IMO it's fine for us to make exceptions to this rule in the unit
tests, but not in the code at large.

Improves the fix to #18963.

it used to be a tri-state, but now it's just a bi-state, so we can
take out all the machinery like the enum.

When we made HidServDirectoryV2 always 1, we removed the situation
where a relay could choose not to be an HSDir. Now simplify the
rest of the code to reflect this decision.

(We have to remove two apparently unrelated free() calls in the unit
tests, since they used to free stuff that we created as a side effect
of calling router_get_my_routerinfo(), and now we no longer call that.)

This simplifies relay behavior, because the relay offers the hsdir
functionality independent of whether the directory authorities have
decided this relay is suitable for clients to use yet.

Implements ticket 18332.

They are no longer "all" digests, but only the "common" digests.

Part of 17795.

This is an automated patch I made with a couple of perl one-liners:

  perl -i -pe 's/crypto_digest_all/crypto_common_digests/g;' src/*/*.[ch]
  perl -i -pe 's/\bdigests_t\b/common_digests_t/g;' src/*/*.[ch]

Update the code for IPv6 authorities and fallbacks for function
argument changes.

Update unit tests affected by the function argument changes in
the patch.

Add unit tests for authority and fallback:
 * adding via a function
 * line parsing
 * adding default authorities
(Adding default fallbacks is unit tested in #15775.)

cypherpunks authored Nov 11, 2015 and Nick Mathewson committed Dec 09, 2015

The tests pass empty digest strings to the dir_server_new function which
copies it into a directory server structure. The copy operation expects
the digest strings to be DIGEST_LEN characters long.

Because the length of the empty digest strings are lower than
DIGEST_LEN, the copy operation reads outside the digest strings which
leads to buffer over-reads.

The issue is resolved by using character arrays with a size of
DIGEST_LEN.

Patch on 4ff08bb5.