[tor-dev] Descriptor-id and responsible hidden service directorate. Changes in version 0.2.4.18-rc - 2013-11-16

[George Kadianakis]

Frank Young <pfcodes at gmail.com> writes:

> I have noticed that since the release of version 0.2.4.18-rc - 2013-11-16,
> Attempts to fetch v2 rendezvous service descriptor are failing.
> The issue seems to get worse as many people are updating their clients.
>
> The calculation of decriptor ids based on specification in rend-spec.tx
> <descriptor-id = H(permanent-id | H(time-period | descriptor-cookie |
> replica))> doeesn't seems to be correct anymore. All 6 responsible
> hidden services directorates return 404 to a GET request for
> /tor/rendezvous2/<base32_encode[descriptor-id]>
>
> I search through the tor source for the release version (0.2.4.18-rc -
> 2013-11-16) in rend_compute_v2_desc_id and
> rend_client_refetch_v2_renddesc but failed to notice any  significant
> change. Could any member of the dev team respond to to this?

You need to use BEGIN_DIR:
https://gitweb.torproject.org/torspec.git/blob/HEAD:/tor-spec.txt#l1364

HSDirs have been using solely BEGIN_DIR for a while. I'm not sure why,
maybe so that the plaintext HTTP requests and responses are not
sniffable by the adversary. There was also a ticket on trac somewhere
that I can't find now.