In this commit, we start to thread thru the new aux tap leaf structures to all relevant areas. This includes: commitment outputs, resolution creation, breach handling, and also HTLC scripts.
In this commit, we update all the taproot scripts to also accept an
optional aux leaf. This aux leaf can be used to add more redemption
paths for advanced channels, or just as an extra commitment space.
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 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.
This commit was previously split into the following parts to ease
review:
- 2d746f68: replace imports
- 4008f0fd: use ecdsa.Signature
- 849e33d1: remove btcec.S256()
- b8f6ebbd: use v2 library correctly
- fa80bca9: bump go modules
This commit modifies the channel state machine to be able to derive the
proper commitment and second-level HTLC output scripts required by the
new script-enforced leased channel commitment type.
Similar to what we do for witnesses, check that the HTLC weight
constants check out.
They actually do not, since the spec is off by one. We ensure we agree
with the spec.
This to more easily track mismatches if constants and get more accurate
fee estimates for the two channel types.
The non-anchor weight estimates will now be smaller, this is okay since
these constants are only being used for fee estimation (and will now be
more accurate).
This commit introduces a new test case that asserts all of the witness
size constants currently in the codebase. We also reintroduce the
AcceptedHtlcSuccessWitnessSize and OfferedHtlcTimeoutWitnessSize
constants that were recently removed for the sake of completeness.
In asserting the witnes sizes, there were three uncovered discrepancies:
* OfferedHtlcSuccessWitnessSize overestimated by about 30% because it
included an extra signature in the calculation.
* ToLocalPenaltyWitnessSize was underestimated by one byte, because it
was missing the length byte for the OP_TRUE. This has implications
the watchtower protocol since the client and server are assumed to
share the same weight estimates used for signing. This commit keeps
the current behavior, with the intention of rolling out negotiation
for which weight estimate to use for a given session.
* AcceptedHtlcScriptSize was underestimated by one byte because it was
missing a length byte for the value 32 pushed on the stack when
asserting the preimage's length. This affects all AcceptedHtlc*
witness sizes.
