[tor-talk] some clarifications on hidden services ...

[grarpamp]

I always thought that document needed a bit of editing as to how things
are phrased, better sectioning out of each step, number of nodes/hops
chosen/controlled by each side, etc. Will look it over again, been a while.

Also, I think rend-spec.txt needs clarified about how things
work regarding:
"
    506    At any time, there are 6 hidden service directories responsible for
    507    keeping replicas of a descriptor; they consist of 2 sets of 3 hidden
    508    service directories with consecutive onion IDs. Bob's OP learns about
    509    the complete list of hidden service directories by filtering the
    510    consensus status document received from the directory authorities. A
    511    hidden service directory is deemed responsible for a descriptor ID if
    512    it has the HSDir flag and its identity digest is one of the
first three
    513    identity digests of HSDir relays following the descriptor ID in a
    514    circular list.
"
That covers the first set of three (as being the first three after your ID).
But where is the second set of three, making up the six, located?

Hmm, I just noticed...
Pretty sure it's the 'replica'. If so, that and it's current values [0,1 or
1,2 or ?], should be cross referenced above "based on replica number"
and around line 274.
"
    273        "replica" denotes the number of the replica. A service publishes
    274        multiple descriptors with different descriptor IDs in order to
    275        distribute them to different places on the ring.
"

The octet map of a v2 descriptor should be included around  line 222.