Merge pull request #1106 from TheBlueMatt/2021-10-no-perm-err-broadcast
[rust-lightning] / lightning / src / ln / chan_utils.rs
index 0db036d33092b55121c6a2c48ef66f79ce8465da..df0378938b42eeb0b1ff0fbd1413f6f140617a12 100644 (file)
@@ -12,8 +12,8 @@
 
 use bitcoin::blockdata::script::{Script,Builder};
 use bitcoin::blockdata::opcodes;
-use bitcoin::blockdata::transaction::{TxIn,TxOut,OutPoint,Transaction, SigHashType};
-use bitcoin::util::bip143;
+use bitcoin::blockdata::transaction::{TxIn,TxOut,OutPoint,Transaction, EcdsaSighashType};
+use bitcoin::util::sighash;
 
 use bitcoin::hashes::{Hash, HashEngine};
 use bitcoin::hashes::sha256::Hash as Sha256;
@@ -26,10 +26,10 @@ use util::ser::{Readable, Writeable, Writer};
 use util::{byte_utils, transaction_utils};
 
 use bitcoin::hash_types::WPubkeyHash;
-use bitcoin::secp256k1::key::{SecretKey, PublicKey};
-use bitcoin::secp256k1::{Secp256k1, Signature, Message};
+use bitcoin::secp256k1::{SecretKey, PublicKey, Scalar};
+use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature, Message};
 use bitcoin::secp256k1::Error as SecpError;
-use bitcoin::secp256k1;
+use bitcoin::{PackedLockTime, secp256k1, Sequence, Witness};
 
 use io;
 use prelude::*;
@@ -39,25 +39,99 @@ use util::transaction_utils::sort_outputs;
 use ln::channel::{INITIAL_COMMITMENT_NUMBER, ANCHOR_OUTPUT_VALUE_SATOSHI};
 use core::ops::Deref;
 use chain;
+use util::crypto::sign;
 
 pub(crate) const MAX_HTLCS: u16 = 483;
+pub(crate) const OFFERED_HTLC_SCRIPT_WEIGHT: usize = 133;
+pub(crate) const OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS: usize = 136;
+// The weight of `accepted_htlc_script` can vary in function of its CLTV argument value. We define a
+// range that encompasses both its non-anchors and anchors variants.
+pub(crate) const MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 136;
+pub(crate) const MAX_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 143;
+
+/// Gets the weight for an HTLC-Success transaction.
+#[inline]
+pub fn htlc_success_tx_weight(opt_anchors: bool) -> u64 {
+       const HTLC_SUCCESS_TX_WEIGHT: u64 = 703;
+       const HTLC_SUCCESS_ANCHOR_TX_WEIGHT: u64 = 706;
+       if opt_anchors { HTLC_SUCCESS_ANCHOR_TX_WEIGHT } else { HTLC_SUCCESS_TX_WEIGHT }
+}
 
-pub(super) const HTLC_SUCCESS_TX_WEIGHT: u64 = 703;
-pub(super) const HTLC_TIMEOUT_TX_WEIGHT: u64 = 663;
+/// Gets the weight for an HTLC-Timeout transaction.
+#[inline]
+pub fn htlc_timeout_tx_weight(opt_anchors: bool) -> u64 {
+       const HTLC_TIMEOUT_TX_WEIGHT: u64 = 663;
+       const HTLC_TIMEOUT_ANCHOR_TX_WEIGHT: u64 = 666;
+       if opt_anchors { HTLC_TIMEOUT_ANCHOR_TX_WEIGHT } else { HTLC_TIMEOUT_TX_WEIGHT }
+}
 
 #[derive(PartialEq)]
-pub(crate) enum HTLCType {
-       AcceptedHTLC,
-       OfferedHTLC
+pub(crate) enum HTLCClaim {
+       OfferedTimeout,
+       OfferedPreimage,
+       AcceptedTimeout,
+       AcceptedPreimage,
+       Revocation,
 }
 
