I08UHdOJ4xhAa67GnlJG7WLNZFK+itl7v3VOOlGsAYAxaG5q\n" +
"kQKQ1mKk6C6oGRpQ0aqKxVhoDc0CgYEA4Je2flPUYs33qy4m09UBFx6Xf91/5LvL\n" +
"iTtEo+HGcMzxmfeV3sawUwtjHhyippN5lTR80JLbYoEvoUMyKt+N5Jnic206alSH\n" +
"hujsQnO4LCRHz/XwkHnB8Ncd3J67Uaq9PUPY630NIA/ChBAQchsqntJSdVn65PZf\n" +
"mw7+hO2WxI8CgYB4eX/qlVhMrlS8R9Z5OvJlKZOdv/LyA0aIHxyoDAkD52TF2F5w\n" +
"b4CmqC8dCNFWOIbzOanuHlzDwkwsEy6y0ysXfB7QFoFvVsKixwo2dhT6lZByNSX5\n" +
"STJiFfe6ZlGOHUpXFkIU9nCgWQGNxoiDCS4CPrkqI8mozTCKW0+RYpseyQKBgQCR\n" +
"cK21UQQQl+Dy8YgjVaTHHABvxTi1HwfHbqIcnnCrS4yJcFOVWIWGwbEGJvUNeiMa\n" +
"BEtvpip7t7zoaWNrcCmrCBwlM27IvMSnEN8uiVGTBEuc2F9YsABvvl6QKBqV4EN8\n" +
"ERvAI9MEGDCW5PBBdGY9Q2YyqHpZG1L+Ts9ztYgU8QKBgB7bP9eNMrDzgZ6i9pFP\n" +
"djlcJ+NE0veOLwTA1eQhiIZFSJTI5eyiePTYNIS3GwIyGauzePw5LeBb6rLVBt4Y\n" +
"NAOgJDeHbPV2bnstONjE7FyUswJivIVD3n3UaVGgBTe6xc468Ws4rmeKZ8/Ph1Nq\n" +
"ylaViyPWz486JAibF3Kudl5B";
/**
* RSA密钥长度必须是64的倍数，在512~65536之间。默认是1024
*/
public static final int KEY_SIZE = 2048;
/**
* 生成公钥、私钥对(keysize=1024)
*/
public static RSAHelper.KeyPairInfo getKeyPair() {
return getKeyPair(KEY_SIZE);
}
private static final String src = "{\"OrderId\":\"HP124456\",\"PrepaymentDate\":\"2020-01-20\"}";
//
// public static void main(String[] args) throws Exception {
// System.out.println("\n");
// KeyPairInfo keyPair = getKeyPair();
// System.out.println("构建RSA密钥对公钥：" + keyPair.getPublicKey());
// System.out.println("构建RSA密钥对私钥：" + keyPair.getPrivateKey());
// // 公钥、私钥生成一次后，调用方、被调用方都要保存
// // 调用方用公钥加密，被调用方用私钥解密
// // 返回值 被调用方公钥加密，调用方用私钥解密
// System.out.println("\n");
// String data1 = encipher(src,keyPair.getPublicKey());
// String data2 = decipher(data1,keyPair.getPrivateKey());
// System.out.println("加密前：" + src);
// System.out.println("加密后HTTP传输内容：" + data1);
// System.out.println("解密后：" + data2);
// System.out.println("***************** 公钥加密私钥解密结束 *****************");
// }
/**
* 生成公钥、私钥对
*
* @param keySize
* @return
*/
public static RSAHelper.KeyPairInfo getKeyPair(int keySize) {
try {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
keyPairGen.initialize(keySize);
// 生成一个密钥对，保存在keyPair中
KeyPair keyPair = keyPairGen.generateKeyPair();
// 得到私钥
RSAPrivateKey oraprivateKey = (RSAPrivateKey) keyPair.getPrivate();
// 得到公钥
RSAPublicKey orapublicKey = (RSAPublicKey) keyPair.getPublic();
RSAHelper.KeyPairInfo pairInfo = new RSAHelper.KeyPairInfo(keySize);
//公钥
byte[] publicKeybyte = orapublicKey.getEncoded();
String publicKeyString = Base64.encodeBase64String(publicKeybyte);
pairInfo.setPublicKey(publicKeyString);
//私钥
byte[] privateKeybyte = oraprivateKey.getEncoded();
String privateKeyString = Base64.encodeBase64String(privateKeybyte);
pairInfo.setPrivateKey(privateKeyString);
return pairInfo;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 获取公钥对象
* @param publicKeyBase64
* @return
* @throws InvalidKeySpecException
* @throws NoSuchAlgorithmException
*/
public static PublicKey getPublicKey(String publicKeyBase64)
throws InvalidKeySpecException, NoSuchAlgorithmException {
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
X509EncodedKeySpec publicpkcs8KeySpec =
new X509EncodedKeySpec(Base64.decodeBase64(publicKeyBase64));
PublicKey publicKey = keyFactory.generatePublic(publicpkcs8KeySpec);
return publicKey;
}
/**
* 获取私钥对象
* @param privateKeyBase64
* @return
* @throws NoSuchAlgorithmException
* @throws InvalidKeySpecException
*/
public static PrivateKey getPrivateKey(String privateKeyBase64)
throws NoSuchAlgorithmException, InvalidKeySpecException {
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PKCS8EncodedKeySpec privatekcs8KeySpec =
