f - check amount_msats against MAX_VALUE_MSAT when parsing

Author: jkczyz

lightning/src/offers/offer.rs

@@ -499,6 +499,9 @@ impl TryFrom<OfferTlvStream> for OfferContents {
 
 		let amount = match (currency, amount) {
 			(None, None) => None,
+			(None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
+				return Err(SemanticError::InvalidAmount);
+			},
 			(None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
 			(Some(_), None) => return Err(SemanticError::MissingAmount),
 			(Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),

lightning/src/offers/parse.rs

@@ -74,6 +74,8 @@ pub enum ParseError {
 pub enum SemanticError {
 	/// An amount was expected but was missing.
 	MissingAmount,
+	/// The amount exceeded the total bitcoin supply.
+	InvalidAmount,
 	/// A required description was not provided.
 	MissingDescription,
 	/// A signing pubkey was not provided.