These docs were first written back when we had both a blocking and a
non-blocking API. I removed all the blocking code a long time ago, leaving on
the Twisted-based non-blocking API, but I forgot to update the docs to match,
which is why some of the text didn't make much sense.
Python.org is still supporting 3.4, but the lastest pypiwin32 stopped
providing binary wheels for windows for 3.4, so we can't run the appveyor CI
tests any more. It might still work there, but you'll have to find a way to
build pypiwin32 yourself.
We still support py3.4 on non-windows platforms.
Previously, w.when_verified() was documented to fire only after a valid
encrypted message was received, but in fact it fired as soon as the shared
key was derived (before any encrypted messages are seen, so no actual
"verification" could occur yet).
This fixes that, and also adds a new w.when_key() API call which fires at the
earlier point. Having something which fires early is useful for the CLI
commands that want to print a pacifier message when the peer is responding
slowly. In particular it helps detect the case where 'wormhole send' has quit
early (after depositing the PAKE message on the server, but before the
receiver has started). In this case, the receiver will compute the shared
key, but then wait forever hoping for a VERSION that will never come. By
starting a timer when w.when_key() fires, and cancelling it when
w.when_verified() fires, we have a good place to tell the user that something
is taking longer than it should have.
This shifts responsibility for notifying Boss.got_verifier, out of Key and
into Receive, since Receive is what notices the first valid encrypted
message. It also shifts the Boss's ordering expectations: it now receives
B.happy() before B.got_verifier(), and consequently got_verifier ought to
arrive in the S2_happy state rather than S1_lonely.
