/**
 * @title: RSATest
 * @projectName 
 * @description: TODO
 * @author 
 * @date 2022/2/9 14:08
 */

import org.apache.commons.codec.binary.Base64;
import org.junit.Test;
import org.springframework.boot.test.context.SpringBootTest;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.security.*;
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;

@SpringBootTest
public class RSATest {
	private static Map<Integer, String> keyMap = new HashMap<Integer, String>();  //用于封装随机产生的公钥与私钥

	@Test
	public void test() throws Exception {
		//生成公钥和私钥
		genKeyPair();
		//加密字符串
		String message = "test1024哈哈哈";
		System.out.println("随机生成的公钥为:" + keyMap.get(0));
		System.out.println("随机生成的私钥为:" + keyMap.get(1));
		String messageEn = encryptRSA(message, keyMap.get(0));
		System.out.println(message + "\t加密后的字符串为:" + messageEn);
		String messageDe = decryptRSA(messageEn, keyMap.get(1));
		System.out.println("还原后的字符串为:" + messageDe);
		/*
		 * 此处使用AES-128-ECB加密模式，key需要为16位。
		 */
		String cKey = "1234567890123456";
		// 需要加密的字串
		String cSrc = "www.baidu.com";
		System.out.println(cSrc);
		// 加密
		String enString = EncryptAES(cSrc, cKey);
		System.out.println("加密后的字串是：" + enString);

		// 解密
		String DeString = DecryptAES(enString, cKey);
		System.out.println("解密后的字串是：" + DeString);
	}

	/**
	 * 随机生成密钥对
	 * @throws NoSuchAlgorithmException
	 */
	public static void genKeyPair() throws NoSuchAlgorithmException {
		// KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
		KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
		// 初始化密钥对生成器，密钥大小为96-1024位
		keyPairGen.initialize(1024, new SecureRandom());
		// 生成一个密钥对，保存在keyPair中
		KeyPair keyPair = keyPairGen.generateKeyPair();
		RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();   // 得到私钥
		RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();  // 得到公钥
		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
		keyMap.put(0, publicKeyString);  //0表示公钥
		keyMap.put(1, privateKeyString);  //1表示私钥
	}

	/**
	 * RSA公钥加密
	 *
	 * @param str
	 *            加密字符串
	 * @param publicKey
	 *            公钥
	 * @return 密文
	 * @throws Exception
	 *             加密过程中的异常信息
	 */
	public static String encryptRSA(String str, String publicKey) throws Exception {
		//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);
		String outStr = Base64.encodeBase64String(cipher.doFinal(str.getBytes("UTF-8")));
		return outStr;
	}

	/**
	 * RSA私钥解密
	 *
	 * @param str
	 *            加密字符串
	 * @param privateKey
	 *            私钥
	 * @return 铭文
	 * @throws Exception
	 *             解密过程中的异常信息
	 */
	public static String decryptRSA(String str, String privateKey) throws Exception {
		//64位解码加密后的字符串
		byte[] inputByte = Base64.decodeBase64(str.getBytes("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);
		String outStr = new String(cipher.doFinal(inputByte));
		return outStr;
	}


	// 加密
	public static String EncryptAES(String sSrc, String sKey) throws Exception {
		if (sKey == null) {
			System.out.print("Key为空null");
			return null;
		}
		// 判断Key是否为16位
		if (sKey.length() != 16) {
			System.out.print("Key长度不是16位");
			return null;
		}
		byte[] raw = sKey.getBytes("utf-8");
		SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
		Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");//"算法/模式/补码方式"
		cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
		byte[] encrypted = cipher.doFinal(sSrc.getBytes("utf-8"));

		return new Base64().encodeToString(encrypted);//此处使用BASE64做转码功能，同时能起到2次加密的作用。
	}

	// 解密
	public static String DecryptAES(String sSrc, String sKey) throws Exception {
		try {
			// 判断Key是否正确
			if (sKey == null) {
				System.out.print("Key为空null");
				return null;
			}
			// 判断Key是否为16位
			if (sKey.length() != 16) {
				System.out.print("Key长度不是16位");
				return null;
			}
			byte[] raw = sKey.getBytes("utf-8");
			SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
			Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
			cipher.init(Cipher.DECRYPT_MODE, skeySpec);
			byte[] encrypted1 = new Base64().decode(sSrc);//先用base64解密
			try {
				byte[] original = cipher.doFinal(encrypted1);
				String originalString = new String(original, "utf-8");
				return originalString;
			} catch (Exception e) {
				System.out.println(e.toString());
				return null;
			}
		} catch (Exception ex) {
			System.out.println(ex.toString());
			return null;
		}
	}


}