Previously the encryption key used for "phase messages" (anything sent
from one side to the other, protected by the shared PAKE-generated
session key) was derived just from the session key and the phase name.
The two sides would use the same key for their first message (but with
random, thus different, nonces).
This uses the sending side's string (a random 5-byte/10-character hex
string) in the derivation process too, so the two sides use different
keys. This gives us an easy way to reject reflected messages. We already
ignore messages that claim to use a "side" which matches our own (to
ignore server echoes of our own outbound messages). With this change, an
attacker (or the server) can't swap in the payload of an outbound
message, change the "side" to make it look like a peer message, and then
let us decrypt it correctly.
It also changes the derivation function to combine the phase and side
values safely. This didn't matter much when we only had one
externally-provided string, but with two, there's an opportunity for
format confusion if they were combined with a simple delimiter. Now we
hash both values before concatenating them.
This breaks interoperability with clients from before this change. They
will always get WrongPasswordErrors.
* add "released" ack-response for "release" command, to sync w.close()
* move websocket URL to root
* relayurl= should now be a "ws://" URL
* many tests pass (except for test_twisted, which will be removed, and
test_scripts)
* still moving integration tests from test_twisted to
test_wormhole.Wormholes
This made sense for ServerSentEvent channels (which has no purpose once
the channel was gone), but not so much for websockets. And it prevented
testing duplicate-close.
Pass in a handle and a pair of functions, rather than an object with two
well-known methods. This should make it easier to subscribe to multiple
channels in the future.
but only if the client is modern enough to include "id" in the message,
which lets us avoid sending acks to an 0.7.5 client (which would cause
them to abort, they don't like unrecognized server messages).
The acks let the client learn the server_rx time of messages that
terminate on the server, like "allocate" and "claim".
This improves the error behavior when --verify is used but there's a
WrongPasswordError: the mismatch is detected before the verifiers are
displayed or confirmation is requested.
It requires that the far end sends a "_confirm" message, which was
introduced in release 0.6.0. Use with older versions (if it doesn't
break for other reasons) will cause a hang.
This patch also deletes test_twisted.Basic.test_verifier_mismatch, since
both sides now detect this on their own. It changes
test_wrong_password() too, since we might now notice the error during
send_data (previously we'd only see it in get_data).
One downside is that we keep the wormhole channel allocated longer (we
have to finish the file transfer before we can deallocate it, which
could take a while for large files). Maybe we can fix this in the
future.
Also clean up test_scripts.PregeneratedCode:
* fetch results from both sides at the same time
* only check rc when using a subprocess, since the direct call doesn't
use rc=0 anymore
* no need to cancel the other side's Deferred when one errors
* provide more information if stderr was non-empty
And provide a close() that can live at the end of a Deferred chain, so
callers can do d.addBoth(w.close).
I like auto-close-on-error in general, but I'm removing it so I can
clean up the error-handling pathways. It will probably come back later.
The constraint is that it must be possible to wait on the return
Deferred that close() gives you (to synchronize tests, or keep the CLI
program running long enough to deallocate the channel) even if something
else (and error handler) called close() earlier. This will require
either a OneShotObserverList, or keeping a "deallocated" Deferred around
in case more callers want to wait on it later.
If we're closing because of an error, we need to sleep through the old
error, to be able to wait for the "deallocated" message. This might want
to be different: maybe clear the error first, or store the errors in a
list and sleep until a second error happens.
These were split out to make the blocking- and twisted- based
implementations share some code, but now that we're down to just
Twisted, it's clearer to merge them back in.
Hitting Control-C (which sends SIGINT) while we're waiting in the
readline-based input_code() function didn't shut down the process
properly: the reactor would wait for the readline thread to exit, which
wouldn't happen until it finished getting a code, which requires the
user to hit Return. I haven't found a good way to force the thread to
exit, or to synthetically inject a newline into stdin. So my compromise
is to tell the user that they need to hit Return to finish interrupting
the command.
