mitmproxy/examples/complex/dns_spoofing.py
Aldo Cortesi e6eeab6094 Revamp how addons work
- Addons now nest, which means that addons can manage addons. This has a number
of salutary effects - the scripts addon no longer has to poke into the global
addons list, we no longer have to replace/remove/boot-outof parent addons when
we load scripts, and this paves the way for making our top-level tools into
addons themselves.
- All addon calls are now wrapped in a safe execution environment where
exceptions are caught, and output to stdout/stderr are intercepted and turned
into logs.
- We no longer support script arguments in sys.argv - creating an option
properly is the only way to pass arguments. This means that all scripts are
always directly controllable from interctive tooling, and that arguments are
type-checked.

For now, I've disabled testing of the har dump example - it needs to be moved
to the new argument handling, and become a class addon. I'll address that in a
separate patch.
2017-04-25 22:13:44 +12:00

58 lines
1.9 KiB
Python

"""
This script makes it possible to use mitmproxy in scenarios where IP spoofing
has been used to redirect connections to mitmproxy. The way this works is that
we rely on either the TLS Server Name Indication (SNI) or the Host header of the
HTTP request. Of course, this is not foolproof - if an HTTPS connection comes
without SNI, we don't know the actual target and cannot construct a certificate
that looks valid. Similarly, if there's no Host header or a spoofed Host header,
we're out of luck as well. Using transparent mode is the better option most of
the time.
Usage:
mitmproxy
-p 443
-s dns_spoofing.py
# Used as the target location if neither SNI nor host header are present.
-R http://example.com/
# To avoid auto rewriting of host header by the reverse proxy target.
--keep-host-header
mitmdump
-p 80
-R http://localhost:443/
(Setting up a single proxy instance and using iptables to redirect to it
works as well)
"""
import re
# This regex extracts splits the host header into host and port.
# Handles the edge case of IPv6 addresses containing colons.
# https://bugzilla.mozilla.org/show_bug.cgi?id=45891
parse_host_header = re.compile(r"^(?P<host>[^:]+|\[.+\])(?::(?P<port>\d+))?$")
class Rerouter:
def request(self, flow):
if flow.client_conn.ssl_established:
flow.request.scheme = "https"
sni = flow.client_conn.connection.get_servername()
port = 443
else:
flow.request.scheme = "http"
sni = None
port = 80
host_header = flow.request.host_header
m = parse_host_header.match(host_header)
if m:
host_header = m.group("host").strip("[]")
if m.group("port"):
port = int(m.group("port"))
flow.request.host_header = host_header
flow.request.host = sni or host_header
flow.request.port = port
addons = [Rerouter()]