DH实现加密算法

1.新建一个java项目，里面新建一个java类，将jar包加入，整体的框架如图所示：

2.DH.java里面的代码如下所示：

import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.X509EncodedKeySpec;
import java.util.Objects;

import javax.crypto.Cipher;
import javax.crypto.KeyAgreement;
import javax.crypto.SecretKey;
import javax.crypto.interfaces.DHPublicKey;
import javax.crypto.spec.DHParameterSpec;

import org.apache.tomcat.util.codec.binary.Base64;

public class DH {

	private static String src = "mu rong fei fei 636";

	public static void main(String[] args) {
		jdkDH();
	}

	public static void jdkDH() {

		try {
			// 1.初始化发送方密钥
			KeyPairGenerator senderKeyPairGenerator = KeyPairGenerator.getInstance("DH");
			// JDK8在下面的参数里面只能写1024，如果写512就会报错
			senderKeyPairGenerator.initialize(1024);
			KeyPair senderKeyPair = senderKeyPairGenerator.generateKeyPair();
			byte[] senderPublicKeyEnc = senderKeyPair.getPublic().getEncoded();

			// 2.初始化接收方的密钥
			KeyFactory receiverKeyFactory = KeyFactory.getInstance("DH");
			X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(senderPublicKeyEnc);
			PublicKey receiverPublicKey = receiverKeyFactory.generatePublic(x509EncodedKeySpec);
			DHParameterSpec dhParameterSpec = ((DHPublicKey) receiverPublicKey).getParams();
			KeyPairGenerator receiverPairGenerator = KeyPairGenerator.getInstance("DH");
			receiverPairGenerator.initialize(dhParameterSpec);
			KeyPair receiverKeyPair = receiverPairGenerator.generateKeyPair();
			PrivateKey receiverPrivateKey = receiverKeyPair.getPrivate();
			byte[] receiverPublicKeyEnc = receiverKeyPair.getPublic().getEncoded();

			// 3.密钥构建
			KeyAgreement receiverKeyAgreement = KeyAgreement.getInstance("DH");
			receiverKeyAgreement.init(receiverPrivateKey);
			receiverKeyAgreement.doPhase(receiverPublicKey, true);
			SecretKey receiverDesKey = receiverKeyAgreement.generateSecret("DES");

			KeyFactory senderKeyFactory = KeyFactory.getInstance("DH");
			x509EncodedKeySpec = new X509EncodedKeySpec(receiverPublicKeyEnc);
			PublicKey senderPublicKey = senderKeyFactory.generatePublic(x509EncodedKeySpec);
			KeyAgreement senderKeyAgreement = KeyAgreement.getInstance("DH");
			senderKeyAgreement.init(senderKeyPair.getPrivate());
			senderKeyAgreement.doPhase(senderPublicKey, true);
			SecretKey senderDesKey = senderKeyAgreement.generateSecret("DES");
			if (Objects.equals(receiverDesKey, senderDesKey)) {
				System.out.println("双方密钥相同");
			}

			// 4.加密
			Cipher cipher = Cipher.getInstance("DES");
			cipher.init(Cipher.ENCRYPT_MODE, senderDesKey);
			byte[] result = cipher.doFinal(src.getBytes());
			// 加入jar包之后要fix一下
			System.out.println("jdk dh eccrypt:" + Base64.encodeBase64String(result));

			// 5.解密
			cipher.init(Cipher.DECRYPT_MODE, receiverDesKey);
			result = cipher.doFinal(result);
			System.out.println("jdk dh decrypt:" + new String(result));
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}

3.运行代码得到如下结果：