Merge pull request #898 from jkczyz/2021-04-invoice-expiry

Require min_final_cltv_expiry in invoices

Author: TheBlueMatt

lightning-invoice/src/lib.rs

@@ -56,6 +56,16 @@ const SYSTEM_TIME_MAX_UNIX_TIMESTAMP: u64 = std::i32::MAX as u64;
 /// it should be rather low as long as we still have to support 32bit time representations
 const MAX_EXPIRY_TIME: u64 = 60 * 60 * 24 * 356;
 
+/// Default expiry time as defined by [BOLT 11].
+///
+/// [BOLT 11]: https://github.com/lightningnetwork/lightning-rfc/blob/master/11-payment-encoding.md
+const DEFAULT_EXPIRY_TIME: u64 = 3600;
+
+/// Default minimum final CLTV expiry as defined by [BOLT 11].
+///
+/// [BOLT 11]: https://github.com/lightningnetwork/lightning-rfc/blob/master/11-payment-encoding.md
+const DEFAULT_MIN_FINAL_CLTV_EXPIRY: u64 = 18;
+
 /// This function is used as a static assert for the size of `SystemTime`. If the crate fails to
 /// compile due to it this indicates that your system uses unexpected bounds for `SystemTime`. You
 /// can remove this functions and run the test `test_system_time_bounds_assumptions`. In any case,
@@ -138,6 +148,7 @@ pub fn check_platform() {
 /// 	.description("Coins pls!".into())
 /// 	.payment_hash(payment_hash)
 /// 	.current_timestamp()
+/// 	.min_final_cltv_expiry(144)
 /// 	.build_signed(|hash| {
 /// 		Secp256k1::new().sign_recoverable(hash, &private_key)
 /// 	})
@@ -156,7 +167,7 @@ pub fn check_platform() {
 ///
 /// (C-not exported) as we likely need to manually select one set of boolean type parameters.
 #[derive(Eq, PartialEq, Debug, Clone)]
-pub struct InvoiceBuilder<D: tb::Bool, H: tb::Bool, T: tb::Bool> {
+pub struct InvoiceBuilder<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> {
 	currency: Currency,
 	amount: Option<u64>,
 	si_prefix: Option<SiPrefix>,
@@ -167,6 +178,7 @@ pub struct InvoiceBuilder<D: tb::Bool, H: tb::Bool, T: tb::Bool> {
 	phantom_d: std::marker::PhantomData<D>,
 	phantom_h: std::marker::PhantomData<H>,
 	phantom_t: std::marker::PhantomData<T>,
+	phantom_c: std::marker::PhantomData<C>,
 }
 
 /// Represents a syntactically and semantically correct lightning BOLT11 invoice.
@@ -414,7 +426,7 @@ pub mod constants {
 	pub const TAG_FEATURES: u8 = 5;
 }
 
-impl InvoiceBuilder<tb::False, tb::False, tb::False> {
+impl InvoiceBuilder<tb::False, tb::False, tb::False, tb::False> {
 	/// Construct new, empty `InvoiceBuilder`. All necessary fields have to be filled first before
 	/// `InvoiceBuilder::build(self)` becomes available.
 	pub fn new(currrency: Currency) -> Self {
@@ -429,14 +441,15 @@ impl InvoiceBuilder<tb::False, tb::False, tb::False> {
 			phantom_d: std::marker::PhantomData,
 			phantom_h: std::marker::PhantomData,
 			phantom_t: std::marker::PhantomData,
+			phantom_c: std::marker::PhantomData,
 		}
 	}
 }
 
-impl<D: tb::Bool, H: tb::Bool, T: tb::Bool> InvoiceBuilder<D, H, T> {
+impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C> {
 	/// Helper function to set the completeness flags.
-	fn set_flags<DN: tb::Bool, HN: tb::Bool, TN: tb::Bool>(self) -> InvoiceBuilder<DN, HN, TN> {
-		InvoiceBuilder::<DN, HN, TN> {
+	fn set_flags<DN: tb::Bool, HN: tb::Bool, TN: tb::Bool, CN: tb::Bool>(self) -> InvoiceBuilder<DN, HN, TN, CN> {
+		InvoiceBuilder::<DN, HN, TN, CN> {
 			currency: self.currency,
 			amount: self.amount,
 			si_prefix: self.si_prefix,
@@ -447,6 +460,7 @@ impl<D: tb::Bool, H: tb::Bool, T: tb::Bool> InvoiceBuilder<D, H, T> {
 			phantom_d: std::marker::PhantomData,
 			phantom_h: std::marker::PhantomData,
 			phantom_t: std::marker::PhantomData,
+			phantom_c: std::marker::PhantomData,
 		}
 	}
 
@@ -482,12 +496,6 @@ impl<D: tb::Bool, H: tb::Bool, T: tb::Bool> InvoiceBuilder<D, H, T> {
 		self
 	}
 
