RSA主要是生成公钥和私钥，公钥给前端加密，私钥用于解密。

1、先在angular中引入jsencrypt

 npm install --save jsencrypt

 在index.html

<script href="../node_modules/jsencrypt/bin/jsencrypt.min.js"></script>

2、访问后端接口获取一个公钥

@GetMapping("/getKey")
    public RetModel<String> getKey(HttpServletRequest request){
        // 生成一个公钥
        String publicKey = RSAUtils.generateBase64PublicKey(); 
        User user = SessionUtils.getCurrentUser();
        if (user != null) {
            user.setPublicKey(publicKey);
        }
        SessionUtils.setCurrentUser(user);
        return new RetModel<String>(publicKey);
    }
3、前端使用公钥对用户名和密码进行加密  加密后传给后端

import * as JsEncryptModule from 'jsencrypt'; //引入JSEncrypt
 
login(name: string, pass: string, publicKey: string): Observable<any> {
    let encrypt = new JsEncryptModule.JSEncrypt();
       encrypt.setPublicKey(publicKey); // 公钥
    name = encrypt.encrypt(name.trim()); // 加密
    pass = encrypt.encrypt(pass.trim()); // 加密
    let user = {
      name: name,
      pass: pass
    }
    return this.http.post(`${this.urlPrefix}/login `, user);
  }
4、后端解密，首先创建一个解密工具类。

 
import org.apache.tomcat.util.codec.binary.Base64;
import javax.crypto.Cipher;
import java.security.*;
import java.security.interfaces.RSAPublicKey;
public class RSAUtils {
    private static final KeyPair keyPair = initKey();
    private static KeyPair initKey() {
        try {
            Provider provider =new org.bouncycastle.jce.provider.BouncyCastleProvider();
            Security.addProvider(provider);
            SecureRandom random = new SecureRandom();
            KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA", provider);
            generator.initialize(1024,random);
            return generator.generateKeyPair();
        } catch(Exception e) {
            throw new RuntimeException(e);
        }
    }
    public static String generateBase64PublicKey() {
        PublicKey publicKey = (RSAPublicKey)keyPair.getPublic();
        return new String(Base64.encodeBase64(publicKey.getEncoded()));
    }
    public static String decryptBase64(String string) {
        return new String(decrypt(Base64.decodeBase64(string.getBytes())));
    }
    private static byte[] decrypt(byte[] byteArray) {
        try {
            Provider provider = new org.bouncycastle.jce.provider.BouncyCastleProvider();
            Security.addProvider(provider);
            Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding", provider);
            PrivateKey privateKey = keyPair.getPrivate();
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            byte[] plainText = cipher.doFinal(byteArray);
            return plainText;
        } catch(Exception e) {
            throw new RuntimeException(e);
        }
    }
}
5、直接调用工具类解密   user.getName()是需要解密的字符串

RSAUtils.decryptBase64(user.getName())
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原文链接：https://blog.csdn.net/weixin_41133806/article/details/102798401