From 595bde2202880971907096e4eeddb2b298c02d07 Mon Sep 17 00:00:00 2001 From: Maximilian Hils Date: Fri, 27 Feb 2015 12:55:16 +0100 Subject: [PATCH] add example inline script for dns spoofing, refs #486 --- examples/README | 1 + examples/dns_spoofing.py | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) create mode 100644 examples/dns_spoofing.py diff --git a/examples/README b/examples/README index 85ab272ae..f24c4de71 100644 --- a/examples/README +++ b/examples/README @@ -1,6 +1,7 @@ # inline script examples add_header.py Simple script that just adds a header to every request. change_upstream_proxy.py Dynamically change the upstream proxy +dns_spoofing.py Use mitmproxy in a DNS spoofing scenario. dup_and_replay.py Duplicates each request, changes it, and then replays the modified request. iframe_injector.py Inject configurable iframe into pages. modify_form.py Modify all form submissions to add a parameter. diff --git a/examples/dns_spoofing.py b/examples/dns_spoofing.py new file mode 100644 index 000000000..cfba7c54b --- /dev/null +++ b/examples/dns_spoofing.py @@ -0,0 +1,35 @@ +""" +This inline scripts 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 80 + -R http://example.com/ // Used as the target location if no Host header is present + mitmproxy + -p 443 + -R https://example.com/ // Used as the target locaction if neither SNI nor host header are present. + +mitmproxy will always connect to the default location first, so it must be reachable. +As a workaround, you can spawn an arbitrary HTTP server and use that for both endpoints, e.g. +mitmproxy -p 80 -R http://localhost:8000 +mitmproxy -p 443 -R https2http://localhost:8000 +""" + + +def request(context, flow): + if flow.client_conn.ssl_established: + # TLS SNI or Host header + flow.request.host = flow.client_conn.connection.get_servername() or flow.request.pretty_host(hostheader=True) + + # If you use a https2http location as default destination, these attributes need to be corrected as well: + flow.request.port = 443 + flow.request.scheme = "https" + else: + # Host header + flow.request.host = flow.request.pretty_host(hostheader=True) \ No newline at end of file