Add static invoice creation utils to ChannelManager

fuzz/src/chanmon_consistency.rs

@@ -133,7 +133,7 @@ impl Router for FuzzRouter {
 
 	fn create_blinded_payment_paths<T: secp256k1::Signing + secp256k1::Verification>(
  &self, _recipient: PublicKey, _first_hops: Vec<ChannelDetails>, _tlvs: ReceiveTlvs,
- _amount_msats: u64, _secp_ctx: &Secp256k1<T>,
+ _amount_msats: Option<u64>, _secp_ctx: &Secp256k1<T>,
 	) -> Result<Vec<BlindedPaymentPath>, ()> {
  unreachable!()
 	}

fuzz/src/full_stack.rs

@@ -160,7 +160,7 @@ impl Router for FuzzRouter {
 
 	fn create_blinded_payment_paths<T: secp256k1::Signing + secp256k1::Verification>(
  &self, _recipient: PublicKey, _first_hops: Vec<ChannelDetails>, _tlvs: ReceiveTlvs,
- _amount_msats: u64, _secp_ctx: &Secp256k1<T>,
+ _amount_msats: Option<u64>, _secp_ctx: &Secp256k1<T>,
 	) -> Result<Vec<BlindedPaymentPath>, ()> {
  unreachable!()
 	}

lightning/src/blinded_path/message.rs

@@ -402,6 +402,24 @@ pub enum AsyncPaymentsContext {
  /// containing the expected [`PaymentId`].
  hmac: Hmac<Sha256>,
 	},
+	/// Context contained within the [`BlindedMessagePath`]s we put in static invoices, provided back
+	/// to us in corresponding [`HeldHtlcAvailable`] messages.
+	///
+	/// [`HeldHtlcAvailable`]: crate::onion_message::async_payments::HeldHtlcAvailable
+	InboundPayment {
+ /// A nonce used for authenticating that a [`HeldHtlcAvailable`] message is valid for a
+ /// preceding static invoice.
+ ///
+ /// [`HeldHtlcAvailable`]: crate::onion_message::async_payments::HeldHtlcAvailable
+ nonce: Nonce,
+ /// Authentication code for the [`HeldHtlcAvailable`] message.
+ ///
+ /// Prevents nodes from creating their own blinded path to us, sending a [`HeldHtlcAvailable`]
+ /// message and trivially getting notified whenever we come online.
+ ///
+ /// [`HeldHtlcAvailable`]: crate::onion_message::async_payments::HeldHtlcAvailable
+ hmac: Hmac<Sha256>,
+	},
 }
 
 impl_writeable_tlv_based_enum!(MessageContext,
@@ -433,6 +451,10 @@ impl_writeable_tlv_based_enum!(AsyncPaymentsContext,
  (2, nonce, required),
  (4, hmac, required),
 	},
+	(1, InboundPayment) => {
+ (0, nonce, required),
+ (2, hmac, required),
+	},
 );
 
 /// Contains a simple nonce for use in a blinded path's context.

lightning/src/blinded_path/payment.rs

@@ -349,6 +349,11 @@ pub enum PaymentContext {
 	/// [`Offer`]: crate::offers::offer::Offer
 	Bolt12Offer(Bolt12OfferContext),
 
+	/// The payment was made for a static invoice requested from a BOLT 12 [`Offer`].
+	///
+	/// [`Offer`]: crate::offers::offer::Offer
+	AsyncBolt12Offer(AsyncBolt12OfferContext),
+
 	/// The payment was made for an invoice sent for a BOLT 12 [`Refund`].
 	///
 	/// [`Refund`]: crate::offers::refund::Refund
@@ -378,6 +383,18 @@ pub struct Bolt12OfferContext {
 	pub invoice_request: InvoiceRequestFields,
 }
 
+/// The context of a payment made for a static invoice requested from a BOLT 12 [`Offer`].
+///
+/// [`Offer`]: crate::offers::offer::Offer
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct AsyncBolt12OfferContext {
+	/// The [`Nonce`] used to verify that an inbound [`InvoiceRequest`] corresponds to this static
+	/// invoice's offer.
+	///
+	/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
+	pub offer_nonce: Nonce,
+}
+
 /// The context of a payment made for an invoice sent for a BOLT 12 [`Refund`].
 ///
 /// [`Refund`]: crate::offers::refund::Refund
@@ -627,6 +644,7 @@ impl_writeable_tlv_based_enum_legacy!(PaymentContext,
 	// 0 for Unknown removed in version 0.1.
 	(1, Bolt12Offer),
 	(2, Bolt12Refund),
+	(3, AsyncBolt12Offer),
 );
 
 impl<'a> Writeable for PaymentContextRef<'a> {
@@ -651,6 +669,10 @@ impl_writeable_tlv_based!(Bolt12OfferContext, {
 	(2, invoice_request, required),
 });
 
+impl_writeable_tlv_based!(AsyncBolt12OfferContext, {
+	(0, offer_nonce, required),
+});
+
 impl_writeable_tlv_based!(Bolt12RefundContext, {});
 
 #[cfg(test)]

lightning/src/events/mod.rs

@@ -181,27 +181,32 @@ impl PaymentPurpose {
 	pub(crate) fn from_parts(
  payment_preimage: Option<PaymentPreimage>, payment_secret: PaymentSecret,
  payment_context: Option<PaymentContext>,
-	) -> Self {
+	) -> Result<Self, ()> {
  match payment_context {
  None => {
- PaymentPurpose::Bolt11InvoicePayment {
+Ok(PaymentPurpose::Bolt11InvoicePayment {
  payment_preimage,
  payment_secret,
- }
+ })
  },
  Some(PaymentContext::Bolt12Offer(context)) => {
- PaymentPurpose::Bolt12OfferPayment {
+Ok(PaymentPurpose::Bolt12OfferPayment {
  payment_preimage,
  payment_secret,
  payment_context: context,
- }
+ })
  },
  Some(PaymentContext::Bolt12Refund(context)) => {
- PaymentPurpose::Bolt12RefundPayment {
+Ok(PaymentPurpose::Bolt12RefundPayment {
  payment_preimage,
  payment_secret,
  payment_context: context,
- }
+ })
+ },
+ Some(PaymentContext::AsyncBolt12Offer(_context)) => {
+ // This code will change to return Self::Bolt12OfferPayment when we add support for async
+ // receive.
+ Err(())
  },
  }
 	}
@@ -1865,7 +1870,8 @@ impl MaybeReadable for Event {
  (13, payment_id, option),
  });
  let purpose = match payment_secret {
- Some(secret) => PaymentPurpose::from_parts(payment_preimage, secret, payment_context),
+ Some(secret) => PaymentPurpose::from_parts(payment_preimage, secret, payment_context)
+ .map_err(|()| msgs::DecodeError::InvalidValue)?,
  None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
  None => return Err(msgs::DecodeError::InvalidValue),
  };