# Secure Portal
>This is a super secure portal with a really unusual HTML file. Try to login.>>http://chall.csivit.com:30281
The page is asking for a password. Looking at the page source I found this obfuscated JavaScript code:
```javascriptvar _0x575c=['\x32\x2d\x34','\x73\x75\x62\x73\x74\x72\x69\x6e\x67','\x34\x2d\x37','\x67\x65\x74\x49\x74\x65\x6d','\x64\x65\x6c\x65\x74\x65\x49\x74\x65\x6d','\x31\x32\x2d\x31\x34','\x30\x2d\x32','\x73\x65\x74\x49\x74\x65\x6d','\x39\x2d\x31\x32','\x5e\x37\x4d','\x75\x70\x64\x61\x74\x65\x49\x74\x65\x6d','\x62\x62\x3d','\x37\x2d\x39','\x31\x34\x2d\x31\x36','\x6c\x6f\x63\x61\x6c\x53\x74\x6f\x72\x61\x67\x65',];(function(_0x4f0aae,_0x575cf8){var _0x51eea2=function(_0x180eeb){while(--_0x180eeb){_0x4f0aae['push'](_0x4f0aae['shift']());}};_0x51eea2(++_0x575cf8);}(_0x575c,0x78));var _0x51ee=function(_0x4f0aae,_0x575cf8){_0x4f0aae=_0x4f0aae-0x0;var _0x51eea2=_0x575c[_0x4f0aae];return _0x51eea2;};function CheckPassword(_0x47df21){var _0x4bbdc3=[_0x51ee('0xe'),_0x51ee('0x3'),_0x51ee('0x7'),_0x51ee('0x4'),_0x51ee('0xa')];window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]]('9-12','BE*');window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]](_0x51ee('0x2'),_0x51ee('0xb'));window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]](_0x51ee('0x6'),'5W');window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]]('16',_0x51ee('0x9'));window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]](_0x51ee('0x5'),'pg');window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]]('7-9','+n');window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]](_0x51ee('0xd'),'4t');window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]](_0x51ee('0x0'),'$F');if(window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_0x51ee('0x8'))===_0x47df21[_0x51ee('0x1')](0x9,0xc)){if(window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_0x51ee('0x2'))===_0x47df21['substring'](0x4,0x7)){if(window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_0x51ee('0x6'))===_0x47df21[_0x51ee('0x1')](0x0,0x2)){if(window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]]('16')===_0x47df21[_0x51ee('0x1')](0x10)){if(window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_0x51ee('0x5'))===_0x47df21[_0x51ee('0x1')](0xc,0xe)){if(window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_0x51ee('0xc'))===_0x47df21[_0x51ee('0x1')](0x7,0x9)){if(window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_0x51ee('0xd'))===_0x47df21[_0x51ee('0x1')](0xe,0x10)){if(window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_0x51ee('0x0'))===_0x47df21[_0x51ee('0x1')](0x2,0x4))return!![];}}}}}}}return![];}```
I found this [really cool JS deobfuscator online](https://lelinhtinh.github.io/de4js/) and I used that to deobfuscate most of the JavaScript.
Unfortunately, it looked like it needed some work. It looked [like this](deobfuscated.js).
I found out that `_0x575c` was just a look up table of strings, so I evaluated it and got the unescaped strings. I found out that it wasn't part of the output from the JS deobfuscator I found, so I had to copy and paste that back in myself. I also renamed some variables and functions that had random hex as its name, to make the code more readable.
```javascriptvar _lookupTable=[ // look up table of strings  '2-4',          'substring',  '4-7',          'getItem',  'deleteItem',   '12-14',  '0-2',          'setItem',  '9-12',         '^7M',  'updateItem',   'bb=',  '7-9',          '14-16',  'localStorage'];```
I also found another function whose only purpose was to convert the first argument from a string to a number and look up that index in the loop up table above.
```javascriptvar _lookUpStringAtPos = function (_op1, _op2) { // argument 1 is hexadecimal!    _op1 = _op1 - 0x0; // convert string to number    var _temp1 = _lookupTable[_op1]; // look up index of lookup table    return _temp1; // return that string from the lookup table};```
You can see below that this function is used often.
