Web Application Programming & Hacking

In this lab, I explored how the web functions at both the protocol and programming levels. Through a combination of network analysis and basic back-end scripting, I gained hands-on experience with the HTTP protocol, request/response mechanisms, and simple web server-side development using C and PHP.

• Used Wireshark to capture and analyze HTTP GET and response messages

• Sent manual HTTP requests to a server using Telnet and compared the structure with browser-based requests

telnet example.com 80
  GET / HTTP/1.1
  Host: example.com

• Developed a basic CGI "Hello World" app in C, hosted via Apache

#include <stdio.h>
  int main(void) {
    printf("Content-Type: text/plain; charset=utf-8\n\n");
    printf("Hello World CGI! From Tejas Ghodke, WAPH\n");
    return 0;
  }


• Created a dynamic HTML-generating CGI script with embedded course/student metadata
• Built a simple PHP application to echo user input and display server configuration

<?php
  echo "You entered: " . $_REQUEST["data"];
  ?>


• Demonstrated and analyzed HTTP GET vs POST methods using curl and browser testing

curl -X POST http://localhost/echo.php -d "data=Tejas"

• Applied concepts of the client-server model, MIME headers, input handling, and basic web security

In Lab 2, I created and deployed a full HTML page showcasing form handling, JavaScript interactivity, AJAX, jQuery, and public API integrations. I explored different types of styling methods (inline, internal, and external), implemented a digital and analog clock, and added dynamic behavior to enhance user interaction.

• Created a form in raw HTML to submit user input to a PHP echo handler via GET

• Added JavaScript for click-based date display, real-time clocks, and input key logging

// Real-time digital clock
  setInterval(() => {
    const now = new Date();
    document.getElementById("digit-clock").innerHTML = now.toLocaleTimeString();
  }, 1000);

• Integrated a local JS file to show/hide email address with toggle behavior
• Loaded and rendered a functional analog clock using an external JS library and canvas

• Implemented raw AJAX requests using XMLHttpRequest to send and display input asynchronously

function getEcho() {
    const input = document.getElementById("ajax-input").value;
    const xhttp = new XMLHttpRequest();
    xhttp.onreadystatechange = function () {
      if (this.readyState === 4 && this.status === 200) {
        document.getElementById("ajax-response").innerHTML = this.responseText;
      }
    };
    xhttp.open("GET", "echo.php?data=" + encodeURIComponent(input), true);
    xhttp.send();
  }


• Applied inline, internal, and external CSS to style content and buttons consistently
• Used jQuery to simplify AJAX GET and POST requests

// jQuery POST request
  $.post("echo.php", { data: input }, function(data) {
    $("#jquery-response").html("Server says:
You entered: " + data);
  });

• Fetched a random programming joke using JokeAPI
• Used Agify.io Web API to predict age from user input