版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/baidu_38990811/article/details/83416532
前言:
1.前面一篇是AES对称加密写了一个demo,为了后面的两者结合使用,今天去了解学习了下RSA非对称加密.
2.这是百度百科对(对称加密丶非对称加密)的解释:
(1)对称加密算法在加密和解密时使用的是同一个秘钥。
(2)非对称加密算法需要两个密钥来进行加密和解密，这两个秘钥是公开密钥（public key，简称公钥）和私有密钥（private key，简称私钥）。
大致思路:
(1)服务端利用RSA创建一对公私钥,服务端存储私钥,将公钥给客户端
(2)每次请求前,将明文数据利用公钥进行加密,然后将密文传递给服务端
(3)服务端拿到密文,利用私钥进行解密,得到明文数据,然后进行业务处理
ps: 如果想做到返回参数也进行加密,那么两个方法,
(1)客户端或服务端创建一对公私钥,然后将公私钥传递给服务端或客户端,(这样就可以使用公钥加密,私钥解密了),但是私钥放在客户端就违背了非对称加密(RSA)的原则性了,
(2)客户端,创建一对公私钥,服务端在重新创建新的一对公私钥,互相各拿对方的公钥,这样就可以进行传参的加密,解密,和响应数据的加解密!!!
但是为了解决RSA加解密性能问题,请看下篇文章RSA+AES(动态获取key)进行混合加密
使用非对称加密(RSA)实践(采用前端加密,后端解密,后端并不返回加密数据):
1.创建spring boot项目,导入相关依赖
2.编写加密工具类
3.编写自定义注解(让加解密细粒度)
4.编写自定义RsaDecodeRequestAdvice
5.创建controller
6.创建jsp或者html,引入js(加密和解密的通用js)
ps:因为这里没https证书,所有使用http, 考虑到前后端分离,使用json来传递数据
第一步: 略,不会的请自行百度spring boot项目如何创建!
第二步:
import org.apache.commons.codec.binary.Base64;
import java.io.ByteArrayOutputStream;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
import javax.crypto.Cipher;
/** */
/**
* <p>
* RSA公钥/私钥/签名工具包
* </p>
* <p>
* 罗纳德·李维斯特（Ron [R]ivest）、阿迪·萨莫尔（Adi [S]hamir）和伦纳德·阿德曼（Leonard [A]dleman）
* </p>
* <p>
* 字符串格式的密钥在未在特殊说明情况下都为BASE64编码格式<br/>
* 由于非对称加密速度极其缓慢，一般文件不使用它来加密而是使用对称加密，<br/>
* 非对称加密算法可以用来对对称加密的密钥加密，这样保证密钥的安全也就保证了数据的安全
* </p>
*
* @author monkey
* @date 2018-10-29
*/
public class RSAUtils {
/** */
/**
* 加密算法RSA
*/
public static final String KEY_ALGORITHM = "RSA";
/** */
/**
* 签名算法
*/
public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
/** */
/**
* 获取公钥的key
*/
private static final String PUBLIC_KEY = "RSAPublicKey";
/** */
/**
* 获取私钥的key
*/
private static final String PRIVATE_KEY = "RSAPrivateKey";
/** */
/**
* RSA最大加密明文大小
*/
private static final int MAX_ENCRYPT_BLOCK = 117;
/** */
/**
* RSA最大解密密文大小
*/
private static final int MAX_DECRYPT_BLOCK = 128;
/** */
/**
* RSA 位数 如果采用2048 上面最大加密和最大解密则须填写: 245 256
*/
private static final int INITIALIZE_LENGTH = 1024;
/** */
/**
* <p>
* 生成密钥对(公钥和私钥)
* </p>
*
* @return
* @throws Exception
*/
public static Map<String, Object> genKeyPair() throws Exception {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
keyPairGen.initialize(INITIALIZE_LENGTH);
KeyPair keyPair = keyPairGen.generateKeyPair();
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
Map<String, Object> keyMap = new HashMap<String, Object>(2);
keyMap.put(PUBLIC_KEY, publicKey);
keyMap.put(PRIVATE_KEY, privateKey);
return keyMap;
}
/** */
/**
* <p>
* 用私钥对信息生成数字签名
* </p>
*
* @param data
* 已加密数据
* @param privateKey
* 私钥(BASE64编码)
*
* @return
* @throws Exception
*/
public static String sign(byte[] data, String privateKey) throws Exception {
byte[] keyBytes = Base64.decodeBase64(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(privateK);
signature.update(data);
return Base64.encodeBase64String(signature.sign());
}
/** */
/**
* <p>
* 校验数字签名
* </p>
*
* @param data
* 已加密数据
* @param publicKey
* 公钥(BASE64编码)
* @param sign
* 数字签名
*
* @return
* @throws Exception
*
*/
public static boolean verify(byte[] data, String publicKey, String sign) throws Exception {
