<?php
$flag='xxx'; 
extract($_GET);
 if(isset($shiyan))
 { 
    $content=trim(file_get_contents($flag));  //將讀取$flag內(nèi)容并去除左右空白后保存到$content
    if($shiyan==$content)
    { 
        echo'ctf{xxx}'; 
    }
   else
   { 
    echo'Oh.no';
   } 
   }
?>

<?php
$info = ""; 
$req = [];
$flag="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
ini_set("display_error", false); //為一個(gè)配置選項(xiàng)設(shè)置值
error_reporting(0); //關(guān)閉所有PHP錯(cuò)誤報(bào)告
if(!isset($_GET['number'])){
   header("hint:26966dc52e85af40f59b4fe73d8c323a.txt"); //HTTP頭顯示hint 26966dc52e85af40f59b4fe73d8c323a.txt
   die("have a fun!!"); //die — 等同于 exit()
}
foreach([$_GET, $_POST] as $global_var) {  //foreach 語法結(jié)構(gòu)提供了遍歷數(shù)組的簡單方式 
    foreach($global_var as $key => $value) { 
        $value = trim($value);  //trim — 去除字符串首尾處的空白字符（或者其他字符）
        is_string($value) && $req[$key] = addslashes($value); // is_string — 檢測變量是否是字符串，addslashes — 使用反斜線引用字符串
    } 
} 
function is_palindrome_number($number) { 
    $number = strval($number); //strval — 獲取變量的字符串值
    $i = 0; 
    $j = strlen($number) - 1; //strlen — 獲取字符串長度
    while($i < $j) { 
        if($number[$i] !== $number[$j]) { 
            return false; 
        } 
        $i++; 
        $j--; 
    } 
    return true; 
} 
if(is_numeric($_REQUEST['number'])) //is_numeric — 檢測變量是否為數(shù)字或數(shù)字字符串 
{
   $info="sorry, you cann't input a number!";
}
elseif($req['number']!=strval(intval($req['number']))) //intval — 獲取變量的整數(shù)值
{
     $info = "number must be equal to it's integer!! ";  
}
else
{
     $value1 = intval($req["number"]);
     $value2 = intval(strrev($req["number"]));  
     if($value1!=$value2){
          $info="no, this is not a palindrome number!";
     }
     else
     {
          if(is_palindrome_number($req["number"])){
              $info = "nice! {$value1} is a palindrome number!"; 
          }
          else
          {
             $info=$flag;
          }
     }
}
echo $info;

if(is_numeric($_REQUEST['number'])) //is_numeric — 檢測變量是否為數(shù)字或數(shù)字字符串 
{
   $info="sorry, you cann't input a number!";
}

elseif($req['number']!=strval(intval($req['number']))) //intval — 獲取變量的整數(shù)值
{
     $info = "number must be equal to it's integer!! ";  
} 

$value1 = intval($req["number"]);
$value2 = intval(strrev($req["number"]));  
if($value1!=$value2){
          $info="no, this is not a palindrome number!";
     }

          if(is_palindrome_number($req["number"])){
              $info = "nice! {$value1} is a palindrome number!"; 
          }
          else
          {
             $info=$flag;
          }

function is_palindrome_number($number) { 
    $number = strval($number); //strval — 獲取變量的字符串值
    $i = 0; 
    $j = strlen($number) - 1; //strlen — 獲取字符串長度
    while($i < $j) { 
        if($number[$i] !== $number[$j]) { 
            return false; 
        } 
        $i++; 
        $j--; 
    } 
    return true; 
} 

<?php
    include 'common.php';
    $requset = array_merge($_GET, $_POST, $_SESSION, $_COOKIE);
    //把一個(gè)或多個(gè)數(shù)組合并為一個(gè)數(shù)組
    class db
    {
        public $where;
        function __wakeup()
        {
            if(!empty($this->where))
            {
                $this->select($this->where);
            }
        }
        function select($where)
        {
            $sql = mysql_query('select * from user where '.$where);
            //函數(shù)執(zhí)行一條 MySQL 查詢。
            return @mysql_fetch_array($sql);
            //從結(jié)果集中取得一行作為關(guān)聯(lián)數(shù)組，或數(shù)字?jǐn)?shù)組，或二者兼有返回根據(jù)從結(jié)果集取得的行生成的數(shù)組，如果沒有更多行則返回 false
        }
    }
    if(isset($requset['token']))
    //測試變量是否已經(jīng)配置。若變量已存在則返回 true 值。其它情形返回 false 值。
    {
        $login = unserialize(gzuncompress(base64_decode($requset['token'])));
        //gzuncompress:進(jìn)行字符串壓縮
        //unserialize: 將已序列化的字符串還原回 PHP 的值
        $db = new db();
        $row = $db->select('user=\''.mysql_real_escape_string($login['user']).'\'');
        //mysql_real_escape_string() 函數(shù)轉(zhuǎn)義 SQL 語句中使用的字符串中的特殊字符。
        if($login['user'] === 'ichunqiu')
        {
            echo $flag;
        }else if($row['pass'] !== $login['pass']){
            echo 'unserialize injection!!';
        }else{
            echo "(╯‵□′)╯︵┴─┴ ";
        }
    }else{
        header('Location: index.php?error=1');
    }
?> 

