java - 如何对java密码程序进行多线程暴力破解

Question

我为 11 年级计算机科学项目创建了一个程序，其中我制作了一个 Java 密码破解程序，可以暴力破解密码。但是，我想获得一些关于如何对我的 java 程序进行多线程处理(下面提供的代码)以加速暴力过程的建议。如果它有帮助的话，我正在运行 Intel 的 i7-3770 处理器，它是四核的，但每个核心有 2 个线程，因此一次有 8 个可能的线程。

这是代码:

import java.util.*;
import java.io.*;
class pwcracker
{
public static void main (String[] args)
{
Scanner scan = new Scanner( System.in );
Random rand = new Random();

Runtime.getRuntime().availableProcessors();

 String pw, choices, guess;
long tries;
int j, length;

System.out.println("Enter a password that is up to 5 chars and contains no numbers: ");
pw = "" + scan.nextLine();
length = pw.length();

choices = "abcdefghijklmnopqrstuvwxyz";
tries = 0;
guess = "";

System.out.println("Your pw is: " + pw);
System.out.println("The length of your pw is: " + length);

System.out.println("for TEST- Guess: " + guess + "pw :"+pw);


 if (guess !=  pw){

 while  (guess !=  pw) 
 { 
    j = 0;
    guess = "";

    while ( j < length )
    {
        guess = guess + choices.charAt( rand.nextInt ( choices.length() ) );
        j = j + 1;

    if (guess == pw)
 {
   System.out.println("Match found, ending loop..");
   break;
 }

    }
            System.out.println("2 Guess: " + guess + " pw :"+pw); 

    tries = tries + 1;                      
}
}
System.out.println("Here is your password: " + guess);
System.out.println("It took " + tries + " tries to guess it.");
 }
 }

Answer 1

这不是并行处理解决方案，而是一种更加优化的强力方法。您可以考虑将 Iterator 更改为 Spliterator。如果时间允许，我可能会在下一篇文章中提供 Spliterator 方法。

package pwcracker;

import java.util.Iterator;
import java.util.Scanner;

public class pwcracker {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        String pw;
        int length;

        System.out.println("Enter a password that is up to 5 chars and contains no numbers: ");
        pw = "" + scan.nextLine();
        length = pw.length();

        SequentialPatternGenerator generator = new SequentialPatternGenerator(length);

        generator.forEachRemaining(test -> {if(pw.equals(test)) {
            System.out.println("Your password: " + test );
        }});

    }
}

class SequentialPatternGenerator implements Iterator<String> {

    private static final char[] CHOICES = new char[]{'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 static final int MAX_INDEX = CHOICES.length - 1;
    private boolean keepProducing = true;
    private final int[] indexes;

    public SequentialPatternGenerator(final int length) {
        indexes = new int[length];
        initIndexes();
    }

    private void initIndexes() {
        for (int i = 0; i < indexes.length; i++) {
            indexes[i] = 0;
        }
    }

    @Override
    public boolean hasNext() {
        if (!keepProducing) {
            return false;
        }

        for (int i = 0; i < indexes.length; i++) {
            if (indexes[i] < MAX_INDEX) {
                return true;
            }
        }

        return false;
    }

    @Override
    public String next() {
        if (!keepProducing || !hasNext()) {
            return null;
        }

        String next = produceString();
        adjustIndexes();

        return next;
    }

    public void stop() {
        keepProducing = false;
    }

    private String produceString() {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < indexes.length; i++) {
            sb.append(CHOICES[indexes[i]]);
        }

        return sb.toString();
    }

    private void adjustIndexes() {
        int i;
        for(i = 0 ; i < indexes.length ; i++) {
            if(indexes[i] < MAX_INDEX) {
                indexes[i] = indexes[i] + 1;
                break;
            }
        }

        for(int j=0; j < i; j++) {
            indexes[j] = 0;
        }
    }
}