Using a Proxy with Tor

[Mike Perry]

Thus spake Tarek Tag (ttag at ironkey.com):

> 1) When setting a proxy, via the HttpProxy/HttpProxyAuthenticator commands,
> does anything else need to be set, or are these the minimum set of commands
> needed? Currently, my torrc file simply contains the following (which
> doesn't seem to be working as expected):
> 
> HttpProxy myproxy.com:port
> 
> HttpProxyAuthenticator myusername:password
> 
> 2) Do both the HttpProxy AND HttpsProxy commands need be set in order to get
> the proxy to work (along with the authenticator information if applicable),
> or do I choose only one depending on the address of my proxy? 

Yes, you need to set both. HttpProxy only proxies directory traffic.
HttpsProxy proxies Tor node traffic. Also, if your proxy only allows
connections to limited ports, you must specify FascistFirewall and
FirewallPorts for those ports, or the more recent (and slightly more
complicated) ReachableAddresses config.

> When I put the HttpProxy/HttpProxyAuthenticator commands in my torrc file,
> and took a look at the traffic through a network analyzer, it doesn't show
> the behaviour that I expected: That is, it shows that all traffic is still
> going from my local computer to the Tor nodes directly, rather then via the
> proxy.

Regretably the proxy behavior with Tor is not all that good. For
example, if for some reason the proxy is unreachable, it fails
silently and reverts to non-proxied connections. If the proxy refuses
to allow you to connect to a particular IP/port (for example, if you
do not specify FascistFirewall), it prints out a warn, and then
reconnects without using the proxy.


-- 
Mike Perry
Mad Computer Scientist
fscked.org evil labs