Remove generic `Signer` parameter where it can be inferred from `KeysInterface`
[rust-lightning] / lightning / src / onion_message / messenger.rs
index 83e0311872b9c4ed562585d75c43396809913a60..b884c2ffebd9f90abdbb6051e83e5c802aad4f8a 100644 (file)
@@ -15,22 +15,23 @@ use bitcoin::hashes::hmac::{Hmac, HmacEngine};
 use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::secp256k1::{self, PublicKey, Scalar, Secp256k1, SecretKey};
 
-use chain::keysinterface::{InMemorySigner, KeysInterface, KeysManager, Recipient, Sign};
-use ln::features::{InitFeatures, NodeFeatures};
-use ln::msgs::{self, OnionMessageHandler};
-use ln::onion_utils;
-use ln::peer_handler::IgnoringMessageHandler;
+use crate::chain::keysinterface::{KeysInterface, KeysManager, Recipient};
+use crate::ln::features::{InitFeatures, NodeFeatures};
+use crate::ln::msgs::{self, OnionMessageHandler};
+use crate::ln::onion_utils;
+use crate::ln::peer_handler::IgnoringMessageHandler;
 use super::blinded_route::{BlindedRoute, ForwardTlvs, ReceiveTlvs};
 pub use super::packet::{CustomOnionMessageContents, OnionMessageContents};
 use super::packet::{BIG_PACKET_HOP_DATA_LEN, ForwardControlTlvs, Packet, Payload, ReceiveControlTlvs, SMALL_PACKET_HOP_DATA_LEN};
 use super::utils;
-use util::events::OnionMessageProvider;
-use util::logger::Logger;
-use util::ser::Writeable;
+use crate::util::events::OnionMessageProvider;
+use crate::util::logger::Logger;
+use crate::util::ser::Writeable;
 
 use core::ops::Deref;
-use sync::{Arc, Mutex};
-use prelude::*;
+use crate::io;
+use crate::sync::{Arc, Mutex};
+use crate::prelude::*;
 
 /// A sender, receiver and forwarder of onion messages. In upcoming releases, this object will be
 /// used to retrieve invoices and fulfill invoice requests from [offers]. Currently, only sending
@@ -47,7 +48,7 @@ use prelude::*;
 /// # use lightning::ln::peer_handler::IgnoringMessageHandler;
 /// # use lightning::onion_message::{BlindedRoute, CustomOnionMessageContents, Destination, OnionMessageContents, OnionMessenger};
 /// # use lightning::util::logger::{Logger, Record};
-/// # use lightning::util::ser::{MaybeReadableArgs, Writeable, Writer};
+/// # use lightning::util::ser::{Writeable, Writer};
 /// # use lightning::io;
 /// # use std::sync::Arc;
 /// # struct FakeLogger {};
@@ -81,13 +82,6 @@ use prelude::*;
 ///            your_custom_message_type
 ///    }
 /// }
-/// impl MaybeReadableArgs<u64> for YourCustomMessage {
-///    fn read<R: io::Read>(r: &mut R, message_type: u64) -> Result<Option<Self>, DecodeError> {
-///            # unreachable!()
-///            // Read your custom onion message of type `message_type` from `r`, or return `None`
-///            // if the message type is unknown
-///    }
-/// }
 /// // Send a custom onion message to a node id.
 /// let intermediate_hops = [hop_node_id1, hop_node_id2];
 /// let reply_path = None;
@@ -110,8 +104,8 @@ use prelude::*;
 ///
 /// [offers]: <https://github.com/lightning/bolts/pull/798>
 /// [`OnionMessenger`]: crate::onion_message::OnionMessenger
-pub struct OnionMessenger<Signer: Sign, K: Deref, L: Deref, CMH: Deref>
-       where K::Target: KeysInterface<Signer = Signer>,
+pub struct OnionMessenger<K: Deref, L: Deref, CMH: Deref>
+       where K::Target: KeysInterface,
              L::Target: Logger,
              CMH:: Target: CustomOnionMessageHandler,
 {
@@ -160,6 +154,15 @@ pub enum SendError {
        InvalidMessage,
        /// Our next-hop peer's buffer was full or our total outbound buffer was full.
        BufferFull,
+       /// Failed to retrieve our node id from the provided [`KeysInterface`].
+       ///
+       /// [`KeysInterface`]: crate::chain::keysinterface::KeysInterface
+       GetNodeIdFailed,
+       /// We attempted to send to a blinded route where we are the introduction node, and failed to
+       /// advance the blinded route to make the second hop the new introduction node. Either
+       /// [`KeysInterface::ecdh`] failed, we failed to tweak the current blinding point to get the
+       /// new blinding point, or we were attempting to send to ourselves.
+       BlindedRouteAdvanceFailed,
 }
 
