SMALL
예전에 풀었다가 만 webhacking.kr 를 동아리 스터디 때문에 다시 불타올라 풀기로 시작하였다.
새로운 마음으로 한땀한땀 풀어보기로 하잣!
처음 문제를 열었을때의 모습과 view_source를 했을때의 모습이다. (길이서 2개로 짜름)
이번문제는
필터링 되는 부분 : base64 인코딩 된값 1~8 특수문자로 replace
해결해야 되는 부분 : $_COOKIE['user'] 를 조작하여 solve 에 해당하는 조건문을 충족 시키면 된다.
먼저 $_COOKIE['user']가 존재하지 않을 시
($val_id = 'guest', $val_pw = '123qwe' ) 이 두개의 변수에 각각 값을 넣어 base64로 인코딩을 한다.
인코딩한값중 1~8 숫자를 replace 해준다. 그 결과로 Setcookie를 통해 쿠키값을 넣어준다. 만료시간은 현재시간+86400 (하루, 60*60*24)
문제를 보니 간단하다 그대로 admin, nimda에 대한 인코딩과 replace된 값을 구해서 cookie에 넣어주면 된다.
<!DOCTYPE html>
<html>
<body>
<?php
$val_id="admin";
$val_pw="nimda";
for($i=0;$i<20;$i++){
$val_id=base64_encode($val_id);
$val_pw=base64_encode($val_pw);
}
$val_id=str_replace("1","!",$val_id);
$val_id=str_replace("2","@",$val_id);
$val_id=str_replace("3","$",$val_id);
$val_id=str_replace("4","^",$val_id);
$val_id=str_replace("5","&",$val_id);
$val_id=str_replace("6","*",$val_id);
$val_id=str_replace("7","(",$val_id);
$val_id=str_replace("8",")",$val_id);
$val_pw=str_replace("1","!",$val_pw);
$val_pw=str_replace("2","@",$val_pw);
$val_pw=str_replace("3","$",$val_pw);
$val_pw=str_replace("4","^",$val_pw);
$val_pw=str_replace("5","&",$val_pw);
$val_pw=str_replace("6","*",$val_pw);
$val_pw=str_replace("7","(",$val_pw);
$val_pw=str_replace("8",")",$val_pw);
echo("user : ".$val_id);
echo "<br>";
echo("pw : ".$val_pw);
echo "<br>";
$decode_id = $val_id;
$decode_pw = $val_pw;
$decode_id=str_replace("!","1",$decode_id);
$decode_id=str_replace("@","2",$decode_id);
$decode_id=str_replace("$","3",$decode_id);
$decode_id=str_replace("^","4",$decode_id);
$decode_id=str_replace("&","5",$decode_id);
$decode_id=str_replace("*","6",$decode_id);
$decode_id=str_replace("(","7",$decode_id);
$decode_id=str_replace(")","8",$decode_id);
$decode_pw=str_replace("!","1",$decode_pw);
$decode_pw=str_replace("@","2",$decode_pw);
$decode_pw=str_replace("$","3",$decode_pw);
$decode_pw=str_replace("^","4",$decode_pw);
$decode_pw=str_replace("&","5",$decode_pw);
$decode_pw=str_replace("*","6",$decode_pw);
$decode_pw=str_replace("(","7",$decode_pw);
$decode_pw=str_replace(")","8",$decode_pw);
for($i=0;$i<20;$i++){
$decode_id=base64_decode($decode_id);
$decode_pw=base64_decode($decode_pw);
}
echo("user : ".$decode_id);
echo "<br>";
echo("pw : ".$decode_pw);
echo "<br>";
?>
</body>
</html>테스트를 해보니 다음과 같이 잘 나온다.
