Java笔记-DH密钥交换获取密钥及AES加解密

Posted 2021-09-23 IT1995

DH密钥交换是这样的：

程序运行截图如下：

D:\\java8\\content\\bin\\java.exe -javaagent:D:\\idea\\content\\lib\\idea_rt.jar=61009:D:\\idea\\content\\bin -Dfile.encoding=UTF-8 -classpath D:\\java8\\content\\jre\\lib\\charsets.jar;D:\\java8\\content\\jre\\lib\\deploy.jar;D:\\java8\\content\\jre\\lib\\ext\\access-bridge-64.jar;D:\\java8\\content\\jre\\lib\\ext\\cldrdata.jar;D:\\java8\\content\\jre\\lib\\ext\\dnsns.jar;D:\\java8\\content\\jre\\lib\\ext\\jaccess.jar;D:\\java8\\content\\jre\\lib\\ext\\jfxrt.jar;D:\\java8\\content\\jre\\lib\\ext\\localedata.jar;D:\\java8\\content\\jre\\lib\\ext\\nashorn.jar;D:\\java8\\content\\jre\\lib\\ext\\sunec.jar;D:\\java8\\content\\jre\\lib\\ext\\sunjce_provider.jar;D:\\java8\\content\\jre\\lib\\ext\\sunmscapi.jar;D:\\java8\\content\\jre\\lib\\ext\\sunpkcs11.jar;D:\\java8\\content\\jre\\lib\\ext\\zipfs.jar;D:\\java8\\content\\jre\\lib\\javaws.jar;D:\\java8\\content\\jre\\lib\\jce.jar;D:\\java8\\content\\jre\\lib\\jfr.jar;D:\\java8\\content\\jre\\lib\\jfxswt.jar;D:\\java8\\content\\jre\\lib\\jsse.jar;D:\\java8\\content\\jre\\lib\\management-agent.jar;D:\\java8\\content\\jre\\lib\\plugin.jar;D:\\java8\\content\\jre\\lib\\resources.jar;D:\\java8\\content\\jre\\lib\\rt.jar;D:\\IDEAProject\\DHDemo\\target\\classes;D:\\newGenRepository\\repository\\commons-codec\\commons-codec\\1.11\\commons-codec-1.11.jar cn.it1995.Test
服务端公钥:MIHgMIGXBgkqhkiG9w0BAwEwgYkCQQD8poLOjhLKuibvzPcRDlJtsHiwXt7LzR60ogjzrhYXrgHzW5Gkfm32NBPF4S7QiZvNEyrNUNmRUb3EPuc3WS4XAkBnhHGyepz0TukaScUUfbGpqvJE8FpDTWSGkx0tFCcbnjUDC3H9c9oXkGmzLik1Yw4cIGI1TQ2iCmxBblC+eUykAgIBgANEAAJBAKvnBpIb+eOiVyKDGkTsSc+8lOlgMdu6hEumGfdl6+yOyu3+Rlw9PwbiJ1Fd7qDD/vpI5+nktCA3C5FstsCF/ZM=
服务端私钥:MIHSAgEAMIGXBgkqhkiG9w0BAwEwgYkCQQD8poLOjhLKuibvzPcRDlJtsHiwXt7LzR60ogjzrhYXrgHzW5Gkfm32NBPF4S7QiZvNEyrNUNmRUb3EPuc3WS4XAkBnhHGyepz0TukaScUUfbGpqvJE8FpDTWSGkx0tFCcbnjUDC3H9c9oXkGmzLik1Yw4cIGI1TQ2iCmxBblC+eUykAgIBgAQzAjEA1JWmuoylaemaZlWJTPz887uUitPZdphkrhv79XsIlHBLjmFB6dFQLJ/6TLaQGNLz
客户端公钥:MIHgMIGXBgkqhkiG9w0BAwEwgYkCQQD8poLOjhLKuibvzPcRDlJtsHiwXt7LzR60ogjzrhYXrgHzW5Gkfm32NBPF4S7QiZvNEyrNUNmRUb3EPuc3WS4XAkBnhHGyepz0TukaScUUfbGpqvJE8FpDTWSGkx0tFCcbnjUDC3H9c9oXkGmzLik1Yw4cIGI1TQ2iCmxBblC+eUykAgIBgANEAAJBAOhfxWPk/NI4wAWhaM14wJVgdUObef9J2kAzRy5yyi5QfrSabMpQh64oE72KzKMjMhgvPfqYSw5NYFu8V8EMW20=
客户端私钥:MIHSAgEAMIGXBgkqhkiG9w0BAwEwgYkCQQD8poLOjhLKuibvzPcRDlJtsHiwXt7LzR60ogjzrhYXrgHzW5Gkfm32NBPF4S7QiZvNEyrNUNmRUb3EPuc3WS4XAkBnhHGyepz0TukaScUUfbGpqvJE8FpDTWSGkx0tFCcbnjUDC3H9c9oXkGmzLik1Yw4cIGI1TQ2iCmxBblC+eUykAgIBgAQzAjEAtjb/+dXXhPMI3xubgp3LipUgNYjMtWok30cn3KxGgkspHEqI35h+TLRmT2CZDopA
客户端计算出的AES密钥:g/tQbIkTCH3I1gXCVNObyyHKsBkWXTsNJIiPG3gVJII=
服务端计算出的AES密钥:g/tQbIkTCH3I1gXCVNObyyHKsBkWXTsNJIiPG3gVJII=
原文:Hello world, 中文
密文:���-�5�5�u�ɫ5>#�Ij>�/hC�
解密:Hello world, 中文

