Mitmproxy is a command-line intercepting proxy. Just like with Burp, you can view and modify requests. It also has some features that distinguish it from other intercepting proxies. In this post, we will look into three features unique to mitmproxy.
Use over SSH
Because it runs on the command line, mitmproxy can be run on a remote server over SSH. If you ever want to intercept HTTP traffic in a remote network, mitmproxy can help out. Since mitmproxy has binaries with Python 3 and OpenSSL included, installing is as easy as extracting the package.
Mitmproxy and mitmdump can be used to record and replay HTTP traffic.
From the mitmproxy interface, it is possible to save the intercepted traffic to a file. This can be streamlined using mitmdump, which purpose is to save HTTP traffic to a file.
$ mitmdump --mode reverse:https://www.sjoerdlangkemper.nl/ -w traffic.mitm Proxy server listening at http://[::]:8080 172.16.122.1:51049: clientconnect 172.16.122.1:51049: GET https://www.sjoerdlangkemper.nl/ << 304 Not Modified 0b ... ^C $
This saves the intercepted requests to
traffic.mitm. The file format is specific to mitmproxy, so you can’t use it with other tools. You can use mitmproxy to view the requests contained in the file:
$ mitmproxy -r traffic.mitm
Modifying traffic files
You can edit request and responses in mitmproxy, and save the result back to a file. It is also possible to automate modification of traffic files using filters:
$ mitmdump --no-server -r traffic.mitm -w out.mitm '! ~u jpg$' 172.16.122.1:51049: GET https://www.sjoerdlangkemper.nl/ << 304 Not Modified 0b ...
This command will remove all requests where the URL ends in
jpg and write the result to
The following command will replay the requests from traffic.mitm:
$ mitmdump --client-replay traffic.mitm
It will perform requests, one by one, in order. This can be useful to create a certain test case and replay it a couple of times.
Besides replaying client requests, it is also possible to replay server responses. This could be useful when developing a client that depends on another server.
Reverse proxy mode
Mitmproxy can also run as a reverse proxy, where it pretends its a website. You can start a reverse proxy with the following command:
mitmproxy --mode reverse:https://www.sjoerdlangkemper.nl/
Now, if you browse to http://localhost:8080/, it will display this website. Any traffic is still intercepted. This could be useful for applications that have no proxy support, but where it is possible to change the URL it retrieves.
I wouldn’t say mitmproxy is the best intercepting proxy all around, but it has some interesting features that make it valueable in some edge cases, where other tools can’t be used.