X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fchan_utils.rs;h=df0378938b42eeb0b1ff0fbd1413f6f140617a12;hb=7544030bb63fee6484fc178bb2ac8f382fe3b5b1;hp=9be58a9cc894e2ec04500e6a75518b6ee92dbe1e;hpb=4bb81ff5942749077613827d6807b64230ecbcd5;p=rust-lightning diff --git a/lightning/src/ln/chan_utils.rs b/lightning/src/ln/chan_utils.rs index 9be58a9c..df037893 100644 --- a/lightning/src/ln/chan_utils.rs +++ b/lightning/src/ln/chan_utils.rs @@ -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 { - 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 { + 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 { + // + Some(Self::Revocation) + } else if witness.len() == 3 && second_to_last.len() == 32 { + // + Some(Self::OfferedPreimage) + } else if witness.len() == 5 && second_to_last.len() == 0 { + // 0 <> + 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 { + // + Some(Self::Revocation) + } else if witness.len() == 3 && second_to_last.len() == 32 { + // + Some(Self::OfferedPreimage) + } else if witness.len() == 5 && second_to_last.len() == 0 { + // 0 <> + Some(Self::OfferedTimeout) + } else if witness.len() == 3 && second_to_last.len() == 0 { + // <> + Some(Self::AcceptedTimeout) + } else if witness.len() == 5 && second_to_last.len() == 32 { + // 0 + 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 { + // + Some(Self::Revocation) + } else if witness.len() == 3 && second_to_last.len() == 0 { + // <> + Some(Self::AcceptedTimeout) + } else if witness.len() == 5 && second_to_last.len() == 32 { + // 0 + 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(secp_ctx: &Secp256k1, 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(secp_ctx: &Secp256k1, 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(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(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) } @@ -482,10 +555,10 @@ impl_writeable_tlv_based!(HTLCOutputInCommitment, { }); #[inline] -pub(crate) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommitment, broadcaster_htlc_key: &PublicKey, countersignatory_htlc_key: &PublicKey, revocation_key: &PublicKey) -> Script { +pub(crate) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommitment, opt_anchors: bool, broadcaster_htlc_key: &PublicKey, countersignatory_htlc_key: &PublicKey, revocation_key: &PublicKey) -> Script { let payment_hash160 = Ripemd160::hash(&htlc.payment_hash.0[..]).into_inner(); if htlc.offered { - Builder::new().push_opcode(opcodes::all::OP_DUP) + let mut bldr = Builder::new().push_opcode(opcodes::all::OP_DUP) .push_opcode(opcodes::all::OP_HASH160) .push_slice(&PubkeyHash::hash(&revocation_key.serialize())[..]) .push_opcode(opcodes::all::OP_EQUAL) @@ -509,11 +582,16 @@ pub(crate) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommit .push_slice(&payment_hash160) .push_opcode(opcodes::all::OP_EQUALVERIFY) .push_opcode(opcodes::all::OP_CHECKSIG) - .push_opcode(opcodes::all::OP_ENDIF) - .push_opcode(opcodes::all::OP_ENDIF) - .into_script() + .push_opcode(opcodes::all::OP_ENDIF); + if opt_anchors { + bldr = bldr.push_opcode(opcodes::all::OP_PUSHNUM_1) + .push_opcode(opcodes::all::OP_CSV) + .push_opcode(opcodes::all::OP_DROP); + } + bldr.push_opcode(opcodes::all::OP_ENDIF) + .into_script() } else { - Builder::new().push_opcode(opcodes::all::OP_DUP) + let mut bldr = Builder::new().push_opcode(opcodes::all::OP_DUP) .push_opcode(opcodes::all::OP_HASH160) .push_slice(&PubkeyHash::hash(&revocation_key.serialize())[..]) .push_opcode(opcodes::all::OP_EQUAL) @@ -540,17 +618,22 @@ pub(crate) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommit .push_opcode(opcodes::all::OP_CLTV) .push_opcode(opcodes::all::OP_DROP) .push_opcode(opcodes::all::OP_CHECKSIG) - .push_opcode(opcodes::all::OP_ENDIF) - .push_opcode(opcodes::all::OP_ENDIF) - .into_script() + .push_opcode(opcodes::all::OP_ENDIF); + if opt_anchors { + bldr = bldr.push_opcode(opcodes::all::OP_PUSHNUM_1) + .push_opcode(opcodes::all::OP_CSV) + .push_opcode(opcodes::all::OP_DROP); + } + bldr.push_opcode(opcodes::all::OP_ENDIF) + .into_script() } } /// Gets