[tor-bugs] #18221 [Tor]: Validate our DH parameters to prevent socat-type fails.

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#18221: Validate our DH parameters to prevent socat-type fails.
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 Reporter:  yawning          |          Owner:
     Type:  enhancement      |         Status:  needs_review
 Priority:  Medium           |      Milestone:  Tor: 0.2.8.x-final
Component:  Tor              |        Version:  Tor: unspecified
 Severity:  Normal           |     Resolution:
 Keywords:  tor-core crypto  |  Actual Points:
Parent ID:                   |         Points:
  Sponsor:                   |
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Comment (by cypherpunks):

 Replying to [comment:3 yawning]:
 > Replying to [comment:2 nickm]:
 > > Looks correctly written.  I'm not clear what exactly the threat model
 is here, though.  "We replace the primes with something we think is prime,
 but we forget to check"?  "An attacker backdoors our software but doesn't
 figure out how to remove this check, or can't for some reason"?
 >
 > More the former than the latter.

 If the threat is the former, why is it necessary to perform the check on
 every startup? Isn't a build-time unit test sufficient?

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/18221#comment:4>
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