[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: [tor-bugs] #17674 [Tor]: circuit_handle_first_hop doesn't respect ExtendAllowPrivateAddresses
#17674: circuit_handle_first_hop doesn't respect ExtendAllowPrivateAddresses
-------------------------------------------------+-------------------------
Reporter: teor | Owner:
Type: defect | Status:
Priority: Very High | needs_information
Component: Tor | Milestone: Tor:
Severity: Major | 0.2.8.x-final
Keywords: dos tor-hs 027-backport | Version:
026-backport security | Resolution:
Parent ID: #17178 | Actual Points:
Sponsor: | Points:
-------------------------------------------------+-------------------------
Changes (by dgoulet):
* status: needs_review => needs_information
Comment:
Replying to [comment:4 teor]:
> Please see my branch first-hop-no-private at
https://github.com/teor2345/tor.git
>
> It modifies circuit_handle_first_hop to refuse any connections to a
private address with a protocol error, unless ExtendAllowPrivateAddresses
is set.
>
> This should catch this issue with relay extends, and hidden service /
RSOS rendezvous from badly behaved clients.
I've played around with this. I've modified a tor client to change the RP
extend info to be a IP/PORT I control (nc -l PORT basically). The result,
and somehow expected is that the remote HS second middle when trying to
extend to the RP does a TLS connection to my IP/PORT.
I've modified an HS I own to always pick the second middle to be a relay
that I controlled (thus could look at the log). I then changed the RP info
to 127.0.0.1. I see that my pinned relay is logging me:
{{{
Dec 07 17:31:56.000 [warn] Client asked me to extend to a private address
}}}
Which is denied by `circuit_extend`. So maybe the use case I've tested is
wrong but it doesn't seem we go through "handle_first_hop" when extending
to the RP (for hidden service). I would be curious why RSOS doesn't also
use `circuit_extend` then?
(All this testing required me to change the HS, client and middle relay so
I might have gone wrong).
--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/17674#comment:6>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online
_______________________________________________
tor-bugs mailing list
tor-bugs@xxxxxxxxxxxxxxxxxxxx
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs