Middleware that applies some fixes for people using
the WebFaction hosting provider. In particular:
* sets 'REMOTE_ADDR' based on 'HTTP_X_FORWARDED_FOR', if the
latter is set.
* Monkey patches request.is_secure() to respect HTTP_X_FORWARDED_SSL.
***PLEASE NOTE*** that this is not secure, since a user or an
active network attacker could set X-Forwarded-SSL manually and the
main WebFaction Apache/nginx instance does not remove it, so it will
appear to be a secure request when it is not.
For some applications, this could be a critical security flaw. For
example, if users typical type in yourdomain.com into browsers, which
will be HTTP by default and your app is supposed to redirect this to
HTTPS, an active MITM attacher could add the X-Forwarded-Ssl header,
causing the connection to procede over HTTP, leaking all your
In this scenario, this middleware will be useful in protecting against
passive network attackers, but not active network attackers.
WebFaction currently have no work-around for this flaw, AFAIK.
def process_request(self, request):
# Fix REMOTE_ADDR
real_ip = request.META['HTTP_X_FORWARDED_FOR']
# HTTP_X_FORWARDED_FOR can be a comma-separated list of IPs. The
# client's IP will be the first one.
real_ip = real_ip.split(",").strip()
request.META['REMOTE_ADDR'] = real_ip
# Fix HTTPS
if 'HTTP_X_FORWARDED_SSL' in request.META:
request.is_secure = lambda: request.META['HTTP_X_FORWARDED_SSL'] == 'on'