Merge pull request #281 from ariard/harden-inbound-htlc-resolved
[rust-lightning] / src / ln / channelmonitor.rs
index be8367ed77b7d8834f3d9777381c009a636338fb..73ae060df72c10a051bd076a2afd644fa5022fe4 100644 (file)
@@ -17,10 +17,12 @@ use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
 use bitcoin::blockdata::script::{Script, Builder};
 use bitcoin::blockdata::opcodes;
 use bitcoin::consensus::encode::{self, Decodable, Encodable};
-use bitcoin::util::hash::{Hash160, BitcoinHash,Sha256dHash};
+use bitcoin::util::hash::{BitcoinHash,Sha256dHash};
 use bitcoin::util::bip143;
 
-use crypto::digest::Digest;
+use bitcoin_hashes::Hash;
+use bitcoin_hashes::sha256::Hash as Sha256;
+use bitcoin_hashes::hash160::Hash as Hash160;
 
 use secp256k1::{Secp256k1,Message,Signature};
 use secp256k1::key::{SecretKey,PublicKey};
@@ -36,7 +38,6 @@ use chain::transaction::OutPoint;
 use chain::keysinterface::SpendableOutputDescriptor;
 use util::logger::Logger;
 use util::ser::{ReadableArgs, Readable, Writer, Writeable, WriterWriteAdaptor, U48};
-use util::sha2::Sha256;
 use util::{byte_utils, events};
 
 use std::collections::{HashMap, hash_map};
@@ -487,9 +488,7 @@ impl ChannelMonitor {
                        let bitpos = bits - 1 - i;
                        if idx & (1 << bitpos) == (1 << bitpos) {
                                res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
-                               let mut sha = Sha256::new();
-                               sha.input(&res);
-                               sha.result(&mut res);
+                               res = Sha256::hash(&res).into_inner();
                        }
                }
                res
@@ -569,6 +568,8 @@ impl ChannelMonitor {
                }
 
                let new_txid = unsigned_commitment_tx.txid();
+               log_trace!(self, "Tracking new remote commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
+               log_trace!(self, "New potential remote commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
                if let Storage::Local { ref mut current_remote_commitment_txid, ref mut prev_remote_commitment_txid, .. } = self.key_storage {
                        *prev_remote_commitment_txid = current_remote_commitment_txid.take();
                        *current_remote_commitment_txid = Some(new_txid);
@@ -988,9 +989,6 @@ impl ChannelMonitor {
                self.write(writer, false)
        }
 
-       //TODO: Functions to serialize/deserialize (with different forms depending on which information
-       //we want to leave out (eg funding_txo, etc).
-
        /// Can only fail if idx is < get_min_seen_secret
        pub(super) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
                for i in 0..self.old_secrets.len() {
@@ -1079,7 +1077,7 @@ impl ChannelMonitor {
                        let local_payment_p2wpkh = if let Some(payment_key) = local_payment_key {
                                // Note that the Network here is ignored as we immediately drop the address for the
                                // script_pubkey version.
-                               let payment_hash160 = Hash160::from_data(&PublicKey::from_secret_key(&self.secp_ctx, &payment_key).serialize());
+                               let payment_hash160 = Hash160::hash(&PublicKey::from_secret_key(&self.secp_ctx, &payment_key).serialize());
                                Some(Builder::new().push_opcode(opcodes::All::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script())
                        } else { None };
 
@@ -1247,6 +1245,44 @@ impl ChannelMonitor {
                        watch_outputs.append(&mut tx.output.clone());
                        self.remote_commitment_txn_on_chain.insert(commitment_txid, (commitment_number, tx.output.iter().map(|output| { output.script_pubkey.clone() }).collect()));
 