-impl HTLCType {
-       /// Check if a given tx witnessScript len matchs one of a pre-signed HTLC
-       pub(crate) fn scriptlen_to_htlctype(witness_script_len: usize) ->  Option<HTLCType> {
-               if witness_script_len == 133 {
-                       Some(HTLCType::OfferedHTLC)
-               } else if witness_script_len >= 136 && witness_script_len <= 139 {
-                       Some(HTLCType::AcceptedHTLC)
+impl HTLCClaim {
+       /// Check if a given input witness attempts to claim a HTLC.
+       pub(crate) fn from_witness(witness: &Witness) -> Option<Self> {
+               debug_assert_eq!(OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS, MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT);
+               if witness.len() < 2 {
+                       return None;
+               }
+               let witness_script = witness.last().unwrap();
+               let second_to_last = witness.second_to_last().unwrap();
+               if witness_script.len() == OFFERED_HTLC_SCRIPT_WEIGHT {
+                       if witness.len() == 3 && second_to_last.len() == 33 {
+                               // <revocation sig> <revocationpubkey> <witness_script>
+                               Some(Self::Revocation)
+                       } else if witness.len() == 3 && second_to_last.len() == 32 {
+                               // <remotehtlcsig> <payment_preimage> <witness_script>
+                               Some(Self::OfferedPreimage)
+                       } else if witness.len() == 5 && second_to_last.len() == 0 {
+                               // 0 <remotehtlcsig> <localhtlcsig> <> <witness_script>
+                               Some(Self::OfferedTimeout)
+                       } else {
+                               None
+                       }
+               } else if witness_script.len() == OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS {
+                       // It's possible for the weight of `offered_htlc_script` and `accepted_htlc_script` to
+                       // match so we check for both here.
+                       if witness.len() == 3 && second_to_last.len() == 33 {
+                               // <revocation sig> <revocationpubkey> <witness_script>
+                               Some(Self::Revocation)
+                       } else if witness.len() == 3 && second_to_last.len() == 32 {
+                               // <remotehtlcsig> <payment_preimage> <witness_script>
+                               Some(Self::OfferedPreimage)
+                       } else if witness.len() == 5 && second_to_last.len() == 0 {
+                               // 0 <remotehtlcsig> <localhtlcsig> <> <witness_script>
+                               Some(Self::OfferedTimeout)
+                       } else if witness.len() == 3 && second_to_last.len() == 0 {
+                               // <remotehtlcsig> <> <witness_script>
+                               Some(Self::AcceptedTimeout)
+                       } else if witness.len() == 5 && second_to_last.len() == 32 {
+                               // 0 <remotehtlcsig> <localhtlcsig> <payment_preimage> <witness_script>
+                               Some(Self::AcceptedPreimage)
+                       } else {
+                               None
+                       }
+               } else if witness_script.len() > MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT &&
+                       witness_script.len() <= MAX_ACCEPTED_HTLC_SCRIPT_WEIGHT {
+                       // Handle remaining range of ACCEPTED_HTLC_SCRIPT_WEIGHT.
+                       if witness.len() == 3 && second_to_last.len() == 33 {
+                               // <revocation sig> <revocationpubkey> <witness_script>
+                               Some(Self::Revocation)
+                       } else if witness.len() == 3 && second_to_last.len() == 0 {
+                               // <remotehtlcsig> <> <witness_script>
+                               Some(Self::AcceptedTimeout)
+                       } else if witness.len() == 5 && second_to_last.len() == 32 {
+                               // 0 <remotehtlcsig> <localhtlcsig> <payment_preimage> <witness_script>
+                               Some(Self::AcceptedPreimage)
+                       } else {
+                               None
+                       }
                } else {
                        None
                }
@@ -87,8 +161,8 @@ pub fn build_closing_transaction(to_holder_value_sat: u64, to_counterparty_value
                ins.push(TxIn {
                        previous_output: funding_outpoint,
                        script_sig: Script::new(),
-                       sequence: 0xffffffff,
-                       witness: Vec::new(),
+                       sequence: Sequence::MAX,
+                       witness: Witness::new(),
                });
                ins
        };
@@ -118,19 +192,19 @@ pub fn build_closing_transaction(to_holder_value_sat: u64, to_counterparty_value
 
        Transaction {
                version: 2,
-               lock_time: 0,
+               lock_time: PackedLockTime::ZERO,
                input: txins,
                output: outputs,
        }
 }
 