    if(isset($requset['token']))
    //測試變量是否已經(jīng)配置。若變量已存在則返回 true 值。其它情形返回 false 值。
    {
        $login = unserialize(gzuncompress(base64_decode($requset['token'])));
        //gzuncompress:進(jìn)行字符串壓縮
        //unserialize: 將已序列化的字符串還原回 PHP 的值
        $db = new db();
        $row = $db->select('user=\''.mysql_real_escape_string($login['user']).'\'');
        //mysql_real_escape_string() 函數(shù)轉(zhuǎn)義 SQL 語句中使用的字符串中的特殊字符。
        if($login['user'] === 'ichunqiu')
        {
            echo $flag;
        }else if($row['pass'] !== $login['pass']){
            echo 'unserialize injection!!';
        }else{
            echo "(╯‵□′)╯︵┴─┴ ";
        }
    }else{
        header('Location: index.php?error=1');
    }

<?php
$arr = array(['user'] === 'ichunqiu');
$token = base64_encode(gzcompress(serialize($arr)));
print_r($token);
?>

<?php
error_reporting(0);
if (!isset($_POST['uname']) || !isset($_POST['pwd'])) {
    echo '<form action="" method="post">'."<br/>";
    echo '<input name="uname" type="text"/>'."<br/>";
    echo '<input name="pwd" type="text"/>'."<br/>";
    echo '<input type="submit" />'."<br/>";
    echo '</form>'."<br/>";
    echo '<!--source: source.txt-->'."<br/>";
    die;
}
function AttackFilter($StrKey,$StrValue,$ArrReq){  
    if (is_array($StrValue)){
//檢測變量是否是數(shù)組
        $StrValue=implode($StrValue);
//返回由數(shù)組元素組合成的字符串
    }
    if (preg_match("/".$ArrReq."/is",$StrValue)==1){   
//匹配成功一次后就會(huì)停止匹配
        print "水可載舟，亦可賽艇！";
        exit();
    }
}
$filter = "and|select|from|where|union|join|sleep|benchmark|,|\(|\)";
foreach($_POST as $key=>$value){ 
//遍歷數(shù)組
    AttackFilter($key,$value,$filter);
}
$con = mysql_connect("XXXXXX","XXXXXX","XXXXXX");
if (!$con){
    die('Could not connect: ' . mysql_error());
}
$db="XXXXXX";
mysql_select_db($db, $con);
//設(shè)置活動(dòng)的 MySQL 數(shù)據(jù)庫
$sql="SELECT * FROM interest WHERE uname = '{$_POST['uname']}'";
$query = mysql_query($sql); 
//執(zhí)行一條 MySQL 查詢
if (mysql_num_rows($query) == 1) { 
//返回結(jié)果集中行的數(shù)目
    $key = mysql_fetch_array($query);
//返回根據(jù)從結(jié)果集取得的行生成的數(shù)組，如果沒有更多行則返回 false
    if($key['pwd'] == $_POST['pwd']) {
        print "CTF{XXXXXX}";
    }else{
        print "亦可賽艇！";
    }
}else{
    print "一顆賽艇！";
}
mysql_close($con);
?>

    if($key['pwd'] == $_POST['pwd']) {
        print "CTF{XXXXXX}";
    }else{
        print "亦可賽艇！";
    }

<?php
$flag = "flag";
if (isset($_GET['a'])) {  
    if (strcmp($_GET['a'], $flag) == 0) //如果 str1 小于 str2 返回 < 0； 如果 str1大于 str2返回 > 0；如果兩者相等，返回 0。 
    //比較兩個(gè)字符串（區(qū)分大小寫） 
        die('Flag: '.$flag);  
    else  
        print 'No';  
}
?>

<?php
$flag = "flag";
if (isset($_GET['name']) and isset($_GET['password'])) 
{
    if ($_GET['name'] == $_GET['password'])
        echo '<p>Your password can not be your name!</p>';
    else if (sha1($_GET['name']) === sha1($_GET['password']))
      die('Flag: '.$flag);
    else
        echo '<p>Invalid password.</p>';
}
else
    echo '<p>Login first!</p>';
?>