When considering introduction point of a service's descriptor, do not remove
an intro point that has an established or pending circuit.
Fixes#31652
Signed-off-by: David Goulet <dgoulet@torproject.org>
When encoding introduction points, we were not checking if that intro points
had an established circuit.
When botting up, the service will pick, by default, 3 + 2 intro points and the
first 3 that establish, we use them and upload the descriptor.
However, the intro point is removed from the service descriptor list only when
the circuit has opened and we see that we have already enough intro points, it
is then removed.
But it is possible that the service establishes 3 intro points successfully
before the other(s) have even opened yet.
This lead to the service encoding extra intro points in the descriptor even
though the circuit is not opened or might never establish (#31561).
Fixes#31548
Signed-off-by: David Goulet <dgoulet@torproject.org>
- The function `decrypt_desc_layer` has a cleaner interface.
- `is_superencrypted_layer` changed from `int` -> `bool`
[ticket details](https://trac.torproject.org/projects/tor/ticket/31589)
add(changes/*): changes file
fix(src/features/hs): is_superencrypted changed from `int` -> `bool`
fix(changes/ticket31589): header
add(changes/ticket31589): subsystem(onion services) to change
Move everything to its own function in order to better log, document and tests
the introduction point validation process.
Signed-off-by: David Goulet <dgoulet@torproject.org>
When consensus changes, we also need to update the circuit INTRO2 defenses
enabled flag and not only the token bucket.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Remove the public functions returning the HS DoS consensus param or default
values as it is exclusively used internally now.
Rename the param_* variables to consensus_param_* for better code semantic.
Finally, make some private functions available to unit tests.
Signed-off-by: David Goulet <dgoulet@torproject.org>
This commit makes it that the hs_dos.c file only uses the consensus parameter
variables set when we initialize and when the consensus changes.
There is no need to call each time networkstatus_get_param(), which is
expensive, when we want access to a consensus value.
Signed-off-by: David Goulet <dgoulet@torproject.org>
A bit cleaner especially that the next commit(s) will make the consensus param
interface private to hs_dos.c so we expose as little as we can outside of the
subsystem.
Part of #30924
Signed-off-by: David Goulet <dgoulet@torproject.org>
This commit makes tor add the DoS cell extension to the ESTABLISH_INTRO cell
if the defense is enabled on the service side with a torrc option.
Furthermore, the cell extension is only added if the introduction point
supports it. The protover version HSIntro=5 is looked for.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Make it clear that these functions return the consensus param only.
Introduction point can not set those values with a torrc option.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Previously, v3 single onion services failed when all intro nodes were
unreachable via a 1-hop path. Now, we select intros that are only available
via a 3-hop path, and use a 3-hop path to connect to them.
Fixes bug 23507; bugfix on 0.3.2.1-alpha.
Previously, we used a 1-hop path when a single onion rend failed
immediately, and a 3-hop path when it failed after trying to build
a circuit.
Fixes bug 23818; bugfix on 0.3.2.1-alpha.
In case the consensus parameters for the rate/burst changes, we need to update
all already established introduction circuits to the newest value.
This commit introduces a "get all intro circ" function from the HS circuitmap
(v2 and v3) so it can be used by the HS DoS module to go over all circuits and
adjust the INTRODUCE2 token bucket parameters.
Signed-off-by: David Goulet <dgoulet@torproject.org>
This commit add the hs_dos.{c|h} file that has the purpose of having the
anti-DoS code for onion services.
At this commit, it only has one which is a function that decides if an
INTRODUCE2 can be sent on the given introduction service circuit (S<->IP)
using a simple token bucket.
The rate per second is 25 and allowed burst to 200.
Basic defenses on #15516.
Signed-off-by: David Goulet <dgoulet@torproject.org>
This shouldn't be possible while Tor is running, but the tests can
hit this code. Rather than force the tests to add a dummy channel
object, let's just tolerate their incompletely built circuits.
This will effectively also deny any bridge to be used as a single hop to the
introduction point since bridge do not authenticate like clients.
Fixes#24963
Signed-off-by: David Goulet <dgoulet@torproject.org>
