This better reflects the purpose of the message. Key confirmation is a
side-effect.
This patch only changes the "phase:" name and the key-derivation string.
A subsequent patch will modify the function and variable names to match.
The file-send protocol now sends a "hints-v1" key in the "transit"
message, which contains a list of JSON data structures that describe the
connection hints (a mixture of direct, tor, and relay hints, for now).
Previously the direct/tor and relay hints were sent in different keys,
and all were sent as strings like "tcp:hostname:1234" which had to be
parsed by the recipient.
The new structures include a version string, to make it easier to add
new types in the future. Transit logs+ignores hints it cannot
understand.
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
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).