byte[] keyBytes = Base64.decodeBase64(publicKey);
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PublicKey publicK = keyFactory.generatePublic(keySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initVerify(publicK);
signature.update(data);
return signature.verify(Base64.decodeBase64(sign));
}
/** */
/**
* <P>
* 私钥解密
* </p>
*
* @param encryptedData
* 已加密数据
* @param privateKey
* 私钥(BASE64编码)
* @return
* @throws Exception
*/
public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey) throws Exception {
byte[] keyBytes = Base64.decodeBase64(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privateK);
int inputLen = encryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
} else {
cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
return decryptedData;
}
/** */
/**
* <p>
* 公钥解密
* </p>
*
* @param encryptedData
* 已加密数据
* @param publicKey
* 公钥(BASE64编码)
* @return
* @throws Exception
*/
public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey) throws Exception {
byte[] keyBytes = Base64.decodeBase64(publicKey);
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicK);
int inputLen = encryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
} else {
cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
return decryptedData;
}
/** */
/**
* <p>
* 公钥加密
* </p>
*
* @param data
* 源数据
* @param publicKey
* 公钥(BASE64编码)
* @return
* @throws Exception
*/
public static byte[] encryptByPublicKey(byte[] data, String publicKey) throws Exception {
byte[] keyBytes = Base64.decodeBase64(publicKey);
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
// 对数据加密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicK);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
return encryptedData;
}
/** */
/**
* <p>
* 私钥加密
* </p>
*
* @param data
* 源数据
* @param privateKey
* 私钥(BASE64编码)
* @return
* @throws Exception
*/
public static byte[] encryptByPrivateKey(byte[] data, String privateKey) throws Exception {
byte[] keyBytes = Base64.decodeBase64(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateK);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
return encryptedData;
}
/** */
/**
* <p>
* 获取私钥
* </p>
*
* @param keyMap
* 密钥对
* @return
* @throws Exception
*/
public static String getPrivateKey(Map<String, Object> keyMap) throws Exception {
Key key = (Key) keyMap.get(PRIVATE_KEY);
return Base64.encodeBase64String(key.getEncoded());
}
/** */
/**
* <p>
* 获取公钥
* </p>
*
* @param keyMap
* 密钥对
* @return
* @throws Exception
*/
public static String getPublicKey(Map<String, Object> keyMap) throws Exception {
Key key = (Key) keyMap.get(PUBLIC_KEY);
return Base64.encodeBase64String(key.getEncoded());
}
/**
* java端公钥加密
*/
public static String encryptedDataOnJava(String data, String PUBLICKEY) {
try {
data = Base64.encodeBase64String(encryptByPublicKey(data.getBytes(), PUBLICKEY));
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return data;
}
/**
* java端私钥解密
*/
public static String decryptDataOnJava(String data, String PRIVATEKEY) {
String temp = "";
try {
byte[] rs = Base64.decodeBase64(data);
temp = new String(RSAUtils.decryptByPrivateKey(rs, PRIVATEKEY),"UTF-8");
