Specifically, you can look at the directory to see if somebody is
lying about a relay (mismatched IDs, etc), but you can't modify
the list of linkspecs.
We were previously a bit unclear on how to handle multiple linkspecs
of type ed25519, and our spec didn't actually permit Tor's current
behavior.
Now we say that both Ed25519 ID and Legacy ID linkspecs MUST appear
at most once in a list of linkspecs, and that parties SHOULD
enforce this.
This is "problem 1" on torspec#193.
These new names are the ones used in arti's hsdir_ring.rs and make a
lot more sense than calling one of them the "directory" index and
the other just the "index".
In C Tor these are calculated by functions called
hs_build_hs_index
hs_build_hsdir_index
That might be a reason *not* to accept this change. Or it might be a
reason to change the C Tor code.
If we don't change the names in the spec the Arti function names
should change.
These names are slightly shorter and a bit more descriptive IMO, and
now (when they are still fresh) is the best time to rename these
keys.
`hs_intro_tid` becomes `hs_ipt_sid`: It is a _session identifier_
key used with an _introduction point_. Using `ipt` here emphasizes
that it is not part of the introduction _handshake_.
`hs_intro_ntor` becomes `hss_ntor`. The extra "s" means it is owned
by the service. Renaming "intro" here removes the implication that
it is held by or used by the introduction point.
`onion_ntor` becomes `ntor`: There is no such thing as an ntor key
that is not an onion key.
It looks like C tor doesn't include a final newline in the middle
layer of its onion service descriptors. That made arti reject them
the first time I tried to parse one! Here I document this behavior,
and tell other implementations what to do.
In particular, give these formal names which contain "hs" (since they
are part of the hidden service protocol, and not any other kind of
authentication or authorisation scheme), and "N" to indicate that they
are hash-generated nonces, not passwords.
Change the references in the formulae, which it really seems to me
ought to refer to the formal names.
All supported versions for relays on the Tor network support v3
onion services. As such, we can mark the sections about "how do I
use an 0.2.9.x relay as my intro/rend point?" as obsolete.
These patch changes describe new default behaviors for extension
field lists, as appear in ntor3 and in many places throughout the
ntor3 protocol. In general:
* Unrecognized extensions MUST be ignored.
Additionally, all the following rules apply _unless otherwise stated
in the documentation for an extension.
* Extensions are sent in sorted order.
* Extensions should only be sent once in a message
* If you receive multiple copies of an extension, only the first
one counts.
This comes out of discussions on tor!525.