new PKCS8EncodedKeySpec(Base64.decodeBase64(privateKeyBase64));
PrivateKey privateKey = keyFactory.generatePrivate(privatekcs8KeySpec);
return privateKey;
}
/**
* 使用工钥加密----分段加密
* @param content 待加密内容
* @param publicKeyBase64 公钥 base64 编码
* @return 经过 base64 编码后的字符串
*/
public static String encipher(String content, String publicKeyBase64) {
return encipher(content, publicKeyBase64, KEY_SIZE / 8 - 11);
}
/**
* 使用公司钥加密（分段加密）
* @param content 待加密内容
* @param publicKeyBase64 公钥 base64 编码
* @param segmentSize 分段大小,一般小于 keySize/8（段小于等于0时，将不使用分段加密）
* @return 经过 base64 编码后的字符串
*/
public static String encipher(String content, String publicKeyBase64, int segmentSize) {
try {
PublicKey publicKey = getPublicKey(publicKeyBase64);
return encipher(content, publicKey, segmentSize);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 分段加密
* @param ciphertext 密文
* @param key 加密秘钥
* @param segmentSize 分段大小，<=0 不分段
* @return
*/
public static String encipher(String ciphertext, java.security.Key key, int segmentSize) {
try {
// 用公钥加密
byte[] srcBytes = ciphertext.getBytes();
// Cipher负责完成加密或解密工作，基于RSA
Cipher cipher = Cipher.getInstance("RSA");
// 根据公钥，对Cipher对象进行初始化
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] resultBytes = null;
if (segmentSize > 0)
resultBytes = cipherDoFinal(cipher, srcBytes, segmentSize); //分段加密
else
resultBytes = cipher.doFinal(srcBytes);
String base64Str = Base64Utils.encodeToString(resultBytes);
return base64Str;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 分段大小
* @param cipher
* @param srcBytes
* @param segmentSize
* @return
* @throws IllegalBlockSizeException
* @throws BadPaddingException
* @throws IOException
*/
public static byte[] cipherDoFinal(Cipher cipher, byte[] srcBytes, int segmentSize)
throws IllegalBlockSizeException, BadPaddingException, IOException {
if (segmentSize <= 0)
throw new RuntimeException("分段大小必须大于0");
ByteArrayOutputStream out = new ByteArrayOutputStream();
int inputLen = srcBytes.length;
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > segmentSize) {
cache = cipher.doFinal(srcBytes, offSet, segmentSize);
} else {
cache = cipher.doFinal(srcBytes, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * segmentSize;
}
byte[] data = out.toByteArray();
out.close();
return data;
}
/**
* 使用私钥解密
* @param contentBase64 待加密内容,base64 编码
* @param privateKeyBase64 私钥 base64 编码
* @return
* @segmentSize 分段大小
*/
public static String decipher(String contentBase64, String privateKeyBase64) {
return decipher(contentBase64, privateKeyBase64, KEY_SIZE / 8);
}
/**
* 使用私钥解密（分段解密）
* @param contentBase64 待加密内容,base64 编码
* @param privateKeyBase64 私钥 base64 编码
* @return
* @segmentSize 分段大小
*/
public static String decipher(String contentBase64, String privateKeyBase64, int segmentSize) {
try {
PrivateKey privateKey = getPrivateKey(privateKeyBase64);
return decipher(contentBase64, privateKey, segmentSize);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 分段解密
* @param contentBase64 密文
* @param key 解密秘钥
* @param segmentSize 分段大小（小于等于0不分段）
* @return
*/
public static String decipher(String contentBase64, java.security.Key key, int segmentSize) {
try {
// 用私钥解密
byte[] srcBytes = Base64Utils.decodeFromString(contentBase64);
// Cipher负责完成加密或解密工作，基于RSA
Cipher deCipher = Cipher.getInstance("RSA");
// 根据公钥，对Cipher对象进行初始化
deCipher.init(Cipher.DECRYPT_MODE, key);
byte[] decBytes = null;//deCipher.doFinal(srcBytes);
if (segmentSize > 0)
decBytes = cipherDoFinal(deCipher, srcBytes, segmentSize); //分段加密
else
decBytes = deCipher.doFinal(srcBytes);
String decrytStr = new String(decBytes);
return decrytStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 秘钥对
*/
public static class KeyPairInfo {
String privateKey;
String publicKey;
int keySize = 0;
public KeyPairInfo(int keySize) {
setKeySize(keySize);
}
public KeyPairInfo(String publicKey, String privateKey) {
setPrivateKey(privateKey);
setPublicKey(publicKey);
}
public String getPrivateKey() {
return privateKey;
}
public void setPrivateKey(String privateKey) {
this.privateKey = privateKey;
}
public String getPublicKey() {
return publicKey;
}
public void setPublicKey(String publicKey) {
this.publicKey = publicKey;
}
public int getKeySize() {
return keySize;
}
public void setKeySize(int keySize) {
this.keySize = keySize;
}
}
}
b.RSAController.java控制类
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import com.alibaba.fastjson.JSON;
import com.anji.ajfes.bao.util.RSAHelper;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
/**
* RSA非对称加密
* @author shixiangcheng
* 2020-04-29
*/
@Api(value = "RSA非对称加密")
@RestController
@RequestMapping(value="/rsa",produces=MediaType.APPLICATION_JSON_UTF8_VALUE)
public class RSAController {
@RequestMapping(value="/testRsa",method = RequestMethod.POST,consumes=MediaType.APPLICATION_JSON_UTF8_VALUE)
@ApiOperation("测试RSA非对称加密")
public void testRsa(HttpServletRequest request,HttpServletResponse response) throws Exception{
request.setCharacterEncoding("UTF-8");
//取得请求报文
ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream();
InputStream is = request.getInputStream();
byte[] buffer = new byte[1024];
while (true) {
int size = is.read(buffer);
if (size <= 0) {
break;
}
arrayOutputStream.write(buffer, 0, size);
}
String inMsg=new String(arrayOutputStream.toByteArray());
//私钥解密
inMsg=RSAHelper.decipher(inMsg,RSAHelper.PRIVATE_KEY_VALUES);
System.out.println("服务端入参解密后:"+inMsg);
//将JSON报文转为对象
DemoDTO demoDTO=JSON.parseObject(inMsg,DemoDTO.class);
demoDTO.setName("服务端返回");
String responseJSON=JSON.toJSONString(demoDTO);
System.out.println("服务端出参加密前:"+responseJSON);
//公钥加密
responseJSON=RSAHelper.encipher(responseJSON,RSAHelper.PUBLIC_KEY_VALUES);
//将结果报文推送
response.setCharacterEncoding("UTF-8");
response.setContentType("application/json; charset=UTF-8");
response.getWriter().print(responseJSON);
response.flushBuffer();
}
}
c.DemoDTO.java实体
package com.shi.anji.util;
import java.io.Serializable;
/**
* 实体对象
* @author shixiangcheng
* 2020-04-29
*/
public class DemoDTO implements Serializable{
private static final long serialVersionUID = 1L;
private int id;
private String name="";
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
d.Test.java测试类
import com.alibaba.fastjson.JSON;
import com.shi.anji.util.DemoDTO;
import com.shi.anji.util.HttpUtil;
import com.shi.anji.util.RSAHelper;
/**
* 测试RSA非对称加密
* @author shixiangcheng
* 2020-04-29
*/
public class Test {
public static void main(String [] args) throws Exception{
DemoDTO d=new DemoDTO();
d.setId(1);
d.setName("RSA加密");
String serviceUrl="http://localhost:8080/rsa/testRsa";//服务地址
String inMsg=JSON.toJSONString(d);//入参(JSON格式)
System.out.println("客户端调用接口参数加密前:"+inMsg);
//公钥加密
inMsg=RSAHelper.encipher(inMsg,RSAHelper.PUBLIC_KEY_VALUES);
//调用接口
String outMsg=HttpUtil.httpPost(serviceUrl,inMsg);
//私钥解密
outMsg=RSAHelper.decipher(outMsg,RSAHelper.PRIVATE_KEY_VALUES);
System.out.println("客户端调用接口返回值解密后:"+outMsg);
}
}
执行日志
--Test类日志
客户端调用接口参数加密前:{"id":1,"name":"RSA加密"}
客户端调用接口返回值解密后:{"id":1,"name":"服务端返回"}
--controller日志
服务端入参解密后:{"id":1,"name":"RSA加密"}
服务端出参加密前:{"id":1,"name":"服务端返回"}
欢迎大家积极留言交流学习心得，点赞的人最美丽，谢谢
版权声明：本文为xiaoxiaodaxiake原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接和本声明。