user : Vm0wd@QyUXlVWGxWV0d^V!YwZDRWMVl$WkRSV0!WbDNXa!JTVjAxV@JETlhhMUpUVmpBeFYySkVUbGhoTVVwVVZtcEJlRll&U@tWVWJHaG9UVlZ$VlZadGNFSmxSbGw!VTJ0V!ZXSkhhRzlVVmxaM!ZsWmFjVkZ0UmxSTmJFcEpWbTEwYTFkSFNrZGpSVGxhVmpOU!IxcFZXbUZrUjA!R!UyMTRVMkpIZHpGV!ZFb$dWakZhV0ZOcmFHaFNlbXhXVm!wT!QwMHhjRlpYYlVaclVqQTFSMWRyV@&kV0!ERkZVbFJHVjFaRmIzZFdha!poVjBaT@NtRkhhRk&sYlhoWFZtMXdUMVF$TUhoalJscFlZbGhTV0ZSV@FFTlNiRnBZWlVaT!ZXSlZXVEpWYkZKRFZqQXhkVlZ!V@xaaGExcFlXa!ZhVDJOc@NFZGhSMnhUVFcxb@IxWXhaREJaVmxsM!RVaG9hbEpzY0ZsWmJGWmhZMnhXY!ZGVVJsTk&WMUo!VmpKNFQxWlhTbFpYVkVwV!lrWktTRlpxUm!GU@JVbDZXa!prYUdFeGNHOVdha0poVkRKT@RGSnJhR@hTYXpWeldXeG9iMWRHV@&STldHUlZUVlpHTTFSVmFHOWhiRXB*WTBac!dtSkdXbWhaTVZwaFpFZFNTRkpyTlZOaVJtOTNWMnhXWVZReFdsaFRiRnBZVmtWd!YxbHJXa$RUUmxweFVtMUdVMkpWYkRaWGExcHJZVWRGZUdOSE9WZGhhMHBvVmtSS!QyUkdTbkpoUjJoVFlYcFdlbGRYZUc&aU!XUkhWMjVTVGxOSGFGQlZiVEUwVmpGU!ZtRkhPVmhTTUhCNVZHeGFjMWR0U@tkWGJXaGFUVzVvV0ZreFdrZFdWa$B*VkdzMVYySkdhM@hXYTFwaFZURlZlRmR!U@s!WFJYQnhWVzB^YjFZeFVsaE9WazVPVFZad@VGVXlkREJXTVZweVkwWndXR0V^Y0ROV@FrWkxWakpPU!dKR!pGZFNWWEJ@Vm!0U!MxUXlUWGxVYTFwb!VqTkNWRmxZY0ZkWFZscFlZMFU!YVUxcmJEUldNalZUVkd^a!NGVnNXbFZXYkhCWVZHdGFWbVZIUmtoUFYyaHBVbGhDTmxkVVFtRmpNV!IwVTJ0a!dHSlhhR0ZVVnpWdlYwWnJlRmRyWkZkV@EzQjZWa@R*TVZZd0!WWmlla!pYWWxoQ!RGUnJXbEpsUm!SellVWlNhVkp!UW&oV!YzaHJWVEZzVjFWc!dsaGlWVnBQVkZaYWQyVkdWWGxrUkVKWFRWWndlVmt$V@&kWFIwVjRZMFJPV@!FeVVrZGFWM@hIWTIxS!IxcEhiRmhTVlhCS!ZtMTBVMU!^VlhoWFdHaFlZbXhhVjFsc!pHOVdSbXhaWTBaa@JHSkhVbGxhVldNMVlWVXhXRlZyYUZkTmFsWlVWa@Q0YTFOR!ZuTlhiRlpYWWtoQ!NWWkdVa@RWTVZwMFVtdG9VRll&YUhCVmJHaERUbXhrVlZGdFJtcE&WMUl$VlRKMGExZEhTbGhoUjBaVlZucFdkbFl$V@&OT@JFcHpXa@R$YVZORlNrbFdNblJyWXpGVmVWTnVTbFJpVlZwWVZGYzFiMWRHWkZkWGJFcHNVbTFTZWxsVldsTmhWa$AxVVd^d!YySllVbGhhUkVaYVpVZEtTVk&zYUdoTk!VcFZWbGN^TkdReVZrZFdiR!JvVW&wc@IxUldXbmRsYkZsNVkwVmtWMDFFUmpGWlZXaExWMnhhV0ZWclpHRldNMmhJV!RJeFMxSXhjRWhpUm!oVFZsaENTMVp0TVRCVk!VMTRWbGhvV0ZkSGFGbFpiWGhoVm!