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).
Due to a recent refactor, the HTLCs are no longer an exported type.
Custom channels need access to those updates, so we provide them in a
read-only manner.
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.
In this commit, we make a new `AuxFundingController` interface capable of processing messages off the wire. In addition, we can use it to abstract away details w.r.t how we obtain a `AuxFundingDesc` for a given channel.
We'll now use this whenever we get a channel funding request, to make sure we pass along the custom state that a channel may require.
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.
The objective of this commit is to make paymentDescriptor a private
data structure so we can quarantine it to the lnwallet package.
To accomplish this we had to prevent it from leaking out via the
arguments or return values of the public functions in lnwallet.
This naturally had consequences for the htlcswitch package as we
choose other mechanisms for tracking the data that paymentDescriptor
was responsible for.
Astoundingly, this was highly successful and allowed us to remove
a ton of redundant code. The diff for this commit represents a
substantial reduction in total lines of code as well as extraneous
arguments and return values from key functions.
This also sets the stage for future commits where we actually will
be attempting to rid lnwallet of paymentDescriptor completely.
probabilityFormula() is expected to return an error if capacity is 0, so
we should exclude that case from fuzzing.
Previously it was attempted to avoid this case by seeding the corpus
with an input that had capacity 1. That is not an effective solution
since the fuzzer can still generate an input with capacity 0.
Currently if an incorrect number of timestamps is given, we fail later
on in the GossipSyncer. It makes more sense to fail right away, since we
already do that for incorrect SCID formats (e.g., unsorted or duplicate
SCIDs). There is already a matching check in Encode for incorrect number
of timestamps, so adding this check to Decode makes things symmetric.
Olaoluwa Osuntokun