offers: send invoice request

src/lib.rs

@@ -8,13 +8,17 @@ mod rate_limit;
 use crate::lnd::{
     features_support_onion_messages, get_lnd_client, string_to_network, LndCfg, LndNodeSigner,
 };
-
+use crate::lndk_offers::{connect_to_peer, validate_amount, OfferError};
 use crate::onion_messenger::MessengerUtilities;
-use bitcoin::secp256k1::PublicKey;
+use bitcoin::network::constants::Network;
+use bitcoin::secp256k1::{Error as Secp256k1Error, PublicKey};
 use home::home_dir;
+use lightning::blinded_path::BlindedPath;
 use lightning::ln::peer_handler::IgnoringMessageHandler;
+use lightning::offers::offer::Offer;
 use lightning::onion_message::{
-    DefaultMessageRouter, OffersMessage, OffersMessageHandler, OnionMessenger, PendingOnionMessage,
+    DefaultMessageRouter, Destination, OffersMessage, OffersMessageHandler, OnionMessenger,
+    PendingOnionMessage,
 };
 use log::{error, info, LevelFilter};
 use log4rs::append::console::ConsoleAppender;
@@ -24,8 +28,9 @@ use log4rs::encode::pattern::PatternEncoder;
 use std::collections::HashMap;
 use std::str::FromStr;
 use std::sync::{Mutex, Once};
-use tokio::sync::mpsc::Sender;
+use tokio::sync::mpsc::{Receiver, Sender};
 use tonic_lnd::lnrpc::GetInfoRequest;
+use tonic_lnd::Client;
 use triggered::{Listener, Trigger};
 
 static INIT: Once = Once::new();
@@ -175,19 +180,97 @@ enum OfferState {
 }
 
 pub struct OfferHandler {
-    _active_offers: Mutex<HashMap<String, OfferState>>,
+    active_offers: Mutex<HashMap<String, OfferState>>,
     pending_messages: Mutex<Vec<PendingOnionMessage<OffersMessage>>>,
     messenger_utils: MessengerUtilities,
 }
 
+pub struct PayOfferParams {
+    pub offer: Offer,
+    pub amount: Option<u64>,
+    pub network: Network,
+    pub client: Client,
+    /// The blinded path the offer creator provided, which we will use to send the invoice request.
+    pub blinded_path: BlindedPath,
+    /// The path we will send back to the offer creator, so it knows where to send back the invoice.
+    pub reply_path: Option<BlindedPath>,
+}
+
 impl OfferHandler {
     pub fn new() -> Self {
         OfferHandler {
-            _active_offers: Mutex::new(HashMap::new()),
+            active_offers: Mutex::new(HashMap::new()),
             pending_messages: Mutex::new(Vec::new()),
             messenger_utils: MessengerUtilities::new(),
         }
     }
+
+    /// Adds an offer to be paid with the amount specified. May only be called once for a single offer.
+    pub async fn pay_offer(
+        &self,
+        mut cfg: PayOfferParams,
+        mut started: Receiver<u32>,
+    ) -> Result<(), OfferError<Secp256k1Error>> {
+        // Wait for onion messenger to give us the signal that it's ready. Once the onion messenger drops
+        // the channel sender, recv will return None and we'll stop blocking here.
+        while (started.recv().await).is_some() {
+            println!("Error: we shouldn't receive any messages on this channel");
+        }
+
+        let validated_amount = validate_amount(&cfg.offer, cfg.amount).await?;
+
+        // For now we connect directly to the introduction node of the blinded path so we don't need any
+        // intermediate nodes here. In the future we'll query for a full path to the introduction node for
+        // better sender privacy.
+        connect_to_peer(cfg.client.clone(), cfg.blinded_path.introduction_node_id).await?;
+
+        let offer_id = cfg.offer.clone().to_string();
+        {
+            let mut active_offers = self.active_offers.lock().unwrap();
+            if active_offers.contains_key(&offer_id.clone()) {
+                return Err(OfferError::AlreadyProcessing);
+            }
+            active_offers.insert(cfg.offer.to_string().clone(), OfferState::OfferAdded);
+        }
+
+        let invoice_request = self
+            .create_invoice_request(
+                cfg.client.clone(),
+                cfg.offer,
+                vec![],
+                cfg.network,
+                validated_amount,
+            )
+            .await?;
+
+        if cfg.reply_path.is_none() {
+            let info = cfg
+                .client
+                .lightning()
+                .get_info(GetInfoRequest {})
+                .await
+                .expect("failed to get info")
+                .into_inner();
+
+            let pubkey = PublicKey::from_str(&info.identity_pubkey).unwrap();
+            cfg.reply_path = Some(self.create_reply_path(cfg.client.clone(), pubkey).await?)
+        };
+        let contents = OffersMessage::InvoiceRequest(invoice_request);
+        let pending_message = PendingOnionMessage {
+            contents,
+            destination: Destination::BlindedPath(cfg.blinded_path.clone()),
+            reply_path: cfg.reply_path,
+        };
+
+        let mut pending_messages = self.pending_messages.lock().unwrap();
+        pending_messages.push(pending_message);
+        std::mem::drop(pending_messages);
+
+        let mut active_offers = self.active_offers.lock().unwrap();
+        active_offers.insert(offer_id, OfferState::InvoiceRequestSent);
+
+        Ok(())
+    }
 }
 