^c@NscEhPV$BTYkhCNFZrY$dOVll^V@&OalJXaFlWa!UxZGxsV!ZYaFhSbFp&WVVaa!RtRnNXbFZXYTJRMFdWWktjMVJ!VG!oU@JGcFlXV$hhUm!ReFduRlJiVVphVm0xU!NWWlhkRzloTVVwMFlVWlNWVlpXY0dGVVZscGhZekZ$UlZWdGNFNVdNVWwzVmxSS0!HRXhaRWhUYkdob!VqQmFWbFp0ZUhkTk!WcHlWMjFHYWxacmNEQmFSV!F$VmpKS@NsTnJhRmRTTTJob!ZrUktSMVl^VG&WVmJFSlhVbFJXV!ZaR!l*RmlNV!JIWWtaV!VsZEhhRlJVVm!SVFpXeHNWbGRzVG!oU!ZFWjZWVEkxYjFZeFdYcFZiR@hZVm!^d!lWcFZXbXRrVmtwelZtMXNWMUl*YURWV0!XUXdXVmRSZVZaclpGZGliRXB&Vld0V!MySXhiRmxqUldSc!ZteEtlbFp0TURWWFIwcEhZMFpvV@sxSGFFeFdNbmhoVjBaV@NscEhSbGROTW!oSlYxUkplRk!^U!hoalJXUmhVbXMxV0ZZd!ZrdE&iRnAwWTBWa!dsWXdWalJXYkdodlYwWmtTR0ZHV@xwaVdHaG9WbTE0YzJOc!pISmtSM0JUWWtad0&GWlhNVEJOUmxsNFYyNU9hbEpYYUZoV@FrNVRWRVpzVlZGWWFGTldhM0I@VmtkNFlWVXlTa!pYV0hCWFZsWndSMVF^V@tOVmJFSlZUVVF$UFE9PQ==
pw : Vm0wd@QyUXlVWGxWV0d^V!YwZDRWMVl$WkRSV0!WbDNXa!JTVjAxV@JETlhhMUpUVmpBeFYySkVUbGhoTVVwVVZtcEJlRll&U@tWVWJHaG9UVlZ$VlZacVFtRlRNbEpJVm!0a!dHSkdjRTlaVjNSR!pVWmFkR0&GU@!^U@JHdzFWVEowVjFaWFNraGhSemxWVmpOT00xcFZXbUZrUjA!R!drWndWMDFFUlRGV!ZFb$dWakZhV0ZOcmFHaFNlbXhXVm0xNFlVMHhXbk&YYlVaclVqQTFSMWRyV@xOVWJVcEdZMFZ$VjJKVVJYZFdha!pYWkVaT@MxZHNhR@xTTW!oWlYxZDRiMkl&Vm&OVmJGWlRZbFZhY@xWcVFURlNNVlY!VFZSU!ZrMXJjRWxhU0hCSFZqRmFSbUl*WkZkaGExcG9WakJhVDJOdFJraGhSazVzWWxob!dGWnRNSGhPUm!^V!RVaG9XR0pyTlZsWmJGWmhZMVphZEdSSFJrNVNiRm9$V@xWYVQxWlhTbFpqUldSYVRVWmFNMVpxU@t0V!ZrcFpXa!p$VjFKV@NIbFdWRUpoVkRKT@MyTkZhR$BTYXpWWVZXcE9iMkl^V@&STldHUlZUVlpXTkZVeGFHOWhiRXB*WTBac!dtSkdXbWhaTW&oWFkxWkdWVkpzVGs!WFJVcElWbXBLTkZReFdsaFRhMlJxVW0xNGFGVXdhRU&UUmxweFVtMUdVMkpWYkRaWGExcHJZVWRGZUdOSE9WZGhhMHBvVmtSS!QyUkdTbkpoUjJoVFlYcFdlbGRYZUc&aU!XUkhWMjVTVGxOSGFGQlZiVEUwVmpGU!ZtRkhPVmhTTUhCNVZHeGFjMWR0U@tkWGJXaGFUVzVvV0ZreFdrZFdWa$B*VkdzMVYySkdhM@hXYTFwaFZURlZlRmR!U@s!WFJYQnhWVzB^YjFZeFVsaE9WazVPVFZad@VGVXlkREJXTVZweVkwWndXR0V^Y0ROV@FrWkxWakpPU!dKR!pGZFNWWEJ@Vm!0U!MxUXlUWGxVYTFwb!VqTkNWRmxZY0ZkWFZscFlZMFU!YVUxcmJEUldNV@h@V!ZaS!IxTnNaRlZXYkZwNlZHeGFZVmRGTlZaUFZtaFRUVWhDU@xac!pEUmpNV!IwVTJ0b@FGSnNTbGhVVlZwM!ZrWmFjVk&yWkZOaVJrcDZWa@N^YzFVeVNuSlRiVVpYVFc!b!dGbHFTa!psUm!SWldrVTFWMVpzY0ZWWFZsSkhaREZaZUdKSVNsaGhNMUpVVlcxNGQyVkdWbGRoUnpsb!RWWndlbFl&Y0VkV0!ERjFZVWhLV@xaWFVrZGFWM@hIWTIxS!IyRkdhRlJTVlhCS!ZtMTBVMU!^VlhoWFdHaFlZbXhhVjFsc!pHOVdSbXhaWTBaa@JHSkhVbGxhVldNMVlWVXhXRlZyYUZkTmFsWlVWa@Q0YTFOR!ZuTlhiRlpYWWtoQ!NWWkdVa@RWTVZwMFVtdG9VRll&YUhCVmJHaERUbXhrVlZGdFJtcE&WMUl$VlRKMGExZEhTbGhoUjBaVlZucFdkbFl$V@&KbFJtUnlXa!prVjJFelFqWldhMlI@VFZaWmQwMVdXbWxsYTFwWVdXeG9RMVJHVW&KWGJFcHNVbTFTZWxsVldsTmhWa$AxVVd^d!YySllVbGhhUkVaYVpVZEtTVk&zYUdoTk!VcFdWbGN^TkdReVZrZFdXR$hyVWpCYWNGVnRlSGRsYkZsNVpVaGtXRkl$VmpSWk!GSlBWMjFGZVZWclpHRldNMmhJV!RJeFMxSXhjRWhpUm!oVFZsaENTMVp0TVRCVk!VMTRWbGhvV0ZkSGFGbFpiWGhoVm!^c@NscEhPV$BTYkhCNFZrY$dOVll^V@&OalJXaFlWa!UxZGxsV!ZYaFhSbFp&WVVaa!RtRnNXbFZXYTJRMFdWWktjMVJ!VG!oU@JGcFlXV$hhUm!ReFduRlJiVVphVm0xU!NWWlhkRzloTVVwMFlVWlNWVlpXY0dGVVZscGhZekZ$UlZWdGNFNVdNVWwzVmxSS0!HRXhaRWhUYkdob!VqQmFWbFp0ZUhkTk!WcHlWMjFHYWxacmNEQmFSV!F$VmpKS@NsTnJhRmRTTTJob!ZrUktSMVl^VG&WVmJFSlhVbFJXV!ZaR!l*RmlNV!JIWWtaV!VsZEhhRlJVVm!SVFpXeHNWbGRzVG!oU!ZFWjZWVEkxYjFZeFdYcFZiR@hZVm!^d!lWcFZXbXRrVmtwelZtMXNWMUl*YURWV0!XUXdXVmRSZVZaclpGZGliRXB&Vld0V!MySXhiRmxqUldSc!ZteEtlbFp0TURWWFIwcEhZMFpvV@sxSGFFeFdNbmhoVjBaV@NscEhSbGROTW!oSlYxUkplRk!^U!hoalJXUmhVbXMxV0ZZd!ZrdE&iRnAwWTBWa!dsWXdWalJXYkdodlYwWmtTR0ZHV@xwaVdHaG9WbTE0YzJOc!pISmtSM0JUWWtad0&GWlhNVEJOUmxsNFYyNU9hbEpYYUZoV@FrNVRWRVpzVlZGWWFGTldhM0I@VmtkNFlWVXlTa!pYV0hCWFZsWndSMVF^V@tOVmJFSlZUVVF$UFE9PQ==
user : admin
pw : nimda
클리어! 이미 풀어서 풀었다고 뜬다. 비교적 수월했던 문제, 오래돼서 기억이 안나서 처음 푼 느낌이 나는건 ..?
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