import java.io.*; import java.security.*; import java.security.spec.*; import javax.crypto.*; import javax.crypto.spec.*; public class DigestEncryptor { public static void main(String[] args) { if (args.length != 2) { System.err.println("Usage: java DigestEncryptor filename password"); return; } String filename = args[0]; String password = args[1]; if (password.length() < 8 ) { System.err.println("Password must be at least eight characters long"); } try { FileInputStream fin = new FileInputStream(filename); FileOutputStream fout = new FileOutputStream(filename +".des"); FileOutputStream digest = new FileOutputStream(filename + ".des.digest"); // create the key byte[] desKeyData = password.getBytes(); DESKeySpec desKeySpec = new DESKeySpec(desKeyData); SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES"); SecretKey desKey = keyFactory.generateSecret(desKeySpec); // use Data Encryption Standard Cipher des = Cipher.getInstance("DES/ECB/PKCS5Padding"); des.init(Cipher.ENCRYPT_MODE, desKey); CipherInputStream cin = new CipherInputStream(fin, des); // use SHA digest algorithm MessageDigest sha = MessageDigest.getInstance("SHA"); DigestInputStream din = new DigestInputStream(cin, sha); byte[] input = new byte[64]; while (true) { int bytesRead = din.read(input); if (bytesRead == -1) break; fout.write(input, 0, bytesRead); } digest.write(sha.digest()); digest.close(); din.close(); fout.flush(); fout.close(); } catch (InvalidKeySpecException e) { System.err.println(e); } catch (InvalidKeyException e) { System.err.println(e); } catch (NoSuchAlgorithmException e) { System.err.println(e); e.printStackTrace(); } catch (NoSuchPaddingException e) { System.err.println(e); } catch (IOException e) { System.err.println(e); } } }