Add min_final_cltv_expiry parameter to invoice utils

All utility functions for invoice construction will now also accept an
Option<>al `min_final_cltv_expiry_delta` which is useful for things like
swaps etc. The `min_final_cltv_expiry_delta` will default back to
`MIN_FINAL_CLTV_EXPIRY_DELTA` if ` None is provided.

Author: dunxen

lightning-invoice/src/de.rs

@@ -22,7 +22,7 @@ use secp256k1;
 use secp256k1::ecdsa::{RecoveryId, RecoverableSignature};
 use secp256k1::PublicKey;
 
-use super::{Invoice, Sha256, TaggedField, ExpiryTime, MinFinalCltvExpiry, Fallback, PayeePubKey, InvoiceSignature, PositiveTimestamp,
+use super::{Invoice, Sha256, TaggedField, ExpiryTime, MinFinalCltvExpiryDelta, Fallback, PayeePubKey, InvoiceSignature, PositiveTimestamp,
 	SemanticError, PrivateRoute, ParseError, ParseOrSemanticError, Description, RawTaggedField, Currency, RawHrp, SiPrefix, RawInvoice,
 	constants, SignedRawInvoice, RawDataPart, InvoiceFeatures};
 
@@ -452,7 +452,7 @@ impl FromBase32 for TaggedField {
 			constants::TAG_EXPIRY_TIME =>
 				Ok(TaggedField::ExpiryTime(ExpiryTime::from_base32(field_data)?)),
 			constants::TAG_MIN_FINAL_CLTV_EXPIRY_DELTA =>
-				Ok(TaggedField::MinFinalCltvExpiry(MinFinalCltvExpiry::from_base32(field_data)?)),
+				Ok(TaggedField::MinFinalCltvExpiryDelta(MinFinalCltvExpiryDelta::from_base32(field_data)?)),
 			constants::TAG_FALLBACK =>
 				Ok(TaggedField::Fallback(Fallback::from_base32(field_data)?)),
 			constants::TAG_PRIVATE_ROUTE =>
@@ -523,13 +523,13 @@ impl FromBase32 for ExpiryTime {
 	}
 }
 
-impl FromBase32 for MinFinalCltvExpiry {
+impl FromBase32 for MinFinalCltvExpiryDelta {
 	type Err = ParseError;
 
-	fn from_base32(field_data: &[u5]) -> Result<MinFinalCltvExpiry, ParseError> {
+	fn from_base32(field_data: &[u5]) -> Result<MinFinalCltvExpiryDelta, ParseError> {
 		let expiry = parse_int_be::<u64, u5>(field_data, 32);
 		if let Some(expiry) = expiry {
-			Ok(MinFinalCltvExpiry(expiry))
+			Ok(MinFinalCltvExpiryDelta(expiry))
 		} else {
 			Err(ParseError::IntegerOverflowError)
 		}
@@ -841,13 +841,13 @@ mod test {
 
 	#[test]
 	fn test_parse_min_final_cltv_expiry_delta() {
-		use crate::MinFinalCltvExpiry;
+		use crate::MinFinalCltvExpiryDelta;
 		use bech32::FromBase32;
 
 		let input = from_bech32("pr".as_bytes());
-		let expected = Ok(MinFinalCltvExpiry(35));
+		let expected = Ok(MinFinalCltvExpiryDelta(35));
 
-		assert_eq!(MinFinalCltvExpiry::from_base32(&input), expected);
+		assert_eq!(MinFinalCltvExpiryDelta::from_base32(&input), expected);
 	}
 
 	#[test]

lightning-invoice/src/lib.rs

@@ -410,7 +410,7 @@ pub enum TaggedField {
 	PayeePubKey(PayeePubKey),
 	DescriptionHash(Sha256),
 	ExpiryTime(ExpiryTime),
-	MinFinalCltvExpiry(MinFinalCltvExpiry),
+	MinFinalCltvExpiryDelta(MinFinalCltvExpiryDelta),
 	Fallback(Fallback),
 	PrivateRoute(PrivateRoute),
 	PaymentSecret(PaymentSecret),
@@ -440,7 +440,7 @@ pub struct ExpiryTime(Duration);
 
