RSA 非对称加密 RSAUtils

RSA 非对称加密，应用过程

非对称算法的在应用的过程如下:

• 接收方生成公钥和私钥，公钥公开，私钥保留；

• 发送方将要发送的消息采用公钥加密，得到密文，然后将密文发送给接收方；

• 接收方收到密文后，用自己的私钥进行解密，获得明文。

RSAUtils工具类：

package com.demo.utils;

import java.util.Map;

@Slf4j
public class RSAUtils {

    public static final String PUBLIC_KEY = "public_key";

    public static final String PRIVATE_KEY = "private_key";


    public static Map<String, String> generateRasKey() {
        Map<String, String> rs = new HashMap<>();
        try {
            // KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
            KeyPairGenerator keyPairGen = null;
            keyPairGen = KeyPairGenerator.getInstance("RSA");
            keyPairGen.initialize(1024, new SecureRandom());
            // 生成一个密钥对，保存在keyPair中
            KeyPair keyPair = keyPairGen.generateKeyPair();
            // 得到私钥 公钥
            RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
            RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
            String publicKeyString = new String(Base64.encodeBase64(publicKey.getEncoded()));
            // 得到私钥字符串
            String privateKeyString = new String(Base64.encodeBase64((privateKey.getEncoded())));
            // 将公钥和私钥保存到Map
            rs.put(PUBLIC_KEY, publicKeyString);
            rs.put(PRIVATE_KEY, privateKeyString);
        } catch (Exception e) {
            log.error("RsaUtils invoke genKeyPair failed.", e);
            throw new RsaException("RsaUtils invoke genKeyPair failed.");
        }
        return rs;
    }


    public static String encrypt(String str, String publicKey) {
        try {
            //base64编码的公钥
            byte[] decoded = Base64.decodeBase64(publicKey);
            RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded));
            //RSA加密
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, pubKey);
            return Base64.encodeBase64String(cipher.doFinal(str.getBytes(StandardCharsets.UTF_8)));
        } catch (Exception e) {
            log.error("RsaUtils invoke encrypt failed.", e);
            throw new RsaException("RsaUtils invoke encrypt failed.");
        }
    }


    public static String decrypt(String str, String privateKey) {

        try {
            //64位解码加密后的字符串
            byte[] inputByte = Base64.decodeBase64(str.getBytes(StandardCharsets.UTF_8));
            //base64编码的私钥
            byte[] decoded = Base64.decodeBase64(privateKey);
            RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded));
            //RSA解密
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.DECRYPT_MODE, priKey);
            return new String(cipher.doFinal(inputByte));
        } catch (Exception e) {
            log.error("RsaUtils invoke decrypt failed.", e);
            throw new RsaException("RsaUtils invoke decrypt failed.");
        }

    }

}

RsaException: 是自定义异常

@Getter
public class RsaException extends RuntimeException {

    private final String message;

    public RsaException(String message) {
        this.message = message;
    }

}

使用：

public class RsaTest {

    /**
     *  用测试生成的公钥，私钥赋值
     */
    private static final String PUBLIC_KEY = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCFtTlL61IqIGd+fRLUhJ0MjsqFXFJswCohJ45m51WvbxDPRP3gllW0WChk74D5JEOpMDSWo4C7RfoGlBRNW7kQ6qYGukYZ5jgYpzoT0+gp3on96fQXEyQJysv9xiTPIdmSXXVVj1HAOJw29RbzxIVKUSzzPXvEtXRTtCC1+wkAJQIDAQAB";

    private static final String PRIVATE_KEY = "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";


    /**
     *  生成公钥私钥
     */
    @Test
    public void generateRsaKey() {
        Map<String, String> map = RSAUtils.generateRasKey();
        System.out.println("随机生成的公钥为:" + map.get(RSAUtils.PUBLIC_KEY));
        System.out.println("随机生成的私钥为:" + map.get(RSAUtils.PRIVATE_KEY));

    }

    /**
     * 加密: Yeidauky/iN1/whevov2+ntzXJKAp2AHfESu5ixnDqH5iB7ww+TcfqJpDfkPHfb12Y0sVXw0gBHNJ4inkh7l2/SJBze3pKQU/mg3oyDokTia3JZIs+e80/iJcSfN+yA1JaqY+eJPYiBiOGAF2S6x0ynvJg/Wj0fwp2Tq3PDzRMo=
     */
    @Test
    public void testEncrypt() {
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("username", "rosh");
        jsonObject.put("password", "123456");
        String str = jsonObject.toJSONString();
        String encrypt = RSAUtils.encrypt(str, PUBLIC_KEY);
        System.out.println(encrypt);
    }

    @Test
    public void testDecrypt() {

        String decrypt = RSAUtils.decrypt("Yeidauky/iN1/whevov2+ntzXJKAp2AHfESu5ixnDqH5iB7ww+TcfqJpDfkPHfb12Y0sVXw0gBHNJ4inkh7l2/SJBze3pKQU/mg3oyDokTia3JZIs+e80/iJcSfN+yA1JaqY+eJPYiBiOGAF2S6x0ynvJg/Wj0fwp2Tq3PDzRMo=",
                PRIVATE_KEY);

        System.out.println(decrypt);
    }


}