DictionaryThread.java

package no.ntnu.item.threads;

import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import no.ntnu.item.bruteforce.BruteForce;
import de.rtner.security.auth.spi.PBKDF2Engine;
import de.rtner.security.auth.spi.PBKDF2Parameters;

public class DictionaryThread implements Runnable {

	private Thread thread;
	private String t_word;
	private SecretKey t_key;
	private byte[] t_plain;
	private byte[] t_salt;
	private byte[] t_cipher;

	public DictionaryThread() {

	}

	public DictionaryThread(String id) {
		synchronized (this) {
			t_salt = BruteForce.salt;
			t_cipher = BruteForce.cipher;
		}
		t_key = null;
		thread = new Thread(this, id);
		thread.start();

	}

	@Override
	public void run() {
		try {
			while (true) {
				synchronized (BruteForce.buf) {
					t_word = BruteForce.buf.readLine();
				}

				if (t_word == null)
					break;

				if (check(t_word)) {
					BruteForce.time = (System.currentTimeMillis() - BruteForce.start) / 1000.0;
					BruteForce.printSuccess(t_word);
					BruteForce.found = true;
					BruteForce.buf.close();
					BruteForce.fr.close();
					break;
				}
			}
			if (!BruteForce.found && Thread.activeCount() == 2) {
				BruteForce.printFail();
			}
		} catch (IOException e) {
		}

	}

	public boolean check(String word) {
		this.setKey(word);
		this.t_plain = symECBDecrypt(t_cipher, t_key);

		// 68 = char D and indicate correct decryption of first byte
		if (this.t_plain != null && this.t_plain[0] == 68) {
			String[] parts = new String(t_plain).split(":");
			String[] parts2 = new String(t_plain).split("|");
			if (parts.length == 4 && parts2.length == 5) {
				return true;
			}
		}
		return false;
	}

	public void setKey(String password) {
		PBKDF2Parameters param = new PBKDF2Parameters("HmacSHA256", "UTF-8",
				t_salt, 4096);
		PBKDF2Engine engine = new PBKDF2Engine(param);
		param.setDerivedKey(engine.deriveKey(password, 16));
		t_key = new SecretKeySpec(param.getDerivedKey(), "AES");
	}

	public byte[] symECBDecrypt(byte[] cipherText, SecretKey key) {
		try {
			Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding", "BC");
			cipher.init(Cipher.DECRYPT_MODE, key);
			BruteForce.words_read++;
			return cipher.doFinal(cipherText);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			if (e.getMessage().equals("Illegal key size or default parameter")) {
				e.printStackTrace();
				System.out
						.println("\nERROR: Have you installed the Java(TM) Cryptography Extension (JCE) Jurisdiction Policy Files?");
				System.exit(0);
			}
		} catch (IllegalBlockSizeException e) {
			e.printStackTrace();
		} catch (BadPaddingException e) {
		} catch (NoSuchProviderException e) {
			e.printStackTrace();
		}
		return null;
	}

}