} catch (Exception e) {
e.printStackTrace();
}
return temp;
}
public static void main(String[] args) throws Exception{
}
}
第三步:
import org.springframework.web.bind.annotation.Mapping;
import java.lang.annotation.*;
/**
* @author monkey
* @desc 请求数据解密
* @date 2018/10/29 20:17
*/
@Target({ElementType.METHOD,ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Mapping
@Documented
public @interface RsaSecurityParameter {
/**
* 入参是否解密，默认解密
*/
boolean inDecode() default true;
/**
* 出参是否加密，默认加密
*/
boolean outEncode() default true;
}第四步:
import com.monkey.springboot.demo.annotation.RsaSecurityParameter;
import com.monkey.springboot.demo.utils.RSAUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.MethodParameter;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.RequestBodyAdvice;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Type;
/**
* @author monkey
* @desc 请求数据解密
* @date 2018/10/29 20:17
*/
@ControllerAdvice(basePackages = "com.monkey.springboot.demo.controller")
public class RsaDecodeRequestBodyAdvice implements RequestBodyAdvice {
private static final Logger logger = LoggerFactory.getLogger(RsaDecodeRequestBodyAdvice.class);
private static final String PRIVATE_KEY="MIICdgIBADANBgkqhkiG9w0BAQEFAASCAmAwggJcAgEAAoGBAIn2zWqU7K/2qm5pOpq5bp9R+3MTnStWTfJU9nC/Vo7UKH9dITPvrELCTK+qlqpx5Fes+l0GY7n6u4n4jyiw4ejsvkZYQ5ww477yLOn2FcoEGuZEwPgSCmfTST0OFUgQqn+/J11k9L92jEHyieE3qmhMkMt0UsVUSJwx/nZxo30ZAgMBAAECgYBD3YHigeuEC4R+14iaf8jo2j0kuGtB3Cxvnlez0otTqw1YyYkBsU49cLKkXvfKVEgM0Ow/QltgKvSBxCE31PrrDka5TygVMqqA/IM7NrDvjUcGLjyoeNmLA8660fWcDxUTlAGN5kxIvUATayVwKVflpWPWu0FPKsWrZustnEo+4QJBAMCmYsWqAKWYMVRXFP3/XGRfio8DV793TOckyBSN9eh8UhgoZyT3u7oeHmDJEwm4aNMHlg1Pcdc6tNsvi1FRCiUCQQC3VNzfF4xOtUgX7vWPL8YVljLuXmy12iVYmg6ofu9l31nwM9FLQ1TRFglvF5LWrIXTQb07PgGd5DJMAQWGsqLlAkAPE7Z9M73TN+L8b8hDzJ1leZi1cpSGdoa9PEKwYR/SrxAZtefEm+LEQSEtf+8OfrEtetWCeyo0pvKKiOEFXytFAkEAgynL/DC0yXsZYUYtmYvshHU5ayFTVagFICbYZeSrEo+BoUDxdI9vl0fU6A5NmBlGhaZ65G+waG5jLc1tTrlvoQJAXBEoPcBNAosiZHQfYBwHqU6mJ9/ZacJh3MtJzGGebfEwJgtln5b154iANqNWXpySBLvkK+Boq7FYRiD83pqmUg==";
@Override
public boolean supports(MethodParameter methodParameter, Type type, Class<? extends HttpMessageConverter<?>> aClass) {
return true;
}
@Override
public Object handleEmptyBody(Object body, HttpInputMessage httpInputMessage, MethodParameter methodParameter, Type type, Class<? extends HttpMessageConverter<?>> aClass) {
return body;
}
@Override
public HttpInputMessage beforeBodyRead(HttpInputMessage inputMessage, MethodParameter methodParameter, Type type, Class<? extends HttpMessageConverter<?>> aClass) throws IOException {
try {
boolean encode = false;
if (methodParameter.getMethod().isAnnotationPresent(RsaSecurityParameter.class)) {
//获取注解配置的包含和去除字段
RsaSecurityParameter serializedField = methodParameter.getMethodAnnotation(RsaSecurityParameter.class);
//入参是否需要解密
encode = serializedField.inDecode();
}
if (encode) {
logger.info("对方法method :【" + methodParameter.getMethod().getName() + "】返回数据进行解密");
return new MyHttpInputMessage(inputMessage);
}else{
return inputMessage;
}
} catch (Exception e) {
