Now that ready_channel is also called on startup upon deserializing
channels, we opt to rename it to a more indicative name.
We also derive `PartialEq` on ChannelTransactionParameters to allow
implementations to determine whether `provide_channel_parameters` calls
are idempotent after the channel parameters have already been provided.
`get_channel_signer` previously had two different responsibilites:
generating unique `channel_keys_id` and using said ID to derive channel
keys. We decide to split it into two methods `generate_channel_keys_id`
and `derive_channel_signer`, such that we can use the latter to fulfill
our goal of re-deriving signers instead of persisting them. There's no
point in storing data that can be easily re-derived.
The `derive_{public,private}_revocation_key` methods hash the two
input keys and then multiply the two input keys by hashed values
before adding them together. Because addition can fail if the tweak
is the inverse of the secret key this method currently returns a
`Result`.
However, it is not cryptographically possible to reach the error
case - in order to create an issue, the point-multiplied-by-hash
values must be the inverse of each other, however each point
commits the SHA-256 hash of both keys together. Thus, because
changing either key changes the hashes (and the ultimate points
added together) in an unpredictable way, there should be no way to
construct such points.
The `derive_{public,private}_key` methods hash the two input keys
and then add them to the input public key. Because addition can
fail if the tweak is the inverse of the secret key this method
currently returns a `Result`.
However, it is not cryptographically possible to reach the error
case - in order to create an issue, the SHA-256 hash of the
`base_point` (and other data) must be the inverse of the
`base_point`('s secret key). Because changing the `base_point`
changes the hash in an unpredictable way, there should be no way to
construct such a `base_point`.
This is a script builder to generate anchor output ones. They can be
satisfied either by a signature for the committed funding pubkey or anyone
after CSV delay expiration.
This is used at anchor output addition while generating commitment transaction.
Previous to this PR, TLV serialization involved iterating from 0 to the highest
given TLV type. This worked until we decided to implement keysend, which has a
TLV type of ~5.48 billion.
So instead, we now specify the type of whatever is being (de)serialized (which
can be an Option, a Vec type, or a non-Option (specified in the serialization macros as "required").
PackageTemplate aims to replace InputMaterial, introducing a clean
interface to manipulate a wide range of claim types without
OnchainTxHandler aware of special content of each.
This is used in next commits.
