Merge pull request #349 from ariard/2019-07-data_loss
[rust-lightning] / src / ln / peer_handler.rs
index e0a1f6f2d76d5c266a131317ed14c7de831cad96..8094f256195d2fa5e1dd5c20c1f44ef3c3489570 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
@@ -41,12 +45,13 @@ pub struct MessageHandler {
 /// careful to ensure you don't have races whereby you might register a new connection with an fd
 /// the same as a yet-to-be-disconnect_event()-ed.
 pub trait SocketDescriptor : cmp::Eq + hash::Hash + Clone {
-       /// Attempts to send some data from the given Vec starting at the given offset to the peer.
+       /// Attempts to send some data from the given slice to the peer.
+       ///
        /// Returns the amount of data which was sent, possibly 0 if the socket has since disconnected.
        /// Note that in the disconnected case, a disconnect_event must still fire and further write
        /// attempts may occur until that time.
        ///
-       /// If the returned size is smaller than data.len() - write_offset, a write_available event must
+       /// If the returned size is smaller than data.len(), a write_available event must
        /// trigger the next time more data can be written. Additionally, until the a send_data event
        /// completes fully, no further read_events should trigger on the same peer!
        ///
@@ -54,7 +59,7 @@ pub trait SocketDescriptor : cmp::Eq + hash::Hash + Clone {
        /// events should be paused to prevent DoS in the send buffer), resume_read may be set
        /// indicating that read events on this descriptor should resume. A resume_read of false does
        /// *not* imply that further read events should be paused.
-       fn send_data(&mut self, data: &Vec<u8>, write_offset: usize, resume_read: bool) -> usize;
+       fn send_data(&mut self, data: &[u8], resume_read: bool) -> usize;
        /// Disconnect the socket pointed to by this SocketDescriptor. Once this function returns, no
        /// more calls to write_event, read_event or disconnect_event may be made with this descriptor.
        /// No disconnect_event should be generated as a result of this call, though obviously races
@@ -113,7 +118,7 @@ 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 +156,25 @@ 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 +206,12 @@ 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 +220,9 @@ 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 +243,19 @@ 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 +265,7 @@ 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
 
@@ -349,7 +388,8 @@ impl<Descriptor: SocketDescriptor> PeerManager<Descriptor> {
                                };
 
                                let should_be_reading = peer.pending_outbound_buffer.len() < MSG_BUFF_SIZE;
-                               let data_sent = descriptor.send_data(next_buff, peer.pending_outbound_buffer_first_msg_offset, should_be_reading);
+                               let pending = &next_buff[peer.pending_outbound_buffer_first_msg_offset..];
+                               let data_sent = descriptor.send_data(pending, should_be_reading);
                                peer.pending_outbound_buffer_first_msg_offset += data_sent;
                                if peer.pending_outbound_buffer_first_msg_offset == next_buff.len() { true } else { false }
                        } {
@@ -475,7 +515,7 @@ 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 => {
@@ -517,7 +557,7 @@ 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)).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
                                                                },
@@ -583,14 +623,6 @@ 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 });
                                                                                                }
@@ -659,11 +691,11 @@ 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 => {
@@ -1088,9 +1120,8 @@ mod tests {
        }
 
        impl SocketDescriptor for FileDescriptor {
-               fn send_data(&mut self, data: &Vec<u8>, write_offset: usize, _resume_read: bool) -> usize {
-                       assert!(write_offset < data.len());
-                       data.len() - write_offset
+               fn send_data(&mut self, data: &[u8], _resume_read: bool) -> usize {
+                       data.len()
                }
 
                fn disconnect_socket(&mut self) {}
@@ -1100,6 +1131,8 @@ mod tests {
                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();
@@ -1110,7 +1143,7 @@ mod tests {
                                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 +1161,7 @@ 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);