[tor-bugs] #24767 [Core Tor/Tor]: All relays are constantly connecting to down relays and failing over and over

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#24767: All relays are constantly connecting to down relays and failing over and
over
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 Reporter:  arma                                 |          Owner:  dgoulet
     Type:  enhancement                          |         Status:
                                                 |  needs_review
 Priority:  Very High                            |      Milestone:  Tor:
                                                 |  0.3.3.x-final
Component:  Core Tor/Tor                         |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  tor-relay, tor-dos, performance,     |  Actual Points:
  review-group-32, 033-must                      |
Parent ID:                                       |         Points:
 Reviewer:  asn, teor                            |        Sponsor:
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Comment (by dgoulet):

 Replying to [comment:22 teor]:
 > There are two design issues here:
 > * the HT implementation only uses 32 bit hashes on 64-bit LP64 systems,
 like macOS and the BSDs, and 32-bit systems (split off into #25365)
 > * the port is user-controlled, so it needs to be hashed before being
 combined with the other hashes

 What is the danger here? The length is fixed so what is the difference
 between "+= 42" or "+= h(42)" ?

 > I fixed the port issue, and the compilation issues in my branch
 bug24767_033_02 on https://github.com/teor2345/tor.git

 For the hash fix, wouldn't it be more efficient to then combined addr +
 digest + port in a buffer and siphash that instead of doing 3 rounds of
 siphash?

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24767#comment:23>
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