php session lost after submitting form - php

The code below page keeps session on GET requests or refreshing browser, but when I submit a form the session data is lost.
$user=$_POST['user']; $pass=$_POST['pass'];
if ($_POST['user'])
{ if($user==$un and $pass=$pw)
{ $_SESSION['uid']=$Xid;header('Location: '.$uri.'?welcome'); }
else { $msg="chybny login"; }
}
if(isset($_GET['logout'])) { session_destroy(); header('Location: '.$uri); }
$cnt=$_SESSION['cnt']+1; $_SESSION['cnt']=$cnt;
Above is the code for login which re-directs me to the welcome page as it was verified, however the session is lost. If I just refresh or repeatedly load the page without submitting, the session holds by echoing the session variable cnt (counts up 1,2,3,...)
After submitting the form, I see session is lost and too cnt variable is reset?

I usually don't work with session directly try the following, place it a the top of your script :
session_start();
$uid = $_SESSION['uid'];
$cnt = $_SESSION['cnt'];
then work with the variable instead

The problem is likely your 'and' statement. It should be &&. The condition is not going to be true.

If you're 100% sure the code is all fine and the PHP.ini is the problem, based on your comments above. Look at this link at check the settings in the .ini http://php.net/manual/en/session.configuration.php

To pass the current session to the next page... I believe is what you are asking...
You are currently not passing the session to the next page and use session_start() at the top of the next page.
Change line 4 to:
{ $_SESSION['uid']=$Xid;header('Location: '.$uri.'?'.SID.'&page=welcome'); } // Where "page" is the name of the data you are retrieving
Or, you can save the session data to a cookie and then retrieve it on the next page.
You can alternately name the session when you use session_start("NameHere") on each page, however if the visitor has recently visited and the session not destroyed, they may see parse errors, if you have them enabled.

First of all, make sure that the the first thing you do on every page is to start a session (I recommend calling it once in a header file that you require on all of your sub sites).
So that you have session_start(); everywhere in the system.
Second of all, tighten up your code; make it easier to read. Something like
$userName = isset($_POST['userName']) ? $_POST['userName'] : false;
$password = isset($_POST['password']) ? $_POST['password'] : false;
$logout = isset($_POST['logout']) ? $_POST['logout'] : false;
$url = '../index.php';
if(!($logout))
{
if($userName && $password)
{
if($userName == $un && $password == $pw)
{
$_SESSION['loggedIn']=true;
$_SESSION['uid']=$Xid;
$_SESSION['message']="success";
}
else
{
$_SESSION['loggedIn']=false;
$_SESSION['message']="fail, incorrect login information.";
}
}
else
{
$_SESSION['loggedIn']=false;
$_SESSION['message']="fail ; username and password not submitted.";
}
header("Location: $url");
}
else
{
session_start();
session_destroy();
session_start();
header("Location: $url");
}
And if you want to display unqiue content depending on whether a user is logged in or not, then you can simply check if the login session is set or not, on each page, instead of modifying the header for that.

Related

How to authenticate securely by session tokens and cookies? updated

I tried to write my own authentication method (school project), and I'm stuck.
Please advise, how to solve a secure authentication:
There is an index.php which contains everything that needs to be "protected". I will copy the relevant parts of my code here.
updated index.php
session_start();
function checkUserAuth(){
$authStatus = false;
if (isset($_SESSION['PHPSESSID'])){
if ($_SESSION['PHPSESSID'] == $_COOKIE['PHPSESSID']){
$authStatus = true;
}
}
return $authStatus;
}
if(!checkUserAuth()){
include_once(dirname(__DIR__).'/admin/authentication/login.php');
exit();
}
If the checkUserAuth() determines, that there is no properly authenticated user, will include the login.php and stop the rest of the script.
updated login.php:
if(array_key_exists($username, $users) && password_verify($password, $users[$username])){
$_SESSION['PHPSESSID'] = $_COOKIE['PHPSESSID'];
$_SESSION['login_user'] = $_POST['user'];
What I imagine that might happen, is that if the login details are correct, the login.php sets a cookie, and refreshes the page. Then the index.php will detect the cookie, and skip the login part.
The login is pretty much figured out, and thanks to Juned, I think it is working now. However I don't know how secure is this?
On a scale from 1 to very, how wrong I am?
There are loads of ways of doing this. The below pseudocode is not the most efficient but should work and I don't think what you've done above will actually work.
Does this help?
login.php pseudocode
<?php
session_start(); // this function checks if there's a session ID already set, if not, sets one.
if(array_key_exists($username, $users) && password_verify($password, $users[$username])){
// do your login details checking here
// if login details correct
// set a flag in the $_SESSION superglobal and whatever else you want to store about the user like their username e.g.
$_SESSION["loggedIn"] = true;
$_SESSION["username"] = "$_POST['user']"; // better practice to fetch a clean version from your database
//else return user to login page
}
?>
index.php pseudocode
<?php
session_start(); // this will fetch the session ID and other variables that you might have set e.g. username, logged in status
function checkUserAuth(){
$authStatus = false;
if (isset($_SESSION['loggedIn']) && $_SESSION['loggedIn'] === true){
$authStatus = true;
}
return $authStatus;
}
if(!checkUserAuth()){
// redirect to login page. e.g.
header('Location: login.php');
exit;
}
?>