 impl Default for OfferHandler {

src/lnd.rs

@@ -29,6 +29,7 @@ pub(crate) fn get_lnd_client(cfg: LndCfg) -> Result<Client, ConnectError> {
 }
 
 /// LndCfg specifies the configuration required to connect to LND's grpc client.
+#[derive(Clone)]
 pub struct LndCfg {
     address: String,
     cert: PathBuf,
@@ -186,7 +187,7 @@ pub(crate) fn string_to_network(network_str: &str) -> Result<Network, NetworkPar
 
 /// MessageSigner provides a layer of abstraction over the LND API for message signing.
 #[async_trait]
-pub(crate) trait MessageSigner {
+pub trait MessageSigner {
     async fn derive_key(&mut self, key_loc: KeyLocator) -> Result<Vec<u8>, Status>;
     async fn sign_message(
         &mut self,

src/lndk_offers.rs

@@ -76,9 +76,8 @@ pub fn decode(offer_str: String) -> Result<Offer, Bolt12ParseError> {
 }
 
 impl OfferHandler {
-    #[allow(dead_code)]
     // create_invoice_request builds and signs an invoice request, the first step in the BOLT 12 process of paying an offer.
-    pub(crate) async fn create_invoice_request(
+    pub async fn create_invoice_request(
         &self,
         mut signer: impl MessageSigner + std::marker::Send + 'static,
         offer: Offer,
@@ -348,6 +347,10 @@ mod tests {
     use std::time::{Duration, SystemTime};
     use tonic_lnd::lnrpc::NodeAddress;
 
+    fn get_offer() -> String {
+        "lno1qgsqvgnwgcg35z6ee2h3yczraddm72xrfua9uve2rlrm9deu7xyfzrcgqgn3qzsyvfkx26qkyypvr5hfx60h9w9k934lt8s2n6zc0wwtgqlulw7dythr83dqx8tzumg".to_string()
+    }
+
     fn build_custom_offer(amount_msats: u64) -> Offer {
         let secp_ctx = Secp256k1::new();
         let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
@@ -367,6 +370,10 @@ mod tests {
         "0313ba7ccbd754c117962b9afab6c2870eb3ef43f364a9f6c43d0fabb4553776ba".to_string()
     }
 
+    fn get_signature() -> String {
+        "28b937976a29c15827433086440b36c2bec6ca5bd977557972dca8641cd59ffba50daafb8ee99a19c950976b46f47d9e7aa716652e5657dfc555b82eff467f18".to_string()
+    }
+
     mock! {
         TestBolt12Signer{}
 
