f - WIP: respond with invoice

Author: jkczyz

lightning/src/ln/channelmanager.rs

@@ -793,7 +793,7 @@ 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

@@ -122,7 +122,7 @@ 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");
 
@@ -145,18 +145,7 @@ impl<'a> InvoiceBuilder<'a> {
 		invoice_request: &'a InvoiceRequest, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>,
 		created_at: Duration, payment_hash: PaymentHash
 	) -> Result<Self, SemanticError> {
-		let amount_msats = match invoice_request.amount_msats() {
-			Some(amount_msats) => amount_msats,
-			None => match invoice_request.contents.offer.amount() {
-				Some(Amount::Bitcoin { amount_msats }) => {
-					amount_msats.checked_mul(invoice_request.quantity().unwrap_or(1))
-						.ok_or(SemanticError::InvalidAmount)?
-				},
-				Some(Amount::Currency { .. }) => return Err(SemanticError::UnsupportedCurrency),
-				None => return Err(SemanticError::MissingAmount),
-			},
-		};
-
+		let amount_msats = Self::amount_msats(invoice_request)?;
 		let contents = InvoiceContents::ForOffer {
 			invoice_request: invoice_request.contents.clone(),
 			fields: InvoiceFields {
@@ -185,6 +174,20 @@ impl<'a> InvoiceBuilder<'a> {
 		Self::new(&refund.bytes, contents)
 	}
 
+	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.offer.amount() {
+				Some(Amount::Bitcoin { amount_msats }) => {
+					amount_msats.checked_mul(invoice_request.quantity().unwrap_or(1))
+						.ok_or(SemanticError::InvalidAmount)
+				},
+				Some(Amount::Currency { .. }) => Err(SemanticError::UnsupportedCurrency),
+				None => Err(SemanticError::MissingAmount),
+			},
+		}
+	}
+
 	fn new(invreq_bytes: &'a Vec<u8>, contents: InvoiceContents) -> Result<Self, SemanticError> {
 		if contents.fields().payment_paths.is_empty() {
 			return Err(SemanticError::MissingPaths);

lightning/src/onion_message/offers.rs

@@ -18,7 +18,7 @@ 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, Invoice, InvoiceBuilder};
 use crate::offers::parse::ParseError;
 use crate::onion_message::messenger::{ResponseError, ResponseErrorHandler};
 use crate::routing::router::Router;
@@ -126,14 +126,40 @@ where
 	fn handle_message(&self, message: OffersMessage) -> Option<OffersMessage> {
 		match message {
 			OffersMessage::InvoiceRequest(invoice_request) => {
-				if invoice_request.verify(&self.inbound_payment_key) {}
+				if !invoice_request.verify(&self.inbound_payment_key) {
+					return Some(OffersMessage::InvoiceError);
+				}
+
+				let amount_msats = match InvoiceBuilder::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 = invoice_request
+							.respond_with(vec![], payment_hash).unwrap()
+							.allow_mpp()
+							.build().unwrap()
+							.sign(|digest, tag, bytes, metadata|
+								self.node_signer.sign_bolt12_message(digest, tag, bytes, metadata)
+							).unwrap();
+
+						Some(OffersMessage::Invoice(invoice))
+					},
+					Err(e) => Some(OffersMessage::InvoiceError),
+				}
 			},
 			OffersMessage::Invoice(invoice) => {
 				if invoice.verify(&self.inbound_payment_key) {}
+				None
+			},
+			OffersMessage::InvoiceError => {
+				// TODO: Log
+				None
 			},
-			OffersMessage::InvoiceError => {},
 		}
-		todo!()
 	}
 }