Padding circuits were regular cells that got closed before their padding
machine could finish. This means that they can still receive regular cells from
their past life, but they have no way or reason to answer them anymore. Hence
let's ignore them before they even get to the proper subsystems.
This test runs practracker with a set of 0 thresholds, to make sure
that it enumerates all its values right. It tries running with an
empty exceptions file, and with an exceptions file that covers
_some_ of the data, and it makes sure that the outputs are as expected.
Now that there is only one toplevel place where we print problems,
we can redirect just that one print to a file when we are
regenerating the exceptions.txt file. Previously we redirected
sys.stdout, which is naughty, and forced us to send warnings (and
warnings alone) to stderr.
These flags let you suppress the message about the number of
problems and warnings, and let you control the thresholds above
which something counts as a problem.
I need this for testing.
Instead of having "consider" functions that have to call a global
ProblemVault, we can now generate all the metrics for the code
separately from the decision about what to do for them.
I'm about to refactor the code into a set of iterators that yield
*all* the metrics for the code, and then add a filter on top of that
to return the problems.
When an exception is present, we can now violate the limit by a little
bit and only produce a warning. The strict flag overrides this
behavior.
I've given file sizes a 2% tolerances and function sizes/include
counts a 10% tolerance.
Part of 30752
Instead of excluding directories at the last minute if they happen
to appear in our filenames, we exclude them early, before recursing
into all their subdirectories.
Part of 29746.
The practracker_tests.py unit test file called a function by its old
name.
Also, practracker counted functions as starting one line after the
function name, and ending with the closing brace. Now they start
with the open brace and end with the closing brace.
Coverity doesn't understand that if begin_cell_parse() returns 0 and
sets is_begindir to 0, its address field will always be set.
Fixes bug 30126; bugfix on 0.2.4.7-alpha; Fixes CID 1447296.
Proposal 289 prevents SENDME-flooding by requiring the other side to
authenticate the data it has received. But this data won't actually
be random if they are downloading a known resource. "No problem",
we said, "let's fell the empty parts of our cells with some
randomness!" and we did that in #26871.
Unfortunately, if the relay data payloads are all completely full,
there won't be any empty parts for us to randomize.
Therefore, we now pick random "randomness windows" between
CIRCWINDOW_INCREMENT/2 and CIRCWINDOW_INCREMENT. We remember whether we have
sent a cell containing at least 16 bytes of randomness in that window. If we
haven't, then when the window is exhausted, we send one. (This window approach
is designed to lower the number of rng checks we have to do. The number 16 is
pulled out of a hat to change the attacker's guessing difficulty to
"impossible".)
Implements 28646.
Turns out that we were only recording the "b_digest" but to have
bidirectionnal authenticated SENDMEs, we need to use the "f_digest" in the
forward cell situation.
Because of the cpath refactoring, this commit plays with the crypt_path_ and
relay_crypto_t API a little bit in order to respect the abstractions.
Previously, we would record the cell digest as the SENDME digest in the
decrypt cell function but to avoid code duplication (both directions needs to
record), we now do that right after iff the cell is recognized (at the edge).
It is now done in circuit_receive_relay_cell() instead.
We now also record the cell digest as the SENDME digest in both relay cell
encryption functions since they are split depending on the direction.
relay_encrypt_cell_outbound() and relay_encrypt_cell_inbound() need to
consider recording the cell digest depending on their direction (f vs b
digest).
Fixes#30428
Signed-off-by: David Goulet <dgoulet@torproject.org>
It turns out that only the exit side is validating the authenticated SENDME v1
logic and never the client side. Which means that if a client ever uploaded
data towards an exit, the authenticated SENDME logic wouldn't apply.
For this to work, we have to record the cell digest client side as well which
introduced a new function that supports both type of edges.
This also removes a test that is not valid anymore which was that we didn't
allow cell recording on an origin circuit (client).
Part of #30428
Signed-off-by: David Goulet <dgoulet@torproject.org>
