Support option_data_loss_protect for remote peer
[rust-lightning] / src / ln / peer_handler.rs
index 87a2e6d1c242b64f6e9b15fb0e9de9ef7cb8f74e..0e390bd32fc9d777dbd7dddbc45e071683c69514 100644 (file)
@@ -20,6 +20,10 @@ use std::sync::{Arc, Mutex};
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::{cmp,error,hash,fmt};
 
+use bitcoin_hashes::sha256::Hash as Sha256;
+use bitcoin_hashes::sha256::HashEngine as Sha256Engine;
+use bitcoin_hashes::{HashEngine, Hash};
+
 /// Provides references to trait impls which handle different types of messages.
 pub struct MessageHandler {
        /// A message handler which handles messages specific to channels. Usually this is just a
@@ -113,7 +117,7 @@ struct Peer {
 }
 
 impl Peer {
-       /// Returns true if the the channel announcements/updates for the given channel should be
+       /// Returns true if the channel announcements/updates for the given channel should be
        /// forwarded to this peer.
        /// If we are sending our routing table to this peer and we have not yet sent channel
        /// announcements/updates for the given channel_id then we will send it when we get to that
@@ -151,12 +155,25 @@ impl<Descriptor: SocketDescriptor> PeerHolder<Descriptor> {
        }
 }
 
+#[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))]
+fn _check_usize_is_32_or_64() {
+       // See below, less than 32 bit pointers may be unsafe here!
+       unsafe { mem::transmute::<*const usize, [u8; 4]>(panic!()); }
+}
+
 /// A PeerManager manages a set of peers, described by their SocketDescriptor and marshalls socket
 /// events into messages which it passes on to its MessageHandlers.
 pub struct PeerManager<Descriptor: SocketDescriptor> {
        message_handler: MessageHandler,
        peers: Mutex<PeerHolder<Descriptor>>,
        our_node_secret: SecretKey,
+       ephemeral_key_midstate: Sha256Engine,
+
+       // Usize needs to be at least 32 bits to avoid overflowing both low and high. If usize is 64
+       // bits we will never realistically count into high:
+       peer_counter_low: AtomicUsize,
+       peer_counter_high: AtomicUsize,
+
        initial_syncs_sent: AtomicUsize,
        logger: Arc<Logger>,
 }
@@ -188,7 +205,12 @@ const INITIAL_SYNCS_TO_SEND: usize = 5;
 /// PeerIds may repeat, but only after disconnect_event() has been called.
 impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
        /// Constructs a new PeerManager with the given message handlers and node_id secret key
-       pub fn new(message_handler: MessageHandler, our_node_secret: SecretKey, logger: Arc<Logger>) -> PeerManager<Descriptor> {
+       /// ephemeral_random_data is used to derive per-connection ephemeral keys and must be
+       /// cryptographically secure random bytes.
+       pub fn new(message_handler: MessageHandler, our_node_secret: SecretKey, ephemeral_random_data: &[u8; 32], logger: Arc<Logger>) -> PeerManager<Descriptor> {
+               let mut ephemeral_key_midstate = Sha256::engine();
+               ephemeral_key_midstate.input(ephemeral_random_data);
+
                PeerManager {
                        message_handler: message_handler,
                        peers: Mutex::new(PeerHolder {
@@ -197,6 +219,9 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
                                node_id_to_descriptor: HashMap::new()
                        }),
                        our_node_secret: our_node_secret,
+                       ephemeral_key_midstate,
+                       peer_counter_low: AtomicUsize::new(0),
+                       peer_counter_high: AtomicUsize::new(0),
                        initial_syncs_sent: AtomicUsize::new(0),
                        logger,
                }
@@ -217,6 +242,19 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
                }).collect()
        }
 
+       fn get_ephemeral_key(&self) -> SecretKey {
+               let mut ephemeral_hash = self.ephemeral_key_midstate.clone();
+               let low = self.peer_counter_low.fetch_add(1, Ordering::AcqRel);
+               let high = if low == 0 {
+                       self.peer_counter_high.fetch_add(1, Ordering::AcqRel)
+               } else {
+                       self.peer_counter_high.load(Ordering::Acquire)
+               };
+               ephemeral_hash.input(&byte_utils::le64_to_array(low as u64));
+               ephemeral_hash.input(&byte_utils::le64_to_array(high as u64));
+               SecretKey::from_slice(&Sha256::from_engine(ephemeral_hash).into_inner()).expect("You broke SHA-256!")
+       }
+
        /// Indicates a new outbound connection has been established to a node with the given node_id.
        /// Note that if an Err is returned here you MUST NOT call disconnect_event for the new
        /// descriptor but must disconnect the connection immediately.
@@ -226,7 +264,7 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
        /// Panics if descriptor is duplicative with some other descriptor which has not yet has a
        /// disconnect_event.
        pub fn new_outbound_connection(&self, their_node_id: PublicKey, descriptor: Descriptor) -> Result<Vec<u8>, PeerHandleError> {
-               let mut peer_encryptor = PeerChannelEncryptor::new_outbound(their_node_id.clone());
+               let mut peer_encryptor = PeerChannelEncryptor::new_outbound(their_node_id.clone(), self.get_ephemeral_key());
                let res = peer_encryptor.get_act_one().to_vec();
                let pending_read_buffer = [0; 50].to_vec(); // Noise act two is 50 bytes
 
