In a nutshell, since a circuit can not exit at its entry point, it's very
easy for an attacker to find the hidden service guard if only one EntryNodes
is specified since for that guard, the HS will refuse to build a rendezvous
circuit to it.
For now, the best solution is to stop tor to allow a single EntryNodes for
an hidden service.
Fixes#14917
Signed-off-by: David Goulet <dgoulet@ev0ke.net>
Only applies to connections with SOCKS auth set, so that non-web Tor
activity is not affected.
Simpler version of Nick's patch because the randomness worried me, and I'm not
otherwise sure why we want a max here.
In validate_recommended_package_line, at this point in the function,
n_entries is always >= 1. Coverity doesn't like us checking it for
0.
CID 1268063.
Removes a check to PublishHidServDescriptors in
rend_consider_services_upload(). This allows descriptors to be
generated and stored in the local cache when PublishHidServDescriptor = 0.
Keep the PublishHidServDescriptors option check in
rend_consider_descriptor_republication(). We will never need to republish
a descriptor if we are not publishing descriptors to the HSDirs.
Service descriptors are now generated regardless of the the
PublishHidServDescriptors option. The generated descriptors are stored
in the service descriptor cache.
The PublishHidServDescriptors = 1 option now prevents descriptor
publication to the HSDirs rather than descriptor generation.
Deindent a block of code inside the PublishHidServDescriptors option
check in upload_service_descriptor(). Stylistic commit to make the
subsequent reworking of this code cleaner.
The HS_DESC CREATED event should be emmited when a new service descriptor
is generated for a local rendevous service. This event is documented
in the control spec.
This commit resolves ticket #16291.
Adds a service descriptor cache which is indexed by service ID. This
descriptor cache is used to store service descriptors generated by a
local rendevous service.
The service-side cach can be queried by calling rend_cache_lookup_entry()
with the 'service' argument set to 1.
We used to use this when we had some controllers that would accept
long names and some that wouldn't. But it's been obsolete for a
while, and it's time to strip it out of the code.
Previously we'd put these strings right on the controllers'
outbufs. But this could cause some trouble, for these reasons:
1) Calling the network stack directly here would make a huge portion
of our networking code (from which so much of the rest of Tor is
reachable) reachable from everything that potentially generated
controller events.
2) Since _some_ events (EVENT_ERR for instance) would cause us to
call connection_flush(), every control_event_* function would
appear to be able to reach even _more_ of the network stack in
our cllgraph.
3) Every time we generated an event, we'd have to walk the whole
connection list, which isn't exactly fast.
This is an attempt to break down the "blob" described in
http://archives.seul.org/tor/dev/Mar-2015/msg00197.html -- the set of
functions from which nearly all the other functions in Tor are
reachable.
Closes ticket 16695.