the witness redeemscript for an HTLC output in a commitment transaction. Note that htlc /// does not need to have its previous_output_index filled. #[inline] -pub fn get_htlc_redeemscript(htlc: &HTLCOutputInCommitment, keys: &TxCreationKeys) -> Script { - get_htlc_redeemscript_with_explicit_keys(htlc, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key) +pub fn get_htlc_redeemscript(htlc: &HTLCOutputInCommitment, opt_anchors: bool, keys: &TxCreationKeys) -> Script { + get_htlc_redeemscript_with_explicit_keys(htlc, opt_anchors, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key) } /// Gets the redeemscript for a funding output from the two funding public keys. @@ -576,7 +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 = Vec::new(); txins.push(TxIn { previous_output: OutPoint { @@ -584,25 +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 = 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, } @@ -626,7 +715,7 @@ pub(crate) fn get_to_countersignatory_with_anchors_redeemscript(payment_point: & /// <> /// (empty vector required to satisfy compliance with MINIMALIF-standard rule) #[inline] -pub(crate) fn get_anchor_redeemscript(funding_pubkey: &PublicKey) -> Script { +pub fn get_anchor_redeemscript(funding_pubkey: &PublicKey) -> Script { Builder::new().push_slice(&funding_pubkey.serialize()[..]) .push_opcode(opcodes::all::OP_CHECKSIG) .push_opcode(opcodes::all::OP_IFDUP) @@ -656,6 +745,9 @@ pub struct ChannelTransactionParameters { pub counterparty_parameters: Option, /// The late-bound funding outpoint pub funding_outpoint: Option, + /// Are anchors (zero fee HTLC transaction variant) used for this channel. Boolean is + /// serialization backwards-compatible. + pub opt_anchors: Option<()> } /// Late-bound per-channel counterparty data used to build transactions. @@ -709,6 +801,7 @@ impl_writeable_tlv_based!(ChannelTransactionParameters, { (4, is_outbound_from_holder, required), (6, counterparty_parameters, option), (8, funding_outpoint, option), + (10, opt_anchors, option), }); /// Static channel fields used to build transactions given per-commitment fields, organized by @@ -761,6 +854,11 @@ impl<'a> DirectedChannelTransactionParameters<'a> { pub fn funding_outpoint(&self) -> OutPoint { self.inner.funding_outpoint.unwrap().into_bitcoin_outpoint() } + + /// Whether to use anchors for this channel + pub fn opt_anchors(&self) -> bool { + self.inner.opt_anchors.is_some() + } } /// Information needed to build and sign a holder's commitment transaction. @@ -803,7 +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(), @@ -824,7 +922,8 @@ 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(); let inner = CommitmentTransaction::new_with_auxiliary_htlc_data(0, 0, 0, false, dummy_key.clone(), dummy_key.clone(), keys, 0, &mut htlcs_with_aux, &channel_parameters.as_counterparty_broadcastable()); @@ -851,16 +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 @@ -889,7 +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) } @@ -897,7 +998,7 @@ impl BuiltCommitmentTransaction { /// because we are about to broadcast a holder transaction. pub fn sign(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1) -> Signature { let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis); - secp_ctx.sign(&sighash, funding_key) + sign(secp_ctx, &sighash, funding_key) } } @@ -906,6 +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, @@ -1012,7 +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) } @@ -1020,7 +1122,7 @@ impl<'a> TrustedClosingTransaction<'a> { /// because we are about to broadcast a holder transaction. pub fn sign(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1) -> Signature { let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis); - secp_ctx.sign(&sighash, funding_key) + sign(secp_ctx, &sighash, funding_key) } } @@ -1124,7 +1226,7 @@ impl CommitmentTransaction { fn make_transaction(obscured_commitment_transaction_number: u64, txins: Vec, outputs: Vec) -> 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, } @@ -1196,7 +1298,7 @@ impl CommitmentTransaction { let mut htlcs = Vec::with_capacity(htlcs_with_aux.len()); for (htlc, _) in htlcs_with_aux { - let script = chan_utils::get_htlc_redeemscript(&htlc, &keys); + let script = chan_utils::get_htlc_redeemscript(&htlc, opt_anchors, &keys); let txout = TxOut { script_pubkey: script.to_v0_p2wsh(), value: htlc.amount_msat / 1000, @@ -1211,7 +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 @@ -1248,9 +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 }; @@ -1350,10 +1452,17 @@ impl<'a> TrustedCommitmentTransaction<'a> { &self.inner.keys } + /// Should anchors be used. + pub fn opt_anchors(&self) -> bool { + self.opt_anchors.is_some() + } + /// Get a signature for each HTLC which was included in the commitment transaction (ie for /// 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(&self, htlc_base_key: &SecretKey, channel_parameters: &DirectedChannelTransactionParameters, secp_ctx: &Secp256k1) -> Result, ()> { let inner = self.inner; let keys = &inner.keys; @@ -1363,12 +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, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_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) } @@ -1385,17 +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 htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc, &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. @@ -1450,12 +1563,14 @@ mod tests { use super::CounterpartyCommitmentSecrets; use ::{hex, chain}; use prelude::*; - use ln::chan_utils::{get_to_countersignatory_with_anchors_redeemscript, get_p2wpkh_redeemscript, CommitmentTransaction, TxCreationKeys, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, HTLCOutputInCommitment}; + use ln::chan_utils::{get_htlc_redeemscript, get_to_countersignatory_with_anchors_redeemscript, get_p2wpkh_redeemscript, CommitmentTransaction, TxCreationKeys, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, HTLCOutputInCommitment}; 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() { @@ -1473,12 +1588,13 @@ mod tests { let holder_pubkeys = signer.pubkeys(); let counterparty_pubkeys = counterparty_signer.pubkeys(); let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint).unwrap(); - let channel_parameters = ChannelTransactionParameters { + let mut channel_parameters = ChannelTransactionParameters { holder_pubkeys: holder_pubkeys.clone(), 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 }; let mut htlcs_with_aux: Vec<(_, ())> = Vec::new(); @@ -1529,25 +1645,58 @@ mod tests { ); assert_eq!(tx.built.transaction.output.len(), 2); - // Generate broadcaster output, an HTLC output and two anchors - let payment_hash = PaymentHash([42; 32]); - let htlc_info = HTLCOutputInCommitment { + let received_htlc = HTLCOutputInCommitment { offered: false, - amount_msat: 1000000, + amount_msat: 400000, + cltv_expiry: 100, + payment_hash: PaymentHash([42; 32]), + transaction_output_index: None, + }; + + let offered_htlc = HTLCOutputInCommitment { + offered: true, + amount_msat: 600000, cltv_expiry: 100, - payment_hash, + payment_hash: PaymentHash([43; 32]), transaction_output_index: None, }; + // Generate broadcaster output and received and offered HTLC outputs, w/o anchors + let tx = CommitmentTransaction::new_with_auxiliary_htlc_data( + 0, 3000, 0, + false, + holder_pubkeys.funding_pubkey, + counterparty_pubkeys.funding_pubkey, + keys.clone(), 1, + &mut vec![(received_htlc.clone(), ()), (offered_htlc.clone(), ())], + &channel_parameters.as_holder_broadcastable() + ); + 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(()); let tx = CommitmentTransaction::new_with_auxiliary_htlc_data( 0, 3000, 0, true, holder_pubkeys.funding_pubkey, counterparty_pubkeys.funding_pubkey, keys.clone(), 1, - &mut vec![(htlc_info, ())], &channel_parameters.as_holder_broadcastable() + &mut vec![(received_htlc.clone(), ()), (offered_htlc.clone(), ())], + &channel_parameters.as_holder_broadcastable() ); - assert_eq!(tx.built.transaction.output.len(), 4); + 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]