```javascriptfunction CheckPassword(password) {    var _0x4bbdc3 = [_lookUpStringAtPos('0xe'), _lookUpStringAtPos('0x3'), _lookUpStringAtPos('0x7'), _lookUpStringAtPos('0x4'), _lookUpStringAtPos('0xa')]; // all functions    window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]]('9-12', 'BE*');    window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]](_lookUpStringAtPos('0x2'), _lookUpStringAtPos('0xb'));    window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]](_lookUpStringAtPos('0x6'), '5W');    window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]]('16', _lookUpStringAtPos('0x9'));    window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]](_lookUpStringAtPos('0x5'), 'pg');    window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]]('7-9', '+n');    window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]](_lookUpStringAtPos('0xd'), '4t');    window[_0x4bbdc3[0x0]][_0x4bbdc3[0x2]](_lookUpStringAtPos('0x0'), '$F');    if (window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_lookUpStringAtPos('0x8')) === password[_lookUpStringAtPos('0x1')](0x9, 0xc)) {        if (window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_lookUpStringAtPos('0x2')) === password.substring(0x4, 0x7)) {            if (window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_lookUpStringAtPos('0x6')) === password[_lookUpStringAtPos('0x1')](0x0, 0x2)) {                if (window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]]('16') === password[_lookUpStringAtPos('0x1')](0x10)) {                    if (window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_lookUpStringAtPos('0x5')) === password[_lookUpStringAtPos('0x1')](0xc, 0xe)) {                        if (window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_lookUpStringAtPos('0xc')) === password[_lookUpStringAtPos('0x1')](0x7, 0x9)) {                            if (window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_lookUpStringAtPos('0xd')) === password[_lookUpStringAtPos('0x1')](0xe, 0x10)) {                                if (window[_0x4bbdc3[0x0]][_0x4bbdc3[0x1]](_lookUpStringAtPos('0x0')) === password[_lookUpStringAtPos('0x1')](0x2, 0x4)) return !![];                            }                        }                    }                }            }        }    }    return ![];}```
So what I did is evaluate each function call to the lookup function and did a find and replace in my text editor with the result.
```javascript> _lookUpStringAtPos('0xe')'localStorage'> _lookUpStringAtPos('0x3')'getItem'> _lookUpStringAtPos('0x7')'setItem'> _lookUpStringAtPos('0x4')'deleteItem'> _lookUpStringAtPos('0xa')'updateItem'> _lookUpStringAtPos('0xb')'bb='> _lookUpStringAtPos('0x2')'4-7'> _lookUpStringAtPos('0x6')'0-2'> _lookUpStringAtPos('0x9')'^7M'> _lookUpStringAtPos('0x5')'12-14'> _lookUpStringAtPos('0xd')'14-16'> _lookUpStringAtPos('0x0')'2-4'> _lookUpStringAtPos('0x8')'9-12'> _lookUpStringAtPos('0x1')'substring'> _lookUpStringAtPos('0xc')'7-9'>```
You can see I did this for `_0x4bbdc3` as well, which I renamed to `_functions`
```javascript> _functions[0x0]'localStorage'> _functions[0x2]'setItem'> _functions[0x1]'getItem'>```
After all that, you can see that we now have some actually readable code!
```javascriptvar _lookupTable=[ // look up table of strings  '2-4',          'substring',  '4-7',          'getItem',  'deleteItem',   '12-14',  '0-2',          'setItem',  '9-12',         '^7M',  'updateItem',   'bb=',  '7-9',          '14-16',  'localStorage'];
(function (_op1, _op2) { // useless function    var _temp1 = function (_op3) {        while (--_op3) {            _op1.push(_op1.shift());        }    };    _temp1(++_op2);}(_lookupTable, 0x78));var _lookUpStringAtPos = function (_op1, _op2) { // argument 1 is hexadecimal!    _op1 = _op1 - 0x0; // convert string to number    var _temp1 = _lookupTable[_op1]; // look up index of lookup table    return _temp1; // return that string from the lookup table};
function CheckPassword(password) {    var _functions = ['localStorage', 'getItem', 'setItem', 'deleteItem', 'updateItem']; // all functions    window['localStorage']['setItem']('9-12', 'BE*');    window['localStorage']['setItem']('4-7', 'bb=');    window['localStorage']['setItem']('0-2', '5W');    window['localStorage']['setItem']('16', '^7M');    window['localStorage']['setItem']('12-14', 'pg');    window['localStorage']['setItem']('7-9', '+n');    window['localStorage']['setItem']('14-16', '4t');    window['localStorage']['setItem']('2-4', '$F');    if (window['localStorage']['getItem']('9-12') === password['substring'](0x9, 0xc)) {        if (window['localStorage']['getItem']('4-7') === password.substring(0x4, 0x7)) {            if (window['localStorage']['getItem']('0-2') === password['substring'](0x0, 0x2)) {                if (window['localStorage']['getItem']('16') === password['substring'](0x10)) {                    if (window['localStorage']['getItem']('12-14') === password['substring'](0xc, 0xe)) {                        if (window['localStorage']['getItem']('7-9') === password['substring'](0x7, 0x9)) {                            if (window['localStorage']['getItem']('14-16') === password['substring'](0xe, 0x10)) {                                if (window['localStorage']['getItem']('2-4') === password['substring'](0x2, 0x4)) return !![];                            }                        }                    }                }            }        }    }    return ![];}```
You can tell by looking at the code that parts of the password are stored in local storage. I know that it's the password because it's being compared to a variable named `password`
What I did is copy and paste the code that stores the password in `localStorage` into firefox developer tools, and then manually copied the password.
![](screenshot.png)
When you submit `5W$Fbb=+nBE*pg4t^7M` as the password, you get the flag!
Flag: `csictf{l3t_m3_c0nfus3_y0u}`