/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package encrpyionproject;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

/**
 *
 * @author mahmudul.hasan
 */

public class EncrpyionProject {

    /**
     * @param args the command line arguments
     */

    public static void main(String[] args) {
        // TODO code application logic here
        try {
            String key = "XXXXXXXXXXX"; // needs to be at least 8 characters for DES

            /*  FileInputStream fis = new FileInputStream("D:\\MedicineD\\keys.txt");
            FileOutputStream fos = new FileOutputStream("D:\\MedicineD\\empty.jpg");
            encrypt(key, fis, fos);*/
//
            FileInputStream fis2 = new FileInputStream("D:\\XXXX\\empty.jpg");
            FileOutputStream fos2 = new FileOutputStream("D:\\XXXXX\\keys_new.txt");
            decrypt(key, fis2, fos2);
        } catch (Throwable e) {
            e.printStackTrace();
        }
    }

    public static void encrypt(String key, InputStream is, OutputStream os) throws Throwable {
        encryptOrDecrypt(key, Cipher.ENCRYPT_MODE, is, os);
    }

    public static void decrypt(String key, InputStream is, OutputStream os) throws Throwable {
        encryptOrDecrypt(key, Cipher.DECRYPT_MODE, is, os);
    }

    public static void encryptOrDecrypt(String key, int mode, InputStream is, OutputStream os) throws Throwable {

        DESKeySpec dks = new DESKeySpec(key.getBytes());
        SecretKeyFactory skf = SecretKeyFactory.getInstance("DES");
        SecretKey desKey = skf.generateSecret(dks);
        Cipher cipher = Cipher.getInstance("DES"); // DES/ECB/PKCS5Padding for SunJCE

        if (mode == Cipher.ENCRYPT_MODE) {
            cipher.init(Cipher.ENCRYPT_MODE, desKey);
            CipherInputStream cis = new CipherInputStream(is, cipher);
            doCopy(cis, os);
        } else if (mode == Cipher.DECRYPT_MODE) {
            cipher.init(Cipher.DECRYPT_MODE, desKey);
            CipherOutputStream cos = new CipherOutputStream(os, cipher);
            doCopy(is, cos);
        }
    }

    public static void doCopy(InputStream is, OutputStream os) throws IOException {
        byte[] bytes = new byte[64];
        int numBytes;
        while ((numBytes = is.read(bytes)) != -1) {
            os.write(bytes, 0, numBytes);
        }
        os.flush();
        os.close();
        is.close();
    }

}