Add BIP21 Unified QR Code Support

Cargo.toml

@@ -61,6 +61,7 @@ reqwest = { version = "0.11", default-features = false, features = ["json", "rus
 rusqlite = { version = "0.28.0", features = ["bundled"] }
 bitcoin = "0.30.2"
 bip39 = "2.0.0"
+bip21 = { version = "0.3.1", features = ["std"], default-features = false }
 
 rand = "0.8.5"
 chrono = { version = "0.4", default-features = false, features = ["clock"] }

bindings/ldk_node.udl

@@ -63,6 +63,7 @@ interface Node {
 	Bolt12Payment bolt12_payment();
 	SpontaneousPayment spontaneous_payment();
 	OnchainPayment onchain_payment();
+	UnifiedQrPayment unified_qr_payment();
 	[Throws=NodeError]
 	void connect(PublicKey node_id, SocketAddress address, boolean persist);
 	[Throws=NodeError]
@@ -148,6 +149,13 @@ interface OnchainPayment {
 	Txid send_all_to_address([ByRef]Address address);
 };
 
+interface UnifiedQrPayment {
+    [Throws=NodeError]
+    string receive(u64 amount_sats, [ByRef]string message, u32 expiry_sec);
+    [Throws=NodeError]
+    QrPaymentResult send([ByRef]string uri_str);
+};
+
 [Error]
 enum NodeError {
 	"AlreadyRunning",
@@ -175,6 +183,7 @@ enum NodeError {
 	"GossipUpdateFailed",
 	"GossipUpdateTimeout",
 	"LiquidityRequestFailed",
+	"UriParameterParsingFailed",
 	"InvalidAddress",
 	"InvalidSocketAddress",
 	"InvalidPublicKey",
@@ -191,6 +200,7 @@ enum NodeError {
 	"InvalidRefund",
 	"InvalidChannelId",
 	"InvalidNetwork",
+	"InvalidUri",
 	"DuplicatePayment",
 	"UnsupportedCurrency",
 	"InsufficientFunds",
@@ -276,6 +286,13 @@ interface PaymentKind {
 	Spontaneous(PaymentHash hash, PaymentPreimage? preimage);
 };
 
+[Enum]
+interface QrPaymentResult {
+    Onchain(Txid txid);
+    Bolt11(PaymentId payment_id);
+    Bolt12(PaymentId payment_id);
+};
+
 enum PaymentDirection {
 	"Inbound",
 	"Outbound",

src/error.rs

@@ -53,6 +53,8 @@ pub enum Error {
 	GossipUpdateTimeout,
 	/// A liquidity request operation failed.
 	LiquidityRequestFailed,
+	/// Parsing a URI parameter has failed.
+	UriParameterParsingFailed,
 	/// The given address is invalid.
 	InvalidAddress,
 	/// The given network address is invalid.
@@ -85,6 +87,8 @@ pub enum Error {
 	InvalidChannelId,
 	/// The given network is invalid.
 	InvalidNetwork,
+	/// The given URI is invalid.
+	InvalidUri,
 	/// A payment with the given hash has already been initiated.
 	DuplicatePayment,
 	/// The provided offer was denonminated in an unsupported currency.
@@ -131,6 +135,7 @@ impl fmt::Display for Error {
 			Self::GossipUpdateFailed => write!(f, "Failed to update gossip data."),
 			Self::GossipUpdateTimeout => write!(f, "Updating gossip data timed out."),
 			Self::LiquidityRequestFailed => write!(f, "Failed to request inbound liquidity."),
+			Self::UriParameterParsingFailed => write!(f, "Failed to parse a URI parameter."),
 			Self::InvalidAddress => write!(f, "The given address is invalid."),
 			Self::InvalidSocketAddress => write!(f, "The given network address is invalid."),
 			Self::InvalidPublicKey => write!(f, "The given public key is invalid."),
@@ -147,6 +152,7 @@ impl fmt::Display for Error {
 			Self::InvalidRefund => write!(f, "The given refund is invalid."),
 			Self::InvalidChannelId => write!(f, "The given channel ID is invalid."),
 			Self::InvalidNetwork => write!(f, "The given network is invalid."),
+			Self::InvalidUri => write!(f, "The given URI is invalid."),
 			Self::DuplicatePayment => {
 				write!(f, "A payment with the given hash has already been initiated.")
 			},

src/lib.rs

@@ -133,7 +133,10 @@ use gossip::GossipSource;
 use graph::NetworkGraph;
 use liquidity::LiquiditySource;
 use payment::store::PaymentStore;
-use payment::{Bolt11Payment, Bolt12Payment, OnchainPayment, PaymentDetails, SpontaneousPayment};
+use payment::{
+	Bolt11Payment, Bolt12Payment, OnchainPayment, PaymentDetails, SpontaneousPayment,
+	UnifiedQrPayment,
+};
 use peer_store::{PeerInfo, PeerStore};
 use types::{
 	Broadcaster, BumpTransactionEventHandler, ChainMonitor, ChannelManager, DynStore, FeeEstimator,
@@ -1072,6 +1075,40 @@ impl Node {
 		))
 	}
 
+	/// Returns a payment handler allowing to create [BIP 21] URIs with an on-chain, [BOLT 11],
+	/// and [BOLT 12] payment options.
+	///
+	/// [BOLT 11]: https://github.com/lightning/bolts/blob/master/11-payment-encoding.md
+	/// [BOLT 12]: https://github.com/lightning/bolts/blob/master/12-offer-encoding.md
+	/// [BIP 21]: https://github.com/bitcoin/bips/blob/master/bip-0021.mediawiki
+	#[cfg(not(feature = "uniffi"))]
+	pub fn unified_qr_payment(&self) -> UnifiedQrPayment {
+		UnifiedQrPayment::new(
+			self.onchain_payment().into(),
+			self.bolt11_payment().into(),
+			self.bolt12_payment().into(),
+			Arc::clone(&self.config),
+			Arc::clone(&self.logger),
+		)
+	}
+
+	/// Returns a payment handler allowing to create [BIP 21] URIs with an on-chain, [BOLT 11],
+	/// and [BOLT 12] payment options.
+	///
+	/// [BOLT 11]: https://github.com/lightning/bolts/blob/master/11-payment-encoding.md
+	/// [BOLT 12]: https://github.com/lightning/bolts/blob/master/12-offer-encoding.md
+	/// [BIP 21]: https://github.com/bitcoin/bips/blob/master/bip-0021.mediawiki
+	#[cfg(feature = "uniffi")]
+	pub fn unified_qr_payment(&self) -> Arc<UnifiedQrPayment> {
+		Arc::new(UnifiedQrPayment::new(
+			self.onchain_payment(),
+			self.bolt11_payment(),
+			self.bolt12_payment(),
+			Arc::clone(&self.config),
+			Arc::clone(&self.logger),
+		))
+	}
+
 	/// Retrieve a list of known channels.
 	pub fn list_channels(&self) -> Vec<ChannelDetails> {
 		self.channel_manager.list_channels().into_iter().map(|c| c.into()).collect()

src/payment/mod.rs

@@ -5,9 +5,11 @@ mod bolt12;
 mod onchain;
 mod spontaneous;
 pub(crate) mod store;
+mod unified_qr;
 
 pub use bolt11::Bolt11Payment;
 pub use bolt12::Bolt12Payment;
 pub use onchain::OnchainPayment;
 pub use spontaneous::SpontaneousPayment;
 pub use store::{LSPFeeLimits, PaymentDetails, PaymentDirection, PaymentKind, PaymentStatus};
+pub use unified_qr::{QrPaymentResult, UnifiedQrPayment};