-	/// Sets `min_final_cltv_expiry`.
-	pub fn min_final_cltv_expiry(mut self, min_final_cltv_expiry: u64) -> Self {
-		self.tagged_fields.push(TaggedField::MinFinalCltvExpiry(MinFinalCltvExpiry(min_final_cltv_expiry)));
-		self
-	}
-
 	/// Adds a fallback address.
 	pub fn fallback(mut self, fallback: Fallback) -> Self {
 		self.tagged_fields.push(TaggedField::Fallback(fallback));
@@ -511,7 +519,7 @@ impl<D: tb::Bool, H: tb::Bool, T: tb::Bool> InvoiceBuilder<D, H, T> {
 	}
 }
 
-impl<D: tb::Bool, H: tb::Bool> InvoiceBuilder<D, H, tb::True> {
+impl<D: tb::Bool, H: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, tb::True, C> {
 	/// Builds a `RawInvoice` if no `CreationError` occurred while construction any of the fields.
 	pub fn build_raw(self) -> Result<RawInvoice, CreationError> {
 
@@ -544,9 +552,9 @@ impl<D: tb::Bool, H: tb::Bool> InvoiceBuilder<D, H, tb::True> {
 	}
 }
 
-impl<H: tb::Bool, T: tb::Bool> InvoiceBuilder<tb::False, H, T> {
+impl<H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<tb::False, H, T, C> {
 	/// Set the description. This function is only available if no description (hash) was set.
-	pub fn description(mut self, description: String) -> InvoiceBuilder<tb::True, H, T> {
+	pub fn description(mut self, description: String) -> InvoiceBuilder<tb::True, H, T, C> {
 		match Description::new(description) {
 			Ok(d) => self.tagged_fields.push(TaggedField::Description(d)),
 			Err(e) => self.error = Some(e),
@@ -555,23 +563,23 @@ impl<H: tb::Bool, T: tb::Bool> InvoiceBuilder<tb::False, H, T> {
 	}
 
 	/// Set the description hash. This function is only available if no description (hash) was set.
-	pub fn description_hash(mut self, description_hash: sha256::Hash) -> InvoiceBuilder<tb::True, H, T> {
+	pub fn description_hash(mut self, description_hash: sha256::Hash) -> InvoiceBuilder<tb::True, H, T, C> {
 		self.tagged_fields.push(TaggedField::DescriptionHash(Sha256(description_hash)));
 		self.set_flags()
 	}
 }
 
-impl<D: tb::Bool, T: tb::Bool> InvoiceBuilder<D, tb::False, T> {
+impl<D: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, tb::False, T, C> {
 	/// Set the payment hash. This function is only available if no payment hash was set.
-	pub fn payment_hash(mut self, hash: sha256::Hash) -> InvoiceBuilder<D, tb::True, T> {
+	pub fn payment_hash(mut self, hash: sha256::Hash) -> InvoiceBuilder<D, tb::True, T, C> {
 		self.tagged_fields.push(TaggedField::PaymentHash(Sha256(hash)));
 		self.set_flags()
 	}
 }
 
-impl<D: tb::Bool, H: tb::Bool> InvoiceBuilder<D, H, tb::False> {
+impl<D: tb::Bool, H: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, tb::False, C> {
 	/// Sets the timestamp.
-	pub fn timestamp(mut self, time: SystemTime) -> InvoiceBuilder<D, H, tb::True> {
+	pub fn timestamp(mut self, time: SystemTime) -> InvoiceBuilder<D, H, tb::True, C> {
 		match PositiveTimestamp::from_system_time(time) {
 			Ok(t) => self.timestamp = Some(t),
 			Err(e) => self.error = Some(e),
@@ -581,14 +589,22 @@ impl<D: tb::Bool, H: tb::Bool> InvoiceBuilder<D, H, tb::False> {
 	}
 
 	/// Sets the timestamp to the current UNIX timestamp.
-	pub fn current_timestamp(mut self) -> InvoiceBuilder<D, H, tb::True> {
+	pub fn current_timestamp(mut self) -> InvoiceBuilder<D, H, tb::True, C> {
 		let now = PositiveTimestamp::from_system_time(SystemTime::now());
 		self.timestamp = Some(now.expect("for the foreseeable future this shouldn't happen"));
 		self.set_flags()
 	}
 }
 
-impl InvoiceBuilder<tb::True, tb::True, tb::True> {
+impl<D: tb::Bool, H: tb::Bool, T: tb::Bool> InvoiceBuilder<D, H, T, tb::False> {
+	/// Sets `min_final_cltv_expiry`.
+	pub fn min_final_cltv_expiry(mut self, min_final_cltv_expiry: u64) -> InvoiceBuilder<D, H, T, tb::True> {
+		self.tagged_fields.push(TaggedField::MinFinalCltvExpiry(MinFinalCltvExpiry(min_final_cltv_expiry)));
+		self.set_flags()
+	}
+}
+
+impl InvoiceBuilder<tb::True, tb::True, tb::True, tb::True> {
 	/// Builds and signs an invoice using the supplied `sign_function`. This function MAY NOT fail
 	/// and MUST produce a recoverable signature valid for the given hash and if applicable also for
 	/// the included payee public key.
@@ -1044,16 +1060,19 @@ impl Invoice {
 		self.signed_invoice.recover_payee_pub_key().expect("was checked by constructor").0
 	}
 
