CS490 Project - Frontend

The frontend to our (unnamed as of right now) CS490 project.

Architecture

Layout

Each php script can be either a sender+receiver or a receiver.

A sender+receiver is a php script which will use cURL to "send" some data to another script and will have some data "returned" to it by the script they called. Front and Mid both belong to this category.

A receiver is a php script that doesn't use cURL to communicate to another script: it simply gets passed some data from another script, performs some logic on it, and returns some data to the script that called it. Back belongs to this category.

Sender-receiver code skeleton

<?php
    //receives data from calling script/document via $_POST
    $v = $_POST['credentials'];

    //performs some optional initial logic with the data
    //i.e hashing, etc.

    //Sends data to "next in chain" script
    $ch = curl_init();
    
    //@TODO: update with correct "following" php path
    curl_setopt($ch, CURLOPT_URL, "the_php_target.php"); 
    curl_setopt($ch, CURLOPT_POST, TRUE);
    //$v may have been modified - it's the data you send to the next script
    curl_setopt($ch, CURLOPT_POSTFIELDS, "credentials=" . $v);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);

    //Get the result from the execution (what the "NiC" script will return)
    $output = curl_exec($ch);
    if($output === false)
        echo 'Curl error: ' . curl_error($ch);
    else {
        //If no errors, (optionally modify/apply logic) and return data to the script that called you
        echo $output;
    }
    
    curl_close($ch);
?>

Receiver code skeleton

<?php
    //receives data from calling script/document via $_POST
    $v = $_POST['credentials'];

    //performs some optional initial logic with the data
    //i.e hashing, etc.

    //DOES NOT CALL CURL - it is the "last in line"
    //Simply returns what it wants to pass onto its caller
    $output = '{"njit":"", "local":"false"}';
    echo $output
?>

Specific Chain of Events

1. Front reads input from HTML, passes a Credentials JSON object to front.php with username and plaintext password.
2. front.php gets this Credentials and passes it onto Middle in mid.php.
3. Middle gets this Credentials and performs spoof logic to NJIT with them and keeps track of the outcome.
4. While doing #3, it makes an extra copy of Credentials, and replaces the plaintext password with a hashed one (via php's hash()). Middle sends this "hashed" Credentials object and passes it onto Back in back.php.
5. Back gets this "hashed" Credentials and compares the hashed password to the hashed password on the DB. Based on the result, Back prepares a partially complete Result JSON object (with only the local result) and returns it.
6. Middle gets this returned Result, and completes the Result by adding the outcome of the NJIT spoof. It returns this complete Result.
7. Frontend receives this Result, and returns it.
8. Within JS, a function is called to update the view on the browser based on the Result.

Data

Will send a Credentials JSON object to Middle.

{
    "user": user_name,
    "password": their_hashed_password
}

Expects a Result JSON object from Middle.

{
    "njit" : "success",
    "local" : "failure"
}