Commit message · Olaoluwa Osuntokunlnwire: add taproot signatures support to closing_complete message
In this commit we, add support for taproot partial signatures with
nonces to the ClosingComplete message. This is the foundation for
taproot RBF cooperative channel closing, implementing the JIT nonce
pattern required for the modern taproot closing flow.
The changes include a new TaprootClosingSigs struct that mirrors the
existing ClosingSigs but uses PartialSigWithNonce for taproot channels.
The decoding and encoding functions are updated to handle both regular
ECDSA signatures and taproot partial signatures. For taproot channels,
the TaprootClosingSigs field is populated while ClosingSigs remains
empty, maintaining backward compatibility.
We also fix a minor typo in the comment for CloserNoClosee field
(clsoee -> closee).
lnwire: add taproot partial signatures support to closing_sig message
In this commit we, extend the ClosingSig message to support taproot
partial signatures for the RBF cooperative close flow. The ClosingSig
message is sent by the closee in response to a ClosingComplete message.
For taproot channels, we add TaprootPartialSigs which contains partial
signatures without nonces since the remote party already knows our
nonce from the previous ClosingComplete message. We also add a
NextCloseeNonce field for RBF iterations, allowing the closee to
provide a new nonce for the next potential RBF round.
The decoding and encoding functions are updated to handle both regular
signatures and taproot partial signatures, maintaining backward
compatibility with existing non-taproot channels while enabling the
advanced taproot RBF flow.
lnwire: add shutdown nonce support for taproot channels
In this commit we, add support for closee nonces in the Shutdown
message to enable taproot RBF cooperative channel closing. The
ShutdownNonce field allows taproot channels to exchange the initial
nonces required for the MuSig2 signing process during cooperative
closure.
This nonce represents the closee nonce that the remote party will use
when they act as the closer in the RBF flow. The nonce is transmitted
as part of the shutdown flow and is essential for the JIT nonce pattern
used in the modern taproot closing protocol.
The changes maintain backward compatibility as the ShutdownNonce field
is optional and only used for taproot channels that support the
enhanced RBF flow.
lnwire: update test message with taproot signature fields
In this commit we, update the test message utilities to include the new
taproot signature fields added to ClosingComplete and ClosingSig
messages. This ensures the wire protocol tests properly exercise the
new taproot partial signature functionality.
chancloser: add taproot channel infrastructure and nonce state management
In this commit we, add the fundamental infrastructure for taproot RBF
cooperative channel closing. This includes adding taproot channel
detection, MuSig2 session management, and nonce state tracking
throughout the closing state machine.
Key additions include the IsTaproot method on Environment to detect
taproot channels based on the presence of MuSig sessions, and
LocalMusigSession/RemoteMusigSession fields for managing the different
signing contexts. We add NonceState tracking to maintain closee nonces
exchanged during the shutdown phase.
The SendShutdown and ShutdownReceived events are extended to carry
closee nonces for taproot channels, and we add proper error handling
for missing nonces in taproot shutdown messages. These changes provide
the foundation for the taproot-specific state transitions while
maintaining compatibility with existing non-taproot channels.
chancloser: implement taproot cooperative close state transitions
In this commit we, implement the complete taproot RBF cooperative close
state machine transitions. This is a comprehensive change that adds all
the necessary components for taproot channel closing support.
The implementation includes several key areas:
First, we add nonce management helpers including initLocalMusigCloseeNonce
and initRemoteMusigCloseeNonce for properly initializing MuSig2 sessions
with the appropriate closee nonces during the RBF flow.
Second, we implement signature extraction and validation helpers including
partialSigToWireSig for converting partial signatures to wire format, and
extractTaprootSigAndNonce, extractSigAndNonce, and validateAndExtractSigAndNonce
for handling both taproot and regular signatures with proper validation.
Third, we add comprehensive signature encoding logic with encodeClosingSignatures
that creates appropriate signature structures for both channel types, and helper
functions like processRemoteTaprootSig, createLocalCloseeSignature, and
createClosingSigMessage for managing the complex taproot signing flow.
Fourth, we extend the shutdown validation logic to require nonces for
taproot channels and update all state transitions to properly handle
nonce exchange, MuSig2 session initialization, and the dual signature
paths for taproot vs non-taproot channels.
Finally, we add signature preparation logic with prepareClosingSignatures
and extraction helpers like extractSigAndNonceFromComplete that handle
the complex musig signature combination required for taproot channels
while maintaining compatibility with existing ECDSA signatures.
The changes maintain backward compatibility with existing non-taproot
channels while enabling the full taproot RBF cooperative close flow
with proper nonce rotation and signature handling.
chancloser: add taproot test infrastructure and test cases
In this commit we, extend the RBF cooperative close test suite to
support taproot channels. This includes adding schnorr signature
test constants, taproot channel test helpers, and comprehensive
test coverage for the taproot RBF flow.
The changes add localSchnorrSig and remoteSchnorrSig test constants
to mirror the existing ECDSA signatures, and include proper imports
for musig2, chainhash, and lnwallet to support the taproot testing
infrastructure.
The test modifications ensure that both taproot and non-taproot
channels are properly tested throughout the RBF cooperative close
state machine, validating the dual signature handling paths and
nonce management logic introduced in the main implementation.
chancloser: update test utilities and message mapping for taproot
In this commit we, update the chancloser test utilities and message
mapping functions to properly handle the new taproot-specific fields
in the RBF cooperative close flow.
The changes ensure that test harnesses and message mapping functions
are aware of the taproot signature fields and nonce handling required
for the extended wire protocol support. This maintains test coverage
for both existing non-taproot functionality and the new taproot
capabilities.
88/100 · StrongMessage clarity
✓ Specific, descriptive subject✓ Names a concrete action or component✓ Provides detailed explanatory context✓ Mentions testing or verification✓ Names security-relevant behavior explicitly
signing boundarydefensive validationsigning or wallet path
AI analysis · Low 46/100This commit adds support for taproot (MuSig2) cooperative channel closing in LND's RBF close protocol. It introduces new wire message fields for taproot partial signatures and nonces, updates the state machine to handle both ECDSA and taproot paths, and adds tests. There is no direct evidence in the commit message or diff that this fixes a known security vulnerability; it appears to be a feature implementation for taproot channel compatibility.
