See AsyncPaymentsContext::hmac, but this prevents the recipient from
deanonymizing us. Without this, if they are able to guess the correct payment
id, then they could create a blinded path to us and confirm our identity.
We also move the PAYMENT_HASH_HMAC_INPUT const to use &[7; 16], which is safe
because this const was added since the last release. This ordering reads more
smoothly.
We want to specify that these methods are only to be used in an outbound offers
payment context, because we'll be adding similar methods for the outbound async
payments context in upcoming commits.
If someone sends us an unexpected or duplicate release_held_htlc onion message,
we should simply ignore it and not persist the entire ChannelManager in
response.
Async payments may have very high expires because we may be waiting for days
for the recipient to come online, so it's important that users be able to
abandon these payments early if needed.
Async receive is not yet supported.
Here we process inbound release_htlc onion messages, check that they actually
correspond to one of our outbound payments, and actually forward the HTLCs.
Valid release_htlc receipt indicates that the recipient has now come online to
receive.
Because we may receive a static invoice to pay days before the recipient
actually comes back online to receive the payment, it's good to do as many
checks as we can up-front. Here we ensure that the blinded paths provided
in the invoice won't cause us to exceed the maximum onion packet size.
Supported when the sender is an always-online node. Here we send the initial
held_htlc_available onion message upon receipt of a static invoice, next we'll
need to actually send HTLCs upon getting a response to said OM.
Adds a pending outbound payment variant for async payments, which indicates
that we have received a static invoice to pay and have generated a keysend preimage
for the eventual payment. When the recipient comes back online, we'll
transition from this new state to Retryable and actually forward the HTLCs.
Useful for ensuring that an inbound static invoice matches one of our outbound
invreqs, otherwise it is an unexpected invoice and should be ignored and not
paid.
Upcoming commits will support sending and receiving held_htlc_available and
release_held_htlc messages. These messages need to be enqueued so that they can
be released in ChannelManager's implementation of AsyncPaymentsMessageHandler
to OnionMessenger for sending.
Useful for using the payment_id within to look up the corresponding outbound
async payment so we know we can safely release the HTLCs to the now-onlinen
recipient.
This context will be used in reply paths for outbound held_htlc_available
messages, so we can authenticate the corresponding release_held_htlc messages.
- Add a test to verify the functionality of the handle_message_received
function.
- Ensure the test covers scenarios where InvoiceRequest messages are retried
for PendingOutboundPayments after a simulated connection loss.
- Introduce the `message_received` function to manage the
behavior when a message is received from any peer.
- This function is used within `ChannelManager` to retry `InvoiceRequest`
messages if we haven't received the corresponding invoice yet.
- This change makes the offer communication robust against sudden
connection drops where the initial attempt to send the message
might have failed.
1. Separate the logic of forming `invoice_request` messages from
`invoice_request` and `reply_paths` and enqueueing them into a
separate function.
2. This logic will be reused in the following commit when reforming
`invoice_request` messages for retrying.
1. To enable the retry of the Invoice Request message, it's necessary
to store the essential data required to recreate the message.
2. A new struct is introduced to manage this data, ensuring the
InvoiceRequest message can be reliably recreated for retries.
3. The addition of an `awaiting_invoice` flag allows tracking of
retryable invoice requests, preventing the need to lock the
`pending_outbound_payment` mutex.
In order to maintain interface consistency, we refactor all message
handler interfaces to take `PublicKey` rather than `&PublicKey`, as the
difference in efficiency should be negigible and the former is easier to
handle in binding languages.
Over time, we also want to move (no pun intended) towards all messaging
interfaces using move semantics, so dropping the reference for
`PublicKey` is the first step in this direction.
Previously, some `RoutingMessageHandler::handle_` methods (in particular
the ones handling node and channel announcements, as well as channel
updates, omitted the `their_node_id` argument. This didn't allow
implementors to discern *who* sent a particular method.
