Fix TLV serialization to work with large types.
[rust-lightning] / lightning / src / ln / channel.rs
index 639ac84495e08f06171f3bfec7f2ed0e83d144cd..80240d0aa9d6fdffb13deba853274f5038affddb 100644 (file)
@@ -15,6 +15,7 @@ use bitcoin::consensus::encode;
 
 use bitcoin::hashes::Hash;
 use bitcoin::hashes::sha256::Hash as Sha256;
+use bitcoin::hashes::sha256d::Hash as Sha256d;
 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
 
 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
@@ -39,9 +40,9 @@ use util::errors::APIError;
 use util::config::{UserConfig,ChannelConfig};
 use util::scid_utils::scid_from_parts;
 
-use std;
-use std::{cmp,mem,fmt};
-use std::ops::Deref;
+use prelude::*;
+use core::{cmp,mem,fmt};
+use core::ops::Deref;
 #[cfg(any(test, feature = "fuzztarget"))]
 use std::sync::Mutex;
 use bitcoin::hashes::hex::ToHex;
@@ -421,6 +422,10 @@ pub(super) struct Channel<Signer: Sign> {
 
        channel_update_status: ChannelUpdateStatus,
 
+       /// Our counterparty's channel_announcement signatures provided in announcement_signatures.
+       /// This can be used to rebroadcast the channel_announcement message later.
+       announcement_sigs: Option<(Signature, Signature)>,
+
        // We save these values so we can make sure `next_local_commit_tx_fee_msat` and
        // `next_remote_commit_tx_fee_msat` properly predict what the next commitment transaction fee will
        // be, by comparing the cached values to the fee of the tranaction generated by
@@ -622,6 +627,8 @@ impl<Signer: Sign> Channel<Signer> {
 
                        channel_update_status: ChannelUpdateStatus::Enabled,
 
+                       announcement_sigs: None,
+
                        #[cfg(any(test, feature = "fuzztarget"))]
                        next_local_commitment_tx_fee_info_cached: Mutex::new(None),
                        #[cfg(any(test, feature = "fuzztarget"))]
@@ -863,6 +870,8 @@ impl<Signer: Sign> Channel<Signer> {
 
                        channel_update_status: ChannelUpdateStatus::Enabled,
 
+                       announcement_sigs: None,
+
                        #[cfg(any(test, feature = "fuzztarget"))]
                        next_local_commitment_tx_fee_info_cached: Mutex::new(None),
                        #[cfg(any(test, feature = "fuzztarget"))]
@@ -1220,7 +1229,7 @@ impl<Signer: Sign> Channel<Signer> {
                // on-chain ChannelsMonitors during block rescan. Ideally we'd figure out a way to drop
                // these, but for now we just have to treat them as normal.
 
-               let mut pending_idx = std::usize::MAX;
+               let mut pending_idx = core::usize::MAX;
                for (idx, htlc) in self.pending_inbound_htlcs.iter().enumerate() {
                        if htlc.htlc_id == htlc_id_arg {
                                assert_eq!(htlc.payment_hash, payment_hash_calc);
@@ -1243,7 +1252,7 @@ impl<Signer: Sign> Channel<Signer> {
                                break;
                        }
                }
-               if pending_idx == std::usize::MAX {
+               if pending_idx == core::usize::MAX {
                        return Err(ChannelError::Ignore("Unable to find a pending HTLC which matched the given HTLC ID".to_owned()));
                }
 
@@ -1342,7 +1351,7 @@ impl<Signer: Sign> Channel<Signer> {
                // on-chain ChannelsMonitors during block rescan. Ideally we'd figure out a way to drop
                // these, but for now we just have to treat them as normal.
 
