mirror of
https://github.com/Grasscutters/mitmproxy.git
synced 2024-11-22 15:37:45 +00:00
73 lines
2.8 KiB
ReStructuredText
73 lines
2.8 KiB
ReStructuredText
.. _replacements:
|
|
|
|
Replacements
|
|
============
|
|
|
|
Mitmproxy lets you specify an arbitrary number of patterns that define text
|
|
replacements within flows. Each pattern has 3 components: a filter that defines
|
|
which flows a replacement applies to, a regular expression that defines what
|
|
gets replaced, and a target value that defines what is substituted in.
|
|
|
|
Replace hooks fire when either a client request or a server response is
|
|
received. Only the matching flow component is affected: so, for example, if a
|
|
replace hook is triggered on server response, the replacement is only run on
|
|
the Response object leaving the Request intact. You control whether the hook
|
|
triggers on the request, response or both using the filter pattern. If you need
|
|
finer-grained control than this, it's simple to create a script using the
|
|
replacement API on Flow components.
|
|
|
|
Replacement hooks are extremely handy in interactive testing of applications.
|
|
For instance you can use a replace hook to replace the text "XSS" with a
|
|
complicated XSS exploit, and then "inject" the exploit simply by interacting
|
|
with the application through the browser. When used with tools like Firebug and
|
|
mitmproxy's own interception abilities, replacement hooks can be an amazingly
|
|
flexible and powerful feature.
|
|
|
|
|
|
On the command-line
|
|
-------------------
|
|
|
|
The replacement hook command-line options use a compact syntax to make it easy
|
|
to specify all three components at once. The general form is as follows:
|
|
|
|
.. code-block:: none
|
|
|
|
/patt/regex/replacement
|
|
|
|
Here, **patt** is a mitmproxy filter expression, **regex** is a valid Python
|
|
regular expression, and **replacement** is a string literal. The first
|
|
character in the expression (``/`` in this case) defines what the separation
|
|
character is. Here's an example of a valid expression that replaces "foo" with
|
|
"bar" in all requests:
|
|
|
|
.. code-block:: none
|
|
|
|
:~q:foo:bar
|
|
|
|
In practice, it's pretty common for the replacement literal to be long and
|
|
complex. For instance, it might be an XSS exploit that weighs in at hundreds or
|
|
thousands of characters. To cope with this, there's a variation of the
|
|
replacement hook specifier that lets you load the replacement text from a file.
|
|
So, you might start **mitmdump** as follows:
|
|
|
|
>>> mitmdump --replace-from-file :~q:foo:~/xss-exploit
|
|
|
|
This will load the replacement text from the file ``~/xss-exploit``.
|
|
|
|
Both the :option:`--replace` and :option:`--replace-from-file` flags can be passed multiple
|
|
times.
|
|
|
|
|
|
Interactively
|
|
-------------
|
|
|
|
The :kbd:`R` shortcut key in the mitmproxy options menu (:kbd:`o`) lets you add and edit
|
|
replacement hooks using a built-in editor. The context-sensitive help (:kbd:`?`) has
|
|
complete usage information.
|
|
|
|
================== =============================
|
|
command-line :option:`--replace`,
|
|
:option:`--replace-from-file`
|
|
mitmproxy shortcut :kbd:`o` then :kbd:`R`
|
|
================== =============================
|