I'm trying to develop an addon in mitmproxy that will analyze some HTTPS/HTTP responses from the endpoint server/website and react to specific responses received.I would then block the response from accessing the client, and instead send a GET request from mitmproxy to the endpoint server, and then receive a response from that same endpoint server, then analyze it, send back a GET request without the previous response getting to the client, and once I get a correct answer from the endpoint, I would forward it to the client.
In other words I want to implement this :
Client Mitmproxy CorporateProxy Endpoint Server/Website [Internet]GET_Request1 --> GET_Request1 --> GET_Request1 -----> GET_Request1 Answer1 <-- Answer1 <----- Answer1 GET_Request2 --> GET_Request2 -----> GET_Request2 Answer2 <-- Answer2 <----- Answer2 GET_Request3 --> GET_Request3 -----> GET_Request3Answer3 <-- Answer3 <-- Answer3 <----- Answer3GET_Request4 --> GET_Request4 --> GET_Request4 -----> GET_Request4Answer4 <-- Answer4 <-- Answer4 <----- Answer4[etc.]Notice I'm using the upstream mode as I'm behind a corporate HTTP proxy server that has its own SSL certificate, so mitmproxy is very useful to decode the traffic here by posing as a CA authority behind the client with self signed SSL certificates.
I don't see in the documentation how one would "generate" a novel GET request from a mitmproxy addon using the API provided. I mostly see addons that modify requests/responses, so I'm unsure how to do it properly.
Since mitmproxy has already a HTTP connection to the endpoint, it seems (maybe I'm wrong) redundant to use e.g. urllib3 to generate those GET requests (adding a new dependency), and beside, I need the responses to the GET requests to go through mitmproxy.
TL;DR How do I generate a completely new GET request with existing mitmproxy facilities, a request that is upstream of the client, which will be answered by a response that will not reach the client?