In this commit, we modify the aux funding work flow slightly. We won't
be able to generate the full AuxFundingDesc until both sides has
sent+received funding params. So we'll now only attempt to bind the
tapscript root as soon as we send+recv the open_channel message.
We'll now also make sure that we pass the tapscript root all the way
down into the musig2 session creation.
In this commit, we rename the files as assembler.go houses the primary
interfaces/abstractions of the package. In the rest of the codebase,
this file is near uniformly called interface.go, so we rename the file
to make the repo more digestible at a scan.
This commit moves the constants LndInternalLockID and
DefaultLockDuration from the walletrpc package to the chanfunding
package, moves DefaultReservationTimeout from lncfg to chanfunding,
and also updates the lncli package with the new location.
We want to re-use the logic that determines what change amount is left
over depending on whether we add or don't add a change output to a
transaction, respecting the change output's dust limit.
We'll want to be able to tell the coin selection algorithm that we
intend to add any change to an existing output instead of assuming that
a change output is always created.
If we add any left over change to an existing output, we can skip the
dust amount check as we assume the selected existing output already has
a non-dust amount requested (responsibility of the caller to assert).
Before this commit the coin selection logic in the chanfunding package
would always assume that there is a P2WSH funding output and potentially
a P2TR change output. But because we want to re-use the coin selection
for things other than just channel funding, we make the logic more
generic by allowing us to specify both the existing weight of the
transaction (the already known, static parts of the TX) as well as the
type of the potential change output we would use.
With this commit we prepare for the lnwallet channel funding logic to be
aware of the config-level coin selection strategy by adding it to the
wallet config.
In this commit, we update the set of intents and assemblers to recognize
musig2. For this change, we use a new bool, `musig2`, then use that to
determine if we need to use the new taproot funding scripts or not.
Allows to define a maximum amount to provision a channel
opening with using a new field `FundUpToMaxAmt` on the
`Request` struct. Also adds a new coin select function
`CoinSelectUpToAmount` to select coins up to a maximum
amount respecting a minimum amount.
Fixes an issue where re-using a sign descriptor in a loop carried over
signing information from one call to the next, which caused the remote
signing issue.
With this commit we support fee calculation in coin selection for p2tr
inputs. We assume that coins in our UTXO selection are only BIP0086
coins. Any other input types with different spend paths won't be
selected by the wallet assembler.
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
The FundingPsbtFinalize step is a safety measure that assures the final
signed funding transaction has the same TXID as was registered during
the funding flow and was used for the commitment transactions.
This step is cumbersome to use if the whole funding process is completed
external to lnd. We allow the finalize step to be skipped for such
cases. The API user/script will need to make sure things are verified
(and possibly cleaned up) properly.
During the final part of the channel funding negotiation we only need to
assemble the full funding TX with the witness if we are going to publish
the transaction ourselves. If the final funding TX is published
externally we don't need this information. This will make it possible to
skip the verify process for fully externally funded PSBT channels.
This commit updates call-sites to use the proper dust limits for
various script types. This also updates the default dust limit used
in the funding flow to be 354 satoshis instead of 573 satoshis.
Fixes#5287.
The PSBT spec is a bit vague when it comes to the WitnessUtxo field of
an input as it's not strictly required for witness inputs. Therefore
Electrum for example does not include the field.
We need to make the SegWit input check a bit more elaborate by looking
at the output script of the UTXO and also the redeem script in case it's
a nested SegWit spend.
Add a dust-limit to `CoinSelect` and let the fee estimation consider if a change output is needed or not, assuring that if the change is below the dust-limit it will go towards the fee instead.
