This updates the RPCAcceptor to send the correct commitment type
even if the zero-conf or scid-alias channel types are set. This also
adds two bools to the ChannelAcceptRequest struct that denotes whether
the funder set the zero-conf and scid-alias channel types.
In this commit, we change the flow of the rpc middleware registration
a bit. In order to allow a client to add rpc middleware interceptors in
a deterministic order, we now make the server send a "registration
complete" message to the client after compeleting the registration
process so that the client knows when it can go ahead and register the
next client.
If we don't flag the /v1/middleware call as request streaming, it can't
be used properly with REST WebSockets because the proxy would close the
connection after the first request message.
AddInvoice,AddHoldInvoice now issue invoices that include our
peer's aliases. Some extra sanity checks are included to ensure we
don't leak our confirmed SCID for a private channel.
feature-bit channels
This allows opening zero-conf chan-type, scid-alias chan-type, and
scid-alias feature-bit channels. scid-alias chan-type channels are
required to be private. Two paths are available for opening a zero-conf
channel:
* explicit chan-type negotiation
* LDK carve-out where chan-types are not used, LND is on the
receiving end, and a ChannelAcceptor is used to enable zero-conf
When a zero-conf channel is negotiated, the funding manager:
* sends a FundingLocked with an alias
* waits for a FundingLocked from the remote peer
* calls addToRouterGraph to persist the channel using our alias in
the graph. The peer's alias is used to send them a ChannelUpdate.
* wait for six confirmations. If public, the alias edge in the
graph is deleted and replaced (not atomically) with the confirmed
edge. Our policy is also read-and-replaced, but the counterparty's
policy won't exist until they send it to us.
When a scid-alias-feature channel is negotiated, the funding manager:
* sends a FundingLocked with an alias:
* calls addToRouterGraph, sends ChannelUpdate with the confirmed SCID
since it exists.
* when six confirmations occurs, the edge is deleted and re-inserted
since the peer may have sent us an alias ChannelUpdate that we are
storing in the graph.
Since it is possible for a user to toggle the scid-alias-feature-bit
to on while channels exist in the funding manager, care has been taken
to ensure that an alias is ALWAYS sent in the funding_locked message
if this happens.
In this commit, we add a new field `TapTweak` to be used for key path
spends. Before this commit, we'd overload the existing `WitnessScript`
field to pass this information to the signing context. This was
confusing as for tapscript spends, this was the leaf script, which
mirrors the other script based spending types.
With this new filed, users need to set this to the script root for
keypath spends where the output key commits to a real merkle root, and
nothing when bip 86 spending is being used.
To make the signing even more explicit, we also add a new field called
sign_method with an enum type that differentiates between the different
segwit v0 and v1 signing methods.
Fixes https://github.com/lightningnetwork/lnd/issues/6446.
eugene