Tor 0.2.7.3-rc: "Extrainfo digest did not match digest256 from routerdesc"

Installing tor the 2nd time in a row gives tons of these warnings :

Sep 24 23:00:53.000 [warn] router info incompatible with extra info (ri id: 000149E6EF7102AACA9690D6E8DD2932124B94AB, ei id 000149E6EF7102AACA9690D6E8DD2932124B94AB, reason: Extrainfo digest did not match digest256 from routerdesc)
...

changed milestone to %Tor: 0.2.7.x-final in legacy/trac

added 027-backport in Legacy / Trac actualpoints::0.3 in Legacy / Trac component::core tor/tor in Legacy / Trac milestone::Tor: 0.2.7.x-final in Legacy / Trac owner::nickm in Legacy / Trac points::small in Legacy / Trac priority::medium in Legacy / Trac resolution::fixed in Legacy / Trac severity::normal in Legacy / Trac status::closed in Legacy / Trac type::defect in Legacy / Trac version::tor 0.2.7 in Legacy / Trac labels

Hm. This should probably get downgraded if it's happening from cache. My guess would be that it happens when you already downloaded a bunch of new ris but haven't gotten the corresponding eis yet.

Trac:
Milestone: N/A to Tor: 0.2.7.x-final

Digest256 for extrainfo is new in 0.2.7 though. I wonder...

I wonder if this code in routerparse.c could be wrong...

  crypto_digest256((char*)extrainfo->digest256, s, end-s, DIGEST_SHA256);

Maybe s is the wrong starting point or end is the wrong ending point...

0b819a2a is where we started enforcing this, and that went into 0.2.7.2-alpha...

Trac:
Priority: normal to major
Status: new to accepted
Sponsor: N/A to N/A
Owner: N/A to nickm

Trac:
Summary: re-installing tor.00.2.7.3 yields to to Tor 0.2.7.3-rc: "Extrainfo digest did not match digest256 from routerdesc"

I pushed one more commit to fix GCC warnings. Valgrind shows no memory issues.

Trac:
Severity: N/A to Normal

(I think that comment above was meant to go on another ticket, probably legacy/trac#16382 (moved))

In backport pass for 0.2.7, and it doesn't look like this ticket ever got fixed. Reassigning to 0.2.8.x-final.

Trac:
Milestone: Tor: 0.2.7.x-final to Tor: 0.2.8.x-final
Reviewer: N/A to N/A

These 0.2.8 items really should get handled in May. Or earlier.

Trac:
Keywords: N/A deleted, TorCoreTeam201605 added

Calling all non-needs_information tickets for May.

hey, there's a patch here.

Trac:
Status: accepted to needs_review
Points: N/A to small
Keywords: TorCoreTeam201605 deleted, TorCoreTeam201605 028-backport added

wait, no there isn't. I think since the warning is already downgraded we can call this 0.2.???

Trac:
Milestone: Tor: 0.2.8.x-final to Tor: 0.2.???
Priority: High to Medium
Keywords: TorCoreTeam201605 028-backport deleted, N/A added

Trac:
Status: needs_review to new

legacy/trac#19017 (moved) is a duplicate, and suggests that this is not as fixed as we might hope.

Trac:
Keywords: N/A deleted, must-fix-before-028-rc added
Actualpoints: N/A to 0.3
Milestone: Tor: 0.2.??? to Tor: 0.2.8.x-final

Please see my branch bug17150_027 for a possible fix (against 0.2.7) and an explanation of the bug.

My branch bug17150_027_extra has an extra fix on top of that branch which makes this error non-repeatable. I suggest that we don't take that extra fix into 0.2.7 (if we backport).

Note that in one of the commits (8acfac73) I chose to duplicate a field instead of moving it, to avoid conflicts with numerous dirauth fixes in 0.2.8 and beyond. The commit message discusses more.

Trac:
Status: new to needs_review
Keywords: must-fix-before-028-rc deleted, must-fix-before-028-rc 027-backport added

The code in both of these branches looks good. bug17150_027_extra passes the unit tests and make test-network-all.

Just one more thing that needs to be done: "I should open another ticket about removing the field from routerinfo_t and extrainfo_t later on."

While I can see why we'd want to backport this to 0.2.7, is it a security bug? Will weasel take it in the tor debian package? If not, it's only worth backporting to 0.2.8.

Trac:
Status: needs_review to merge_ready