Des 加解密工具類

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import java.nio.charset.Charset;
import java.security.SecureRandom;

/**
 * Des 加解密工具類
 *
 * @author muraty
 * @since 2019-05-29
 */
public class DesUtil {
    private static final String DES = "DES";
    private static final Charset CHARSET = Charset.forName("UTF8");

    /**
     * 加密
     *
     * @param src 明文
     * @param key 公匙
     * @return 密文
     */
    public static String encrypt(String src, String key) {
        byte[] s = src.getBytes(CHARSET);
        byte[] buf = des(s, key, Cipher.ENCRYPT_MODE);
        return parseByte2HexStr(buf);
    }

    /**
     * 解密
     *
     * @param data 密文
     * @param key  公鑰
     * @return 明文
     */
    public static String decrypt(String data, String key) {
        byte[] d = parseHexStr2Byte(data);
        byte[] buf = des(d, key, Cipher.DECRYPT_MODE);
        return new String(buf, CHARSET);
    }

    /**
     * 將二進制轉換成16進制
     */
    private static String parseByte2HexStr(byte[] buf) {
        StringBuilder sb = new StringBuilder();
        for (byte b : buf) {
            String hex = Integer.toHexString(b & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }

    /**
     * 將16進制轉換爲二進制
     */
    private static byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1) {
            return null;
        }
        byte[] result = new byte[hexStr.length() / 2];
        for (int i = 0; i < hexStr.length() / 2; i++) {
            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }

    /**
     * DES 加/解密 核心
     */
    private static byte[] des(byte[] src, String key, int mode) {
        try {
            byte[] k = key.getBytes();
            // DES算法要求有一個可信任的隨機數源
            SecureRandom random = new SecureRandom();
            // 創建一個DESKeySpec對象
            DESKeySpec desKey = new DESKeySpec(k);
            // 創建一個密匙工廠
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
            // 將DESKeySpec對象轉換成SecretKey對象
            SecretKey secureKey = keyFactory.generateSecret(desKey);
            // Cipher對象實際完成解密操作
            Cipher cipher = Cipher.getInstance(DES);
            // 用密匙初始化Cipher對象
            cipher.init(mode, secureKey, random);
            // 真正開始解密操作
            return cipher.doFinal(src);
        } catch (Throwable e) {
            e.printStackTrace();
        }
        return null;
    }

}

public class MainApp {
    private static final String KEY = "983F0495B28B46DA9F7500D4E69FFC8F";

    public static void main(String[] args) {
        // 明文
        String s = "中文,English,¢€£∞";
        // 加密
        String data = DesUtil.encrypt(s, KEY);
        // 解密
        String result = DesUtil.decrypt(data, KEY);

        System.out.println("公鑰: " + KEY);
        System.out.println("明文: " + s);
        System.out.println("密文: " + data);
        System.out.println("解密: " + result);
    }
}