In this commit, we add a new AuxSweeper interface. This'll take a set of
inputs, and a change addr for the sweep transaction, then optionally
return a new sweep output to be added to the sweep transaction.
We also add a new NotifyBroadcast method. This'll be used to notify
that we're _about_ to broadcast a sweeping transaction. The set of
inputs is passed in, which allows the caller to prepare for the ultimate
broadcast of the sweeping transaction.
We also add ExtraTxOut to BumpRequest pass fees to NotifyBroadcast. This
allows the callee to know the total fee of the sweeping transaction.
This will be used by external callers to modify the way we resolve
contracts on chain. For a given contract, we'll store an extra "blob",
that will later be presented during the sweeping phase.
We always need to set the close output in order for us to be able
to calculate the closing keys. Especially if there is only a dust
balance in BTC terms but perhaps a valuable amount in custom channel
funds.
In this commit, we move to add the internal key to the delivery addr. This way, we give the aux chan closer the extra information it may need to properly augment the normal co-op close process.
To avoid sorting issues with identical HTLCs (equal size, equal payment
hash, equal CLTV), we need to also use the HTLC index to be able to
distinguish between them.
It doesn't make sense to do multiple encode/decode round trips on the
custom data of an HTLC. So we just use the same custom record type
everywhere, which also simplifies some of the code again.
In this commit, we start to use the new AuxSigner to obtain+verify aux sigs for all second level HTLCs. This is similar to the existing SigPool, but we'll only attempt to do this if the AuxSigner is present (won't be for most channels).
In this commit, we add a new aux signer interface that's meant to mirror the SigPool. If present, this'll be used to (maybe) obtain signatures for second level HTLCs for certain classes of custom channels.
For the initiator, once we get the signal that the PSBT has been
finalized, we'll call into the aux funder to get the funding desc. For
the responder, once we receive the funding_created message, we'll do the
same.
We now also have local+remote aux leaves for the commitment transaction.
Some old TODO comments that in retrospect aren't required anymore are
removed as well.
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.
This struct will house all the information we'll need to do a class of custom channels that relies primarily on adding additional items to the tapscript root of the HTLC/commitment/funding outputs.
In this commit, we start to thread thru the new aux tap leaf structures to all relevant areas. This includes: commitment outputs, resolution creation, breach handling, and also HTLC scripts.
In this commit, we add a TLV blob to the PaymentDescriptor struct. We also now thread through this value from the UpdateAddHTLC message to the PaymentDescriptor mapping, and the other way around.
In this commit, we add a new AuxLeafStore which can be used to dynamically fetch the latest aux leaves for a given state. This is useful for custom channel types that will store some extra information in the form of a custom blob, then will use that information to derive the new leaf tapscript leaves that may be attached to reach state.
In this commit, we also add the custom TLV blob to the internal commitment struct that we use within the in-memory commitment linked list.
This'll be useful to ensure that we're tracking the current blob for our in memory commitment for when we need to write it to disk.
In this commit, we update all the taproot scripts to also accept an
optional aux leaf. This aux leaf can be used to add more redemption
paths for advanced channels, or just as an extra commitment space.
With this commit, the channel is now aware of if it's a musig2 channel, that also has a tapscript root. We'll need to always pass in the tapscript root each time we: make the funding output, sign a new state, and also verify a new state.
This isn't hooked up yet to the funding manager, but with this commit, we can now start to write internal unit tests that handle musig2 channels with a tapscript root.
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.
