In this commit, we create a new chainfee package, that houses all fee
related functionality used within the codebase. The creation of this new
package furthers our long-term goal of extracting functionality from the
bloated `lnwallet` package into new distinct packages. Additionally,
this new packages resolves a class of import cycle that could arise if a
new package that was imported by something in `lnwallet` wanted to use
the existing fee related functions in the prior `lnwallet` package.
In this commit, we convert the existing `channeldb.ChannelType` type
into a _bit field_. This doesn't require us to change the current
serialization or interpretation or the type as it is, since all the
current defined values us a distinct bit. This PR lays the ground work
for any future changes that may introduce new channel types (like anchor
outputs), and also any changes that may modify the existing invariants
around channels (if we're the initiator, we always have the funding
transaction).
Without this, it was possible for a combination of our balance and max
fee allocation to result in a fee rate below the fee floor causing the
remote party to reject the update and close the channel.
In this commit, we use the recently added `chanvalidate` package to
verify channels once they have been confirmed in the funding manager. We
expose a new method on the `LightningWallet` struct: `ValidateChannels`
which calls the new shared 1st party verification code.
After the channel is fully confirmed in the funding manager, we'll now
use this newly exposed method to handle all validation. As a result, we
can remove the existing validation code in the funding manager, and rely
on the new code in isolation.
In this commit, we create a new `chanvalidate` package which it to house
all logic required for 1st and 3rd party channel verification. 1st party
verification occurs when we find a channel in the chain that is
allegedly ours, while 3rd party verification will occur when a peer
sends us a channel proof of a new channel.
In the scope of the recent CVE, we actually fully verified 3rd party
channels, but failed to also include those checks in our 1st party
verification code. In order to unify this logic, and prevent future
issues, in this PR we move to concentrate all validation logic into a
single function. Both 1st and 3rd party validation will then use this
function. Additionally, having all the logic in a single place makes it
easier to audit, and also write tests against.
In this commit, we move to make a full deep copy of the commitment
transaction in `getSignedCommitTx` to ensure that we don't mutate the
commitment on disk, possibly resulting in a "hot commitment".
In this commit, we consolidate the number of areas where we derive our
commitment keys. Before this commit, the `isOurCommitment` function in
the chain watcher used a custom routine to derive the expected
scripts/keys for our commitment at that height. With the recent changes,
we now have additional logic in `DeriveCommitmentKeys` that wasn't
copied over to this area. As a result, the prior logic would erroneously
detect if it was our commitment that had hit the chain or not.
In this commit, we remove the old custom code, and use
`DeriveCommitmentKeys` wihtin the chain watcher as well. This ensures
that we only need to maintain the key derivation code in a single place,
preventing future bugs of this nature.
In this commit, we update the brar logic in the channel state machine,
and also the brar itself to be aware of the new commitment format.
Similar to the unilateral close summary, we'll now blank out the
SingleTweak field in `NewBreachRetribution` if it's a tweakless
commitment. The brar will then use this to properly identify the
commitment type, to ensure we use the proper witness generation function
when we're handling our own breach.
In this commit, we update the funding workflow to be aware of the new
channel type that doesn't tweak the remote party's output within the
non-delay script on their commitment transaction. To do this, we now
allow the caller of `InnitChannelReservation` to signal if they want the
old or new (tweakless) commitment style.
The funding tests are also updated to test both funding variants, as
we'll still need to understand the legacy format for older nodes.
In this commit, we update the channel state machine to be aware of
tweakless commits. In several areas, we'll now check the channel's type
to see if it's `SingleFunderTweakless`. If so, then we'll opt to use the
remote party's non-delay based point directly in the script, skipping
any additional cryptographic operations. Along the way we move the
`validateCommitmentSanity` method to be defined _before_ it's used as is
cutomary within the codebase.
Notably, within the `NewUnilateralCloseSummary` method, we'll now _blank
out_ the `SingleTweak` value if the commitment is tweakless. This
indicates to callers the witness type they should map to, as the value
isn't needed at all any longer when sweeping a non-delay output.
We also update the signing+verification tests to also test that we're
able to properly generate a valid witness for the new tweakless
commitment format.
Instead of marking the database state when processing the channel
reestablishment message, we wait for the result of this processing to
arrive in the link, and mark it accordingly in the database here.
We do this move the logic determining whether we should force close the
channel or not, and what state to mark it in the DB, to the same place,
as these need to be consistent.
This commit converts the ErrCommitSyncLocalDataLoss error into a struct,
that also holds the received last unrevoked commit point from the remote
party.
Checks that we get ErrDoubleSpend as expected when publishing a
conflicting mempool transaction with the same fee as the existing one,
and that we can publish a replacement with a higher fee successfully.
error
Since btcwallet will return typed errors now, we can simplify the
matching logic in order to return ErrDoubleSpend.
In case a transaction cannot be published since it did not satisfy the
requirements for a valid replacement, return ErrDoubleSpend to indicate
it was not propagated.
The cache wasn't really serving a purpose as FetchInputInfo isn't known
to be a hot path. Also, with a planned addition of returning the
confirmation status of an output within FetchInputInfo in a later
commit, caching won't be useful as we'll have to go to disk anyway to
determine the confirmation status.
In this commit, we address an edge case that can happen a user rescans
w/ their seed, while retaining their existing `channel.db`. Once they
rescan, if they go to sign for a channel sweep for example, the
commitment key family (actually an account) may not yet have been
created, causing the signing attempt to fail.
We remedy this always creating the account if we go to sign, and the
account isn't found. The change has been structured to make this the
exception, so we'll avoid always needing to do 2 DB hits (check if
account exists, sign), each time we sign.
A new test has been added to exercise this behavior. If the diff from
the `signer.go` file is removed, then the test will fail.
This commit adds a SubtractFees option to the funding request, letting
the caller specify that the fees should be deducted from the funding
amount. This paves the way for letting the funding manager spend up to a
given amount when creating a channel, like the rest of the funds in the
wallet.
This makes the method independent of the ChannelContribution struct.
We also add a function closure to the return of selectCoinsAndChange,
that let is unlock the selected output in case of error.