@@ -388,6 +395,78 @@ mod tests {
          }
     }
 
+    #[tokio::test]
+    async fn test_request_invoice() {
+        let mut signer_mock = MockTestBolt12Signer::new();
+
+        signer_mock.expect_derive_key().returning(|_| {
+            Ok(PublicKey::from_str(&get_pubkey())
+                .unwrap()
+                .serialize()
+                .to_vec())
+        });
+
+        signer_mock.expect_sign_message().returning(|_, _, _| {
+            Ok(Signature::from_str(&get_signature())
+                .unwrap()
+                .as_ref()
+                .to_vec())
+        });
+
+        let offer = decode(get_offer()).unwrap();
+        let handler = OfferHandler::new();
+        assert!(handler
+            .create_invoice_request(signer_mock, offer, vec![], Network::Regtest, 10000)
+            .await
+            .is_ok())
+    }
+
+    #[tokio::test]
+    async fn test_request_invoice_derive_key_error() {
+        let mut signer_mock = MockTestBolt12Signer::new();
+
+        signer_mock
+            .expect_derive_key()
+            .returning(|_| Err(Status::unknown("error testing")));
+
+        signer_mock.expect_sign_message().returning(|_, _, _| {
+            Ok(Signature::from_str(&get_signature())
+                .unwrap()
+                .as_ref()
+                .to_vec())
+        });
+
+        let offer = decode(get_offer()).unwrap();
+        let handler = OfferHandler::new();
+        assert!(handler
+            .create_invoice_request(signer_mock, offer, vec![], Network::Regtest, 10000)
+            .await
+            .is_err())
+    }
+
+    #[tokio::test]
+    async fn test_request_invoice_signer_error() {
+        let mut signer_mock = MockTestBolt12Signer::new();
+
+        signer_mock.expect_derive_key().returning(|_| {
+            Ok(PublicKey::from_str(&get_pubkey())
+                .unwrap()
+                .serialize()
+                .to_vec())
+        });
+
+        signer_mock
+            .expect_sign_message()
+            .returning(|_, _, _| Err(Status::unknown("error testing")));
+
+        let offer = decode(get_offer()).unwrap();
+        let handler = OfferHandler::new();
+        assert!(handler
+            .create_invoice_request(signer_mock, offer, vec![], Network::Regtest, 10000)
+            .await
+            .is_err())
+    }
+
     #[tokio::test]
     async fn test_validate_amount() {
         // If the amount the user provided is greater than the offer-provided amount, then

tests/common/mod.rs

@@ -151,7 +151,7 @@ pub struct LndNode {
     pub cert_path: String,
     pub macaroon_path: String,
     _handle: Child,
-    client: Option<Client>,
+    pub client: Option<Client>,
 }
 
 impl LndNode {

tests/integration_tests.rs

@@ -1,12 +1,17 @@
 mod common;
 use lndk;
 
