mitmproxy

mitmproxy is a super handy tool that acts like an SSL-capable intercepting HTTP proxy. It lets you watch, tweak, and replay requests and responses on the fly. The cool part? The library it’s built on can also help you do all this programmatically!

Getting Started with mitmproxy

When you fire up mitmproxy, it launches with a simple, user-friendly interface similar to Mutt—so if you're familiar with that, you're in luck! You can hit “?” to pull up the help page, which has all the info you need. Just a heads-up: requests and responses are kept in memory until you clear them out. So, if you leave mitmproxy running for too long or try to process huge data amounts, it could cause some issues.

SSL Certificates in mitmproxy

The first time you start mitmproxy, it creates a fake SSL certificate (you’ll find it at ~/.mitmproxy/cert.pem). This cert is what helps with the browser-side of intercepted traffic. Since it doesn’t match any website’s domain or verify against any authority, you'll need to add exceptions for every site you visit. For SSL requests, we assume all CONNECT requests are HTTPS. Basically, we wrap the connection from your browser in SSL and read the request by pretending to be the server it's trying to connect to. Then we open an SSL request to the destination server and replay that request.

Requirements for Using mitmproxy

• * SSL certificates are generated using openssl


• * The curses interface relies on a current version of urwid


• * The test suite uses the pry unit testing library

Console Environment Setup

To get everything running smoothly with mitmproxy, make sure your console environment is set up right:

• * Set your EDITOR environment variable so mitmproxy knows which editor to use.


• * Use PAGER environment variable for determining which pager to use.


• * Have proper entries in your mailcap files for external viewers related to request and response contents.

If you're ready to dive into this awesome tool, check out more about downloading mitmproxy here!