f - WIP: respond with invoice

Author: jkczyz

lightning/src/ln/channelmanager.rs

@@ -814,7 +814,7 @@ where
 	pub(super) best_block: RwLock<BestBlock>,
 	#[cfg(not(test))]
 	best_block: RwLock<BestBlock>,
-	secp_ctx: Secp256k1<secp256k1::All>,
+	pub(crate) secp_ctx: Secp256k1<secp256k1::All>,
 
 	/// Storage for PaymentSecrets and any requirements on future inbound payments before we will
 	/// expose them to users via a PaymentClaimable event. HTLCs which do not meet the requirements
@@ -977,7 +977,7 @@ where
 	persistence_notifier: Notifier,
 
 	entropy_source: ES,
-	node_signer: NS,
+	pub(crate) node_signer: NS,
 	signer_provider: SP,
 
 	logger: L,

lightning/src/offers/invoice.rs

@@ -124,7 +124,7 @@ use crate::prelude::*;
 #[cfg(feature = "std")]
 use std::time::SystemTime;
 
-const DEFAULT_RELATIVE_EXPIRY: Duration = Duration::from_secs(7200);
+pub(crate) const DEFAULT_RELATIVE_EXPIRY: Duration = Duration::from_secs(7200);
 
 pub(super) const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice", "signature");
 
@@ -169,7 +169,7 @@ impl<'a> InvoiceBuilder<'a, ExplicitSigningPubkey> {
 		invoice_request: &'a InvoiceRequest, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>,
 		created_at: Duration, payment_hash: PaymentHash
 	) -> Result<Self, SemanticError> {
-		let amount_msats = Self::check_amount_msats(invoice_request)?;
+		let amount_msats = Self::amount_msats(invoice_request)?;
 		let signing_pubkey = invoice_request.contents.inner.offer.signing_pubkey();
 		let contents = InvoiceContents::ForOffer {
 			invoice_request: invoice_request.contents.clone(),
@@ -202,7 +202,7 @@ impl<'a> InvoiceBuilder<'a, DerivedSigningPubkey> {
 		invoice_request: &'a InvoiceRequest, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>,
 		created_at: Duration, payment_hash: PaymentHash, keys: KeyPair
 	) -> Result<Self, SemanticError> {
-		let amount_msats = Self::check_amount_msats(invoice_request)?;
+		let amount_msats = Self::amount_msats(invoice_request)?;
 		let signing_pubkey = invoice_request.contents.inner.offer.signing_pubkey();
 		let contents = InvoiceContents::ForOffer {
 			invoice_request: invoice_request.contents.clone(),
@@ -232,7 +232,7 @@ impl<'a> InvoiceBuilder<'a, DerivedSigningPubkey> {
 }
 
 impl<'a, S: SigningPubkeyStrategy> InvoiceBuilder<'a, S> {
-	fn check_amount_msats(invoice_request: &InvoiceRequest) -> Result<u64, SemanticError> {
+	pub(crate) fn amount_msats(invoice_request: &InvoiceRequest) -> Result<u64, SemanticError> {
 		match invoice_request.amount_msats() {
 			Some(amount_msats) => Ok(amount_msats),
 			None => match invoice_request.contents.inner.offer.amount() {

lightning/src/onion_message/offers.rs

@@ -17,7 +17,7 @@ use crate::io::{self, Read};
 use crate::ln::channelmanager::ChannelManager;
 use crate::ln::msgs::DecodeError;
 use crate::offers::invoice_request::InvoiceRequest;
-use crate::offers::invoice::Invoice;
+use crate::offers::invoice::{DEFAULT_RELATIVE_EXPIRY, DerivedSigningPubkey, Invoice, InvoiceBuilder};
 use crate::offers::parse::ParseError;
 use crate::onion_message::messenger::{ResponseError, ResponseErrorHandler};
 use crate::routing::router::Router;
@@ -126,14 +126,36 @@ where
 	fn handle_message(&self, message: OffersMessage) -> Option<OffersMessage> {
 		match message {
 			OffersMessage::InvoiceRequest(invoice_request) => {
-				if invoice_request.verify(&self.inbound_payment_key) {}
+				let amount_msats = match InvoiceBuilder::<DerivedSigningPubkey>::amount_msats(
+					&invoice_request
+				) {
+					Ok(amount_msats) => Some(amount_msats),
+					Err(_) => return Some(OffersMessage::InvoiceError),
+				};
+				let relative_expiry = DEFAULT_RELATIVE_EXPIRY.as_secs() as u32;
+
+				match self.create_inbound_payment(amount_msats, relative_expiry, None) {
+					Ok((payment_hash, payment_secret)) => {
+						let invoice = match invoice_request.verify_and_respond_using_derived_keys(
+							vec![], payment_hash, &self.inbound_payment_key, &self.secp_ctx
+						) {
+							Ok(builder) => builder.allow_mpp().build_and_sign(&self.secp_ctx).unwrap(),
+							Err(_) => return Some(OffersMessage::InvoiceError),
+						};
+						Some(OffersMessage::Invoice(invoice))
+					},
+					Err(_) => Some(OffersMessage::InvoiceError),
+				}
 			},
 			OffersMessage::Invoice(invoice) => {
-				if invoice.verify(&self.inbound_payment_key) {}
+				if invoice.verify(&self.inbound_payment_key, &self.secp_ctx) {}
+				None
+			},
+			OffersMessage::InvoiceError => {
+				// TODO: Log
+				None
 			},
-			OffersMessage::InvoiceError => {},
 		}
-		todo!()
 	}
 }