<?php
 static $query_xss_char;
 static $found_word_xss=0;
 static $found_char=0;
 static $found_word_sqli;
function firewall_xss_alarm($sanitizeit)//This Function checks for Blacklisted words and logs
//the ip if possible attack is found
{
    $sanitizeit=  strtolower($sanitizeit);
    $blacklist_word_xss= array("src","javascript","alert","onload","onmouseover","onerror","onmouseout","prompt");
    foreach ($blacklist_word_xss as $blacklist_word_temp)
    {
        if (strpos($sanitizeit,$blacklist_word_temp)!==FALSE)
        {
           $GLOBALS['found_word_xss']=1;
        }
        if ($GLOBALS['found_word_xss']===1)
        {
            $logs=fopen("logs.txt","a");
            fwrite($logs,"Attacker IP=".$_SERVER['REMOTE_ADDR'].":::Possible Attack String:".$sanitizeit."\n") or die("Cannot Write into file");
            break;
        }
        if ($GLOBALS['found_word_xss']===1)
        {
         $ip=fopen("ip.txt","a");
         fwrite($ip,$_SERVER['REMOTE_ADDR']."::");
         }
    }
}
 function firewall_charcheck_xss($sanitizeit)//This Fuction checks the input for blacklisted characters and words
//,replace it with space if any illegal character or word is found and returns sanitized string
{
$sanitizeit=strtolower($sanitizeit);
$array1=str_split($sanitizeit);//Splitting String into an array
$blacklist_char=array("<",">","%","#","=","'",'"',"/",";","",",","&","onload","onmouseover","onerror","onmouseout","src");//Characters to block
$GLOBALS['query_xss_char'] = str_replace($blacklist_char," ",$sanitizeit);
return $GLOBALS['query_xss_char'];
}
////Illegal Character Checking Fucntion ENDS Here
////////////////////////////////////////////////////////////
///////////////////////////////////////////////////
//Illegal words Checking Function STARTS here
function firewall_wordcheck_sqli($input)//this function checks for different sql injection words and logs the ip
//if such word is found
{
    $input=  strtoupper($input);
    $blacklist_word=array("UNION","SELECT","DATABASE()","CONCAT","GROUP_CONCAT");
    foreach ($blacklist_word as $blacklist_word_temp)
    {
        if (strpos($input,$blacklist_word_temp)!==FALSE)
        {
           $GLOBALS['found_word_sqli']=1;
        }
        if ($GLOBALS['found_word_sqli']===1)
        {
    $logs=fopen("logs.txt", "a");
    fwrite($logs,"Attacker Ip:".$_SERVER['REMOTE_ADDR'].":::") or die("Cannot Write into file");
    fwrite($logs,"Attack String:".$input."\n");
    break;
        }
    }
}
?>