Java DES 加解密（"DES/EBC/NoPadding"）

private static final Cipher DES_CIPHER;

static {
    try {
        DES_CIPHER = Cipher.getInstance("DES/ECB/NoPadding");
    } catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
        throw Throwables.propagate(e);
    }
}

public static String encryptDES(String encryptString, String encryptKey) {
    try {
        DES_CIPHER.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(encryptKey.getBytes(IcbcConstant.ENCODING_GBK), "DES"));
        byte[] encryptedData = DES_CIPHER.doFinal(encryptString.getBytes(IcbcConstant.ENCODING_GBK));
        return new String(encryptedData, IcbcConstant.ENCODING_GBK);
    } catch (Throwable e) {
        throw Throwables.propagate(e);
    }
}

public static String decryptDES(String decryptString, String decryptKey) {
    try {
        DES_CIPHER.init(Cipher.DECRYPT_MODE, new SecretKeySpec(decryptKey.getBytes(IcbcConstant.ENCODING_GBK), "DES"));
        byte decryptedData[] = DES_CIPHER.doFinal(decryptString.getBytes(IcbcConstant.ENCODING_GBK));
        return new String(decryptedData, IcbcConstant.ENCODING_GBK);
    } catch (Throwable e) {
        throw Throwables.propagate(e);
    }
}

nopadding模式下的補位，此例為補空格。

 private static byte[] formatData(String str) {
        int yu = str.length() % 8;
        if (yu == 0) {
            return str.getBytes(Charset.forName(Constants.Charset));
        }
        int size = 8 - yu;
        byte[] arr = new byte[str.length() + size];
        byte[] data = str.getBytes(Charset.forName(Constants.Charset));
        int i = 0;
        for (; i < data.length; i++) {
            arr[i] = data[i];
        }
        for (int j = 0; j < size; j++, i++) {
            arr[i] = ' ';
        }
        return arr;
    }

    private static byte[] formatByte(byte[] arr) {
        int i = 0;
        for (; i < arr.length; i++) {
            if ((char) arr[i] == ' ') {
                break;
            }
        }
        byte[] result = new byte[i];
        System.arraycopy(arr, 0, result, 0, i);
        return result;
    }