@@ -234,7 +272,7 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
                if peers.peers.insert(descriptor, Peer {
                        channel_encryptor: peer_encryptor,
                        outbound: true,
-                       their_node_id: Some(their_node_id),
+                       their_node_id: None,
                        their_global_features: None,
                        their_local_features: None,
 
@@ -438,9 +476,6 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
 
                                                        macro_rules! try_potential_handleerror {
                                                                ($thing: expr) => {
-                                                                       try_potential_handleerror!($thing, false);
-                                                               };
-                                                               ($thing: expr, $pre_noise: expr) => {
                                                                        match $thing {
                                                                                Ok(x) => x,
                                                                                Err(e) => {
@@ -449,9 +484,6 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
                                                                                                        msgs::ErrorAction::DisconnectPeer { msg: _ } => {
                                                                                                                //TODO: Try to push msg
                                                                                                                log_trace!(self, "Got Err handling message, disconnecting peer because {}", e.err);
-                                                                                                               if $pre_noise {
-                                                                                                                       peer.their_node_id = None; // Unset so that we don't generate a peer_disconnected event
-                                                                                                               }
                                                                                                                return Err(PeerHandleError{ no_connection_possible: false });
                                                                                                        },
                                                                                                        msgs::ErrorAction::IgnoreError => {
@@ -481,11 +513,17 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
                                                                                        match e {
                                                                                                msgs::DecodeError::UnknownVersion => return Err(PeerHandleError{ no_connection_possible: false }),
                                                                                                msgs::DecodeError::UnknownRequiredFeature => {
-                                                                                                       log_debug!(self, "Got a channel/node announcement with an known required feature flag, you may want to udpate!");
+                                                                                                       log_debug!(self, "Got a channel/node announcement with an known required feature flag, you may want to update!");
                                                                                                        continue;
                                                                                                },
-                                                                                               msgs::DecodeError::InvalidValue => return Err(PeerHandleError{ no_connection_possible: false }),
-                                                                                               msgs::DecodeError::ShortRead => return Err(PeerHandleError{ no_connection_possible: false }),
+                                                                                               msgs::DecodeError::InvalidValue => {
+                                                                                                       log_debug!(self, "Got an invalid value while deserializing message");
+                                                                                                       return Err(PeerHandleError{ no_connection_possible: false });
+                                                                                               },
+                                                                                               msgs::DecodeError::ShortRead => {
+                                                                                                       log_debug!(self, "Deserialization failed due to shortness of message");
+                                                                                                       return Err(PeerHandleError{ no_connection_possible: false });
+                                                                                               },
                                                                                                msgs::DecodeError::ExtraAddressesPerType => {
                                                                                                        log_debug!(self, "Error decoding message, ignoring due to lnd spec incompatibility. See https://github.com/lightningnetwork/lnd/issues/1407");
                                                                                                        continue;
@@ -517,16 +555,17 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
                                                        let next_step = peer.channel_encryptor.get_noise_step();
                                                        match next_step {
                                                                NextNoiseStep::ActOne => {
-                                                                       let act_two = try_potential_handleerror!(peer.channel_encryptor.process_act_one_with_key(&peer.pending_read_buffer[..], &self.our_node_secret), true).to_vec();
+                                                                       let act_two = try_potential_handleerror!(peer.channel_encryptor.process_act_one_with_keys(&peer.pending_read_buffer[..], &self.our_node_secret, self.get_ephemeral_key())).to_vec();
                                                                        peer.pending_outbound_buffer.push_back(act_two);
                                                                        peer.pending_read_buffer = [0; 66].to_vec(); // act three is 66 bytes long
                                                                },
                                                                NextNoiseStep::ActTwo => {
-                                                                       let act_three = try_potential_handleerror!(peer.channel_encryptor.process_act_two(&peer.pending_read_buffer[..], &self.our_node_secret), true).to_vec();
-                                                                       peer.pending_outbound_buffer.push_back(act_three);
+                                                                       let (act_three, their_node_id) = try_potential_handleerror!(peer.channel_encryptor.process_act_two(&peer.pending_read_buffer[..], &self.our_node_secret));
+                                                                       peer.pending_outbound_buffer.push_back(act_three.to_vec());
                                                                        peer.pending_read_buffer = [0; 18].to_vec(); // Message length header is 18 bytes
                                                                        peer.pending_read_is_header = true;
 