-               let mut pending_idx = std::usize::MAX;
+               let mut pending_idx = core::usize::MAX;
                for (idx, htlc) in self.pending_inbound_htlcs.iter().enumerate() {
                        if htlc.htlc_id == htlc_id_arg {
                                match htlc.state {
@@ -1359,7 +1368,7 @@ impl<Signer: Sign> Channel<Signer> {
                                pending_idx = idx;
                        }
                }
-               if pending_idx == std::usize::MAX {
+               if pending_idx == core::usize::MAX {
                        return Err(ChannelError::Ignore("Unable to find a pending HTLC which matched the given HTLC ID".to_owned()));
                }
 
@@ -1419,9 +1428,6 @@ impl<Signer: Sign> Channel<Signer> {
                if msg.channel_reserve_satoshis > self.channel_value_satoshis {
                        return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must not be greater than ({})", msg.channel_reserve_satoshis, self.channel_value_satoshis)));
                }
-               if msg.dust_limit_satoshis > msg.channel_reserve_satoshis {
-                       return Err(ChannelError::Close(format!("Bogus channel_reserve ({}) and dust_limit ({})", msg.channel_reserve_satoshis, msg.dust_limit_satoshis)));
-               }
                if msg.channel_reserve_satoshis < self.holder_dust_limit_satoshis {
                        return Err(ChannelError::Close(format!("Peer never wants payout outputs? channel_reserve_satoshis was ({}). dust_limit is ({})", msg.channel_reserve_satoshis, self.holder_dust_limit_satoshis)));
                }
@@ -3823,6 +3829,8 @@ impl<Signer: Sign> Channel<Signer> {
        /// closing).
        /// Note that the "channel must be funded" requirement is stricter than BOLT 7 requires - see
        /// https://github.com/lightningnetwork/lightning-rfc/issues/468
+       ///
+       /// This will only return ChannelError::Ignore upon failure.
        pub fn get_channel_announcement(&self, node_id: PublicKey, chain_hash: BlockHash) -> Result<(msgs::UnsignedChannelAnnouncement, Signature), ChannelError> {
                if !self.config.announced_channel {
                        return Err(ChannelError::Ignore("Channel is not available for public announcements".to_owned()));
@@ -3853,6 +3861,63 @@ impl<Signer: Sign> Channel<Signer> {
                Ok((msg, sig))
        }
 
