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package exercise1;
import java.io.UnsupportedEncodingException;
import java.security.NoSuchAlgorithmException;
/**
*
* @author mdw937
*/
public class BruteForceAlgorithm {
private char[] numbers = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};
private char[] lower = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k',
'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z'};
private char[] upper = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K',
'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
'W', 'X', 'Y', 'Z'};
private char[] all = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k',
'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z',
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K',
'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
'W', 'X', 'Y', 'Z'};
private String input;
private int maxlen = 3;
public BruteForceAlgorithm(String a) {
input = a;
}
static void threadMessage(String message) {
String threadName = Thread.currentThread().getName();
System.out.format("%s: %s%n", threadName, message);
}
// A class to compute all the possible combinations of a given symbol set.
// We can make many threads of these within the brute force object.
// We interupt the active threads when the password is found.
class recursive implements Runnable {
// The symbol set we're working with
char[] syms;
Thread thisThread;
public recursive(char[] symbols) {
thisThread = Thread.currentThread();
syms = symbols;
}
// Declared as private for compiler inline performance
private void bruteNext(String old) {
if (Thread.interrupted()){
//We've been interrupted: no more crunching.
return;
} else {
if (check(old)) {
// Password found!
System.out.println("Found!");
return;
} else {
// Search for next combination
for (int i = 0; i < syms.length; i++) {
if (old.length() <= maxlen) {
bruteNext(old.concat(new Character(syms[i]).toString()));
//System.out.println(old);
}
}
}
}
}
public void run() {
for (int i = 0; i < syms.length; i++) {
// Call this method recursivley
bruteNext(new Character(syms[i]).toString());
}
threadMessage(" No Match (by brute force)");
}
}
// Declared as private for compiler inline performance
private boolean check(String temp) {
try {
String guess = ConvertToSHA1.SHA1(temp);
// Check if password is correct!
if (input.matches(guess)) {
threadMessage(" Match (by brute force) " + temp);
//Thread.currentThread().interrupt();
Thread.currentThread().stop();
// Password Found!
return true;
}
else {
// No Password found!
return false;
}
// Catach exceptions
} catch (NoSuchAlgorithmException ex) {
System.out.println("NoSuchAlgorithmException thrown whilst trying to convert password to SHA1");
return false;
} catch (UnsupportedEncodingException ex) {
System.out.println("UnsupportedEncodingException thrown whilst trying to convert password to SHA1");
return false;
}
}
public void run() {
// Thread 0
Thread a = new Thread(new recursive(all));
a.start();
// Thread 1
Thread b = new Thread(new recursive(lower));
b.start();
// Thread 2
Thread c = new Thread(new recursive(upper));
c.start();
// Thread 3
Thread d = new Thread(new recursive(numbers));
d.start();
}
}
Refactorings
No refactoring yet !
Sly
December 15, 2009, December 15, 2009 20:23, permalink
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add a synchronized method like bool is_psw_found(). This will return a global bool shared by all instances of that class. Then, at the start of your recurse thing, call that method and, if true, return.
MaryTenderLOS
December 17, 2011, December 17, 2011 00:06, permalink
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Can you improve the speed of my brute forcer?
Its not quite finished yet, the threads part at the end will ideally stop all threads crunching the password when one thread finds a match.