See the _warn_readline() function for a list of other potential
approaches.
This should speed up the protocol, since we don't have to wait for
acks (HTTP responses) unless we really want to. It also makes it easier
to have multiple messages in flight at once. The protocol is still
compatible with the old HTTP version (which is still used by the
blocking flavor), but requires an updated Rendezvous server that speaks
websockets.
set_code() no longer touches the network: it just stores the code and
channelid for later. We hold off doing 'claim' and 'watch' until we need
messages, triggered by get_verifier() or get_data() or send_data().
We check for error before sleeping, not just after waking. This makes it
possible to detect a WrongPasswordError in get_data() even if the other
side hasn't done a corresponding send_data(), as long as the other side
finished PAKE (and thus sent a CONFIRM message). The unit test was doing
just this, and was hanging.
This allows the Wormhole setup path to be simpler: consistently doing a
claim() just before watch(), regardless of whether we allocated the
channelid (with get_code), or dictated it (with set_code or
from_serialized).
The websocket lives on a Resource of the main rendezvous web site, and
the websocket URL is derived from the main "relay_url", so there's no
extra port to allocate, and no extra service to shut down.
Deliver not-yet-JSONed objects to listeners (both in broadcast_message
and as the "catch-up" responses to add_listener). Also make the (web)
frontend responsible for adding "sent" timestamps. This all makes
rendezvous.py less web-centric.
This uses a single TCP connection to the relay server for all
requests (although it probably uses a second one for the downstream
EventSource feed). This should squeeze out some of the round-trip times.
This adds an expected= argument to Connection.connectConsumer(), which
then returns a Deferred that fires when enough bytes have been written
to the consumer. It also adds Connection.writeToFile(), a helper method
that writes bytes to a filehandle.
I made the classic dataReceived() mistake, and exited the function after
delivering the first record. Keep at it until there are no complete
records left.
The previous commits improve test failures by dropping relay connections
at shutdown, and flunking a test quickly when one client fails but the
other one hangs.
If that doesn't work (say, some client has a time.sleep(), or other
stall that isn't affected by the relay shutdown), we'll be left with an
active thread holding that hanging client.
This patch adds a check to wormhole.test.common.ServerBase.tearDown that
looks for active threads, waits a second (after stopService), then
checks the threadpool again. If the threadpool is empty, everything is
fine. If not, it prints a message (to stdout) to inform the impatient
user why the test is probably hanging.
When test_scripts ran two clients at the same time, an error in one
could leave the other hanging (in a thread). One Deferred would errback,
the other would hang. Tests wait on one Deferred at a time, so if we're
unlucky and were waiting on the hanging Deferred (instead of the
erroring one), we'll wait forever, or at least until the default test
timeout of 180 seconds.
This adds an errback to notice when either client has errored, and
cancels the other Deferred, so it doesn't matter which one we wait upon
first.
'readline' is part of the python stdlib, so declaring a dependency on it
doesn't help. It doesn't exist on windows, and the pypi 'readline'
module doesn't work on windows. So instead, just attempt to import
readline, and if that fails, fall back to a non-completion flavor.
This ensures that we'll be ready for them. Previously there was a race
between us revealing the direct hints to the peer, and us setting the
transit key (thus allowing us to check inbound handshake requests). The
Transit instance didn't handle the race, causing errors to be thrown
when the other side connected quickly.
This ensures that we'll be ready for them. Previously there was a race
between us revealing the direct hints to the peer, and us setting the
transit key (thus allowing us to check inbound handshake requests). The
Transit instance handles this race (with an interlock on the transit
key), but it's still nicer to do it cleanly.
This exposed a new race in Transit, where the inbound connection would
complete before transit.connect() had been called. The previous commit
adds an interlock to wait for that too. Until this change, the transit
key lock was covering that one up.
Some tests failed to override --transit-helper, which meant they
intermittently talked to the real transit server (briefly, before
deciding the local+direct connection was better).
