This commit makes sure an input is only added to the cluster when it has
successfully estimated its fee rate. Previously, when an error is
returned from `feeRateForPreference`, we'd still add this input to the
cluster, resulting a **lower** fee rates being used because when
averaging the fee rates, we'd think this input has zero fee rate
specified.
An unit test is patched to make the method `clusterByLockTime` more
robust.
In this commit, we modify the musig2 interfaces to instead use an
explicit value for the local nonces. Before this commit, we used the
functional option, but we want to also support specifying this value
over RPC for the remote signer. The functional option pattern is opaque,
so we can't get the nonce value we need. To get around this, we'll just
make this an explicit pointer, then map this to the functional option at
the very last moment.
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 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.
By using the multimutex here, we'll no longer rely on a single mutex for
the entire musig session set like we used to. Instead, we can use the
session ID to key into a map of mutexes and use those directly.
In this commit, we extract the musig2 session management into a new
module. This allows us to re-use the session logic elsewhere in unit
tests so we don't need to instantiate the entire wallet.
In this commit, we modify the to_local script to use a script path for
the revocation scenario. With this change, we ensure that the internal
key is always revealed which means the anchor outputs can still always
be swept.
In this commit, we restore usage of the NUMS key for the to remote
output, as this allows a remote party to scan the chain in order to find
their remote output that in emergency recovery scenarios.
Unlike the old HTLC scripts, we now need to handle the various control
block interactions. As is, we opt to simply re-compute the entire tree
when needed, as the tree only has two leaves.
In this commit, we add GenTaprootFundingScript, which'll return the
taproot pkScript and output for a taproot+musig2 channel. This uses
musig2 key aggregation with sorting activated.
The final key produced uses a bip86 tweak, meaning that the output key
provably doesn't commit to any script path. In the future, we may want
to permit this, as then it allows for a greater degree of
programmability of the funding output.
The default allocation of 500 bytes for the script that is
used in NewScriptBuilder is way too much for most of our scripts.
With the new functional option we can tune the allocation to exactly
what we need.
With this commit we bump the github.com/btcd/btcec/v2 library to v2.3.2
which implements the MuSig2 BIP version v1.0.0rc2. With this the
github.com/btcsuite/btcd/btcec/v2/schnorr/musig2 package becomes
v1.0.0rc2 and the github.com/lightningnetwork/lnd/internal/musig2v040
stays at the old v0.4.0 version.
We put the calls that don't use musig2 package specific types as
parameters or return values behind an interface so we can easily call
those directly in the RPC without needing to know the underlying
implementation version. Some calls can't be used in the interface
because they use the specific package version's types. These calls are
implemented in helper functions in the input package instead that do the
necessary type switches.
To allow us to properly test all test vectors, we can't default to true
on key sorting. Instead we add a parameter to the input package and move
the default value to the RPC server.
As a preparation for making it possible to version switch calls to the
MuSig2 API, we move some of the calls to the input package where in a
future commit we'll call the corresponding code in the correct package.