Process finished with exit code 0

程序结构如下：

代码如下：

DataSecret.java

package cn.it1995;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

public class DataSecret {

    private static final String SELECT_ALGORITHM = "AES";   //DES、DESede或者AES

    public static byte[] encrypt(byte[] data, byte[] key) throws Exception {

        //生成本地密钥
        SecretKey secretKey = new SecretKeySpec(key, SELECT_ALGORITHM);

        //加密
        Cipher cipher = Cipher.getInstance(secretKey.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        return cipher.doFinal(data);
    }

    public static byte[] decrypt(byte[] data, byte[] key) throws Exception {

        SecretKey secretKey = new SecretKeySpec(key, SELECT_ALGORITHM);
        Cipher cipher = Cipher.getInstance(secretKey.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        return cipher.doFinal(data);
    }
}

DH.java

package cn.it1995;

import javax.crypto.KeyAgreement;
import javax.crypto.SecretKey;
import javax.crypto.interfaces.DHPrivateKey;
import javax.crypto.interfaces.DHPublicKey;
import java.security.*;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;

public abstract class DH {

    private static final String KEY_ALGORITHM = "DH";
    private static final int KEY_SIZE = 512;
    private static final String PUBLIC_KEY = "DHPublicKey";
    private static final String PRIVATE_KEY = "DHPrivateKey";
    private static final String SELECT_ALGORITHM = "AES";   //DES、DESede或者AES

    /***
     * 初始化服务端密钥
     * @return
     * @throws Exception
     */
    public static Map<String, Object> initKey() throws Exception {

        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KEY_ALGORITHM);
        keyPairGenerator.initialize(KEY_SIZE);
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        DHPublicKey publicKey = (DHPublicKey)keyPair.getPublic();
        DHPrivateKey privateKey = (DHPrivateKey)keyPair.getPrivate();

        Map<String, Object> keyMap = new HashMap<>();
        keyMap.put(PUBLIC_KEY, publicKey);
        keyMap.put(PRIVATE_KEY, privateKey);

        return keyMap;
    }

    public static byte[] getSecretKey(byte[] publicKey, byte[] privateKey) throws Exception {

        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(publicKey);
        PublicKey pubKey = keyFactory.generatePublic(x509KeySpec);

        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(privateKey);
        PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);

        KeyAgreement keyAgree = KeyAgreement.getInstance(keyFactory.getAlgorithm());

        keyAgree.init(priKey);
        keyAgree.doPhase(pubKey, true);
        SecretKey secretKey = keyAgree.generateSecret(SELECT_ALGORITHM);
        return secretKey.getEncoded();
    }

    public static byte[] getPublicKey(Map<String, Object> keyMap){

        Key key = (Key) keyMap.get(PUBLIC_KEY);
        return key.getEncoded();
    }

    public static byte[] getPrivateKey(Map<String, Object> keyMap){

        Key key = (Key) keyMap.get(PRIVATE_KEY);
        return key.getEncoded();
    }

}

 Test.java

package cn.it1995;

import org.apache.commons.codec.binary.Base64;

import java.util.Map;

public class Test {

    private static byte[] publicKey1;
    private static byte[] privateKey1;
    private static byte[] key1;

    private static byte[] publicKey2;
    private static byte[] privateKey2;
    private static byte[] key2;

    public static void main(String[] args) throws Exception {

        System.getProperties().setProperty("jdk.crypto.KeyAgreement.legacyKDF", "true");

        //服务端密钥
        Map<String, Object> keyMap1 = DH.initKey();
        publicKey1 = DH.getPublicKey(keyMap1);
        privateKey1 = DH.getPrivateKey(keyMap1);
        System.out.println("服务端公钥:" + Base64.encodeBase64String(publicKey1));
        System.out.println("服务端私钥:" + Base64.encodeBase64String(privateKey1));

        //客户端密钥
        Map<String, Object> keyMap2 = DH.initKey();
        publicKey2 = DH.getPublicKey(keyMap2);
        privateKey2 = DH.getPrivateKey(keyMap2);
        System.out.println("客户端公钥:" + Base64.encodeBase64String(publicKey2));
        System.out.println("客户端私钥:" + Base64.encodeBase64String(privateKey2));

        //服务端公钥和客户端私钥生成密钥
        key1 = DH.getSecretKey(publicKey1, privateKey2);
        System.out.println("客户端计算出的AES密钥:" + Base64.encodeBase64String(key1));

        //客户端公钥和服务端私钥生成密钥
        key2 = DH.getSecretKey(publicKey2, privateKey1);
        System.out.println("服务端计算出的AES密钥:" + Base64.encodeBase64String(key2));

        //开始进行加密
        String string = "Hello world, 中文";
        byte[] encrypt = DataSecret.encrypt(string.getBytes(), key1);
        byte[] decrypt = DataSecret.decrypt(encrypt, key2);

        System.out.println("原文:" + string);
        System.out.println("密文:" + new String(encrypt));
        System.out.println("解密:" + new String(decrypt));
    }
}