 /// Handler for custom onion messages. If you are using [`SimpleArcOnionMessenger`],
@@ -178,10 +181,13 @@ pub trait CustomOnionMessageHandler {
        type CustomMessage: CustomOnionMessageContents;
        /// Called with the custom message that was received.
        fn handle_custom_message(&self, msg: Self::CustomMessage);
+       /// Read a custom message of type `message_type` from `buffer`, returning `Ok(None)` if the
+       /// message type is unknown.
+       fn read_custom_message<R: io::Read>(&self, message_type: u64, buffer: &mut R) -> Result<Option<Self::CustomMessage>, msgs::DecodeError>;
 }
 
-impl<Signer: Sign, K: Deref, L: Deref, CMH: Deref> OnionMessenger<Signer, K, L, CMH>
-       where K::Target: KeysInterface<Signer = Signer>,
+impl<K: Deref, L: Deref, CMH: Deref> OnionMessenger<K, L, CMH>
+       where K::Target: KeysInterface,
              L::Target: Logger,
              CMH::Target: CustomOnionMessageHandler,
 {
@@ -201,7 +207,7 @@ impl<Signer: Sign, K: Deref, L: Deref, CMH: Deref> OnionMessenger<Signer, K, L,
 
        /// Send an onion message with contents `message` to `destination`, routing it through `intermediate_nodes`.
        /// See [`OnionMessenger`] for example usage.
-       pub fn send_onion_message<T: CustomOnionMessageContents>(&self, intermediate_nodes: &[PublicKey], destination: Destination, message: OnionMessageContents<T>, reply_path: Option<BlindedRoute>) -> Result<(), SendError> {
+       pub fn send_onion_message<T: CustomOnionMessageContents>(&self, intermediate_nodes: &[PublicKey], mut destination: Destination, message: OnionMessageContents<T>, reply_path: Option<BlindedRoute>) -> Result<(), SendError> {
                if let Destination::BlindedRoute(BlindedRoute { ref blinded_hops, .. }) = destination {
                        if blinded_hops.len() < 2 {
                                return Err(SendError::TooFewBlindedHops);
@@ -210,6 +216,19 @@ impl<Signer: Sign, K: Deref, L: Deref, CMH: Deref> OnionMessenger<Signer, K, L,
                let OnionMessageContents::Custom(ref msg) = message;
                if msg.tlv_type() < 64 { return Err(SendError::InvalidMessage) }
 
+               // If we are sending straight to a blinded route and we are the introduction node, we need to
+               // advance the blinded route by 1 hop so the second hop is the new introduction node.
+               if intermediate_nodes.len() == 0 {
+                       if let Destination::BlindedRoute(ref mut blinded_route) = destination {
+                               let our_node_id = self.keys_manager.get_node_id(Recipient::Node)
+                                       .map_err(|()| SendError::GetNodeIdFailed)?;
+                               if blinded_route.introduction_node_id == our_node_id {
+                                       blinded_route.advance_by_one(&self.keys_manager, &self.secp_ctx)
+                                               .map_err(|()| SendError::BlindedRouteAdvanceFailed)?;
+                               }
+                       }
+               }
+
                let blinding_secret_bytes = self.keys_manager.get_secure_random_bytes();
                let blinding_secret = SecretKey::from_slice(&blinding_secret_bytes[..]).expect("RNG is busted");
                let (introduction_node_id, blinding_point) = if intermediate_nodes.len() != 0 {
@@ -276,10 +295,10 @@ fn outbound_buffer_full(peer_node_id: &PublicKey, buffer: &HashMap<PublicKey, Ve
        false
 }
 