 /// Implements the per-commitment secret storage scheme from
-/// [BOLT 3](https://github.com/lightningnetwork/lightning-rfc/blob/dcbf8583976df087c79c3ce0b535311212e6812d/03-transactions.md#efficient-per-commitment-secret-storage).
+/// [BOLT 3](https://github.com/lightning/bolts/blob/dcbf8583976df087c79c3ce0b535311212e6812d/03-transactions.md#efficient-per-commitment-secret-storage).
 ///
-/// Allows us to keep track of all of the revocation secrets of counterarties in just 50*32 bytes
+/// Allows us to keep track of all of the revocation secrets of our counterparty in just 50*32 bytes
 /// or so.
 #[derive(Clone)]
-pub(crate) struct CounterpartyCommitmentSecrets {
+pub struct CounterpartyCommitmentSecrets {
        old_secrets: [([u8; 32], u64); 49],
 }
 
@@ -146,7 +220,8 @@ impl PartialEq for CounterpartyCommitmentSecrets {
 }
 
 impl CounterpartyCommitmentSecrets {
-       pub(crate) fn new() -> Self {
+       /// Creates a new empty `CounterpartyCommitmentSecrets` structure.
+       pub fn new() -> Self {
                Self { old_secrets: [([0; 32], 1 << 48); 49], }
        }
 
@@ -160,7 +235,9 @@ impl CounterpartyCommitmentSecrets {
                48
        }
 
-       pub(crate) fn get_min_seen_secret(&self) -> u64 {
+       /// Returns the minimum index of all stored secrets. Note that indexes start
+       /// at 1 << 48 and get decremented by one for each new secret.
+       pub fn get_min_seen_secret(&self) -> u64 {
                //TODO This can be optimized?
                let mut min = 1 << 48;
                for &(_, idx) in self.old_secrets.iter() {
@@ -184,7 +261,9 @@ impl CounterpartyCommitmentSecrets {
                res
        }
 
-       pub(crate) fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), ()> {
+       /// Inserts the `secret` at `idx`. Returns `Ok(())` if the secret
+       /// was generated in accordance with BOLT 3 and is consistent with previous secrets.
+       pub fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), ()> {
                let pos = Self::place_secret(idx);
                for i in 0..pos {
                        let (old_secret, old_idx) = self.old_secrets[i as usize];
@@ -199,8 +278,9 @@ impl CounterpartyCommitmentSecrets {
                Ok(())
        }
 
-       /// Can only fail if idx is < get_min_seen_secret
-       pub(crate) fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
+       /// Returns the secret at `idx`.
+       /// Returns `None` if `idx` is < [`CounterpartyCommitmentSecrets::get_min_seen_secret`].
+       pub fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
                for i in 0..self.old_secrets.len() {
                        if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
                                return Some(Self::derive_secret(self.old_secrets[i].0, i as u8, idx))
@@ -244,9 +324,7 @@ pub fn derive_private_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_co
        sha.input(&PublicKey::from_secret_key(&secp_ctx, &base_secret).serialize());
        let res = Sha256::from_engine(sha).into_inner();
 
-       let mut key = base_secret.clone();
-       key.add_assign(&res)?;
-       Ok(key)
+       base_secret.clone().add_tweak(&Scalar::from_be_bytes(res).unwrap())
 }
 
 /// Derives a per-commitment-transaction public key (eg an htlc key or a delayed_payment key)
@@ -267,7 +345,7 @@ pub fn derive_public_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_com
 
 /// Derives a per-commitment-transaction revocation key from its constituent parts.
 ///
-/// Only the cheating participant owns a valid witness to propagate a revoked 
+/// Only the cheating participant owns a valid witness to propagate a revoked
 /// commitment transaction, thus per_commitment_secret always come from cheater
 /// and revocation_base_secret always come from punisher, which is the broadcaster
 /// of the transaction spending with this key knowledge.
@@ -293,19 +371,16 @@ pub fn derive_private_revocation_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1
                Sha256::from_engine(sha).into_inner()
        };
 
-       let mut countersignatory_contrib = countersignatory_revocation_base_secret.clone();
-       countersignatory_contrib.mul_assign(&rev_append_commit_hash_key)?;
-       let mut broadcaster_contrib = per_commitment_secret.clone();
-       broadcaster_contrib.mul_assign(&commit_append_rev_hash_key)?;
-       countersignatory_contrib.add_assign(&broadcaster_contrib[..])?;
-       Ok(countersignatory_contrib)
+       let countersignatory_contrib = countersignatory_revocation_base_secret.clone().mul_tweak(&Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap())?;
+       let broadcaster_contrib = per_commitment_secret.clone().mul_tweak(&Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap())?;
+       countersignatory_contrib.add_tweak(&Scalar::from_be_bytes(broadcaster_contrib.secret_bytes()).unwrap())
 }
 