e.printStackTrace();
logger.error("对方法method :【" + methodParameter.getMethod().getName() + "】返回数据进行解密出现异常："+e.getMessage());
return inputMessage;
}
}
@Override
public Object afterBodyRead(Object body, HttpInputMessage httpInputMessage, MethodParameter methodParameter, Type type, Class<? extends HttpMessageConverter<?>> aClass) {
return body;
}
class MyHttpInputMessage implements HttpInputMessage {
private HttpHeaders headers;
private InputStream body;
public MyHttpInputMessage(HttpInputMessage inputMessage) throws Exception {
this.headers = inputMessage.getHeaders();
String content = easpString(IOUtils.toString(inputMessage.getBody(),"utf-8"));
this.body = IOUtils.toInputStream(RSAUtils.decryptDataOnJava(content,PRIVATE_KEY));
}
@Override
public InputStream getBody() throws IOException {
return body;
}
@Override
public HttpHeaders getHeaders() {
return headers;
}
/**
*
* @param requestData
* @return
*/
public String easpString(String requestData){
if(requestData != null && !requestData.equals("")){
String s = "{\"requestData\":";
if(!requestData.startsWith(s)){
throw new RuntimeException("参数【requestData】缺失异常！");
}else{
int closeLen = requestData.length()-1;
int openLen = "{\"requestData\":".length();
String substring = StringUtils.substring(requestData, openLen, closeLen);
return substring;
}
}
return "";
}
}
}第五步:
/**
* 跳转rsa页面
*
* @return
*/
@RequestMapping("/rsa")
public String goRsa() {
return "rsa";
}
/**
* RSA测试
*
* @return object
*/
@RequestMapping("/rsaTest")
@ResponseBody
@RsaSecurityParameter
public Persion rsaTest(@RequestBody Persion info) {
System.out.println(info.getName());
String content = "内容";
info.setName(content);
return info;
}第六步:
只需要引入这两个js文件,然后自定义一个html,这里采用了thymeleaf模板引擎.具体语法自行百度,很简单!
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>RSA 加解密</title>
<script type="text/javascript" th:src="@{~/js/jquery-2.2.3.min.js}"></script>
<script type="text/javascript" th:src="@{~/js/jsencrypt.min.js}"></script>
</head>
<body>
<script type="text/javascript">
$(function() {
$("#bt").click(
function() {
var encrypt = new JSEncrypt();
encrypt.setPublicKey($("#publickey").val());
$.ajax({
type: "POST",
url:"/rsaTest",
data:"{\"requestData\":"+encrypt.encrypt(JSON.stringify({name:"好看"}))+"}",
dataType:'json',
contentType: "application/json",
success: function(result) {
alert("解密的名称：" + uncrypted);
}
});
});
});
</script>
<h2>公钥：</h2>
<textarea id="publickey" rows="5" cols="45">MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCJ9s1qlOyv9qpuaTqauW6fUftzE50rVk3yVPZwv1aO1Ch/XSEz76xCwkyvqpaqceRXrPpdBmO5+ruJ+I8osOHo7L5GWEOcMOO+8izp9hXKBBrmRMD4Egpn00k9DhVIEKp/vyddZPS/doxB8onhN6poTJDLdFLFVEicMf52caN9GQIDAQAB
</textarea>
<input type="button" id="bt" value="提交" />
</body>
</html>后记(实际整合到项目中必须要知道的问题):
只要加密的key不泄露，别人得到你的数据也没用，问题是如何保证key不泄露呢？服务端的安全性较高，可以存储在数据库中或者配置文件中，毕竟在我们自己的服务器上，最危险的其实就时前端了，app还好，可以打包，但是要防止反编译等等问题。如果是webapp则可以依赖于js加密来实现(但是webapp相比app容易破解的多)
综上所述,其实并不能说采用了加密,就是绝对安全的,还有配合一系列的操作,做的越多,安全性越高.比如:
- 通信使用https
- 请求签名，防止参数被篡改
- 身份确认机制，每次请求都要验证是否合法
- APP中使用ssl pinning防止抓包操作
- 对所有请求和响应都进行加解密操作
- 等等方案.......