In this commit, we carry out a new notion introduced during a recent
spec meeting to use a feature bit plus 100 before the feature has been
finalized in the spec.
We split into the Final and Staging bits.
We use a helper function to ensure that anytime we're about to make a
normal sighash, we consult the channel type to check if we should use
the default value or sighash all explicitly.
In this commit, we remove the internal call to `InitRemoteMusigNonces`.
We don't need this since when we go to process the remote party's chan
reest message, we'll already call this method. Otherwise, we'll get an
error here since the pending verification nonce has been wiped out after
each call.
Otherwise, in the itests (which are mainly based on implicit
negotiation), we won't try to open taproot chans when we actually need
to.
We may want to revisit this however, since it may lock in parties trying
to use the defaults that aren't currently setting the explicit commit
type during funding.
This is a preparatory change for the upcoming "simple channel close"
feature which'll utilize RBF to allow either side to resign the co-op
close transaction for broadcast at any point.
In this commit, we update the channel state machine to use the new
ScriptDescriptor interface. This fixes some subtle issues with the
existing commits, as for p2wsh we always sign the same witness script,
but for p2tr, the witness script differs depending on which branch is
taken.
With the new abstractions, we can treat p2wsh and p2tr as the same
mostly, right up until we need to obtain a control block or a tap tweak.
All tests have been updated accordingly.
In this commit, we add a new interface, the `ScriptDesciptor` to
abstract over details of a given output script. The purpose of this
interface, and the taproot superset, is to be able to paper over the
differences of a p2wsh vs a p2tr output. With this new interface, we can
treat them as the same, but then use a type assertion to get at any
control block related methods if needed.
In this commit, we update the breach arb to support taproot channels. We
utilize the new taproot briefcase space to store both control blocks,
and also the first+second level scripts for the set of HTLCs.
We pull the information from the sign descriptors and store them in the
resolutions. However, the resolvers created end up duplicating the
resolution data, so we update the sign descs as needed during start up.
In this commit, we add a new taproot specific briefcase to store the
control block and tap tweaks for all taproot outputs. We chose this
route as many of the existing fields are serialized in line, so we
aren't able to serialize this new taproot specific information in the
existing briefcase.
For taproot channels, we need to thread through the control block in the
sign descriptor. We also ensure that the proper sign method is set. We
leverage the new input.Signature generalization be able to support
handling both schnorr and ECDSA signatures for the second level output.
In this commit, we add the tapscript tree to the ScriptInfo struct, as
in many cases the caller needs the tree in order to generate the control
block or obtain the taptweak which is needed to spend revoked outputs.
In this commit, we update all the taproot scripts spends to optionally
make the control block. This is useful in cases where we've already
created the control block, or may not have the items needed to construct
it in the first place.
We also add the control block to the sign descriptor itself.
