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
In order to sweep the commitment and HTLC outputs belonging to a
script-enforced leased channel, each resolver must know whether the
additional CLTV clause on the channel initiator applies to them. To do
so, we retrieve the historical channel state stored within the database
and supplement it to the resolvers to provide them with what's needed in
order to sweep the necessary outputs and resolve their respective
contracts.
To allow us to write the outcome of our resolver to disk, we add
optional resolver reports to the CheckPoint function. Variadic params
are used because some checkpoints may have no reports (when the resolver
is not yet complete) and some may have two (in the case of a two stage
resolution).
This fixes an issue where the contract court could leave a completely
swept commit tx unresolved if it was swept by the remote party.
This could happen if (our) commit tx just published was actually a
previously revoked state, in which case the remote party would claim the
funds via a justice transaction.
This manifested itself in the testRevokedCloseRetribution integration
test where at the end of the test Bob was left with a pending channel
that never resolved itself.
We use the fact that we can tell whether the commit is local or remote
by inspecting the witness script. We cannot use the maturity delay
anymore, as we can have delayed to_remote outputs also now.
Co-authored-by: Joost Jager <joost.jager@gmail.com>
The channel arbitrator no longer passes the direct commitment output to
the nursery for incubation. Instead the resolver itself will await the
csv lock if any.
The reason to change this now is to prevent having to deal with the
(legacy) nursery code for a planned anchor outputs related change to the
commit sweep resolver (also csv lock to_remote).
It is no problem if there are any lingering incubating outputs at the
time of upgrade. This just means that the output will be offered twice
to the sweeper and this doesn't hurt.
In this commit, we update the `commitSweepResolver` to be aware of
tweakless commitments. We'll now use the new behavior of the uni close
summary (leaving out the single tweak) to detect if we're dealing with a
new, or modern commitment. Depending on the commitment type, we'll then
set the witness type accordingly so we can generate the proper signature
within the sweeper.
In this commit, we introduce support for arbitrary client fee
preferences when accepting input sweep requests. This is possible with
the addition of fee rate buckets. Fee rate buckets are buckets that
contain inputs with similar fee rates within a specific range, e.g.,
1-10 sat/vbyte, 11-20 sat/vbyte, etc. Having these buckets allows us to
batch and sweep inputs from different clients with similar fee rates
within a single transaction, allowing us to save on chain fees.
With this addition, we can now get rid of the UtxoSweeper's default fee
preference. As of this commit, any clients using the it to sweep inputs
specify the same fee preference to not change their behavior. Each of
these can be fine-tuned later on given their use cases.
Now that the sweeper is available, it isn't necessary anymore for the
commit resolver to craft its own sweep tx. Instead it can offer its
input to the sweeper and wait for the outcome.
This commit is a step to split the lnwallet package. It puts the Input
interface and implementations in a separate package along with all their
dependencies from lnwallet.
