Inbuilt Map Remote Functionality

Charles Proxy has a Map Remote feature which maps one URL to another.

This can be achieved in mitm by using a script similar to:

def request(flow):
    if "google.com" in flow.url:
        flow.request.url = flow.request.url.replace("google.com", "google.jp")

I think we should have this feature inbuilt (just like content replacements) rather than expecting users to write custom scripts.

[mhils]

@ujjwal96: I think there are still lots of improvements to be made regarding the UX. Consider the following user story:

I want to show the contents of ~/foo.css when I access example.com/style.css.

I think this is something that’s not viable with replacements right now. I think it would be very useful to have a dedicated “map remote” functionality that can be used to map URLs to other URLs or local files. It would be interesting to see how other tools are solving this (@dufferzafar mentions Charles Proxy), I haven’t looked into that yet. To make the distinction a bit more clear, we may want to have the replacements addon operate on the request path only, not the full URL, and handle the URL in the map remote editor.

[kajojify]

@eu81273 Hello! Yes, you are right, unfortunately, our documentation doesn’t describe some moments very clearly. I hope we will change it in the nearest future. But nevertheless there is something in the documentation you may be interested in: Filter expressions -> https://docs.mitmproxy.org/stable/concepts-filters/ Replacements -> https://docs.mitmproxy.org/stable/overview-features/#replacements

Shortly speaking, here @~u@http://target.com/js/aaa.js@http://localhost:3000/js/aaa.js, ~u - mitmproxy filter expression that defines which flows a replacement applies to; http://target.com/js/aaa.js - a valid Python regular expression that defines what gets replaced; http://localhost:3000/js/aaa.js - a string literal that is substituted in.

The thing is ~u isn’t correct. To get the flows you want relying on url, you need to use ~u regex or just regex (which is equivalent to ~u regex). For example, you can write: @"~u google\.com"@google@yahoo @google\.com@google@yahoo This replacement takes all flows, which have google.com into their urls and replace google with yahoo. You can also write @google@yahoo. It means, that the pattern set to the default .*.