[tor-bugs] #32588 [Core Tor/Tor]: Setting ORPort [ipv6]:auto mistakenly advertises port 94

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#32588: Setting ORPort [ipv6]:auto mistakenly advertises port 94
-----------------------------------------------+---------------------------
 Reporter:  arma                               |          Owner:  neel
     Type:  defect                             |         Status:
                                               |  needs_information
 Priority:  Medium                             |      Milestone:  Tor:
                                               |  0.4.3.x-final
Component:  Core Tor/Tor                       |        Version:  Tor:
                                               |  0.4.1.6
 Severity:  Normal                             |     Resolution:
 Keywords:  ipv6, memory-safety, security-low  |  Actual Points:
Parent ID:                                     |         Points:
 Reviewer:                                     |        Sponsor:
-----------------------------------------------+---------------------------
Description changed by arma:

Old description:

> Start your Tor with
> {{{
> ORPort 9001
> ORPort [2a01:238:43e4:2b00:ae5a:a980:1f63:cc5e]:auto nolisten
> DirPort 9030
> }}}
> and let it start up. Then go to http://127.0.0.1/tor/server/authority and
> check out how it has the line
> {{{
> or-address [2a01:238:43e4:2b00:ae5a:a980:1f63:cc5e]:94
> }}}
>
> First: How did it pick that number? It's a weird choice for a port.
>
> Second: If this is actually your ipv6 address, you can leave out the
> nolisten, and that's where things get interesting. Your logs will say
> something like
> {{{
> Nov 24 01:53:42 v4 tor[10988]: Nov 24 01:53:42.001 [notice] Opening OR
> listener on [2a01:238:43e4:2b00:ae5a:a980:1f63:cc5e]:0
> Nov 24 01:53:42 v4 tor[10988]: Nov 24 01:53:42.002 [notice] Opened OR
> listener on [2a01:238:43e4:2b00:ae5a:a980:1f63:cc5e]:41535
> }}}
>
> but then your descriptor will still say :94.
>
> This is happening right now to relay "Testbit": they have set :auto for
> their ipv6 address in their ORPort, they get the above line about how
> it's opened on port 41535, and yet their descriptor says it's on port 94.

New description:

 Start your Tor with
 {{{
 ORPort 9001
 ORPort [2a01:238:43e4:2b00:ae5a:a980:1f63:cc5e]:auto nolisten
 DirPort 9030
 }}}
 and let it start up. Then go to http://127.0.0.1:9030/tor/server/authority
 and check out how it has the line
 {{{
 or-address [2a01:238:43e4:2b00:ae5a:a980:1f63:cc5e]:94
 }}}

 First: How did it pick that number? It's a weird choice for a port.

 Second: If this is actually your ipv6 address, you can leave out the
 nolisten, and that's where things get interesting. Your logs will say
 something like
 {{{
 Nov 24 01:53:42 v4 tor[10988]: Nov 24 01:53:42.001 [notice] Opening OR
 listener on [2a01:238:43e4:2b00:ae5a:a980:1f63:cc5e]:0
 Nov 24 01:53:42 v4 tor[10988]: Nov 24 01:53:42.002 [notice] Opened OR
 listener on [2a01:238:43e4:2b00:ae5a:a980:1f63:cc5e]:41535
 }}}

 but then your descriptor will still say :94.

 This is happening right now to relay "Testbit": they have set :auto for
 their ipv6 address in their ORPort, they get the above line about how it's
 opened on port 41535, and yet their descriptor says it's on port 94.

--

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/32588#comment:8>
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