 /// Derives a per-commitment-transaction revocation public key from its constituent parts. This is
 /// the public equivalend of derive_private_revocation_key - using only public keys to derive a
 /// public key instead of private keys.
 ///
-/// Only the cheating participant owns a valid witness to propagate a revoked 
+/// Only the cheating participant owns a valid witness to propagate a revoked
 /// commitment transaction, thus per_commitment_point always come from cheater
 /// and revocation_base_point always come from punisher, which is the broadcaster
 /// of the transaction spending with this key knowledge.
@@ -328,10 +403,8 @@ pub fn derive_public_revocation_key<T: secp256k1::Verification>(secp_ctx: &Secp2
                Sha256::from_engine(sha).into_inner()
        };
 
-       let mut countersignatory_contrib = countersignatory_revocation_base_point.clone();
-       countersignatory_contrib.mul_assign(&secp_ctx, &rev_append_commit_hash_key)?;
-       let mut broadcaster_contrib = per_commitment_point.clone();
-       broadcaster_contrib.mul_assign(&secp_ctx, &commit_append_rev_hash_key)?;
+       let countersignatory_contrib = countersignatory_revocation_base_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap())?;
+       let broadcaster_contrib = per_commitment_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap())?;
        countersignatory_contrib.combine(&broadcaster_contrib)
 }
 
@@ -586,7 +659,7 @@ pub fn make_funding_redeemscript(broadcaster: &PublicKey, countersignatory: &Pub
 ///
 /// Panics if htlc.transaction_output_index.is_none() (as such HTLCs do not appear in the
 /// commitment transaction).
-pub fn build_htlc_transaction(commitment_txid: &Txid, feerate_per_kw: u32, contest_delay: u16, htlc: &HTLCOutputInCommitment, broadcaster_delayed_payment_key: &PublicKey, revocation_key: &PublicKey) -> Transaction {
+pub fn build_htlc_transaction(commitment_txid: &Txid, feerate_per_kw: u32, contest_delay: u16, htlc: &HTLCOutputInCommitment, opt_anchors: bool, broadcaster_delayed_payment_key: &PublicKey, revocation_key: &PublicKey) -> Transaction {
        let mut txins: Vec<TxIn> = Vec::new();
        txins.push(TxIn {
                previous_output: OutPoint {
@@ -594,25 +667,31 @@ pub fn build_htlc_transaction(commitment_txid: &Txid, feerate_per_kw: u32, conte
                        vout: htlc.transaction_output_index.expect("Can't build an HTLC transaction for a dust output"),
                },
                script_sig: Script::new(),
-               sequence: 0,
-               witness: Vec::new(),
+               sequence: Sequence(if opt_anchors { 1 } else { 0 }),
+               witness: Witness::new(),
        });
 
-       let total_fee = if htlc.offered {
-                       feerate_per_kw as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000
-               } else {
-                       feerate_per_kw as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000
-               };
+       let weight = if htlc.offered {
+               htlc_timeout_tx_weight(opt_anchors)
+       } else {
+               htlc_success_tx_weight(opt_anchors)
+       };
+       let output_value = if opt_anchors {
+               htlc.amount_msat / 1000
+       } else {
+               let total_fee = feerate_per_kw as u64 * weight / 1000;
+               htlc.amount_msat / 1000 - total_fee
+       };
 
        let mut txouts: Vec<TxOut> = Vec::new();
        txouts.push(TxOut {
                script_pubkey: get_revokeable_redeemscript(revocation_key, contest_delay, broadcaster_delayed_payment_key).to_v0_p2wsh(),
-               value: htlc.amount_msat / 1000 - total_fee //TODO: BOLT 3 does not specify if we should add amount_msat before dividing or if we should divide by 1000 before subtracting (as we do here)
+               value: output_value,
        });
 
        Transaction {
                version: 2,
-               lock_time: if htlc.offered { htlc.cltv_expiry } else { 0 },
+               lock_time: PackedLockTime(if htlc.offered { htlc.cltv_expiry } else { 0 }),
                input: txins,
                output: txouts,
        }
@@ -666,7 +745,8 @@ pub struct ChannelTransactionParameters {
        pub counterparty_parameters: Option<CounterpartyChannelTransactionParameters>,
        /// The late-bound funding outpoint
        pub funding_outpoint: Option<chain::transaction::OutPoint>,
-       /// Are anchors used for this channel.  Boolean is serialization backwards-compatible
+       /// Are anchors (zero fee HTLC transaction variant) used for this channel. Boolean is
+       /// serialization backwards-compatible.
        pub opt_anchors: Option<()>
 }
 
