With this commit, the reservation workflow for the single funder use
case is now aware of the usage of revocation keys.
The changes are relatively minor:
* contributions now have RevocationKeys instead of RevocationHashes
* CompleteReservationSingle now takes the initiators revocation key
This unifies some inconstancies across the code-base with hashes being
32 vs 20 bytes. All hashes, whether payment or revocation are now
uniformly 32 bytes everywhere. As a result, only OP_SHA256 will be used
within commitment and HTLC scripts. The rationale for using sha256
instead of hash160 for the HTLC payment pre-image is that alternative
chains are more likely to have sha256 implemented, rather than
ripemd160.
A forthcoming commit will update the current commitment, and HTLC
scripts.
This commit adds 3 methods to lnwallet.ChannelReservation intended to
facilitating a single funder channel workflow between two nodes. A
single funder workflow is characterized as the initiator committing all
the funds to a channel, with the responder only providing public keys,
and a revocation hash.
The workflow remains the same for the initiator of the funding
transaction, however for the responder, the following methods are
instead called in order:
* .ProcessSingleConribution()
* .CompleteSingleContribution()
* .FinalizeReservation()
These methods are required for the responder as they are never able to
construct the full funding transaction, and only receive the out point
of the funding transaction once available.
* Hooks into the ChainNotifier infrastructure to receive a notification
once the funding transaction gets enough notifications.
* Still need to set up the notification grouting within a
LightningChannel to watch for uncooperative closures, and broadcasts
and revoked channel states.
* Workflow along with expected call orders have been documented.
* With this, the initial iteration of ChannelReservation is mostly
complete.
* However, there are still some unfinished steps internally within the
wallet related to processing. Such as factoring proper tx fees,
splitting fees, some node interaction etc.
* Initial draft of brain dump of chandler. Nothing yet set in stone.
* Will most likely move the storage of all structs to a more “column”
oriented approach. Such that, small updates like incrementing the total
satoshi sent don’t result in the entire struct being serialized and
written.
* Some skeleton structs for other possible data we might want to store
are also included.
* Seem valuable to record as much data as possible for record keeping,
visualization, debugging, etc. Will need to set up a time+space+dirty
cache to ensure performance isn’t impacted too much.
* Contribution from remote host necessary to construct the initial
commitment transaction is now also expected
* All message structs and handlers updated accordingly
* AddContribution now also generates both commitment tnxs, and
generates a signature for their version of the commitment transaction
