session.php

<?php

/* 
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 */
//global $passwdHash;
$passwdHash ="40bd001563085fc35165329ea1ff5c5ecbdbbeef";

function createSession($password) {
    
    if(checkPasswd($password)){
        global $passwdHash;
        session_start();
        $_SESSION["hash"] = $passwdHash; 
        return true;
    }
    return false;
}

function checkPasswd($passwd) {
    global $passwdHash;
    session_start();
    if(sha1($passwd)==$passwdHash){
       return true;
    }
    return false;
}

function checkSession() {
    global $passwdHash;
    session_start();
    if($_SESSION["hash"]==$passwdHash) {
        return true;
    }
    return false;
}

function setNewPassword($newPass) {
    $newPasswordHash = sha1($newPass);
    system('sed -i \'s/^$passwdHash =.*/$passwdHash ="'.$newPasswordHash.'";/\' session.php');
}