+                                                                       peer.their_node_id = Some(their_node_id);
                                                                        insert_node_id!();
                                                                        let mut local_features = msgs::LocalFeatures::new();
                                                                        if self.initial_syncs_sent.load(Ordering::Acquire) < INITIAL_SYNCS_TO_SEND {
@@ -539,7 +578,7 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
                                                                        }, 16);
                                                                },
                                                                NextNoiseStep::ActThree => {
-                                                                       let their_node_id = try_potential_handleerror!(peer.channel_encryptor.process_act_three(&peer.pending_read_buffer[..]), true);
+                                                                       let their_node_id = try_potential_handleerror!(peer.channel_encryptor.process_act_three(&peer.pending_read_buffer[..]));
                                                                        peer.pending_read_buffer = [0; 18].to_vec(); // Message length header is 18 bytes
                                                                        peer.pending_read_is_header = true;
                                                                        peer.their_node_id = Some(their_node_id);
@@ -582,14 +621,6 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
                                                                                                        log_info!(self, "Peer local features required unknown version bits");
                                                                                                        return Err(PeerHandleError{ no_connection_possible: true });
                                                                                                }
-                                                                                               if msg.local_features.requires_data_loss_protect() {
-                                                                                                       log_info!(self, "Peer local features required data_loss_protect");
-                                                                                                       return Err(PeerHandleError{ no_connection_possible: true });
-                                                                                               }
-                                                                                               if msg.local_features.requires_upfront_shutdown_script() {
-                                                                                                       log_info!(self, "Peer local features required upfront_shutdown_script");
-                                                                                                       return Err(PeerHandleError{ no_connection_possible: true });
-                                                                                               }
                                                                                                if peer.their_global_features.is_some() {
                                                                                                        return Err(PeerHandleError{ no_connection_possible: false });
                                                                                                }
@@ -658,11 +689,11 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
                                                                                        // Channel control:
                                                                                        32 => {
                                                                                                let msg = try_potential_decodeerror!(msgs::OpenChannel::read(&mut reader));
-                                                                                               try_potential_handleerror!(self.message_handler.chan_handler.handle_open_channel(&peer.their_node_id.unwrap(), &msg));
+                                                                                               try_potential_handleerror!(self.message_handler.chan_handler.handle_open_channel(&peer.their_node_id.unwrap(), peer.their_local_features.clone().unwrap(), &msg));
                                                                                        },
                                                                                        33 => {
                                                                                                let msg = try_potential_decodeerror!(msgs::AcceptChannel::read(&mut reader));
-                                                                                               try_potential_handleerror!(self.message_handler.chan_handler.handle_accept_channel(&peer.their_node_id.unwrap(), &msg));
+                                                                                               try_potential_handleerror!(self.message_handler.chan_handler.handle_accept_channel(&peer.their_node_id.unwrap(), peer.their_local_features.clone().unwrap(), &msg));
                                                                                        },
 
                                                                                        34 => {
@@ -1096,10 +1127,11 @@ mod tests {
        }
 
        fn create_network(peer_count: usize) -> Vec<PeerManager<FileDescriptor>> {
-               let secp_ctx = Secp256k1::new();
                let mut peers = Vec::new();
                let mut rng = thread_rng();
                let logger : Arc<Logger> = Arc::new(test_utils::TestLogger::new());
+               let mut ephemeral_bytes = [0; 32];
+               rng.fill_bytes(&mut ephemeral_bytes);
 
                for _ in 0..peer_count {
                        let chan_handler = test_utils::TestChannelMessageHandler::new();
@@ -1107,10 +1139,10 @@ mod tests {
                        let node_id = {
                                let mut key_slice = [0;32];
                                rng.fill_bytes(&mut key_slice);
-                               SecretKey::from_slice(&secp_ctx, &key_slice).unwrap()
+                               SecretKey::from_slice(&key_slice).unwrap()
                        };
                        let msg_handler = MessageHandler { chan_handler: Arc::new(chan_handler), route_handler: Arc::new(router) };
-                       let peer = PeerManager::new(msg_handler, node_id, Arc::clone(&logger));
+                       let peer = PeerManager::new(msg_handler, node_id, &ephemeral_bytes, Arc::clone(&logger));
                        peers.push(peer);
                }
 
@@ -1128,7 +1160,7 @@ mod tests {
        #[test]
        fn test_disconnect_peer() {
                // Simple test which builds a network of PeerManager, connects and brings them to NoiseState::Finished and
-               // push an DisconnectPeer event to remove the node flagged by id
+               // push a DisconnectPeer event to remove the node flagged by id
                let mut peers = create_network(2);
                establish_connection(&peers[0], &peers[1]);
                assert_eq!(peers[0].peers.lock().unwrap().peers.len(), 1);