File Encryption and Decryption Algorithm
public class Encrypter { public void encrypt(String key, InputStream is, OutputStream os) throws Throwable { encryptOrDecrypt(key, Cipher.ENCRYPT_MODE, is, os); } public void decrypt(String key, InputStream is, OutputStream os) throws Throwable { encryptOrDecrypt(key, Cipher.DECRYPT_MODE, is, os); } public 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, d...