 /// `min_final_cltv_expiry_delta` to use for the last HTLC in the route
 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
-pub struct MinFinalCltvExpiry(pub u64);
+pub struct MinFinalCltvExpiryDelta(pub u64);
 
 // TODO: better types instead onf byte arrays
 /// Fallback address in case no LN payment is possible
@@ -656,7 +656,7 @@ impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb
 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, tb::False, S> {
 	/// Sets `min_final_cltv_expiry_delta`.
 	pub fn min_final_cltv_expiry_delta(mut self, min_final_cltv_expiry_delta: u64) -> InvoiceBuilder<D, H, T, tb::True, S> {
-		self.tagged_fields.push(TaggedField::MinFinalCltvExpiry(MinFinalCltvExpiry(min_final_cltv_expiry_delta)));
+		self.tagged_fields.push(TaggedField::MinFinalCltvExpiryDelta(MinFinalCltvExpiryDelta(min_final_cltv_expiry_delta)));
 		self.set_flags()
 	}
 }
@@ -925,8 +925,8 @@ impl RawInvoice {
 		find_extract!(self.known_tagged_fields(), TaggedField::ExpiryTime(ref x), x)
 	}
 
-	pub fn min_final_cltv_expiry_delta(&self) -> Option<&MinFinalCltvExpiry> {
-		find_extract!(self.known_tagged_fields(), TaggedField::MinFinalCltvExpiry(ref x), x)
+	pub fn min_final_cltv_expiry_delta(&self) -> Option<&MinFinalCltvExpiryDelta> {
+		find_extract!(self.known_tagged_fields(), TaggedField::MinFinalCltvExpiryDelta(ref x), x)
 	}
 
 	pub fn payment_secret(&self) -> Option<&PaymentSecret> {
@@ -1297,7 +1297,7 @@ impl TaggedField {
 			TaggedField::PayeePubKey(_) => constants::TAG_PAYEE_PUB_KEY,
 			TaggedField::DescriptionHash(_) => constants::TAG_DESCRIPTION_HASH,
 			TaggedField::ExpiryTime(_) => constants::TAG_EXPIRY_TIME,
-			TaggedField::MinFinalCltvExpiry(_) => constants::TAG_MIN_FINAL_CLTV_EXPIRY_DELTA,
+			TaggedField::MinFinalCltvExpiryDelta(_) => constants::TAG_MIN_FINAL_CLTV_EXPIRY_DELTA,
 			TaggedField::Fallback(_) => constants::TAG_FALLBACK,
 			TaggedField::PrivateRoute(_) => constants::TAG_PRIVATE_ROUTE,
 			TaggedField::PaymentSecret(_) => constants::TAG_PAYMENT_SECRET,
@@ -1444,6 +1444,9 @@ pub enum CreationError {
 	///
 	/// [phantom invoices]: crate::utils::create_phantom_invoice
 	MissingRouteHints,
+
+	/// The provided `min_final_cltv_expiry_delta` was less than `MIN_FINAL_CLTV_EXPIRY_DELTA`.
+	MinFinalCltvExpiryDeltaTooShort,
 }
 
 impl Display for CreationError {
@@ -1454,6 +1457,8 @@ impl Display for CreationError {
 			CreationError::TimestampOutOfBounds => f.write_str("The Unix timestamp of the supplied date is less than zero or greater than 35-bits"),
 			CreationError::InvalidAmount => f.write_str("The supplied millisatoshi amount was greater than the total bitcoin supply"),
 			CreationError::MissingRouteHints => f.write_str("The invoice required route hints and they weren't provided"),
+			CreationError::MinFinalCltvExpiryDeltaTooShort => f.write_str(
+				"The supplied final CLTV expiry delta was less than LDK's `MIN_FINAL_CLTV_EXPIRY_DELTA`"),
 		}
 	}
 }

lightning-invoice/src/payment.rs

@@ -2082,7 +2082,7 @@ mod tests {
 
 		assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager_and_duration_since_epoch(
 			&nodes[1].node, nodes[1].keys_manager, nodes[1].logger, Currency::Bitcoin,
-			Some(100_010_000), "Invoice".to_string(), duration_since_epoch(), 3600).unwrap())
+			Some(100_010_000), "Invoice".to_string(), duration_since_epoch(), 3600, None).unwrap())
 			.is_ok());
 		let htlc_msgs = nodes[0].node.get_and_clear_pending_msg_events();
 		assert_eq!(htlc_msgs.len(), 2);
@@ -2127,7 +2127,7 @@ mod tests {
 
 		assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager_and_duration_since_epoch(
 			&nodes[1].node, nodes[1].keys_manager, nodes[1].logger, Currency::Bitcoin,
-			Some(100_010_000), "Invoice".to_string(), duration_since_epoch(), 3600).unwrap())
+			Some(100_010_000), "Invoice".to_string(), duration_since_epoch(), 3600, None).unwrap())
 			.is_ok());
 		let htlc_msgs = nodes[0].node.get_and_clear_pending_msg_events();
 		assert_eq!(htlc_msgs.len(), 2);
@@ -2208,7 +2208,7 @@ mod tests {
 
 		assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager_and_duration_since_epoch(
 			&nodes[1].node, nodes[1].keys_manager, nodes[1].logger, Currency::Bitcoin,
-			Some(100_010_000), "Invoice".to_string(), duration_since_epoch(), 3600).unwrap())
+			Some(100_010_000), "Invoice".to_string(), duration_since_epoch(), 3600, None).unwrap())
 			.is_ok());
 		let htlc_updates = SendEvent::from_node(&nodes[0]);
 		check_added_monitors!(nodes[0], 1);

lightning-invoice/src/ser.rs

@@ -3,7 +3,7 @@ use core::fmt::{Display, Formatter};
 use bech32::{ToBase32, u5, WriteBase32, Base32Len};
 use crate::prelude::*;
 
-use super::{Invoice, Sha256, TaggedField, ExpiryTime, MinFinalCltvExpiry, Fallback, PayeePubKey, InvoiceSignature, PositiveTimestamp,
+use super::{Invoice, Sha256, TaggedField, ExpiryTime, MinFinalCltvExpiryDelta, Fallback, PayeePubKey, InvoiceSignature, PositiveTimestamp,
 	PrivateRoute, Description, RawTaggedField, Currency, RawHrp, SiPrefix, constants, SignedRawInvoice, RawDataPart};
 
 /// Converts a stream of bytes written to it to base32. On finalization the according padding will
@@ -313,13 +313,13 @@ impl Base32Len for ExpiryTime {
 	}
 }
 
-impl ToBase32 for MinFinalCltvExpiry {
+impl ToBase32 for MinFinalCltvExpiryDelta {
 	fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 		writer.write(&encode_int_be_base32(self.0))
 	}
 }
 
-impl Base32Len for MinFinalCltvExpiry {
+impl Base32Len for MinFinalCltvExpiryDelta {
 	fn base32_len(&self) -> usize {
 		encoded_int_be_base32_size(self.0)
 	}
@@ -434,7 +434,7 @@ impl ToBase32 for TaggedField {
 			TaggedField::ExpiryTime(ref duration) => {
 				write_tagged_field(writer, constants::TAG_EXPIRY_TIME, duration)
 			},
-			TaggedField::MinFinalCltvExpiry(ref expiry) => {
+			TaggedField::MinFinalCltvExpiryDelta(ref expiry) => {
 				write_tagged_field(writer, constants::TAG_MIN_FINAL_CLTV_EXPIRY_DELTA, expiry)
 			},
 			TaggedField::Fallback(ref fallback_address) => {