Send http response to application from server using captured packets

Question

I am trying to simulate a response from a web server login confirmation to a windows application. I have the captured packets that detail the conversation between the server and the application for successful login already as it is my application, this is for debugging and MIME simulation to test application and network security. communications create what I hope can be a custom foolproof way to prevent a MIME but I dont have a way to test it, so here I am to ask for guidance.

How would I go about simulating the response from the server to the application?

I have some idea in the direction I would possibly need to go to achieve my desired outcome:

Utilizing my network: I have a Linux machine set up as a dynamic router, dhcp, routing, and my Linksys router just acts as an access point and ethernet switch.

1: Set up web server on Linux machine.

2: redirect traffic from application port to Linux server.

3: run server-side script to respond to application request using packets captured to establish replay successful login to server.

So, I am kinda new to using Linux tools. I have setup a Linux router, captured basic information utilizing Wireshark, and am able to program in VB, javascript, some java. I have not done much network-oriented programming other than some simple communication for authentication I have successfully established.

Any information to point me in the right direction I am grateful for!

Answer 1

Most logins use encryption (https / TLS) so capturing the packets won't help.

If not, the packets will form a http request, and you should be able to see the format of the request, whether the login credentials are part of the URL for GET or part of the http body for POST. It is not hard to create your own http request.

How are parameters sent in an HTTP POST request?

Each http request will be followed by an http response from the server, and the format of the headers or body will contain the login result (http requests and responses are similar in format, but the headers are not the same).

More sophisticated logins may involve a series of requests/responses.

You will need to write a simpler server to receive the requests and send the responses. Java is probably your best choice, given the languages you know, plus there will be plenty of examples online. With JS it may be possible but for the most part JS is used in browsers, so not a great choice. VB is a Windows language not supported on Linux.