@@ -821,7 +901,7 @@ impl HolderCommitmentTransaction {
        pub fn dummy() -> Self {
                let secp_ctx = Secp256k1::new();
                let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
-               let dummy_sig = secp_ctx.sign(&secp256k1::Message::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap());
+               let dummy_sig = sign(&secp_ctx, &secp256k1::Message::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap());
 
                let keys = TxCreationKeys {
                        per_commitment_point: dummy_key.clone(),
@@ -842,7 +922,7 @@ impl HolderCommitmentTransaction {
                        holder_selected_contest_delay: 0,
                        is_outbound_from_holder: false,
                        counterparty_parameters: Some(CounterpartyChannelTransactionParameters { pubkeys: channel_pubkeys.clone(), selected_contest_delay: 0 }),
-                       funding_outpoint: Some(chain::transaction::OutPoint { txid: Default::default(), index: 0 }),
+                       funding_outpoint: Some(chain::transaction::OutPoint { txid: Txid::all_zeros(), index: 0 }),
                        opt_anchors: None
                };
                let mut htlcs_with_aux: Vec<(_, ())> = Vec::new();
@@ -870,16 +950,18 @@ impl HolderCommitmentTransaction {
                // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
                let mut tx = self.inner.built.transaction.clone();
                tx.input[0].witness.push(Vec::new());
+               let mut ser_holder_sig = holder_sig.serialize_der().to_vec();
+               ser_holder_sig.push(EcdsaSighashType::All as u8);
+               let mut ser_cp_sig = self.counterparty_sig.serialize_der().to_vec();
+               ser_cp_sig.push(EcdsaSighashType::All as u8);
 
                if self.holder_sig_first {
-                       tx.input[0].witness.push(holder_sig.serialize_der().to_vec());
-                       tx.input[0].witness.push(self.counterparty_sig.serialize_der().to_vec());
+                       tx.input[0].witness.push(ser_holder_sig);
+                       tx.input[0].witness.push(ser_cp_sig);
                } else {
-                       tx.input[0].witness.push(self.counterparty_sig.serialize_der().to_vec());
-                       tx.input[0].witness.push(holder_sig.serialize_der().to_vec());
+                       tx.input[0].witness.push(ser_cp_sig);
+                       tx.input[0].witness.push(ser_holder_sig);
                }
-               tx.input[0].witness[1].push(SigHashType::All as u8);
-               tx.input[0].witness[2].push(SigHashType::All as u8);
 
                tx.input[0].witness.push(funding_redeemscript.as_bytes().to_vec());
                tx
@@ -908,7 +990,7 @@ impl BuiltCommitmentTransaction {
        ///
        /// This can be used to verify a signature.
        pub fn get_sighash_all(&self, funding_redeemscript: &Script, channel_value_satoshis: u64) -> Message {
-               let sighash = &bip143::SigHashCache::new(&self.transaction).signature_hash(0, funding_redeemscript, channel_value_satoshis, SigHashType::All)[..];
+               let sighash = &sighash::SighashCache::new(&self.transaction).segwit_signature_hash(0, funding_redeemscript, channel_value_satoshis, EcdsaSighashType::All).unwrap()[..];
                hash_to_message!(sighash)
        }
 
@@ -916,7 +998,7 @@ impl BuiltCommitmentTransaction {
        /// because we are about to broadcast a holder transaction.
        pub fn sign<T: secp256k1::Signing>(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) -> Signature {
                let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis);
-               secp_ctx.sign(&sighash, funding_key)
+               sign(secp_ctx, &sighash, funding_key)
        }
 }
 
@@ -925,6 +1007,7 @@ impl BuiltCommitmentTransaction {
 ///
 /// This class can be used inside a signer implementation to generate a signature given the relevant
 /// secret key.
+#[derive(Clone, Hash, PartialEq)]
 pub struct ClosingTransaction {
        to_holder_value_sat: u64,
        to_counterparty_value_sat: u64,
@@ -1031,7 +1114,7 @@ impl<'a> TrustedClosingTransaction<'a> {
        ///
        /// This can be used to verify a signature.
        pub fn get_sighash_all(&self, funding_redeemscript: &Script, channel_value_satoshis: u64) -> Message {
-               let sighash = &bip143::SigHashCache::new(&self.inner.built).signature_hash(0, funding_redeemscript, channel_value_satoshis, SigHashType::All)[..];
+               let sighash = &sighash::SighashCache::new(&self.inner.built).segwit_signature_hash(0, funding_redeemscript, channel_value_satoshis, EcdsaSighashType::All).unwrap()[..];
                hash_to_message!(sighash)
        }
 
@@ -1039,7 +1122,7 @@ impl<'a> TrustedClosingTransaction<'a> {
        /// because we are about to broadcast a holder transaction.
        pub fn sign<T: secp256k1::Signing>(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) -> Signature {
                let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis);
-               secp_ctx.sign(&sighash, funding_key)
+               sign(secp_ctx, &sighash, funding_key)
        }
 }
 
@@ -1143,7 +1226,7 @@ impl CommitmentTransaction {
        fn make_transaction(obscured_commitment_transaction_number: u64, txins: Vec<TxIn>, outputs: Vec<TxOut>) -> Transaction {
                Transaction {
                        version: 2,
-                       lock_time: ((0x20 as u32) << 8 * 3) | ((obscured_commitment_transaction_number & 0xffffffu64) as u32),
+                       lock_time: PackedLockTime(((0x20 as u32) << 8 * 3) | ((obscured_commitment_transaction_number & 0xffffffu64) as u32)),
                        input: txins,
                        output: outputs,
                }
@@ -1230,7 +1313,7 @@ impl CommitmentTransaction {
                                if let &Some(ref b_htlcout) = b {
                                        a_htlcout.cltv_expiry.cmp(&b_htlcout.cltv_expiry)
                                                // Note that due to hash collisions, we have to have a fallback comparison
-                                               // here for fuzztarget mode (otherwise at least chanmon_fail_consistency
+                                               // here for fuzzing mode (otherwise at least chanmon_fail_consistency
                                                // may fail)!
                                                .then(a_htlcout.payment_hash.0.cmp(&b_htlcout.payment_hash.0))
                                // For non-HTLC outputs, if they're copying our SPK we don't really care if we
@@ -1267,9 +1350,9 @@ impl CommitmentTransaction {
                        ins.push(TxIn {
                                previous_output: channel_parameters.funding_outpoint(),
                                script_sig: Script::new(),
-                               sequence: ((0x80 as u32) << 8 * 3)
-                                       | ((obscured_commitment_transaction_number >> 3 * 8) as u32),
-                               witness: Vec::new(),
+                               sequence: Sequence(((0x80 as u32) << 8 * 3)
+                                       | ((obscured_commitment_transaction_number >> 3 * 8) as u32)),
+                               witness: Witness::new(),
                        });
                        ins
                };
@@ -1378,6 +1461,8 @@ impl<'a> TrustedCommitmentTransaction<'a> {
        /// which HTLCOutputInCommitment::transaction_output_index.is_some()).
        ///
        /// The returned Vec has one entry for each HTLC, and in the same order.
+       ///
+       /// This function is only valid in the holder commitment context, it always uses EcdsaSighashType::All.
        pub fn get_htlc_sigs<T: secp256k1::Signing>(&self, htlc_base_key: &SecretKey, channel_parameters: &DirectedChannelTransactionParameters, secp_ctx: &Secp256k1<T>) -> Result<Vec<Signature>, ()> {
                let inner = self.inner;
                let keys = &inner.keys;
@@ -1387,12 +1472,12 @@ impl<'a> TrustedCommitmentTransaction<'a> {
 
                for this_htlc in inner.htlcs.iter() {
                        assert!(this_htlc.transaction_output_index.is_some());
-                       let htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
+                       let htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, self.opt_anchors(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
 
                        let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc, self.opt_anchors(), &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key);
 
-                       let sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, this_htlc.amount_msat / 1000, SigHashType::All)[..]);
-                       ret.push(secp_ctx.sign(&sighash, &holder_htlc_key));
+                       let sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, this_htlc.amount_msat / 1000, EcdsaSighashType::All).unwrap()[..]);
+                       ret.push(sign(secp_ctx, &sighash, &holder_htlc_key));
                }
                Ok(ret)
        }
@@ -1409,17 +1494,21 @@ impl<'a> TrustedCommitmentTransaction<'a> {
                // Further, we should never be provided the preimage for an HTLC-Timeout transaction.
                if  this_htlc.offered && preimage.is_some() { unreachable!(); }
 
