Question

我今天被给了一个小脚本，我被要求查看。因为我对Javascript看起来很新，我不确定它的功能，我正在寻找一些帮助解密它并弄清楚它实际上做了什么。请参阅下面的代码

<script>
        function hsh(dat) {
            /* basic hash */
            resultA = 3141592654;
            resultB = 1234567890;
            for (i=0; i<2; i++) {
                initA = resultA;
                initB = resultB;
                for (j=0; j<dat.length; j++) {
                    resultA += dat.toLowerCase().charCodeAt(j);
                    resultB = (resultA * 31) ^ resultB;
                    tmp = resultA & resultA;
                    resultA = resultB & resultB;
                    resultB = tmp;
                }
                resultA = resultA ^ initA;
                resultB = resultB ^ initB;
            }
            return [resultA, resultB];
        }
        $("#answercheckform").submit(function(e) {
            answer = $("#answer_a").val() + '\0' + $("#answer_b").val() + '\0' + $("#answer_c").val();
            res = hsh(answer);
            if ((res[0] == 1824745082) && (res[1] == 560037081)) {
                $("#answercheckresult").html("All your answers are correct!<br/><br/>Please go to page <b>next.html</b> at IP address <b>"+$("#answer_a").val()+"."+$("#answer_b").val()+"."+$("#answer_c").val()+"</b> for Part 5.");
            } else {
                $("#answercheckresult").html("One or more of your answers is incorrect. Please try again.");
            }
            e.preventDefault();
        });
    </script>

我给出的HTML如下

<div id="ctl00_PlaceHolderMain_ctl01_label" style="display:none">Page Content</div>
                                <div id="ctl00_PlaceHolderMain_ctl01__ControlWrapper_RichHtmlField" class="ms-rtestate-field" style="display:inline" aria-labelledby="ctl00_PlaceHolderMain_ctl01_label">
                                    <p class="gx-rteElement-H4">&nbsp;</p>
<h4 class="gx-rteElement-H4">Congratulations on solving&#160;Part 3 of the Director&#39;s puzzle.</h4> <p>&#160;</p> <p>Part 4 consists of three questions, the answers to which can be combined to make an IP address. </p> <p>&#160;</p> <p>Find the missing number in the following sequences:&#160;</p> <p>&#160;</p> <ol type="A"><li>2, 4, 8, 1, 3, 6, 18, 26, <strong>?</strong>, 12, 24, 49, 89, 134, 378, 656, 117, 224, 548, 1456, 2912, 4934, 8868, 1771, 3543, ...<br/>&#160;<br/></li> <li>-101250000, -1728000, -4900, 360, 675, 200, <strong>?</strong>, ...<br/>&#160;<br/></li> <li>321, 444, 675, 680, 370, 268, 949, 206, 851, <strong>?</strong>, ...</li></ol> <p>&#160;&#160;</p> <p>Part 5 can be accessed via IP address <strong>A</strong>.<strong>B</strong>.<strong>C</strong>.&#160;Please check your answers below first.&#160;</p> <p>&#160;</p>

    <h4>Submit your answers</h4>
    <p>To obtain instructions to the next part of the puzzle, please enter your answers here:</p>
    <form class="form-horizontal" id="answercheckform">
        <div class="form-group">
          <label for="answer_a" class="control-label col-sm-3">Answer A</label>
          <div class="col-sm-5">
            <input type="text" class="form-control" id="answer_a" placeholder="A" value="">
          </div>
        </div>
        <div class="form-group">
          <label for="answer_b" class="control-label col-sm-3">Answer B</label>
          <div class="col-sm-5">
            <input type="text" class="form-control" id="answer_b" placeholder="B" value="">
          </div>
        </div>
        <div class="form-group">
          <label for="answer_c" class="control-label col-sm-3">Answer C</label>
          <div class="col-sm-5">
            <input type="text" class="form-control" id="answer_c" placeholder="C" value="">
          </div>
        </div>
        <div class="form-group">
          <div class="col-sm-offset-3 col-sm-5">
            <button type="submit" class="btn btn-primary">Check answer</button>
          </div>
        </div>
    </form>
    <div id="answercheckresult">&nbsp;</div>
    <br/>

Answer 1

这不是一个小问题＆＃34;你得到了它，它是GCHQ挑战引发的第三个问题的代码片段。

http://s3-eu-west-1.amazonaws.com/puzzleinabucket/bb1f263f70e45b3d.html

Answer 2

以下是此脚本试图解决的问题：如何在页面中放置正确的答案而不是简单地将它们放在纯文本中。显然他们不想使用服务器来检查它们，这是有效的。

所以，他们采取正确的答案和单向哈希。这些是您在if条件下底部看到的数字。

然后他们嵌入哈希算法并通过它运行用户提供的答案。如果哈希匹配，则答案匹配。这样做的好处是用户不可能从哈希中反转正确的答案。他们还将两个答案一起散列，这样用户就无法确定哪个答案是错误的，这可能是好的还是坏的，具体取决于用例。

至于散列中涉及的实际数学，你想要解释一下吗？

未知的javascript哈希码

2 个答案: