Bindings aren't currently able to handle a struct with a generic
which is actually exposed - we map all structs concretely to a
single type, whereas having fluctuating types on a struct requires
mapping the inner field to a trait first.
Since this isn't super practical, we make `PendingOnionMessage` a
tuple in bindings, rather than a struct.
Because the bindings changes now require further changes to our
type definitions, avoiding building the `Simple*` type aliases
entirely makes the patchset there simpler.
In 26c1639ab6 we switched to using
`Default::default()` to initialize `()` for scoring parameters in
tests. A number of `()`s slipped back in recently, which we replace
here.
`sign_holder_commitment_and_htlcs` never really made sense. Unlike
`sign_counterparty_commitment`, the signatures for holder HTLC
transactions may be required much later than the commitment
transaction's. While it was nice for us to only reach the signer once to
obtain all holder signatures, it's not really ideal anymore as we want
our signatures to be random and not reused.
We no longer return all holder HTLC signatures and instead defer to
obtaining them via `EcdsaChannelSigner::sign_holder_htlc_transaction`.
We want to ensure we use fresh random signatures to prevent certain
classes of transaction replacement attacks at the bitcoin P2P layer.
This was already covered for commitment transactions and zero fee holder
HTLC transactions, but was missing for holder HTLC transactions on
non-anchors channels.
We can easily do this by reusing the existing
`EcdsaChannelSigner::sign_holder_htlc_transaction` method and
circumventing the existing `holder_htlc_sigs/prev_holder_htlc_sigs`
caches, which will be removed in a later commit anyway.
If the user declines to specify a `max_total_routing_fee_msat` in
the new BOLT12 payment methods, rather than defaulting to no limit
on the fee we pay at all, we should default to our "usual default",
ie the one calculated in
`RouteParameters::from_payment_params_and_value`.
We do this here, as well as documenting the behavior on the payment
methods.
Anchor outputs channels are no longer susceptible to fee spikes as they
now mostly target the dynamic minimum mempool fee and can contribute the
remainder of fees when closing.
We should make sure the funding amount of a channel can cover all its
associated costs, including the value of anchor outputs, to make sure
that it is actually usable once "opened".
This could lead us to sending/forwarding HTLCs that would put us below
our reserve, forcing our counterparty to close the channel on us due to
an invalid update.
`OnchainTxHandler` will need to construct `HTLCDescriptor`s for holder
HTLCs, but it did not have access to all of the derivation parameters
that need to be provided.
We plan to use `EcdsaChannelSigner::sign_holder_htlc_transaction` to
also sign holder HTLC transactions on non-anchor outputs channels.
`HTLCDescriptor` was only used in an anchor outputs context, so a few
things needed changing, mostly to handle the different scripts and
feerate.
Define the BOLT 12 message flow in ChannelManager's
OffersMessageHandler implementation.
- An invoice_request message results in responding with an invoice
message if it can be verified that the request is for a valid offer.
- An invoice is paid if it can be verified to have originated from a
sent invoice_request or a refund.
- An invoice_error is sent in some failure cases.
- Initial messages enqueued for sending are released to OnionMessenger
Building an invoice will fail if the underlying offer or refund has
already expired. The check was skipped in no-std since there is no
system clock. However, the invoice creation time can be used instead.
This prevents responding to an invoice request if the offer has already
expired.
Add a utility to ChannelManager for creating a Bolt12Invoice for a
Refund such that the ChannelManager can recognize the PaymentHash and
reconstruct the PaymentPreimage from the PaymentSecret, the latter of
which is contained in a BlindedPath within the invoice.
Add a utility to ChannelManager for sending an InvoiceRequest for an
Offer such that derived keys are used for the payer id. This allows for
stateless verification of any Invoice messages before it is paid.
Also tracks future payments using the given PaymentId such that the
corresponding Invoice is paid only once.
Pending outbound payments use an absolute expiry to determine when they
are considered stale and should be fail. In `no-std`, this may result in
long timeouts as the highest seen block time is used. Instead, allow for
expiration based on timer ticks. This will be use in an upcoming commit
for invoice request expiration.
Upcoming commits will add utilities for sending an InvoiceRequest for an
Offer and an Invoice for a Refund. These messages need to be enqueued so
that they can be released in ChannelManager's implementation of
OffersMessageHandler to OnionMessenger for sending.
These messages do not need to be serialized as they must be resent upon
restart.