-               let mut htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
+               let mut htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, self.opt_anchors(), &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
 
                let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc, self.opt_anchors(), &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key);
 
+               let sighashtype = if self.opt_anchors() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
+
                // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
                htlc_tx.input[0].witness.push(Vec::new());
 
-               htlc_tx.input[0].witness.push(counterparty_signature.serialize_der().to_vec());
-               htlc_tx.input[0].witness.push(signature.serialize_der().to_vec());
-               htlc_tx.input[0].witness[1].push(SigHashType::All as u8);
-               htlc_tx.input[0].witness[2].push(SigHashType::All as u8);
+               let mut cp_sig_ser = counterparty_signature.serialize_der().to_vec();
+               cp_sig_ser.push(sighashtype as u8);
+               htlc_tx.input[0].witness.push(cp_sig_ser);
+               let mut holder_sig_ser = signature.serialize_der().to_vec();
+               holder_sig_ser.push(EcdsaSighashType::All as u8);
+               htlc_tx.input[0].witness.push(holder_sig_ser);
 
                if this_htlc.offered {
                        // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
@@ -1478,8 +1567,10 @@ mod tests {
        use bitcoin::secp256k1::{PublicKey, SecretKey, Secp256k1};
        use util::test_utils;
        use chain::keysinterface::{KeysInterface, BaseSign};
-       use bitcoin::Network;
+       use bitcoin::{Network, Txid};
+       use bitcoin::hashes::Hash;
        use ln::PaymentHash;
+       use bitcoin::hashes::hex::ToHex;
 
        #[test]
        fn test_anchors() {
@@ -1502,7 +1593,7 @@ mod tests {
                        holder_selected_contest_delay: 0,
                        is_outbound_from_holder: false,
                        counterparty_parameters: Some(CounterpartyChannelTransactionParameters { pubkeys: counterparty_pubkeys.clone(), selected_contest_delay: 0 }),
-                       funding_outpoint: Some(chain::transaction::OutPoint { txid: Default::default(), index: 0 }),
+                       funding_outpoint: Some(chain::transaction::OutPoint { txid: Txid::all_zeros(), index: 0 }),
                        opt_anchors: None
                };
 
@@ -1583,6 +1674,10 @@ mod tests {
                assert_eq!(tx.built.transaction.output.len(), 3);
                assert_eq!(tx.built.transaction.output[0].script_pubkey, get_htlc_redeemscript(&received_htlc, false, &keys).to_v0_p2wsh());
                assert_eq!(tx.built.transaction.output[1].script_pubkey, get_htlc_redeemscript(&offered_htlc, false, &keys).to_v0_p2wsh());
+               assert_eq!(get_htlc_redeemscript(&received_htlc, false, &keys).to_v0_p2wsh().to_hex(),
+                                  "002085cf52e41ba7c099a39df504e7b61f6de122971ceb53b06731876eaeb85e8dc5");
+               assert_eq!(get_htlc_redeemscript(&offered_htlc, false, &keys).to_v0_p2wsh().to_hex(),
+                                  "002049f0736bb335c61a04d2623a24df878a7592a3c51fa7258d41b2c85318265e73");
 
                // Generate broadcaster output and received and offered HTLC outputs,  with anchors
                channel_parameters.opt_anchors = Some(());
@@ -1598,6 +1693,10 @@ mod tests {
                assert_eq!(tx.built.transaction.output.len(), 5);
                assert_eq!(tx.built.transaction.output[2].script_pubkey, get_htlc_redeemscript(&received_htlc, true, &keys).to_v0_p2wsh());
                assert_eq!(tx.built.transaction.output[3].script_pubkey, get_htlc_redeemscript(&offered_htlc, true, &keys).to_v0_p2wsh());
+               assert_eq!(get_htlc_redeemscript(&received_htlc, true, &keys).to_v0_p2wsh().to_hex(),
+                                  "002067114123af3f95405bae4fd930fc95de03e3c86baaee8b2dd29b43dd26cf613c");
+               assert_eq!(get_htlc_redeemscript(&offered_htlc, true, &keys).to_v0_p2wsh().to_hex(),
+                                  "0020a06e3b0d4fcf704f2b9c41e16a70099e39989466c3142b8573a1154542f28f57");
        }
 
        #[test]