Instead of blindly signing provided witnessScript, signer must derive
channel keys corresponding to the provided per-commitment-point and
regenerate templated witnessScript to ensure its syntax correctness.
Dry-up remote pubkeys tracking in one struct.
This introduce a duplicate of RemoteTxCache, which is going
to be removed in next commit when OnchainTxHandler version is
removed.
Add sign_payment_transaction in ChanSigner to be able to spend
SpendableOutputDescriptor in test framework
Extend ChannelKeys with remote_pubkeys to access remote revocation
basepoint for witnessScript construction.
A dynamic-p2wsh-output like `to_local` on local commitment/HTLC txn
require a signature from delayed_payment_key to be spend. Instead of
sending private key in descriptor, we ask for spender to derive again
the corresponding ChannelKeys based on key state, uniquely identifying
a channel and encompassing its unique start data.
Descriptor modification is done in next commit.
* Return Self instead of the fully-written types for constructors,
* Place definitions before use (in this case for KeysInterface),
* Don't import foo::bar::self, but import foo::bar
+ a spelling fix in the KeysInterface docs for get_onion_rand.
In next commit, we add derive_channel_keys, a helper to rederive
keys from a SpendableOuptutDescriptor. We still need to ensure
that user rederive same set of keys even if KeyManager is started
at a later time. For doing so we need to pass starting time as
part of the re-derived sha_state, therefore we need to make it
accessible and part of channel state key material.
Seed is already required to be conserved between KeysManager
serializations.
This makes it easier for our automated bindings generator to
function as it tries to automatically create a ::new if the struct
contains only pub elements who's type is convertible.
This caused a bunch of cascading changes, including
passing loggers down to Channels in function calls
rather than having each Channel have a pointer to the
ChannelManager's Logger (which was a circular reference).
Other structs that the Channel had passed its Logger to also
had their loggers removed. Other newly unused Loggers were
also removed, especially when keeping them would've caused
a bunch of extra test changes to be necessary, e.g. with
the ChainWatchInterfaceUtil's Logger.
This simplifies channelmonitor quite nicely (as expected) as we
never have to be concerned with learning data in a DataLossProtect
which is require for us to claim our funds from the latest remote
commitment transaction.
1107ab06c3 introduced an API to have a
ChannelKeys implementer sign HTLC transactions by calling into the
LocalCommitmentTransaction object, which would then store the tx.
This API was incredibly awkward, both because it required an
external signer trust our own internal interfaces, but also because
it didn't allow for any inspection of what was about to be signed.
Further, it signed the HTLC transactions one-by-one in a somewhat
inefficient way, and there isn't a clear way to resolve this (as
the which-HTLC parameter has to refer to something in between the
HTLC's arbitrary index, and its index in the commitment tx, which
has "holes" for the non-HTLC outputs and skips some HTLCs).
We replace it with a new function in ChannelKeys which allows us
to sign all HTLCs in a given commitment transaction (which allows
for a bit more effeciency on the signers' part, as well as
sidesteps the which-HTLC issue). This may also simplify the signer
implementation as we will always want to sign all HTLCs spending a
given commitment transaction at once anyway.
We also de-mut the LocalCommitmentTransaction passed to the
ChanKeys, instead opting to make LocalCommitmentTransaction const
and avoid storing any new HTLC-related data in it.
This cleans up sign_local_commitment somewhat by returning a
Result<Signaure, ()> over the local commitment transaction instead
of modifying the struct which was passed in.
This is the first step in making LocalCommitmentTransaction a
completely pub struct, using it just to communicate enough
information to the user to allow them to construct a signaure
instead of having it contain a bunch of logic.
This should make it much easier to implement a custom ChannelKeys
by disconnecting the local commitment transaction signing from our
own datastructures.
The ChanKeys is created with knowledge of the Channel's value and
funding redeemscript up-front, so we should not be providing it
when making signing requests.
HTLC Transaction can't be bumped without sighash changes
so their gneeration is one-time for nwo. We move them in
OnchainTxHandler for simplifying ChannelMonitor and to prepare
storage of keys material behind one external signer interface.
Some tests break due to change in transaction broadcaster order.
Number of transactions may vary because of temporary anti-duplicata
tweak can't dissociate between 2- broadcast from different
origins (ChannelMonitor, ChannelManager) and 2-broadcast from same
component.
Extend external signer interface to sign HTLC transactions on its
behalf without seckey passing. This move will allow us to remove
key access access from ChannelMonitor hot memory in further work.
HTLC transactions should stay half-signed by remote until
we need to broadcast them for timing-out/claiming HTLCs onchain.
Extend external signer interface to sign local commitment transactions
on its behalf without seckey passing. This move will allow us to remove
key access from ChannelMonitor hot memory in further work.
Local commitment transaction should stay half-signed by remote until
we need to broadcast for a channel force-close or a HTLC to timeout onchain.
Add an unsafe test-only version of sign_local_commitment to fulfill our
test_framework needs.
We delay SpendableOutputDescriptor until reaching ANTI_REORG_DELAY
to avoid misleading user wallet in case of reorg and alternative
settlement on a channel output.
Fix tests in consequence.
This makes Readable symmetric with Writeable and makes sense -
something which is Readable should be Readable for any stream which
implements std::io::Read, not only for a stream type it decides on.
This solves some lifetime-compatibility issues in trying to read()
from a LengthLimitingReader in arbitrary Readable impls.
As noted in the docs, Events don't round-trip fully, but round-trip
in a way that is useful for ChannelManagers, specifically some events
don't make sense anymore after a restart.
This removes the somewhat-easy-to-misuse Clone from ChannelMonitors,
opening us up to being able to track Events in ChannelMonitors with
less risk of misuse.
Sadly it doesn't remove the Clone requirement for ChannelKeys,
though gets us much closer - we now just need to request a second
copy once when we go to create the ChannelMonitors.
Currently Channel relies on its own internal channel_monitor copy
to keep track of funding_txo information, which is both a bit
awkward and not ideal if we want to get rid of the ChannelMonitor
copy in Channel.
Instead, just duplicate it (its small) and keep it directly in
Channel, allowing us to remove the (super awkward)
ChannelMonitor::unset_funding_txo().
This tests, after each functional test, that if we serialize and
reload all of our ChannelMonitors we end up tracking the same set
of outputs as before.
* Fixed a number of grammar issues
* Clarified the docs for users who are intimately farmiliar with
arbitrary lines of text copied from the BOLTs
* Added a bit more text so that things are easier to read and less
disjoint.
* Clarified exactly how the witness stack should look since I had
to go dig for it.
Additional changes:
* Update fuzz crate to match ChannelManager's new API
* Update lightning-net-tokio library to match ChannelManager's new ChannelMonitor Deref API
* Update tests to match ChannelManager's new ChannelMonitor Deref API
