Support option_data_loss_protect for remote peer
[rust-lightning] / src / ln / peer_handler.rs
index cfdc6f1cb81ce9bfff7f0ca335aae4bfe6ba21db..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
@@ -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
 
@@ -517,7 +555,7 @@ 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 +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 });
                                                                                                }
@@ -659,11 +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 => {
@@ -1100,6 +1130,8 @@ 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 +1142,7 @@ 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);
                }