如何避免 javascript 中的内存不足错误

Question

我正在尝试编写一个基本的暴力类型脚本来处理我制作的示例 php 页面。这是我写的脚本：

var userElement = document.getElementById('username');
var passElement = document.getElementById('password');
//sets username, not randomized
var username = 'admin';
//expected characters
var alphabet = ['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', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '!', '@', '#', '$', '%', '^', '&', '*', '(', ')'];
var numOfGuesses = 0; //for fun
var numOfGuessesGenerated = 0; //for fun
var guesses1 = [];
var guesses2 = [];
var guesses3 = [];
var guesses4 = [];
var guesses5 = [];
var guesses6 = [];
var guesses7 = [];
var guesses8 = [];
var guess = "";
var memhandle = 0;

//first for loop is to get all different lengths covered, max being sixteen
var maxNumOfChars = 16;
//generates guesses one character at a time and appends them to array name guesses
for (var y = 0; y < maxNumOfChars; y++) {
    for (var i = 0; i < alphabet.length; i++) {
    while (i < maxNumOfChars) {
            guess+=alphabet[i];
    }
    }
    if (memhandle == 0) {
        guesses1.push(guess);
        memhandle = 1
    } else if (memhandle == 1) {
        guesses2.push(guess);
        memhandle = 2;
    } else if (memhandle == 2) {
        guesses3.push(guess);
        memhandle = 3;
    } else if (memhandle == 3) {
        guesses4.push(guess);
        memhandle = 4;
    } else if (memhandle == 4) {
        guesses5.push(guess);
        memhandle = 5;
    } else if (memhandle == 5) {
        guesses6.push(guess);
        memhandle = 6;
    } else if (memhandle == 6) {
        guesses7.push(guess);
        memhandle = 7;
    } else if (memhandle == 7) {
        guesses8.push(guess);
        memhandle = 0;
    } 


    numOfGuessesesGenerated++;
    guess = "";
}

numOfGuessesesGenerated++;
console.log(numOfGuessesesGenerated);
console.log(guesses);

//try the guesses!
for (var x = 0; x < guesses.length; x++) {
    userElement.value = username;
    passElement.value = guesses[x];
    numOfGuesses++;
    console.log(numOfGuesses);
    document.getElementById("myForm").submit(); //myForm IS the name of the form
}   



document.getElementById("fid").submit();

我包含 "memhandle" 变量的原因是尝试将所有猜测拆分到不同的数组中，这也是我有这么多数组的原因。每当我尝试时，页面总是崩溃，有什么方法可以在 javascript 中做到这一点，或者我是否需要将用户名存储在某个地方然后从那里提取？我通过在 url 栏中执行 javascript: 来注入 javascript，这也可能是我出现问题的原因。感谢任何帮助

Answer 1

您遇到的主要问题是 while (i < maxNumOfChars) {。这个循环永远不会完成。你做了 guess+=alphabet[i]; 但你根本没有增加 i （在这个循环内），所以它最终以崩溃告终。

我是否可以建议查看 iterator functions 以完全避免使用数组？

var userElement = document.getElementById('username');
var passElement = document.getElementById('password');
//sets username, not randomized
var username = 'admin';
//expected characters
var alphabet = ['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', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '!', '@', '#', '$', '%', '^', '&', '*', '(', ')'];
var numOfGuesses = 0; //for fun
var numOfGuessesGenerated = 0; //for fun
var guess = "";
var memhandle = 0;

//first for loop is to get all different lengths covered, max being sixteen
var maxNumOfChars = 16;
//generates guesses one character at a time and appends them to array name guesses
function *getNextGuess() {
  for (var y = 0; y < maxNumOfChars; y++) {
      for (var i = 0; i < alphabet.length; i++) {
        //while (i < maxNumOfChars) {
              guess+=alphabet[i];
        //}
      }
      yield guess;
  }
}

//try the guesses!
for (var guess of getNextGuess()) {
  console.log(guess);
  numOfGuesses++;
  console.log(numOfGuesses);
  
  if (numOfGuesses > 10)
    break;
}   



//document.getElementById("fid").submit();

如何避免 javascript 中的内存不足错误

How to avoid full memory error in javascript

javascript

php

memory

arrays

brute-force