[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 zwol):

 I generated new logs from both client and server, at "debug" level, with
 "SafeLogging 0".  The client is 172.19.151.215 and the server (bridge) is
 128.2.142.99. It looks like the offending CREATE cell is indeed coming
 from another relay (185.21.101.40 = afo3.torproject.afo-tm.org).  I'm not
 sure why this would happen for a relay with PublishServerDescriptor 0 set,
 though.

 For the record, here is the complete server torrc:

 {{{
 BandwidthRate  100000000 B
 BandwidthBurst 100000000 B
 DataDirectory  tbbscraper_tor.data
 ContactInfo    if this appears somewhere public, something is horribly
 wrong
 Log            debug stdout
 SafeLogging    0
 HardwareAccel  1
 Address        128.2.142.99
 ExitPolicy     reject *:*
 #MyFamily
 $B0171148A7081858EE639B9451AF4D6CE0F68361,$6B6B1718DCF6BECB2A8D2FE09A80325E9060E6CD,$B4FDE846864BAD0AD1CA428FBEFABF2CD8CF13A6,$B6B7FBA5874DD4F4337CCFAA460C3B92C264C0ED,$E841B711D279EC27C1555281FA61568B6C45A919
 Nickname       tbbscraperentry
 PublishServerDescriptor 0
 AssumeReachable 1
 ShutdownWaitLength 10
 SOCKSPort 0
 #DirPort 8999
 BridgeRelay 1
 BridgeRecordUsageByCountry 0
 DirReqStatistics 0
 ExtraInfoStatistics 0
 ExtendAllowPrivateAddresses 1
 ORPort 128.2.142.99:9002 IPv4Only
 }}}

 and client torrc:

 {{{
 # If non-zero, try to write to disk less frequently than we would
 otherwise.
 AvoidDiskWrites 1
 # Store working data, state, keys, and caches here.
 DataDirectory /home/user/tbb_VteJUc/Data/Tor
 GeoIPFile /home/user/tbb_VteJUc/Data/Tor/geoip
 # Where to send logging messages.  Format is minSeverity[-maxSeverity]
 # (stderr|stdout|syslog|file FILENAME).
 Log notice stdout
 # Bind to this address to listen to connections from SOCKS-speaking
 # applications.
 SocksListenAddress 127.0.0.1
 SocksPort 9150
 ControlPort 9151

 CookieAuthentication 1
 #ExcludeNodes
 $B0171148A7081858EE639B9451AF4D6CE0F68361,$6B6B1718DCF6BECB2A8D2FE09A80325E9060E6CD,$B4FDE846864BAD0AD1CA428FBEFABF2CD8CF13A6,$B6B7FBA5874DD4F4337CCFAA460C3B92C264C0ED,$E841B711D279EC27C1555281FA61568B6C45A919
 Bridge 128.2.142.99:9002
 UseBridges 1
 UseMicroDescriptors 0
 SafeLogging 0
 Log debug stderr
 }}}

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/9546#comment:7>
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