package com.sahadev; 
 
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.commons.codec.binary.Hex; 
 
public class DH { 
 
  public static String src = "Hello,sahadev!"; 
 
  public static void main(String[] args) { 
    JDKDH(); 
  } 
 
  public static void JDKDH() { 
    try { 
      // 初始化發(fā)送方密鑰 
      KeyPairGenerator senderKeyPairGenerator = KeyPairGenerator.getInstance("DH"); 
      senderKeyPairGenerator.initialize(512); 
      KeyPair senderKeyPair = senderKeyPairGenerator.generateKeyPair(); 
      byte[] senderPublicKey = senderKeyPair.getPublic().getEncoded(); 
 
      // 初始化接收方的密鑰 
      KeyFactory instance = KeyFactory.getInstance("DH"); 
      X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(senderPublicKey); 
      PublicKey sendPublicKeyTemp = instance.generatePublic(x509EncodedKeySpec); 
      DHParameterSpec dhParameterSpec = ((DHPublicKey) sendPublicKeyTemp).getParams(); 
      KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("DH"); 
      keyPairGenerator.initialize(dhParameterSpec); 
      // 接收方生成密鑰 
      KeyPair generateKeyPair = keyPairGenerator.generateKeyPair(); 
      byte[] receiverPublicKey = generateKeyPair.getPublic().getEncoded(); 
      PrivateKey receiverPrivateKey = generateKeyPair.getPrivate(); 
 
      // 接收方密鑰構建 
      KeyAgreement receiverKeyAgreement = KeyAgreement.getInstance("DH"); 
      receiverKeyAgreement.init(receiverPrivateKey); 
      receiverKeyAgreement.doPhase(senderKeyPair.getPublic(), true); 
      // 使用我的密鑰和你的公鑰生成密鑰 
      SecretKey receiverDesKey = receiverKeyAgreement.generateSecret("DES"); 
 
      // 發(fā)送方密鑰構建 
      KeyFactory keyFactory = KeyFactory.getInstance("DH"); 
      X509EncodedKeySpec x509EncodedKeySpec2 = new X509EncodedKeySpec(receiverPublicKey); 
      PublicKey receiverPublicKeyTemp = keyFactory.generatePublic(x509EncodedKeySpec2); 
 
      // 發(fā)送方拿到接收方返回的公鑰做本地密鑰 
      KeyAgreement senderKeyAgreement = KeyAgreement.getInstance("DH"); 
      senderKeyAgreement.init(senderKeyPair.getPrivate()); 
      senderKeyAgreement.doPhase(receiverPublicKeyTemp, true); 
      // 使用你的密鑰我的公鑰進行構建 
      SecretKey senderDesKey = senderKeyAgreement.generateSecret("DES"); 
 
      // 判斷雙方的本地密鑰是否相同 
      if (Objects.equals(receiverDesKey, senderDesKey)) { 
        System.out.println("雙方密鑰相同"); 
      } 
 
      // 加密 
      Cipher cipher = Cipher.getInstance("DES"); 
      cipher.init(Cipher.ENCRYPT_MODE, senderDesKey); 
      byte[] result = cipher.doFinal(src.getBytes()); 
      System.out.println("加密結果為 : " + Hex.encodeHexString(result)); 
 
      // 解密 
      cipher.init(Cipher.DECRYPT_MODE, senderDesKey); 
      result = cipher.doFinal(result); 
      System.out.println("解密結果為 : " + new String(result)); 
    } catch (Exception e) { 
      e.printStackTrace(); 
    } 
 
  } 
 
} 

雙方密鑰相同 
DES : da1cc13d388423e82a110539414b1ec0 
解密結果為 : Hello,sahadev!