DES对称加密算法的简单实现

网上看到的都是用了第三方包的，我这里写了个纯java无依赖的

环境

1. JDK11
2. Windows7
3. VS Code

代码

源代码都发布在Gitee上了

import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.AlgorithmParameterSpec;
import java.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.IvParameterSpec;

/**
 * DES算法实现
 */
public class DES {
 
    /**
     * iv向量
     */
    private static final byte[] DESIV = { (byte) 0xCE, (byte) 0x35, (byte) 0x5,
        (byte) 0xD, (byte) 0x98, (byte) 0x91, (byte) 0x8, (byte) 0xA };
 
    /**
     * AlgorithmParameterSpec
     */
    private static AlgorithmParameterSpec IV = null;
 
    /**
     * 加密模式
     */
    private static final int ENCRYPT_MODE = 1;
 
    /**
     * 解密模式
     */
    private static final int DECRYPT_MODE = 2;
 
    /**
     * **
     */
    private Key key;
 
    public DES(String str) {
        getKey(str);
    }
 
    public Key getKey() {
        return key;
    }
 
    public void setKey(Key key) {
        this.key = key;
    }
 
    /**
     * 通过**获得key
     * @param secretKey **
     */
    public void getKey(String secretKey) {
        try {
            SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
            secureRandom.setSeed(secretKey.getBytes());
            KeyGenerator generator = null;
            try {
                generator = KeyGenerator.getInstance("DES");
            } catch (NoSuchAlgorithmException e) {
            }
            generator.init(secureRandom);
            IV = new IvParameterSpec(DESIV);
            this.key = generator.generateKey();
            generator = null;
 
        } catch (Exception e) {
            throw new RuntimeException("Error in getKey(String secretKey), Cause: " + e);
        }
    }
 
    /**
     * 字符串des加密
     * @param data 需要加密的字符串
     * @return 加密结果
     * @throws Exception 异常
     */
    public byte[] encrypt(byte[] data) throws Exception {
        Cipher cipher = getPattern(ENCRYPT_MODE);
        return cipher.doFinal(data);
    }
 
    /**
     * 字符串des解密
     * @param data 需要解密的字符串
     * @return 解密结果
     * @throws Exception 异常
     */
    public byte[] decrypt(byte[] data) throws Exception {
        Cipher cipher = getPattern(DECRYPT_MODE);
        return cipher.doFinal(data);
    }
 
    /**
     * 初始化cipher
     * @param cipherMode cipher工作模式 1：加密； 2：解密
     * @return cipher
     * @throws Exception 异常
     */
    private Cipher getPattern(int cipherMode) throws Exception {
        Cipher cipher;
        cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        cipher.init(cipherMode, key, IV);
        return cipher;
    }
 
    public static void main(String[] args) throws Exception {
        String testString = "I am YiMi";
        DES des = new DES("blockchain");   // 秘钥
        String stringMi = Base64.getEncoder().encodeToString(des.encrypt(testString.getBytes()));
        System.out.println("密文：" + stringMi);
        byte[] stringMing = des.decrypt(Base64.getDecoder().decode(stringMi));
        System.out.println("明文：" + new String(stringMing));
    }
 
}