+       /// Signs the given channel announcement, returning a ChannelError::Ignore if no keys are
+       /// available.
+       fn sign_channel_announcement(&self, our_node_secret: &SecretKey, our_node_id: PublicKey, msghash: secp256k1::Message, announcement: msgs::UnsignedChannelAnnouncement, our_bitcoin_sig: Signature) -> Result<msgs::ChannelAnnouncement, ChannelError> {
+               if let Some((their_node_sig, their_bitcoin_sig)) = self.announcement_sigs {
+                       let were_node_one = announcement.node_id_1 == our_node_id;
+
+                       let our_node_sig = self.secp_ctx.sign(&msghash, our_node_secret);
+                       Ok(msgs::ChannelAnnouncement {
+                               node_signature_1: if were_node_one { our_node_sig } else { their_node_sig },
+                               node_signature_2: if were_node_one { their_node_sig } else { our_node_sig },
+                               bitcoin_signature_1: if were_node_one { our_bitcoin_sig } else { their_bitcoin_sig },
+                               bitcoin_signature_2: if were_node_one { their_bitcoin_sig } else { our_bitcoin_sig },
+                               contents: announcement,
+                       })
+               } else {
+                       Err(ChannelError::Ignore("Attempted to sign channel announcement before we'd received announcement_signatures".to_string()))
+               }
+       }
+
+       /// Processes an incoming announcement_signatures message, providing a fully-signed
+       /// channel_announcement message which we can broadcast and storing our counterparty's
+       /// signatures for later reconstruction/rebroadcast of the channel_announcement.
+       pub fn announcement_signatures(&mut self, our_node_secret: &SecretKey, our_node_id: PublicKey, chain_hash: BlockHash, msg: &msgs::AnnouncementSignatures) -> Result<msgs::ChannelAnnouncement, ChannelError> {
+               let (announcement, our_bitcoin_sig) = self.get_channel_announcement(our_node_id.clone(), chain_hash)?;
+
+               let msghash = hash_to_message!(&Sha256d::hash(&announcement.encode()[..])[..]);
+
+               if self.secp_ctx.verify(&msghash, &msg.node_signature, &self.get_counterparty_node_id()).is_err() {
+                       return Err(ChannelError::Close(format!(
+                               "Bad announcement_signatures. Failed to verify node_signature. UnsignedChannelAnnouncement used for verification is {:?}. their_node_key is {:?}",
+                                &announcement, self.get_counterparty_node_id())));
+               }
+               if self.secp_ctx.verify(&msghash, &msg.bitcoin_signature, self.counterparty_funding_pubkey()).is_err() {
+                       return Err(ChannelError::Close(format!(
+                               "Bad announcement_signatures. Failed to verify bitcoin_signature. UnsignedChannelAnnouncement used for verification is {:?}. their_bitcoin_key is ({:?})",
+                               &announcement, self.counterparty_funding_pubkey())));
+               }
+
+               self.announcement_sigs = Some((msg.node_signature, msg.bitcoin_signature));
+
+               self.sign_channel_announcement(our_node_secret, our_node_id, msghash, announcement, our_bitcoin_sig)
+       }
+
+       /// Gets a signed channel_announcement for this channel, if we previously received an
+       /// announcement_signatures from our counterparty.
+       pub fn get_signed_channel_announcement(&self, our_node_secret: &SecretKey, our_node_id: PublicKey, chain_hash: BlockHash) -> Option<msgs::ChannelAnnouncement> {
+               let (announcement, our_bitcoin_sig) = match self.get_channel_announcement(our_node_id.clone(), chain_hash) {
+                       Ok(res) => res,
+                       Err(_) => return None,
+               };
+               let msghash = hash_to_message!(&Sha256d::hash(&announcement.encode()[..])[..]);
+               match self.sign_channel_announcement(our_node_secret, our_node_id, msghash, announcement, our_bitcoin_sig) {
+                       Ok(res) => Some(res),
+                       Err(_) => None,
+               }
+       }
+
        /// May panic if called on a channel that wasn't immediately-previously
        /// self.remove_uncommitted_htlcs_and_mark_paused()'d
        pub fn get_channel_reestablish<L: Deref>(&self, logger: &L) -> msgs::ChannelReestablish where L::Target: Logger {
@@ -4314,37 +4379,11 @@ fn is_unsupported_shutdown_script(their_features: &InitFeatures, script: &Script
 const SERIALIZATION_VERSION: u8 = 1;
 const MIN_SERIALIZATION_VERSION: u8 = 1;
 
-impl Writeable for InboundHTLCRemovalReason {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               match self {
-                       &InboundHTLCRemovalReason::FailRelay(ref error_packet) => {
-                               0u8.write(writer)?;
-                               error_packet.write(writer)?;
-                       },
-                       &InboundHTLCRemovalReason::FailMalformed((ref onion_hash, ref err_code)) => {
-                               1u8.write(writer)?;
-                               onion_hash.write(writer)?;
-                               err_code.write(writer)?;
-                       },
-                       &InboundHTLCRemovalReason::Fulfill(ref payment_preimage) => {
-                               2u8.write(writer)?;
-                               payment_preimage.write(writer)?;
-                       },
-               }
-               Ok(())
-       }
-}
-
-impl Readable for InboundHTLCRemovalReason {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
-               Ok(match <u8 as Readable>::read(reader)? {
-                       0 => InboundHTLCRemovalReason::FailRelay(Readable::read(reader)?),
-                       1 => InboundHTLCRemovalReason::FailMalformed((Readable::read(reader)?, Readable::read(reader)?)),
-                       2 => InboundHTLCRemovalReason::Fulfill(Readable::read(reader)?),
-                       _ => return Err(DecodeError::InvalidValue),
-               })
-       }
-}
+impl_writeable_tlv_based_enum!(InboundHTLCRemovalReason,;
+       (0, FailRelay),
+       (1, FailMalformed),
+       (2, Fulfill),
+);
 
 impl Writeable for ChannelUpdateStatus {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
@@ -4376,8 +4415,7 @@ impl<Signer: Sign> Writeable for Channel<Signer> {
                // Note that we write out as if remove_uncommitted_htlcs_and_mark_paused had just been
                // called.
 