+                       log_trace!(self, "Got broadcast of non-revoked remote commitment transaction {}", commitment_txid);
+
+                       // TODO: We really should only fail backwards after our revocation claims have been
+                       // confirmed, but we also need to do more other tracking of in-flight pre-confirm
+                       // on-chain claims, so we can do that at the same time.
+                       macro_rules! check_htlc_fails {
+                               ($txid: expr, $commitment_tx: expr, $id: tt) => {
+                                       if let Some(&(_, ref latest_outpoints)) = self.remote_claimable_outpoints.get(&$txid) {
+                                               $id: for &(ref payment_hash, ref source, _) in latest_outpoints.iter() {
+                                                       // Check if the HTLC is present in the commitment transaction that was
+                                                       // broadcast, but not if it was below the dust limit, which we should
+                                                       // fail backwards immediately as there is no way for us to learn the
+                                                       // payment_preimage.
+                                                       // Note that if the dust limit were allowed to change between
+                                                       // commitment transactions we'd want to be check whether *any*
+                                                       // broadcastable commitment transaction has the HTLC in it, but it
+                                                       // cannot currently change after channel initialization, so we don't
+                                                       // need to here.
+                                                       for &(_, ref broadcast_source, ref output_idx) in per_commitment_data.1.iter() {
+                                                               if output_idx.is_some() && source == broadcast_source {
+                                                                       continue $id;
+                                                               }
+                                                       }
+                                                       log_trace!(self, "Failing HTLC with payment_hash {} from {} remote commitment tx due to broadcast of remote commitment transaction", log_bytes!(payment_hash.0), $commitment_tx);
+                                                       htlc_updated.push(((*source).clone(), None, payment_hash.clone()));
+                                               }
+                                       }
+                               }
+                       }
+                       if let Storage::Local { ref current_remote_commitment_txid, ref prev_remote_commitment_txid, .. } = self.key_storage {
+                               if let &Some(ref txid) = current_remote_commitment_txid {
+                                       check_htlc_fails!(txid, "current", 'current_loop);
+                               }
+                               if let &Some(ref txid) = prev_remote_commitment_txid {
+                                       check_htlc_fails!(txid, "previous", 'prev_loop);
+                               }
+                       }
+
                        if let Some(revocation_points) = self.their_cur_revocation_points {
                                let revocation_point_option =
                                        if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
@@ -1578,6 +1614,9 @@ impl ChannelMonitor {
        /// Should not be used if check_spend_revoked_transaction succeeds.
        fn check_spend_local_transaction(&self, tx: &Transaction, _height: u32) -> (Vec<Transaction>, Vec<SpendableOutputDescriptor>, (Sha256dHash, Vec<TxOut>)) {
                let commitment_txid = tx.txid();
+               // TODO: If we find a match here we need to fail back HTLCs that were't included in the
+               // broadcast commitment transaction, either because they didn't meet dust or because they
+               // weren't yet included in our commitment transaction(s).
                if let &Some(ref local_tx) = &self.current_local_signed_commitment_tx {
                        if local_tx.txid == commitment_txid {
                                match self.key_storage {
@@ -1614,7 +1653,7 @@ impl ChannelMonitor {
                if tx.input[0].sequence == 0xFFFFFFFF && !tx.input[0].witness.is_empty() && tx.input[0].witness.last().unwrap().len() == 71 {
                        match self.key_storage {
                                Storage::Local { ref shutdown_pubkey, .. } =>  {
-                                       let our_channel_close_key_hash = Hash160::from_data(&shutdown_pubkey.serialize());
+                                       let our_channel_close_key_hash = Hash160::hash(&shutdown_pubkey.serialize());
                                        let shutdown_script = Builder::new().push_opcode(opcodes::All::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
                                        for (idx, output) in tx.output.iter().enumerate() {
                                                if shutdown_script == output.script_pubkey {
@@ -1746,6 +1785,16 @@ impl ChannelMonitor {
        }
 
