simple js

simple js

题目描述：小宁发现了一个网页，但却一直输不对密码。(Flag格式为 Cyberpeace{xxxxxxxxx} )

打开题目后，有一个Enter password框，要求输入密码，随便输入“123”

输入“123”结果为

开发者工具F12查看页面源代码

将JS代码复制出来进行分析

   function dechiffre(pass_enc){
        var pass = "70,65,85,88,32,80,65,83,83,87,79,82,68,32,72,65,72,65"; 
        var tab  = pass_enc.split(',');
                var tab2 = pass.split(',');var i,j,k,l=0,m,n,o,p = "";i = 0;j = tab.length;
                        k = j + (l) + (n=0);
                        n = tab2.length;
                        for(i = (o=0); i < (k = j = n); i++ ){o = tab[i-l];p += String.fromCharCode((o = tab2[i]));
                                if(i == 5)break;}
                        for(i = (o=0); i < (k = j = n); i++ ){
                        o = tab[i-l];
                                if(i > 5 && i < k-1)
                                        p += String.fromCharCode((o = tab2[i]));
                        }
        p += String.fromCharCode(tab2[17]);
        pass = p;return pass;
    }
    String["fromCharCode"](dechiffre("x35x35x2cx35x36x2cx35x34x2cx37x39x2cx31x31x35x2cx36x39x2cx31x31x34x2cx31x31x36x2cx31x30x37x2cx34x39x2cx35x30"));

    h = window.prompt('Enter password');
    alert( dechiffre(h) );

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看到x35x35x2cx35x36x2cx35x34x2cx37x39x2cx31x31x35x2cx36x39x2cx31x31x34x2cx31x31x36x2cx31x30x37x2cx34x39x2cx35x30"想到把x转换为%，将字符串转换为URL编码，%35%35%2c%35%36%2c%35%34%2c%37%39%2c%31%31%35%2c%36%39%2c%31%31%34%2c%31%31%36%2c%31%30%37%2c%34%39%2c%35%30
解码得：55,56,54,79,115,69,114,116,107,49,50

将这串数字进行ASCII码转换得：786OsErtk12
根据提示flag格式为Cyberpeace{xxxxxxxxx} ，提交Cyberpeace{786OsErtk12}得到正确答案。