PHP login script in a separated file

I have been developing the following php script (+ sqlite database) to create a login for my web.
Up to now I had used just one PHP file, but now I want to use different files for login and protected contents, I mean, I used to have all my web in one file php (contents and password script were together) but now I want to detach it in different php files (one for the login, login.php, and other phps protected: index.php, calendar.php...)
I used this code to password-protect php content:
<?php require_once "Login.php"; ?>
but it doesn't seem to work: it displays the form to login next to the content I wanted to protect.
This is the php script I'm using as login.php:
<?php
$db = new PDO('sqlite:data.db');
session_start();
if (isset($_GET['logout'])) {
unset($_SESSION['pass']);
header('location: index.php');
exit();
}
if (isset($_SESSION['timeout'])) {
if ($_SESSION['timeout'] + 4 < time()) {
session_destroy();
}
}
if (!empty($_POST['pass'])) {
$result = $db->query("SELECT user,password FROM users");
foreach ($result as $row) {
if (password_verify($_POST['pass'], $row['password'])) {
echo "Welcome! You're logged in " . $row['user'] . "! <a href='index.php?logout=true'>logout</a>";
$_SESSION['pass'] = $_POST['pass'];
$_SESSION['timeout'] = time();
}
}
}
if (empty($_SESSION['pass'])) {
echo '<form method="POST" action=""><input type="password" name="pass"><form>';
}
?>
MY QUESTION IS: How can I use my php script to protect different files?Is there any way to embed a logout link too?
One way is to store a token in session variables when a user logs in. Confirm the token is there on each page, if it isn't redirect the user to the login page. For example assert_login.php:
<?php
session_start();
if('' == $_SESSION['token']) {
header("Location: login.php");
exit();
}
?>
Then, in the PHP at the top of each of your pages:
<?php
require('assert_login.php');
?>
You can also clear the session variable on logout, logout.php for example:
<?php
require('assert_login.php'); // has session_start() already
$_SESSION['token'] = ''; // empty the token
unset($_SESSION['token']); // belt and suspenders
header("Location: login.php");
exit();
?>
I was also going through same issue & the way I solved it:
PSEUDO CODE:
PHP SESSION START
if(isset(GET(logout){
SetLogout();
die()}
$redirect=false
if not session[auth] exists
if SERVER REQUEST METHOD IS POST
$redirect=true;
if POST(username) && POST(pass) exists
Sanitize both of them & assign to $user& $pass
if user == "John" && $pass == "secret"
Go To SetLogin();
else{
Go To SetLogout();
echo "Wrong Username or Password"
drawlogin();
die();}
} //user pass comparing ends
} //Server method is NOT POST, so maybe it is GET.
//Do nothing, let the control pass to next lines.
}//SESSION(auth) does not exists, so ask user to login
else {
drawlogin();
}
//Post-Redirect-Get
if ($redirect)
redirect header to this same page, with 301
die()
// Secret Content here.
function SetLogin($user){
$SESSION(auth) = TRUE;}
function SetLogout($user){
if SESSION(auth) exists
unset($SESSION(auth))
redirect back with 301, without query string //shake ?logout
}
function drawlogin(){
echo all the HTML for Login Form
What it does is, it checks various things/variables, and if all passes, the control passes to Secret Content.
Save it as pw.php, & include it on top of any file you want to protect. Logout can be triggered by Logout
Note that this is just a pseudo code, typed on a tablet. I will try to update it with actual version. It is not checked for errors. Use all standard PHP Security precautions..

