[tor-bugs] #9546 [Tor]: Link handshake fails with "Received unexpected cell command 10" when clocks are skewed

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#9546: Link handshake fails with "Received unexpected cell command 10" when clocks
are skewed
-----------------------------------+----------------------------------------
 Reporter:  zwol                   |          Owner:                    
     Type:  defect                 |         Status:  new               
 Priority:  normal                 |      Milestone:  Tor: 0.2.4.x-final
Component:  Tor                    |        Version:  Tor: 0.2.4.15-rc  
 Keywords:  tor-bridge tor-client  |         Parent:                    
   Points:                         |   Actualpoints:                    
-----------------------------------+----------------------------------------

Comment(by karsten):

 Confirming that this happens on a private bridge that performs
 reachability tests:

 {{{
 Aug 20 17:46:02.829 [info] update_consensus_router_descriptor_downloads():
 0 router descriptors downloadable. 0 delayed; 4383 present (0 of those
 were in old_routers); 0 would_reject; 0 wouldnt_use; 0 in progress.
 Aug 20 17:46:02.831 [info] consider_testing_reachability(): Testing
 reachability of my ORPort: 174.129.86.221:9001.
 Aug 20 17:46:02.831 [info] onion_pick_cpath_exit(): Using requested exit
 node '$224FC9615C2899B3C982A947FF7912201F986B1C~utpbridge at
 174.129.86.221'
 Aug 20 17:46:02.834 [info] circuit_send_next_onion_skin(): First hop:
 finished sending CREATE_FAST cell to
 '$64186650FFE4469EBBE52B644AE543864D32F43C=PsychoOnion3 at 89.187.142.208'
 Aug 20 17:46:02.834 [info] routerlist_remove_old_routers(): We have 4383
 live routers and 10402 old router descriptors.
 Aug 20 17:46:02.937 [info] circuit_finish_handshake(): Finished building
 circuit hop:
 Aug 20 17:46:02.937 [info] internal circ (length 3, last hop utpbridge):
 PsychoOnion3(open) fmj(closed)
 $224FC9615C2899B3C982A947FF7912201F986B1C(closed)
 Aug 20 17:46:02.937 [info] circuit_send_next_onion_skin(): Sending extend
 relay cell.
 Aug 20 17:46:03.192 [info] circuit_finish_handshake(): Finished building
 circuit hop:
 Aug 20 17:46:03.192 [info] internal circ (length 3, last hop utpbridge):
 PsychoOnion3(open) fmj(open)
 $224FC9615C2899B3C982A947FF7912201F986B1C(closed)
 Aug 20 17:46:03.193 [info] circuit_send_next_onion_skin(): Sending extend
 relay cell.
 Aug 20 17:46:03.399 [info] channel_register(): Channel 0x7f466fadb510
 (global ID 5) in state opening (1) registered with no identity digest
 Aug 20 17:46:03.595 [info] channel_tls_process_versions_cell(): Negotiated
 version 3 with 91.213.195.244:44739; Sending cells: VERSIONS CERTS NETINFO
 Aug 20 17:46:03.701 [info] channel_tls_process_certs_cell(): Got some good
 certificates from 91.213.195.244:44739: Waiting for AUTHENTICATE.
 Aug 20 17:46:03.825 [info] channel_tls_handle_cell(): Received unexpected
 cell command 1 in chan state opening / conn state handshaking (Tor, v3
 handshake); closing the connection.
 Aug 20 17:46:04.010 [info] circuit_testing_failed(): Our testing circuit
 (to see if your ORPort is reachable) has failed. I'll try again later.
 }}}

 This is latest maint-0.2.4 on a machine with a non-skewed clock.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/9546#comment:5>
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