        pub(super) fn would_broadcast_at_height(&self, height: u32) -> bool {
+               // TODO: We need to consider HTLCs which weren't included in latest local commitment
+               // transaction (or in any of the latest two local commitment transactions). This probably
+               // needs to use the same logic as the revoked-tx-announe logic - checking the last two
+               // remote commitment transactions. This probably has implications for what data we need to
+               // store in local commitment transactions.
+               // TODO: We need to consider HTLCs which were below dust threshold here - while they don't
+               // strictly imply that we need to fail the channel, we need to go ahead and fail them back
+               // to the source, and if we don't fail the channel we will have to ensure that the next
+               // updates that peer sends us are update_fails, failing the channel if not. It's probably
+               // easier to just fail the channel as this case should be rare enough anyway.
                if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
                        for &(ref htlc, _, _) in cur_local_tx.htlc_outputs.iter() {
                                // For inbound HTLCs which we know the preimage for, we have to ensure we hit the
@@ -1795,9 +1844,12 @@ impl ChannelMonitor {
                                        }
                                        if payment_data.is_none() {
                                                for htlc_output in $htlc_outputs {
-                                                       if input.previous_output.vout == htlc_output.transaction_output_index {
+                                                       if input.previous_output.vout == htlc_output.transaction_output_index && !htlc_output.offered {
                                                                log_info!(self, "Input spending {}:{} in {} resolves inbound HTLC with timeout from {}", input.previous_output.txid, input.previous_output.vout, tx.txid(), $source);
                                                                continue 'outer_loop;
+                                                       } else if input.previous_output.vout == htlc_output.transaction_output_index && tx.lock_time > 0 {
+                                                               log_info!(self, "Input spending {}:{} in {} resolves offered HTLC with HTLC-timeout from {}", input.previous_output.txid, input.previous_output.vout, tx.txid(), $source);
+                                                               continue 'outer_loop;
                                                        }
                                                }
                                        }
@@ -2081,13 +2133,9 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
 
                let payment_preimages_len: u64 = Readable::read(reader)?;
                let mut payment_preimages = HashMap::with_capacity(cmp::min(payment_preimages_len as usize, MAX_ALLOC_SIZE / 32));
-               let mut sha = Sha256::new();
                for _ in 0..payment_preimages_len {
                        let preimage: PaymentPreimage = Readable::read(reader)?;
-                       sha.reset();
-                       sha.input(&preimage.0[..]);
-                       let mut hash = PaymentHash([0; 32]);
-                       sha.result(&mut hash.0[..]);
+                       let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
                        if let Some(_) = payment_preimages.insert(hash, preimage) {
                                return Err(DecodeError::InvalidValue);
                        }
@@ -2131,12 +2179,12 @@ impl<R: ::std::io::Read> ReadableArgs<R, Arc<Logger>> for (Sha256dHash, ChannelM
 mod tests {
        use bitcoin::blockdata::script::Script;
        use bitcoin::blockdata::transaction::Transaction;
-       use crypto::digest::Digest;
+       use bitcoin_hashes::Hash;
+       use bitcoin_hashes::sha256::Hash as Sha256;
        use hex;
        use ln::channelmanager::{PaymentPreimage, PaymentHash};
        use ln::channelmonitor::ChannelMonitor;
        use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys};
-       use util::sha2::Sha256;
        use util::test_utils::TestLogger;
        use secp256k1::key::{SecretKey,PublicKey};
        use secp256k1::{Secp256k1, Signature};
@@ -2527,10 +2575,7 @@ mod tests {
                        for _ in 0..20 {
                                let mut preimage = PaymentPreimage([0; 32]);
                                rng.fill_bytes(&mut preimage.0[..]);
-                               let mut sha = Sha256::new();
-                               sha.input(&preimage.0[..]);
-                               let mut hash = PaymentHash([0; 32]);
-                               sha.result(&mut hash.0[..]);
+                               let hash = PaymentHash(Sha256::hash(&preimage.0[..]).into_inner());
                                preimages.push((preimage, hash));
                        }
                }