[tor-bugs] #29700 [Core Tor/Tor]: ntor handshake auth failures with RPs

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#29700: ntor handshake auth failures with RPs
------------------------------+--------------------
     Reporter:  mikeperry     |      Owner:  (none)
         Type:  defect        |     Status:  new
     Priority:  Medium        |  Milestone:
    Component:  Core Tor/Tor  |    Version:
     Severity:  Normal        |   Keywords:
Actual Points:                |  Parent ID:
       Points:                |   Reviewer:
      Sponsor:                |
------------------------------+--------------------
 My vanguards addon was detecting dropped cells on my v3 service side due
 to ntor failures to client chosen RPs. This happened while testing
 vanguards 0.3.0 with tor 0.4.0.2-alpha and a v3 onion service that was
 only for my testing.

 This corresponded to control port lines like:

 {{{
 DEBUG[Thu Mar 07 09:51:28 2019]: 650 CIRC 12674 FAILED
 $DD5DA21CC5036533AE2010DE2C7E72BE2CDF9C5E~Unnamed,$28C52CDBB78DA46124DA62EC1D6796689E719210~ayb,$516C2CCBB1502B7E46E4265D82474257324DF8E2~Unnamed,$E37724D8AD87B149EAD2F3DFD3E1681624AC9EE0~sheldon
 BUILD_FLAGS=IS_INTERNAL,NEED_CAPACITY,NEED_UPTIME PURPOSE=HS_SERVICE_REND
 HS_STATE=HSSR_CONNECTING
 REND_QUERY=jxzsbx2wov6yrzwysw7mbmxal2ab6vwje745djczv4kyxe36a2rhmnid
 TIME_CREATED=2019-03-07T09:47:54.889121 REASON=TORPROTOCOL
 }}}

 Which matched loglines:

 {{{
 Mar 07 09:51:28.000 [info] onion_skin_ntor_client_handshake(): Invalid
 result from curve25519 handshake: 4
 Mar 07 09:51:28.000 [info] circuit_mark_for_close_(): Circuit 3610696346
 (id: 12674) marked for close at src/core/or/relay.c:1731 (orig reason: 1,
 new reason: 0)
 Mar 07 09:51:28.000 [info] circuit_build_failed(): Couldn't connect to the
 client's chosen rend point "" (last hop failed).
 Mar 07 09:51:28.000 [info] can_relaunch_service_rendezvous_point():
 Attempt to build a rendezvous circuit to [scrubbed] has failed with 1
 attempts and expiry time 1551952317. Giving up building.
 }}}

 I caused this by using Tor version 0.3.5.7 (git-9beb085c10562a25) to
 connect to my HS like so:

 {{{
 while [ true ]; do
   torsocks wget  http://$MYV3_ONION_NAME.onion/404 -O /dev/null
   killall -HUP tor;
 done
 }}}

 That v3 404 url is in fact non-existent -- it does just send back a HTTP
 404.

 I think this might be caused by just normal onion key rotation of the
 RP... In which case there might now be anything we can do?

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/29700>
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