[tor-bugs] #32314 [Core Tor/Tor]: Can't connect to literal IPv6 address containing double colon

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#32314: Can't connect to literal IPv6 address containing double colon
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 Reporter:  liberat       |          Owner:  (none)
     Type:  defect        |         Status:  new
 Priority:  Medium        |      Milestone:  Tor: 0.4.3.x-final
Component:  Core Tor/Tor  |        Version:  Tor: 0.4.1.6
 Severity:  Normal        |     Resolution:
 Keywords:                |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
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Comment (by liberat):

 > This isn't quite right. Addresses and ports in Tor cells are binary. So
 the string parsing all happens on the client.

 I could be wrong.  But according to the spec, the payload of the
 RELAY_BEGIN cell is:
 {{{
          ADDRPORT [nul-terminated string]
          FLAGS    [4 bytes]

    ADDRPORT is made of ADDRESS | ':' | PORT | [00]

    where  ADDRESS can be a DNS hostname, or an IPv4 address in
    dotted-quad format, or an IPv6 address surrounded by square brackets;
    and where PORT is a decimal integer between 1 and 65535, inclusive.
 }}}

 If the SOCKS client encodes the address in one ASCII format, Tor is able
 to connect.  If the SOCKS client encodes exactly the same address in a
 slightly different ASCII format, Tor is not able to connect.  When it
 fails, it seems to be that the exit node reports an error.  So I am
 assuming that the ASCII string supplied by the client is indeed what is
 transmitted in the RELAY_BEGIN cell.

 And I assume the fact that this sometimes ''works'' when the client
 supplies an address without brackets is a lucky accident, due to the
 permissive behavior of tor_addr_port_split.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/32314#comment:4>
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