In this commit, we make sig job handling when singing a next commitment
non-blocking by allowing the shutdown of a channel link to prevent
further waiting on sig jobs by the channel state machine. This addresses
possible cases where the aux signer may be shut down via a separate quit
signal, so the state machine could block indefinitely on receiving an
update on a sig job.
In this commit, we expand some of the existing chan sync tests to cover
taproot channels (the others already did). Along the way, we always
assert that the `PartialSig` is populated on retransmission. In
addition, we now send the new commit sig rather than the existing
in-memory one to test the new logic that re-signs the commitment.
In this commit, we fix an existing bug with the taproot channel type that can cause force closes if a peer disconnects while attempting to send the commitment signature.
Before this commit, since the `PartialSig` we send is never committed to disk, the version read wouldn't contain the musig2 partial sig. We never write these signatures to disk, as each time we make a new session, we need to generate fresh nonces to avoid nonce-reuse.
Due to the above interaction, if we went to re-send a signature after a disconnection, the `CommitSig` message we sent wouldn't actualy contain a `PartialSigWithNonce`, causing a protocol error.
Before this commit, we weren't properly setting the aux HTLC blob when
we went to retransmit a signature. We fix this by setting the
`ExtraData` field as expected in the `CommitSig` message.
In this commit, we fix three existing bugs in the way we make
`ResolutionReq` for breach handling:
1. We were passing in the commit blob of the *current* channel state,
instead of the one stored in the revocation log for this breached
state.
2. We were using theirDelay for CsvDelay, when we want ourDelay, which
in this case will be 1 CSV, as this is a non delayed output.
3. We also need to pass in the delay for the remote party's to_local
delayed output.
In this commit, we add a new AuxSweeper interface. This'll take a set of
inputs, and a change addr for the sweep transaction, then optionally
return a new sweep output to be added to the sweep transaction.
We also add a new NotifyBroadcast method. This'll be used to notify
that we're _about_ to broadcast a sweeping transaction. The set of
inputs is passed in, which allows the caller to prepare for the ultimate
broadcast of the sweeping transaction.
We also add ExtraTxOut to BumpRequest pass fees to NotifyBroadcast. This
allows the callee to know the total fee of the sweeping transaction.
This will be used by external callers to modify the way we resolve
contracts on chain. For a given contract, we'll store an extra "blob",
that will later be presented during the sweeping phase.
We always need to set the close output in order for us to be able
to calculate the closing keys. Especially if there is only a dust
balance in BTC terms but perhaps a valuable amount in custom channel
funds.
In this commit, we move to add the internal key to the delivery addr. This way, we give the aux chan closer the extra information it may need to properly augment the normal co-op close process.
To avoid sorting issues with identical HTLCs (equal size, equal payment
hash, equal CLTV), we need to also use the HTLC index to be able to
distinguish between them.
It doesn't make sense to do multiple encode/decode round trips on the
custom data of an HTLC. So we just use the same custom record type
everywhere, which also simplifies some of the code again.
In this commit, we start to use the new AuxSigner to obtain+verify aux sigs for all second level HTLCs. This is similar to the existing SigPool, but we'll only attempt to do this if the AuxSigner is present (won't be for most channels).
In this commit, we add a new aux signer interface that's meant to mirror the SigPool. If present, this'll be used to (maybe) obtain signatures for second level HTLCs for certain classes of custom channels.
For the initiator, once we get the signal that the PSBT has been
finalized, we'll call into the aux funder to get the funding desc. For
the responder, once we receive the funding_created message, we'll do the
same.
We now also have local+remote aux leaves for the commitment transaction.
Some old TODO comments that in retrospect aren't required anymore are
removed as well.
In this commit, we modify the aux funding work flow slightly. We won't
be able to generate the full AuxFundingDesc until both sides has
sent+received funding params. So we'll now only attempt to bind the
tapscript root as soon as we send+recv the open_channel message.
We'll now also make sure that we pass the tapscript root all the way
down into the musig2 session creation.
