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 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.
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.
This ensures that when loading the channel again after a normal chan
reest, we generate the local nonces, which ensures we can then process
nonces the remote party sends us in their chan reest message.
In this commit, we update the logic to handle nonce init in
ProcessChanSyncMsg. Once a channel is already open, this is where we'll
get the new nonce data from the remote party we'll use to gain the nonce
we need to sign for their next state.
Before this commit, we would conditionally generate nonces in
RevokeCurrentCommitment. We move this to generateRevocation as this is
called when doing channel sync, and we want to make sure we send the
correct set of nonces.
In this commit, we fix a bug in the `deriveMusig2Shachain` function
where it didn't actually use the passed in revocation root as part of
the hmac invocation.
We also modify the function to be more generally useable as well, as now
the caller can just pass in the revocation root things should be derived
from.
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.
In this commit, we update the genHtlcSigValidationJobs function to be
taproot aware. As we actually need a schnorr signature for the taproot
validation, we need to coerce the entire wire type into a schnorr sig
with the ForceSchnorr() method.
In this commit, we update the genRemoteHtlcSigJobs function to be able
to generate taproot jobs. We also modify the sigpool to now use a
input.Signature everywhere. This'll allow us to pass around both ECDSA
and Schnorr signatures via the same interface.
We use a tapscript sighash in this case, as all the HTLC spends will
actually be script path spends.
In this commit, we update the channel state machine with a new set of
functional options that can be used to create/set the musig session
state. When a channel is made during the funding process, the set of
nonces we want to use is already known, so we allow them to be passed
in. Similarly, once the channel is confirmed, then we'll need to create
another channel instance that this times carries the newly generated
nonces to send along side funding_locked.
We also add some utility methods to permit callers to properly generate
nonces in the various contexts.
In this commit, we add a new NewCommitState struct. This preps us for
the future change wherein a partial signature is also added to the mix.
All related tests and type signatures have also been updated
accordingly.
In this commit, we build on all the prior commits and integrate the new
taproot channels into the existing internal funding flow. Along the way,
we do some refactoring to unify things like signing and verifying
incoming commitment transaction signatures.
For our local nonce, we use the existing functional option type to
derive the nonce based on the initial shachain pre-image we'll use as
our revocation.
In this commit, we update the Sig type to support ECDSA and schnorr
signatures. We need to do this as the HTLC signatures will become
schnorr sigs for taproot channels. The current spec draft opts to
overload this field since both the sigs are actually 64 bytes in length.
The only consideration with this move is that callers need to "coerce" a
sig to the proper type if they need schnorr signatures.
We know that onion blobs in lightning are _exactly_ 1366 bytes in
lightning, but they are currently expressed as a byte slice in
channeldb's HTLC struct. Blobs are currently serialized as var bytes,
so we can take advantage of this known length and variable length
to add additional data to the inline serialization of our HTLCs, which
are otherwise not easily extensible (without creating a new bucket).
This commit replaces `FundingLocked` found in docs using the following
command,
```shell
find . -name "*.go" -exec sed -i '' 's/FundingLocked/ChannelReady/g' {} \;
find . -name "*.go" -exec sed -i '' 's/FundingLock/ChannelReady/g' {} \;
```
In this commit, the NewBreachRetribution function is adjusted so that a
caller can optionally set the spendTx parameter to nil. In this case,
the function will check the revocation log to see if the local and
remote amount fields are available there and use them if they are.
If the fields are not present, which they might not be given a previous
migration that removed the fields, then an error is returned.
Add a new subpackage to `lnd/channeldb` to hold some of the types that
are used in the package itself and in other packages that should not
depend on `channeldb`.
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
This commit changes the `NewBreachRetribution` to use the new revocation
log format, while maintaining the compatibilty to use an older
revocation log format. Unit tests have been added to make sure a breach
retribution can be created in both log formats.
This also means the watch tower needs to pass the relevant commit tx at
its backup height when creating the breach retribution during backing
up. This is achieved by recording the current remote commitment state
before advancing the remote commitment chain.
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
