Add invalid_token_provided API method

We add a method that allows the LSP to signal to the client the token
they used was invalid.

We use the `102` error code as proposed in
lightning/blips#68.

Author: tnull

lightning-liquidity/src/lsps1/msgs.rs

@@ -35,6 +35,7 @@ pub(crate) const _LSPS1_CREATE_ORDER_REQUEST_INVALID_PARAMS_ERROR_CODE: i32 = -3
 pub(crate) const LSPS1_CREATE_ORDER_REQUEST_ORDER_MISMATCH_ERROR_CODE: i32 = 100;
 #[cfg(lsps1_service)]
 pub(crate) const LSPS1_GET_ORDER_REQUEST_ORDER_NOT_FOUND_ERROR_CODE: i32 = 101;
+pub(crate) const LSPS1_CREATE_ORDER_REQUEST_UNRECOGNIZED_OR_STALE_TOKEN_ERROR_CODE: i32 = 102;
 
 /// The identifier of an order.
 #[derive(Clone, Debug, PartialEq, Eq, Deserialize, Serialize, Hash)]

lightning-liquidity/src/lsps1/service.rs

@@ -9,8 +9,6 @@
 
 //! Contains the main bLIP-51 / LSPS1 server object, [`LSPS1ServiceHandler`].
 
-use alloc::string::String;
-
 use core::future::Future as StdFuture;
 use core::ops::Deref;
 use core::pin::pin;
@@ -23,6 +21,7 @@ use super::msgs::{
 	LSPS1GetOrderRequest, LSPS1Message, LSPS1Options, LSPS1OrderId, LSPS1OrderParams,
 	LSPS1OrderState, LSPS1PaymentInfo, LSPS1Request, LSPS1Response,
 	LSPS1_CREATE_ORDER_REQUEST_ORDER_MISMATCH_ERROR_CODE,
+	LSPS1_CREATE_ORDER_REQUEST_UNRECOGNIZED_OR_STALE_TOKEN_ERROR_CODE,
 	LSPS1_GET_ORDER_REQUEST_ORDER_NOT_FOUND_ERROR_CODE,
 };
 use super::peer_state::PeerState;
@@ -55,8 +54,6 @@ use bitcoin::secp256k1::PublicKey;
 /// Server-side configuration options for bLIP-51 / LSPS1 channel requests.
 #[derive(Clone, Debug)]
 pub struct LSPS1ServiceConfig {
-	/// A token to be send with each channel request.
-	pub token: Option<String>,
 	/// The options supported by the LSP.
 	pub supported_options: LSPS1Options,
 }
@@ -429,6 +426,42 @@ where
 		Ok(())
 	}
 
+	/// Used by LSP to inform a client that an order was rejected because the used token was invalid.
+	///
+	/// Should be called in response to receiving a [`LSPS1ServiceEvent::RequestForPaymentDetails`]
+	/// event if the provided token is invalid.
+	///
+	/// [`LSPS1ServiceEvent::RequestForPaymentDetails`]: crate::lsps1::event::LSPS1ServiceEvent::RequestForPaymentDetails
+	pub fn invalid_token_provided(
+		&self, counterparty_node_id: PublicKey, request_id: LSPSRequestId,
+	) -> Result<(), APIError> {
+		let mut message_queue_notifier = self.pending_messages.notifier();
+
+		match self.per_peer_state.read().unwrap().get(&counterparty_node_id) {
+			Some(inner_state_lock) => {
+				let mut peer_state_lock = inner_state_lock.lock().unwrap();
+				peer_state_lock.remove_request(&request_id).map_err(|e| {
+					debug_assert!(false, "Failed to send response due to: {}", e);
+					let err = format!("Failed to send response due to: {}", e);
+					APIError::APIMisuseError { err }
+				})?;
+
+				let response = LSPS1Response::CreateOrderError(LSPSResponseError {
+					code: LSPS1_CREATE_ORDER_REQUEST_UNRECOGNIZED_OR_STALE_TOKEN_ERROR_CODE,
+					message: "An unrecognized or stale token was provided".to_string(),
+					data: None,
+				});
+
+				let msg = LSPS1Message::Response(request_id, response).into();
+				message_queue_notifier.enqueue(&counterparty_node_id, msg);
+				Ok(())
+			},
+			None => Err(APIError::APIMisuseError {
+				err: format!("No state for the counterparty exists: {}", counterparty_node_id),
+			}),
+		}
+	}
+
 	fn handle_get_order_request(
 		&self, request_id: LSPSRequestId, counterparty_node_id: &PublicKey,
 		params: LSPS1GetOrderRequest,
@@ -589,6 +622,15 @@ where
 		}
 	}
 
+	/// Used by LSP to inform a client that an order was rejected because the used token was invalid.
+	///
+	/// Wraps [`LSPS1ServiceHandler::invalid_token_provided`].
+	pub fn invalid_token_provided(
+		&self, counterparty_node_id: PublicKey, request_id: LSPSRequestId,
+	) -> Result<(), APIError> {
+		self.inner.invalid_token_provided(counterparty_node_id, request_id)
+	}
+
 	/// Used by LSP to give details to client regarding the status of channel opening.
 	///
 	/// Wraps [`LSPS1ServiceHandler::update_order_status`].

lightning-liquidity/tests/lsps0_integration_tests.rs

@@ -49,7 +49,7 @@ fn list_protocols_integration_test() {
 			min_channel_balance_sat: 100_000,
 			max_channel_balance_sat: 100_000_000,
 		};
-		LSPS1ServiceConfig { supported_options, token: None }
+		LSPS1ServiceConfig { supported_options }
 	};
 	let lsps5_service_config = LSPS5ServiceConfig::default();
 	let service_config = LiquidityServiceConfig {

lightning-liquidity/tests/lsps1_integration_tests.rs

@@ -35,7 +35,7 @@ use lightning_liquidity::utils::time::TimeProvider;
 fn build_lsps1_configs(
 	supported_options: LSPS1Options,
 ) -> (LiquidityServiceConfig, LiquidityClientConfig) {
-	let lsps1_service_config = LSPS1ServiceConfig { token: None, supported_options };
+	let lsps1_service_config = LSPS1ServiceConfig { supported_options };
 	let service_config = LiquidityServiceConfig {
 		lsps1_service_config: Some(lsps1_service_config),
 		lsps2_service_config: None,
@@ -281,7 +281,6 @@ fn lsps1_service_handler_persistence_across_restarts() {
 	let service_config = LiquidityServiceConfig {
 		lsps1_service_config: Some(LSPS1ServiceConfig {
 			supported_options: supported_options.clone(),
-			token: None,
 		}),
 		lsps2_service_config: None,
 		lsps5_service_config: None,