How to change PHP session time in this code?

I am trying to change the session time in my login code, and here is the code I want to change the session time in:
<?php
if(session_id()==='')
{
session_start();
}
if(!(isset($_SESSION['status']) && $_SESSION['status'] == "logged_in"))
{
die("sorry, you must be logged in to view this page");
} else {
?>
How would I go about changing the session time?
Also, if you can't change the session time in this, is there any code that can replace this and still work the same?
You may try session_cache_expire
session_cache_expire(30);
$cache_expire = session_cache_expire();
or see this

Tracking a page for redirection with a session variable

I am currently using a SESSION variable for redirection. Hoprfully code snippets will make it clear.
addForm.php:
if (!isset($_SESSION['myusername'])){
if (isset($_COOKIE['username'])){
$_SESSION['myusername'] = $_COOKIE['username'];
}
else{
#using a session var to redirect back to addForm.php
$_SESSION['addForm'] = 1;
header("location:loginForm.php");
}
}
LoginSuccess.php
session_start();
if (!isset($_COOKIE['username'])){
header("location:loginForm.php");
}
if (isset($_SESSION['addForm'])){
header("location:addForm.php");
}
the above works (redirects to addForm.php). My question is, are there any risks in doing it this way? is there a better way to do it? I guess i'm looking for 'best practice'.
You have some errors:
The valid header is header('Location: http://www.example.org/script.php'); notice L and full URL?
After each header('Location: http://www.example.org/script.php'); it should be exit();
You cannot rely just on $_COOKIE['username'], you need to have something from password, I mean not the password, maybe an MD5() hashed password in $_COOKIE also. And you should know not to rely on $_COOKIE that much.
In LoginSuccess.php you have to unset($_SESSION['addForm']) before redirection, addForm from session will still be set.
Personnaly, I prefer store the entry current URI in session varible. Then, when my login process are successfull, I use the stored URI to redirect the user to the previous page.
Pseudo Code
if (!isset($_SESSION['userloginobj'])) {
$_SESSION['callbackuri'] = get_current_url_depending_of_your_process();
header('location:' . get_base_url() . 'index.php?do=login');
exit(0);
}
elseif ('login' == get_param('do')) {
// Show the login form
if ( is_login_successfull() ) {
$_SESSION['userloginobj'] = "userinfo";
header('location:' . $_SESSION['callbackurl']);
exit(0);
}
}
else {
// Normal process
}
But your proccess seems to be a good start if you don't use a framework.

php session creating / reading problem

I'm trying to create a very simple login in php. All i want to do is,
register a session called user if the login is successful and direct the user to an inner page. in that inner page i have a include file which should check if the user session is created or not
if created -> authorize user
if not created -> redirect to login again.
But still I couldnt get this up and running. below is my code
login.php
session_start();
global $user;
if (($_POST['Submit'])){
$login = $_POST['login'];
$password = $_POST['password'];
if ((do_login($login, encrypt_password($password))) > 0){
$_SESSION['user'] = $login;
header('Location: home/dashboard.php');
}
else{
// load login again
}
}
and in my dashboard.php page this is how I'm checking it (and this part i have in another file called 'authentication.inc')
<?php
session_start(); // If
if (!isset($_SESSION['user'])) {
// User is not logged in, so send user away.
header("Location:/login");
die();
}
?>
updated ::
when I do an echo $_SESSION['user'], I'm expecting to see login name ($login) of the user which i done get :C
Am I missing something here... thanks in advance
cheers
sameera
if (!isset ($_POST['Submit']) || $_POST['Submit'] != 'Login'){
The code inside that if block won't get run if the form is submitted properly, because that condition reads " if Submit isn't set or it isn't 'Login' ". Try flipping the logic of that condition, ie:
if (isset ($_POST['Submit']) && $_POST['Submit'] == 'Login'){
-> " if Submit is set and it is 'Login' "
The Location header takes an absolute URL, not a relative URL, of the form:
header("Location: http://www.example.com/login.php");
There is an example on the PHP Manual header() page that can help to create the absolute URL.
And what #Brian says regarding the logic of your IF expression.

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