How to send data between ajax and php in secure way? - php

Question

I have index.php, ajax.js and process.php (where I get my AJAX data).
I am using AJAX this way:
var = $('user_id').val();
$.ajax({
url : "somefile.php",
method : "GET",
data : {'user_id' : user_id},
cache : false,
success : function(data) {
// do something with "data"
}
);
User_id I receive from PHP file:
<input value="<?php echo $user_id; ?>" id="user_id" />
What do I need to do for increasing security?

Answer 1

Following can be added, just for increasing security measures,
In PHP code
<input value="<?php echo base64_encode($user_id); ?>" id="user_id" />
In JS Code:
var = $('user_id').val();
$.ajax({
url : "somefile.php",
method : "POST",
data : {'user_id' : user_id},
cache : false,
success : function(data) {
// do something with "data"
}
);
In "somefile.php"
for getting the file use the $_POST method, if will only accept the variable posted by using POST method. This can be used:
if(isset($_POST['user_id']))
{
$user_id=$_POST['user_id']
$user_id=base64_decode($user_id);
//all functionality here
}
else
{
//shoot error message
}

Answer 2

I'd recommend you don't provide the userid to the client. Can you store it in a session variable instead?

Answer 3

If this user_id is being used to retrieve some confidential information related to the logged in user then that sounds like a security flaw.
You should be getting the user_id from a session variable

Answer 4

I think is not an good idea to put 'user_id' in client HTML and send back to server. You need to do more validation with data that sent from client (do some checking and filtering).
I recommend to use session instead of sending it to client, But you will have problem if editing two or more data at same time (multi tab), So you need to use session and some trick.
With this example your real user_id will never sent to the client.
index.php:
session_start();
$edit_session_id = md5(uniqid() . microtime(true));
$_SESSION['edit_' . $edit_session_id] = $user_id;
ajax.js:
var edit_session_id = $('#edit_session_id').val();
$.ajax({
url : "process.php",
method : "POST",
data : {'edit_session_id' : edit_session_id},
cache : false,
success : function(data) {
// do code
}
);
process.php:
session_start();
$edit_session_id = $_POST['edit_session_id'];
if(!isset($_SESSION['edit_' . $edit_session_id]))
{
die('Invalid edit session, please go back & refresh');
}
$user_id = $_SESSION['edit_' . $edit_session_id];
// Do something with user_id
//Clear the editing session
unset($_SESSION['edit_' . $edit_session_id]);

Answer 5

You should use POST instead of GET and you should also use ssl so that yuor urls sart with https instead of http.Now you are secured enough but you can increase security by adding extra encryption layer.