-               writer.write_all(&[SERIALIZATION_VERSION; 1])?;
-               writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
+               write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
 
                self.user_id.write(writer)?;
                self.config.write(writer)?;
@@ -4390,8 +4428,8 @@ impl<Signer: Sign> Writeable for Channel<Signer> {
 
                let mut key_data = VecWriter(Vec::new());
                self.holder_signer.write(&mut key_data)?;
-               assert!(key_data.0.len() < std::usize::MAX);
-               assert!(key_data.0.len() < std::u32::MAX as usize);
+               assert!(key_data.0.len() < core::usize::MAX);
+               assert!(key_data.0.len() < core::u32::MAX as usize);
                (key_data.0.len() as u32).write(writer)?;
                writer.write_all(&key_data.0[..])?;
 
@@ -4452,9 +4490,10 @@ impl<Signer: Sign> Writeable for Channel<Signer> {
                                &OutboundHTLCState::Committed => {
                                        1u8.write(writer)?;
                                },
-                               &OutboundHTLCState::RemoteRemoved(ref fail_reason) => {
-                                       2u8.write(writer)?;
-                                       fail_reason.write(writer)?;
+                               &OutboundHTLCState::RemoteRemoved(_) => {
+                                       // Treat this as a Committed because we haven't received the CS - they'll
+                                       // resend the claim/fail on reconnect as we all (hopefully) the missing CS.
+                                       1u8.write(writer)?;
                                },
                                &OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref fail_reason) => {
                                        3u8.write(writer)?;
@@ -4566,6 +4605,9 @@ impl<Signer: Sign> Writeable for Channel<Signer> {
                self.commitment_secrets.write(writer)?;
 
                self.channel_update_status.write(writer)?;
+
+               write_tlv_fields!(writer, {(0, self.announcement_sigs, option)});
+
                Ok(())
        }
 }
@@ -4574,11 +4616,7 @@ const MAX_ALLOC_SIZE: usize = 64*1024;
 impl<'a, Signer: Sign, K: Deref> ReadableArgs<&'a K> for Channel<Signer>
                where K::Target: KeysInterface<Signer = Signer> {
        fn read<R : ::std::io::Read>(reader: &mut R, keys_source: &'a K) -> Result<Self, DecodeError> {
-               let _ver: u8 = Readable::read(reader)?;
-               let min_ver: u8 = Readable::read(reader)?;
-               if min_ver > SERIALIZATION_VERSION {
-                       return Err(DecodeError::UnknownVersion);
-               }
+               let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
 
                let user_id = Readable::read(reader)?;
                let config: ChannelConfig = Readable::read(reader)?;
@@ -4740,6 +4778,9 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<&'a K> for Channel<Signer>
 
                let channel_update_status = Readable::read(reader)?;
 
+               let mut announcement_sigs = None;
+               read_tlv_fields!(reader, {(0, announcement_sigs, option)});
+
                let mut secp_ctx = Secp256k1::new();
                secp_ctx.seeded_randomize(&keys_source.get_secure_random_bytes());
 
@@ -4816,6 +4857,8 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<&'a K> for Channel<Signer>
 
                        channel_update_status,
 
+                       announcement_sigs,
+
                        #[cfg(any(test, feature = "fuzztarget"))]
                        next_local_commitment_tx_fee_info_cached: Mutex::new(None),
                        #[cfg(any(test, feature = "fuzztarget"))]
@@ -4858,6 +4901,7 @@ mod tests {
        use bitcoin::hashes::Hash;
        use bitcoin::hash_types::{Txid, WPubkeyHash};
        use std::sync::Arc;
+       use prelude::*;
 
        struct TestFeeEstimator {
                fee_est: u32