DesUtils工具类

Posted 2020-11-18 syp172654682

public final class DesUtils {
    private static final String DES = "DES";
    private static final String KEY = "4YztMHI7PsT4rLZN";

    private DesUtils() {}

    private static byte[] encrypt(byte[] src, byte[] key) throws Exception {
        SecureRandom sr = new SecureRandom();
        DESKeySpec dks = new DESKeySpec(key);
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey secretKey = keyFactory.generateSecret(dks);
        Cipher cipher = Cipher.getInstance(DES);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey, sr);
        return cipher.doFinal(src);
    }

    private static byte[] decrypt(byte[] src, byte[] key) throws Exception {
        SecureRandom sr = new SecureRandom();
        DESKeySpec dks = new DESKeySpec(key);
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey secretKey = keyFactory.generateSecret(dks);
        Cipher cipher = Cipher.getInstance(DES);
        cipher.init(Cipher.DECRYPT_MODE, secretKey, sr);
        return cipher.doFinal(src);
    }

    private static String byte2hex(byte[] b) {
        String hs = "";
        String temp = "";
        for (int n = 0; n < b.length; n++) {
            temp = (java.lang.Integer.toHexString(b[n] & 0XFF));
            if (temp.length() == 1)
                hs = hs + "0" + temp;
            else
                hs = hs + temp;
        }
        return hs.toUpperCase();

    }

    private static byte[] hex2byte(byte[] b) {
        if ((b.length % 2) != 0)
            throw new IllegalArgumentException("length not even");
        byte[] b2 = new byte[b.length / 2];
        for (int n = 0; n < b.length; n += 2) {
            String item = new String(b, n, 2);
            b2[n / 2] = (byte) Integer.parseInt(item, 16);
        }
        return b2;
    }

    private static String decode(String src, String key) {
        String decryptStr = "";
        try {
            byte[] decrypt = decrypt(hex2byte(src.getBytes()), key.getBytes());
            decryptStr = new String(decrypt);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return decryptStr;
    }

    private static String encode(String src, String key){
        byte[] bytes = null;
        String encryptStr = "";
        try {
            bytes = encrypt(src.getBytes(), key.getBytes());
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        if (bytes != null)
            encryptStr = byte2hex(bytes);
        return encryptStr;
    }

    /**
     * 解密
     */
    public static String decode(String src) {
        return decode(src, KEY);
    }

    /**
     * 加密
     */
    public static String encode(String src) {
        return encode(src, KEY);
    }
}

测试

public static void main(String[] args) {
    String ss = "[email protected]#$";
    String encodeSS = encode(ss);
    System.out.println(encodeSS);
    String decodeSS = decode(encodeSS);
    System.out.println(decodeSS);
}
result:
    6EA84873A948B299936006D75B7CA819
    [email protected]#$