With this commit, the channel is now aware of if it's a musig2 channel, that also has a tapscript root. We'll need to always pass in the tapscript root each time we: make the funding output, sign a new state, and also verify a new state.
In this commit, we update new Taproot related TLVs (nonces, partial sig,
sig with nonce, etc). Along the way we were able to get rid of some
boiler plate, but most importantly, we're able to better protect against
API misuse (using a nonce that isn't initialized, etc) with the new
options API. In some areas this introduces a bit of extra boiler plate,
and where applicable I used some new helper functions to help cut down
on the noise.
Note to reviewers: this is done as a single commit, as changing the API
breaks all callers, so if we want things to compile it needs to be in a
wumbo commit.
ShutdownInfo contains any info about a previous Shutdown message that we
have sent. This commit adds this type along with read and write methods
for it in the channel db. The existence of the ShutdownInfo on disk
represents the fact that we have previously sent the Shutdown message
and hence that we should resend it on re-establish.
In this commit, we update the co-op close flow to support the new musig2
keyspend flow. We'll use some new functional options to allow a caller
to pass in an active musig2 session. If this is present, then we'll use
that to complete the musig2 flow by signing with a partial signature,
and then ultimately combining the signatures at the end.
Our OpenChannelRPC was accepting invalid values for the closing address
field. If we were able to decode the address we would use it in the
script even if the address is for another bitcoin net.
In this commit, we modify the way we compute the starting ideal fee for
the co-op close transaction. Before thsi commit, channel.CalcFee was
used, which'll compute the fee based on the commitment transaction
itself, rathern than the co-op close transaction. As the co-op close
transaction is potentailly bigger (two P2TR outputs) than the commitment
transaction, this can cause us to under estimate the fee, which can
result in the fee rate being too low to propagate.
To remedy this, we now compute a fee estimate from scratch, based on the
delivery fees of the two parties.
We also add a bug fix in the chancloser unit tests that wasn't caught
due to loop variable shadowing.
The wallet import itest has been updated as well, since we'll now pay
600 extra saothis to close the channel, since we're accounting for the
added weight of the P2TR outputs.
Fixes#6953
Introduces a new chancloser package which exposes a ChanCloser
struct that handles the cooperative channel closure negotiation
and is meant to replace chancloser.go in the lnd package. Updates
all references to chancloser.go to instead use chancloser package.
