Merge pull request #2023 from futurepaul/fallback-to-address

add `Fallback` getter that returns `Address`

Author: jkczyz

lightning-invoice/Cargo.toml

@@ -27,6 +27,7 @@ num-traits = { version = "0.2.8", default-features = false }
 bitcoin_hashes = { version = "0.11", default-features = false }
 hashbrown = { version = "0.8", optional = true }
 serde = { version = "1.0.118", optional = true }
+bitcoin = { version = "0.29.0", default-features = false }
 
 [dev-dependencies]
 lightning = { version = "0.0.114", path = "../lightning", default-features = false, features = ["_test_utils"] }

lightning-invoice/src/de.rs

@@ -1,5 +1,6 @@
 #[cfg(feature = "std")]
 use std::error;
+use core::convert::TryFrom;
 use core::fmt;
 use core::fmt::{Display, Formatter};
 use core::num::ParseIntError;
@@ -8,6 +9,8 @@ use core::str::FromStr;
 
 use bech32::{u5, FromBase32};
 
+use bitcoin::{PubkeyHash, ScriptHash};
+use bitcoin::util::address::WitnessVersion;
 use bitcoin_hashes::Hash;
 use bitcoin_hashes::sha256;
 use crate::prelude::*;
@@ -550,27 +553,24 @@ impl FromBase32 for Fallback {
 				if bytes.len() < 2 || bytes.len() > 40 {
 					return Err(ParseError::InvalidSegWitProgramLength);
 				}
-
+				let version = WitnessVersion::try_from(version).expect("0 through 16 are valid SegWit versions");
 				Ok(Fallback::SegWitProgram {
 					version,
 					program: bytes
 				})
 			},
 			17 => {
-				if bytes.len() != 20 {
-					return Err(ParseError::InvalidPubKeyHashLength);
-				}
-				//TODO: refactor once const generics are available
-				let mut pkh = [0u8; 20];
-				pkh.copy_from_slice(&bytes);
+				let pkh = match PubkeyHash::from_slice(&bytes) {
+					Ok(pkh) => pkh,
+					Err(bitcoin_hashes::Error::InvalidLength(_, _)) => return Err(ParseError::InvalidPubKeyHashLength),
+				};
 				Ok(Fallback::PubKeyHash(pkh))
 			}
 			18 => {
-				if bytes.len() != 20 {
-					return Err(ParseError::InvalidScriptHashLength);
-				}
-				let mut sh = [0u8; 20];
-				sh.copy_from_slice(&bytes);
+				let sh = match ScriptHash::from_slice(&bytes) {
+					Ok(sh) => sh,
+					Err(bitcoin_hashes::Error::InvalidLength(_, _)) => return Err(ParseError::InvalidScriptHashLength),
+				};
 				Ok(Fallback::ScriptHash(sh))
 			}
 			_ => Err(ParseError::Skip)
@@ -852,26 +852,29 @@ mod test {
 	fn test_parse_fallback() {
 		use crate::Fallback;
 		use bech32::FromBase32;
+		use bitcoin::{PubkeyHash, ScriptHash};
+		use bitcoin::util::address::WitnessVersion;
+		use bitcoin_hashes::Hash;
 
 		let cases = vec![
 			(
 				from_bech32("3x9et2e20v6pu37c5d9vax37wxq72un98".as_bytes()),
-				Ok(Fallback::PubKeyHash([
+				Ok(Fallback::PubKeyHash(PubkeyHash::from_slice(&[
 					0x31, 0x72, 0xb5, 0x65, 0x4f, 0x66, 0x83, 0xc8, 0xfb, 0x14, 0x69, 0x59, 0xd3,
 					0x47, 0xce, 0x30, 0x3c, 0xae, 0x4c, 0xa7
-				]))
+				]).unwrap()))
 			),
 			(
 				from_bech32("j3a24vwu6r8ejrss3axul8rxldph2q7z9".as_bytes()),
-				Ok(Fallback::ScriptHash([
+				Ok(Fallback::ScriptHash(ScriptHash::from_slice(&[
 					0x8f, 0x55, 0x56, 0x3b, 0x9a, 0x19, 0xf3, 0x21, 0xc2, 0x11, 0xe9, 0xb9, 0xf3,
 					0x8c, 0xdf, 0x68, 0x6e, 0xa0, 0x78, 0x45
-				]))
+				]).unwrap()))
 			),
 			(
 				from_bech32("qw508d6qejxtdg4y5r3zarvary0c5xw7k".as_bytes()),
 				Ok(Fallback::SegWitProgram {
-					version: u5::try_from_u8(0).unwrap(),
+					version: WitnessVersion::V0,
 					program: Vec::from(&[
 						0x75u8, 0x1e, 0x76, 0xe8, 0x19, 0x91, 0x96, 0xd4, 0x54, 0x94, 0x1c, 0x45,
 						0xd1, 0xb3, 0xa3, 0x23, 0xf1, 0x43, 0x3b, 0xd6

lightning-invoice/src/lib.rs

@@ -47,8 +47,9 @@ extern crate serde;
 use std::time::SystemTime;
 
 use bech32::u5;
-use bitcoin_hashes::Hash;
-use bitcoin_hashes::sha256;
+use bitcoin::{Address, Network, PubkeyHash, ScriptHash};
+use bitcoin::util::address::{Payload, WitnessVersion};
+use bitcoin_hashes::{Hash, sha256};
 use lightning::ln::PaymentSecret;
 use lightning::ln::features::InvoiceFeatures;
 #[cfg(any(doc, test))]
@@ -446,17 +447,16 @@ pub struct ExpiryTime(Duration);
 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
 pub struct MinFinalCltvExpiryDelta(pub u64);
 
-// TODO: better types instead onf byte arrays
 /// Fallback address in case no LN payment is possible
 #[allow(missing_docs)]
 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
 pub enum Fallback {
 	SegWitProgram {
-		version: u5,
+		version: WitnessVersion,
 		program: Vec<u8>,
 	},
-	PubKeyHash([u8; 20]),
-	ScriptHash([u8; 20]),
+	PubKeyHash(PubkeyHash),
+	ScriptHash(ScriptHash),
 }
 
 /// Recoverable signature
@@ -1300,6 +1300,33 @@ impl Invoice {
 		self.signed_invoice.fallbacks()
 	}
 
+	/// Returns a list of all fallback addresses as [`Address`]es
+	pub fn fallback_addresses(&self) -> Vec<Address> {
+		self.fallbacks().iter().map(|fallback| {
+			let network = match self.currency() {
+				Currency::Bitcoin => Network::Bitcoin,
+				Currency::BitcoinTestnet => Network::Testnet,
+				Currency::Regtest => Network::Regtest,
+				Currency::Simnet => Network::Regtest,
+				Currency::Signet => Network::Signet,
+			};
+
+			let payload = match fallback {
+				Fallback::SegWitProgram { version, program } => {
+					Payload::WitnessProgram { version: *version, program: program.to_vec() }
+				}
+				Fallback::PubKeyHash(pkh) => {
+					Payload::PubkeyHash(*pkh)
+				}
+				Fallback::ScriptHash(sh) => {
+					Payload::ScriptHash(*sh)
+				}
+			};
+
+			Address { payload, network }
+		}).collect()
+	}
+
 	/// Returns a list of all routes included in the invoice
 	pub fn private_routes(&self) -> Vec<&PrivateRoute> {
 		self.signed_invoice.private_routes()
@@ -1609,6 +1636,7 @@ impl<'de> Deserialize<'de> for Invoice {
 
 #[cfg(test)]
 mod test {
+	use bitcoin::Script;
 	use bitcoin_hashes::hex::FromHex;
 	use bitcoin_hashes::sha256;
 
@@ -1972,7 +2000,7 @@ mod test {
 			.payee_pub_key(public_key)
 			.expiry_time(Duration::from_secs(54321))
 			.min_final_cltv_expiry_delta(144)
-			.fallback(Fallback::PubKeyHash([0;20]))
+			.fallback(Fallback::PubKeyHash(PubkeyHash::from_slice(&[0;20]).unwrap()))
 			.private_route(route_1.clone())
 			.private_route(route_2.clone())
 			.description_hash(sha256::Hash::from_slice(&[3;32][..]).unwrap())
@@ -1998,7 +2026,9 @@ 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_delta(), 144);
-		assert_eq!(invoice.fallbacks(), vec![&Fallback::PubKeyHash([0;20])]);
+		assert_eq!(invoice.fallbacks(), vec![&Fallback::PubKeyHash(PubkeyHash::from_slice(&[0;20]).unwrap())]);
+		let address = Address::from_script(&Script::new_p2pkh(&PubkeyHash::from_slice(&[0;20]).unwrap()), Network::Testnet).unwrap();
+		assert_eq!(invoice.fallback_addresses(), vec![address]);
 		assert_eq!(invoice.private_routes(), vec![&PrivateRoute(route_1), &PrivateRoute(route_2)]);
 		assert_eq!(
 			invoice.description(),

lightning-invoice/src/ser.rs

@@ -329,7 +329,7 @@ impl ToBase32 for Fallback {
 	fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 		match *self {
 			Fallback::SegWitProgram {version: v, program: ref p} => {
-				writer.write_u5(v)?;
+				writer.write_u5(Into::<u5>::into(v))?;
 				p.write_base32(writer)
 			},
 			Fallback::PubKeyHash(ref hash) => {

lightning-invoice/tests/ser_de.rs

@@ -5,9 +5,10 @@ extern crate lightning_invoice;
 extern crate secp256k1;
 extern crate hex;
 
+use bitcoin::util::address::WitnessVersion;
+use bitcoin::{PubkeyHash, ScriptHash};
 use bitcoin_hashes::hex::FromHex;
 use bitcoin_hashes::{sha256, Hash};
-use bech32::u5;
 use lightning::ln::PaymentSecret;
 use lightning::routing::gossip::RoutingFees;
 use lightning::routing::router::{RouteHint, RouteHintHop};
@@ -115,7 +116,7 @@ fn get_test_tuples() -> Vec<(String, SignedRawInvoice, bool, bool)> {
 				.payment_hash(sha256::Hash::from_hex(
 					"0001020304050607080900010203040506070809000102030405060708090102"
 				).unwrap())
-				.fallback(Fallback::PubKeyHash([49, 114, 181, 101, 79, 102, 131, 200, 251, 20, 105, 89, 211, 71, 206, 48, 60, 174, 76, 167]))
+				.fallback(Fallback::PubKeyHash(PubkeyHash::from_slice(&[49, 114, 181, 101, 79, 102, 131, 200, 251, 20, 105, 89, 211, 71, 206, 48, 60, 174, 76, 167]).unwrap()))
 				.build_raw()
 				.unwrap()
 				.sign(|_| {
@@ -137,7 +138,7 @@ fn get_test_tuples() -> Vec<(String, SignedRawInvoice, bool, bool)> {
 				.payment_hash(sha256::Hash::from_hex(
 					"0001020304050607080900010203040506070809000102030405060708090102"
 				).unwrap())
-				.fallback(Fallback::PubKeyHash([4, 182, 31, 125, 193, 234, 13, 201, 148, 36, 70, 76, 196, 6, 77, 197, 100, 217, 30, 137]))
+				.fallback(Fallback::PubKeyHash(PubkeyHash::from_slice(&[4, 182, 31, 125, 193, 234, 13, 201, 148, 36, 70, 76, 196, 6, 77, 197, 100, 217, 30, 137]).unwrap()))
 				.private_route(RouteHint(vec![RouteHintHop {
 					src_node_id: PublicKey::from_slice(&hex::decode(
 							"029e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255"
@@ -176,7 +177,7 @@ fn get_test_tuples() -> Vec<(String, SignedRawInvoice, bool, bool)> {
 				.payment_hash(sha256::Hash::from_hex(
 					"0001020304050607080900010203040506070809000102030405060708090102"
 				).unwrap())
-				.fallback(Fallback::ScriptHash([143, 85, 86, 59, 154, 25, 243, 33, 194, 17, 233, 185, 243, 140, 223, 104, 110, 160, 120, 69]))
+				.fallback(Fallback::ScriptHash(ScriptHash::from_slice(&[143, 85, 86, 59, 154, 25, 243, 33, 194, 17, 233, 185, 243, 140, 223, 104, 110, 160, 120, 69]).unwrap()))
 				.build_raw()
 				.unwrap()
 				.sign(|_| {
@@ -198,7 +199,7 @@ fn get_test_tuples() -> Vec<(String, SignedRawInvoice, bool, bool)> {
 				.payment_hash(sha256::Hash::from_hex(
 					"0001020304050607080900010203040506070809000102030405060708090102"
 				).unwrap())
-				.fallback(Fallback::SegWitProgram { version: u5::try_from_u8(0).unwrap(),
+				.fallback(Fallback::SegWitProgram { version: WitnessVersion::V0,
 					program: vec![117, 30, 118, 232, 25, 145, 150, 212, 84, 148, 28, 69, 209, 179, 163, 35, 241, 67, 59, 214]
 				})
 				.build_raw()
@@ -222,7 +223,7 @@ fn get_test_tuples() -> Vec<(String, SignedRawInvoice, bool, bool)> {
 				.payment_hash(sha256::Hash::from_hex(
 					"0001020304050607080900010203040506070809000102030405060708090102"
 				).unwrap())
-				.fallback(Fallback::SegWitProgram { version: u5::try_from_u8(0).unwrap(),
+				.fallback(Fallback::SegWitProgram { version: WitnessVersion::V0,
 					program: vec![24, 99, 20, 60, 20, 197, 22, 104, 4, 189, 25, 32, 51, 86, 218, 19, 108, 152, 86, 120, 205, 77, 39, 161, 184, 198, 50, 150, 4, 144, 50, 98]
 				})
 				.build_raw()