Opened 8 years ago

Closed 8 years ago

Last modified 8 years ago

#5898 closed defect (fixed)

publishing two hidden services descriptors to the same relay will use the same circuit

Reported by: arma Owned by:
Priority: Medium Milestone: Tor: 0.2.3.x-final
Component: Core Tor/Tor Version:
Severity: Keywords: tor-hs
Cc: Actual Points:
Parent ID: Points:
Reviewer: Sponsor:


#5283 made me notice another fun side effect: if your Tor operates two hidden services, and they happen to pick overlapping hsdir points, and happen to publish somewhat nearby in time, the descriptor publishes will share the same circuit, linking the hidden services together from the perspective of the hsdir.

A less dangerous variation of this issue is when you visit a hidden service whose hsdir is the same as the hsdir chosen by the hidden service you offer.

Child Tickets

Change History (6)

comment:1 Changed 8 years ago by arma

Milestone: Tor: 0.2.3.x-final

I'm not sure what milestone to pick -- it depends on the complexity of the patch.

I wonder if the fix is to never mix anonymized begin-dir requests.

comment:2 Changed 8 years ago by arma

Turns out this is already fixed in 0.2.3 by the ISO_STREAM flag for anonymized begindir requests:

    /* Anonymized tunneled connections can never share a circuit.
     * One-hop directory connections can share circuits with each other
     * but nothing else. */
    int iso_flags = anonymized_connection ? ISO_STREAM : ISO_SESSIONGRP;

So the question is, do we solve this for 0.2.2, or do we treat it as a bugfix that 0.2.3 provides? I'd suggest leaving 0.2.2 alone and focusing on other 0.2.3 things.

comment:3 Changed 8 years ago by nickm

Milestone: Tor: 0.2.3.x-finalTor: 0.2.2.x-final

Moving back to 0.2.2, since this is fixed in 0.2.3. Still need an answer for my question above.

comment:4 Changed 8 years ago by nickm

Milestone: Tor: 0.2.2.x-finalTor: 0.2.3.x-final
Resolution: fixed
Status: newclosed

Not backporting onto 0.2.2

comment:5 Changed 8 years ago by nickm

Keywords: tor-hs added

comment:6 Changed 8 years ago by nickm

Component: Tor Hidden ServicesTor
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