Here, we add `their_node_id: Option<&PublicKey>` to have them learn who
sent a message, and set `None` if our own node it the originator of a
broadcast operation.
1. Updated the Offers Test to check the reply paths in BOLT12 Invoices.
2. Changed the `extract_invoice` return type from `Option<BlindedMessagePath>`
to `BlindedMessagePath` since all BOLT12Invoices now have a corresponding
reply path by default.
1. Introduced reply_path in BOLT12Invoices to address a gap in error handling.
Previously, if a BOLT12Invoice sent in the offers flow generated an Invoice Error,
the payer had no way to send this error back to the payee.
2. By adding a reply_path to the Invoice Message, the payer can now communicate
any errors back to the payee, ensuring better error handling and communication
within the offers flow.
Introduce HMAC and nonce calculation when sending Invoice with
reply path, so that if we receive InvoiceError back for the
corresponding Invoice we can verify the payment hash before logging it.
...and drop the old, confusing, "protocol error" message when we
get a duplicate connection from a peer.
This should slightly further disambiguate disconnection reasons,
which are a key debugging tool for assigning blame.
- The trait defines the public method one may define for creating and
verifying the HMAC.
- Using a pub trait to define these method allows the flexibility for
other `OffersMessageHandler` construct to construct the HMAC and
authenticate the message.
If we receive `{channel,node}_announcement` messages which we
already have, we first validate their signatures and then look in
our graph and discover that we should discard the messages. This
avoids a second lock in `node_announcement` handling but does not
impact our locking in `channel_announcement` handling. It also
avoids lock contention in cases where the signatures are invalid,
but that should be exceedingly rare.
For nodes with relatively few peers, this is a fine state to be in,
however for nodes with many peers, we may see the same messages
hundreds of times. This causes a rather substantial waste of CPU
resources validating gossip messages.
Instead, here, we change to checking our network graph first and
then validate the signatures only if we don't already have the
message.
In addressing a followup to test reconnection during closing negotation
with async signing, we change things to only return a `ShutdownResult`
when we actually finish shutting down the channel, i.e. we have the
signature ready to send the final closing signed. This slightly
simplifies the logic where we would shutdown our channel
prematurely before we got the final signature. This also means
that we don't push multiple `ChannelClosed` events if we receive closing
signed, reconnect, and receive closing signed again.
`ChannelId`s are almost always referenced as hex, so having debug
output print the raw bytes is somewhat annoying. Instead, we should
dump them as hex the same way we do for `Display`.
This uses the `hex_conservative` `impl_fmt_macros` which does all
the work for us, like we use for `lightning_types`.
When a InvoiceError is received for a sent BOLT12Invoice, the
corresponding PaymentHash is to be logged. Introduce hmac construction
and verification function for PaymentHash for this purpose.
`ANCHOR_INPUT_WITNESS_WEIGHT` is too high by two weight units,
likely it was calculated to include the SegWit marker bytes, but
it is used to describe an `Input::satisfaction_weight`, which does
not expect the marker bytes.
This corrects that oversight, reducing the constant by two and
adding the marker bytes back in our own internal weight
calculations. It also fixes a second issue where the constant was
too low by one when `grind_signatures` is not set, as that may
result in a signature being one byte longer than we expect.
We should always select at least as many coins as is required to
meet the feerate target, but its perfectly fine if we overshoot.
Specifically, we may overshoot deliberately if we choose to burn
change to fee instead.
When we do coin selection for channel close anchor spends, we may
do coin selection targeting exactly the input values we need.
However, if coin selection does not include a change output, we may
add an OP_RETURN output, which may cause us to end up with less
fee than we wanted on the resulting package.
Here we address this issue by running coin selection twice - first
without seeking the extra weight of the OP_RETURN output, and again
if we find that we under-selected.
In 11ab302087 we accidentally removed
the `not(ldk_bench)` bound before outputting logs to stderr, which
we restore here. Instead of simply ignoring logs in benchmarks,
which we did previously, we instead format logs (in a way that LLVM
will not optimize out).