-impl<Signer: Sign, K: Deref, L: Deref, CMH: Deref> OnionMessageHandler for OnionMessenger<Signer, K, L, CMH>
-       where K::Target: KeysInterface<Signer = Signer>,
+impl<K: Deref, L: Deref, CMH: Deref> OnionMessageHandler for OnionMessenger<K, L, CMH>
+       where K::Target: KeysInterface,
              L::Target: Logger,
-             CMH::Target: CustomOnionMessageHandler,
+             CMH::Target: CustomOnionMessageHandler + Sized,
 {
        /// Handle an incoming onion message. Currently, if a message was destined for us we will log, but
        /// soon we'll delegate the onion message to a handler that can generate invoices or send
@@ -308,8 +327,8 @@ impl<Signer: Sign, K: Deref, L: Deref, CMH: Deref> OnionMessageHandler for Onion
                                }
                        }
                };
-               match onion_utils::decode_next_hop(onion_decode_ss, &msg.onion_routing_packet.hop_data[..],
-                       msg.onion_routing_packet.hmac, control_tlvs_ss)
+               match onion_utils::decode_next_untagged_hop(onion_decode_ss, &msg.onion_routing_packet.hop_data[..],
+                       msg.onion_routing_packet.hmac, (control_tlvs_ss, &*self.custom_handler))
                {
                        Ok((Payload::Receive::<<<CMH as Deref>::Target as CustomOnionMessageHandler>::CustomMessage> {
                                message, control_tlvs: ReceiveControlTlvs::Unblinded(ReceiveTlvs { path_id }), reply_path,
@@ -420,8 +439,8 @@ impl<Signer: Sign, K: Deref, L: Deref, CMH: Deref> OnionMessageHandler for Onion
        }
 }
 
-impl<Signer: Sign, K: Deref, L: Deref, CMH: Deref> OnionMessageProvider for OnionMessenger<Signer, K, L, CMH>
-       where K::Target: KeysInterface<Signer = Signer>,
+impl<K: Deref, L: Deref, CMH: Deref> OnionMessageProvider for OnionMessenger<K, L, CMH>
+       where K::Target: KeysInterface,
              L::Target: Logger,
              CMH::Target: CustomOnionMessageHandler,
 {
@@ -443,7 +462,7 @@ impl<Signer: Sign, K: Deref, L: Deref, CMH: Deref> OnionMessageProvider for Onio
 ///
 /// [`SimpleArcChannelManager`]: crate::ln::channelmanager::SimpleArcChannelManager
 /// [`SimpleArcPeerManager`]: crate::ln::peer_handler::SimpleArcPeerManager
-pub type SimpleArcOnionMessenger<L> = OnionMessenger<InMemorySigner, Arc<KeysManager>, Arc<L>, IgnoringMessageHandler>;
+pub type SimpleArcOnionMessenger<L> = OnionMessenger<Arc<KeysManager>, Arc<L>, IgnoringMessageHandler>;
 /// Useful for simplifying the parameters of [`SimpleRefChannelManager`] and
 /// [`SimpleRefPeerManager`]. See their docs for more details.
 ///
@@ -451,7 +470,7 @@ pub type SimpleArcOnionMessenger<L> = OnionMessenger<InMemorySigner, Arc<KeysMan
 ///
 /// [`SimpleRefChannelManager`]: crate::ln::channelmanager::SimpleRefChannelManager
 /// [`SimpleRefPeerManager`]: crate::ln::peer_handler::SimpleRefPeerManager
-pub type SimpleRefOnionMessenger<'a, 'b, L> = OnionMessenger<InMemorySigner, &'a KeysManager, &'b L, IgnoringMessageHandler>;
+pub type SimpleRefOnionMessenger<'a, 'b, L> = OnionMessenger<&'a KeysManager, &'b L, IgnoringMessageHandler>;
 
 /// Construct onion packet payloads and keys for sending an onion message along the given
 /// `unblinded_path` to the given `destination`.
@@ -491,12 +510,8 @@ fn packet_payloads_and_keys<T: CustomOnionMessageContents, S: secp256k1::Signing
                                        next_blinding_override: Some(blinding_pt),
                                })), control_tlvs_ss));
                        }
-                       if let Some(encrypted_payload) = enc_payload_opt {
-                               payloads.push((Payload::Forward(ForwardControlTlvs::Blinded(encrypted_payload)),
-                                       control_tlvs_ss));
-                       } else { debug_assert!(false); }
-                       blinded_path_idx += 1;
-               } else if blinded_path_idx < num_blinded_hops - 1 && enc_payload_opt.is_some() {
+               }
+               if blinded_path_idx < num_blinded_hops.saturating_sub(1) && enc_payload_opt.is_some() {
                        payloads.push((Payload::Forward(ForwardControlTlvs::Blinded(enc_payload_opt.unwrap())),
                                control_tlvs_ss));
                        blinded_path_idx += 1;