-use bitcoin::secp256k1::PublicKey;
+use bitcoin::secp256k1::{PublicKey, Secp256k1};
+use bitcoin::Network;
 use chrono::Utc;
 use ldk_sample::node_api::Node as LdkNode;
-use lndk::LifecycleSignals;
+use lightning::blinded_path::BlindedPath;
+use lightning::offers::offer::Quantity;
+use lndk::onion_messenger::MessengerUtilities;
+use lndk::{LifecycleSignals, PayOfferParams};
 use std::path::PathBuf;
 use std::str::FromStr;
+use std::time::SystemTime;
 use tokio::select;
 use tokio::sync::mpsc;
 use tokio::sync::mpsc::{Receiver, Sender};
@@ -36,7 +41,6 @@ async fn wait_to_receive_onion_message(
 async fn check_for_message(ldk: LdkNode) -> LdkNode {
     loop {
         if ldk.onion_message_handler.messages.lock().unwrap().len() == 1 {
-            println!("MESSAGE: {:?}", ldk.onion_message_handler.messages);
             return ldk;
         }
         sleep(Duration::from_secs(2)).await;
@@ -102,3 +106,95 @@ async fn test_lndk_forwards_onion_message() {
         }
     }
 }
+
+#[tokio::test(flavor = "multi_thread")]
+// Here we test the beginning of the BOLT 12 offers flow. We show that lndk successfully builds an
+// invoice_request and sends it.
+async fn test_lndk_send_invoice_request() {
+    let test_name = "lndk_send_invoice_request";
+    let (_bitcoind, mut lnd, ldk1, ldk2, lndk_dir) =
+        common::setup_test_infrastructure(test_name).await;
+
+    // Here we'll produce a little network path:
+    //
+    // ldk1 <-> ldk2 <-> lnd
+    //
+    // ldk1 will be the offer creator, which will build a blinded route from ldk2 to ldk1.
+    let (pubkey, _) = ldk1.get_node_info();
+    let (pubkey_2, addr_2) = ldk2.get_node_info();
+    let lnd_info = lnd.get_info().await;
+    let lnd_pubkey = PublicKey::from_str(&lnd_info.identity_pubkey).unwrap();
+
+    ldk1.connect_to_peer(pubkey_2, addr_2).await.unwrap();
+    lnd.connect_to_peer(pubkey_2, addr_2).await;
+
+    let path_pubkeys = vec![pubkey_2, pubkey];
+    let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
+    let offer = ldk1
+        .create_offer(
+            &path_pubkeys,
+            Network::Regtest,
+            20_000,
+            Quantity::One,
+            expiration,
+        )
+        .await
+        .expect("should create offer");
+
+    // Now we'll spin up lndk, which should forward the invoice request to ldk2.
+    let (shutdown, listener) = triggered::trigger();
+    let lnd_cfg = lndk::lnd::LndCfg::new(
+        lnd.address.clone(),
+        PathBuf::from_str(&lnd.cert_path).unwrap(),
+        PathBuf::from_str(&lnd.macaroon_path).unwrap(),
+    );
+    let (tx, rx): (Sender<u32>, Receiver<u32>) = mpsc::channel(1);
+    let signals = LifecycleSignals {
+        shutdown: shutdown.clone(),
+        listener,
+        started: tx,
+    };
+
+    let lndk_cfg = lndk::Cfg {
+        lnd: lnd_cfg,
+        log_dir: Some(
+            lndk_dir
+                .join(format!("lndk-logs.txt"))
+                .to_str()
+                .unwrap()
+                .to_string(),
+        ),
+        signals,
+    };
+
+    let client = lnd.client.clone().unwrap();
+    let blinded_path = offer.paths()[0].clone();
+    let messenger_utils = MessengerUtilities::new();
+    let secp_ctx = Secp256k1::new();
+    let reply_path =
+        BlindedPath::new_for_message(&[pubkey_2, lnd_pubkey], &messenger_utils, &secp_ctx).unwrap();
+
+    // Make sure lndk successfully sends the invoice_request.
+    let handler = lndk::OfferHandler::new();
+    let messenger = lndk::LndkOnionMessenger::new(handler);
+    let pay_cfg = PayOfferParams {
+        offer,
+        amount: Some(20_000),
+        network: Network::Regtest,
+        client: client.clone(),
+        blinded_path: blinded_path.clone(),
+        reply_path: Some(reply_path),
+    };
+    select! {
+        val = messenger.run(lndk_cfg) => {
+            panic!("lndk should not have completed first {:?}", val);
+        },
+        // We wait for ldk2 to receive the onion message.
+        res = messenger.offer_handler.pay_offer(pay_cfg, rx) => {
+            assert!(res.is_ok());
+            shutdown.trigger();
+            ldk1.stop().await;
+            ldk2.stop().await;
+        }
+    }
+}