1.發送方構建公鑰私鑰。

2.發送方發布發送方公鑰。

3.接收方接收發送方公鑰構建接收方公鑰私鑰。

4.接收方發布接收方公鑰。

5.發送方通過發送方的私鑰和接收方的公鑰構建對稱加密秘鑰用于加密。

6.接收方通過接收方的私鑰和發送方的公鑰構建對稱加密秘鑰用于解密。

7.發送方通過秘鑰加密數據并發送。

8.接收方接收數據并通過秘鑰解密數據。

我稍微整理了下

public?static?void?jdkDHFlow()?throws?Exception?{
????//1.發送方構建公鑰私鑰
????KeyPair?senderKeyPair?=?jdkSenderPublicKey();
????//2.發送方發布公鑰
????byte[]?senderPublicKeyEncode?=?senderKeyPair.getPublic().getEncoded();
????//3.接收方構建公鑰私鑰->接收方通過發送方公鑰構建公鑰私鑰
????KeyPair?receiverKeyPair?=?jdkreceiverPublicKey(senderPublicKeyEncode);
????//4.接收方發布公鑰
????byte[]?receiverPublicKeyEncode?=?receiverKeyPair.getPublic().getEncoded();
????//5.發送方構建對稱加密的秘鑰->依據接收方公鑰和自己的公鑰私鑰構建
????SecretKey?senderDesKey?=?jdkGetSecretKey(senderKeyPair,receiverPublicKeyEncode);
????//6.接收方構建對稱加密秘鑰->依據發送方公鑰和接收方公鑰撕咬構建
????SecretKey?receiverDesKey?=?jdkGetSecretKey(receiverKeyPair,senderPublicKeyEncode);
????//對比雙方對稱加密秘鑰是否安相同?查看是否測試成功
????if(Objects.equals(receiverDesKey,senderDesKey)){
????????System.out.println("雙方秘鑰相同");
????}
????//7.發送方加密
????Cipher?cipher?=?Cipher.getInstance("DES");
????cipher.init(Cipher.ENCRYPT_MODE,senderDesKey);
????byte[]?result?=?cipher.doFinal(BASE_STRING.getBytes());
????System.out.println("JDK?DH?加密:"+?Base64.encodeBase64String(result));
????//8.接收方解密
????cipher.init(Cipher.DECRYPT_MODE,receiverDesKey);
????result?=?cipher.doFinal(result);
????System.out.println("JDK?DH?解密:"+new?String(result));
}

/**
??*?發送方構建發送方公鑰
??*?@return?構建完成的公鑰
??*/
?public?static?KeyPair?jdkSenderPublicKey()?throws?NoSuchAlgorithmException?{
?????//1.初始化發送方秘鑰
?????KeyPairGenerator?senderKeyPairGenerator?=?KeyPairGenerator.getInstance("DH");
?????senderKeyPairGenerator.initialize(512);
?????//生成秘鑰
?????KeyPair?senderKeyPair?=?senderKeyPairGenerator.generateKeyPair();
?????return??senderKeyPair;
?}

?/**
??*?依據發送方公鑰生成接收方公鑰
??*?@param?senderPublicKey?發送方公鑰
??*?@return?接收方公鑰
??*/
?public?static?KeyPair?jdkreceiverPublicKey(byte[]?senderPublicKey)?throws?Exception?{
?????KeyFactory?receiverKeyFactory?=?KeyFactory.getInstance("DH");
?????X509EncodedKeySpec?x509EncodedKeySpec?=?new?X509EncodedKeySpec(senderPublicKey);
?????PublicKey?receiverPublicKey?=?receiverKeyFactory.generatePublic(x509EncodedKeySpec);
?????//使用和發送方一樣的參數初始化
?????DHParameterSpec?dhParameterSpec?=?((DHPublicKey)?receiverPublicKey).getParams();
?????KeyPairGenerator?receiverKeyPairGenerator?=?KeyPairGenerator.getInstance("DH");
?????//發送方公鑰解析出來的dhParameterSpec
?????receiverKeyPairGenerator.initialize(dhParameterSpec);
?????KeyPair?receiverKeyPair?=?receiverKeyPairGenerator.generateKeyPair();
?????return?receiverKeyPair;
?}

?/**
??*?自己的公鑰私鑰與對方的公鑰構建?對稱秘鑰
??*?@param?keyPair?自己秘鑰對
??*?@param?publicKey?對方公鑰
??*?@return?本地對稱加密秘鑰
??*/
?public?static?SecretKey?jdkGetSecretKey(KeyPair?keyPair,byte[]?publicKey)?throws?Exception?{
?????KeyFactory?keyFactory?=?KeyFactory.getInstance("DH");
?????X509EncodedKeySpec?x509EncodedKeySpec?=?new?X509EncodedKeySpec(publicKey);
?????PublicKey?senderPublicKey?=?keyFactory.generatePublic(x509EncodedKeySpec);
?????KeyAgreement?keyAgreement?=?KeyAgreement.getInstance("DH");
?????keyAgreement.init(keyPair.getPrivate());
?????keyAgreement.doPhase(senderPublicKey,true);
?????SecretKey?secretKey?=?keyAgreement.generateSecret("DES");
?????return??secretKey;
?}