-	/// Returns the invoice's expiry time if present
+	/// Returns the invoice's expiry time, if present, otherwise [`DEFAULT_EXPIRY_TIME`].
 	pub fn expiry_time(&self) -> Duration {
 		self.signed_invoice.expiry_time()
 			.map(|x| x.0)
-			.unwrap_or(Duration::from_secs(3600))
+			.unwrap_or(Duration::from_secs(DEFAULT_EXPIRY_TIME))
 	}
 
-	/// Returns the invoice's `min_cltv_expiry` time if present
-	pub fn min_final_cltv_expiry(&self) -> Option<u64> {
-		self.signed_invoice.min_final_cltv_expiry().map(|x| x.0)
+	/// Returns the invoice's `min_final_cltv_expiry` time, if present, otherwise
+	/// [`DEFAULT_MIN_FINAL_CLTV_EXPIRY`].
+	pub fn min_final_cltv_expiry(&self) -> u64 {
+		self.signed_invoice.min_final_cltv_expiry()
+			.map(|x| x.0)
+			.unwrap_or(DEFAULT_MIN_FINAL_CLTV_EXPIRY)
 	}
 
 	/// Returns a list of all fallback addresses
@@ -1479,7 +1498,8 @@ mod test {
 
 		let builder = InvoiceBuilder::new(Currency::Bitcoin)
 			.payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
-			.current_timestamp();
+			.current_timestamp()
+			.min_final_cltv_expiry(144);
 
 		let too_long_string = String::from_iter(
 			(0..1024).map(|_| '?')
@@ -1596,7 +1616,6 @@ mod test {
 			.payee_pub_key(public_key.clone())
 			.expiry_time(Duration::from_secs(54321))
 			.min_final_cltv_expiry(144)
-			.min_final_cltv_expiry(143)
 			.fallback(Fallback::PubKeyHash([0;20]))
 			.route(route_1.clone())
 			.route(route_2.clone())
@@ -1608,7 +1627,7 @@ mod test {
 		}).unwrap();
 
 		assert!(invoice.check_signature().is_ok());
-		assert_eq!(invoice.tagged_fields().count(), 9);
+		assert_eq!(invoice.tagged_fields().count(), 8);
 
 		assert_eq!(invoice.amount_pico_btc(), Some(123));
 		assert_eq!(invoice.currency(), Currency::BitcoinTestnet);
@@ -1618,7 +1637,7 @@ mod test {
 		);
 		assert_eq!(invoice.payee_pub_key(), Some(&public_key));
 		assert_eq!(invoice.expiry_time(), Duration::from_secs(54321));
-		assert_eq!(invoice.min_final_cltv_expiry(), Some(144));
+		assert_eq!(invoice.min_final_cltv_expiry(), 144);
 		assert_eq!(invoice.fallbacks(), vec![&Fallback::PubKeyHash([0;20])]);
 		assert_eq!(invoice.routes(), vec![&RouteHint(route_1), &RouteHint(route_2)]);
 		assert_eq!(
@@ -1630,4 +1649,28 @@ mod test {
 		let raw_invoice = builder.build_raw().unwrap();
 		assert_eq!(raw_invoice, *invoice.into_signed_raw().raw_invoice())
 	}
+
+	#[test]
+	fn test_default_values() {
+		use ::*;
+		use secp256k1::Secp256k1;
+		use secp256k1::key::SecretKey;
+
+		let signed_invoice = InvoiceBuilder::new(Currency::Bitcoin)
+			.description("Test".into())
+			.payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
+			.current_timestamp()
+			.build_raw()
+			.unwrap()
+			.sign::<_, ()>(|hash| {
+				let privkey = SecretKey::from_slice(&[41; 32]).unwrap();
+				let secp_ctx = Secp256k1::new();
+				Ok(secp_ctx.sign_recoverable(hash, &privkey))
+			})
+			.unwrap();
+		let invoice = Invoice::from_signed(signed_invoice).unwrap();
+
+		assert_eq!(invoice.min_final_cltv_expiry(), DEFAULT_MIN_FINAL_CLTV_EXPIRY);
+		assert_eq!(invoice.expiry_time(), Duration::from_secs(DEFAULT_EXPIRY_TIME));
+	}
 }

lightning-invoice/tests/ser_de.rs

@@ -112,13 +112,14 @@ fn get_test_tuples() -> Vec<(String, SignedRawInvoice, Option<SemanticError>)> {
 				.amount_pico_btc(20000000000)
 				.timestamp(UNIX_EPOCH + Duration::from_secs(1496314658))
 				.payment_secret(PaymentSecret([42; 32]))
-				.build_signed(|msg_hash| {
+				.build_raw()
+				.unwrap()
+				.sign::<_, ()>(|msg_hash| {
 					let privkey = SecretKey::from_slice(&[41; 32]).unwrap();
 					let secp_ctx = Secp256k1::new();
-					secp_ctx.sign_recoverable(msg_hash, &privkey)
+					Ok(secp_ctx.sign_recoverable(msg_hash, &privkey))
 				})
-				.unwrap()
-				.into_signed_raw(),
+				.unwrap(),
 			None
 		)
 	]