X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fkeysinterface.rs;h=e56ac96f0632bfeb9efe704e6951ccb14c6e723d;hb=151d4ac0a3a6aa94d3f93995b71c874b7ea95967;hp=55bf7c65d62b71e16c5ce82a15f87db5f969e0f1;hpb=ed84b02a0aef7d97a887d187ea0429dcd780a6b3;p=rust-lightning diff --git a/lightning/src/chain/keysinterface.rs b/lightning/src/chain/keysinterface.rs index 55bf7c65..e56ac96f 100644 --- a/lightning/src/chain/keysinterface.rs +++ b/lightning/src/chain/keysinterface.rs @@ -1,8 +1,17 @@ +// This file is Copyright its original authors, visible in version control +// history. +// +// This file is licensed under the Apache License, Version 2.0 or the MIT license +// , at your option. +// You may not use this file except in accordance with one or both of these +// licenses. + //! keysinterface provides keys into rust-lightning and defines some useful enums which describe //! spendable on-chain outputs which the user owns and is responsible for using just as any other //! on-chain output which is theirs. -use bitcoin::blockdata::transaction::{Transaction, OutPoint, TxOut}; +use bitcoin::blockdata::transaction::{Transaction, TxOut, SigHashType}; use bitcoin::blockdata::script::{Script, Builder}; use bitcoin::blockdata::opcodes; use bitcoin::network::constants::Network; @@ -22,9 +31,10 @@ use bitcoin::secp256k1; use util::byte_utils; use util::ser::{Writeable, Writer, Readable}; +use chain::transaction::OutPoint; use ln::chan_utils; -use ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, LocalCommitmentTransaction}; -use ln::msgs; +use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction}; +use ln::msgs::UnsignedChannelAnnouncement; use std::sync::atomic::{AtomicUsize, Ordering}; use std::io::Error; @@ -35,7 +45,7 @@ use ln::msgs::DecodeError; /// spend on-chain. The information needed to do this is provided in this enum, including the /// outpoint describing which txid and output index is available, the full output which exists at /// that txid/index, and any keys or other information required to sign. -#[derive(Clone, PartialEq)] +#[derive(Clone, Debug, PartialEq)] pub enum SpendableOutputDescriptor { /// An output to a script which was provided via KeysInterface, thus you should already know /// how to spend it. No keys are provided as rust-lightning was never given any keys - only the @@ -61,15 +71,15 @@ pub enum SpendableOutputDescriptor { /// it is an output from an old state which we broadcast (which should never happen). /// /// To derive the delayed_payment key which is used to sign for this input, you must pass the - /// local delayed_payment_base_key (ie the private key which corresponds to the pubkey in + /// holder delayed_payment_base_key (ie the private key which corresponds to the pubkey in /// ChannelKeys::pubkeys().delayed_payment_basepoint) and the provided per_commitment_point to /// chan_utils::derive_private_key. The public key can be generated without the secret key /// using chan_utils::derive_public_key and only the delayed_payment_basepoint which appears in /// ChannelKeys::pubkeys(). /// - /// To derive the remote_revocation_pubkey provided here (which is used in the witness - /// script generation), you must pass the remote revocation_basepoint (which appears in the - /// call to ChannelKeys::set_remote_channel_pubkeys) and the provided per_commitment point + /// To derive the revocation_pubkey provided here (which is used in the witness + /// script generation), you must pass the counterparty revocation_basepoint (which appears in the + /// call to ChannelKeys::ready_channel) and the provided per_commitment point /// to chan_utils::derive_public_revocation_key. /// /// The witness script which is hashed and included in the output script_pubkey may be @@ -91,8 +101,8 @@ pub enum SpendableOutputDescriptor { /// The channel keys state used to proceed to derivation of signing key. Must /// be pass to KeysInterface::derive_channel_keys. key_derivation_params: (u64, u64), - /// The remote_revocation_pubkey used to derive witnessScript - remote_revocation_pubkey: PublicKey + /// The revocation_pubkey used to derive witnessScript + revocation_pubkey: PublicKey }, /// An output to a P2WPKH, spendable exclusively by our payment key (ie the private key which /// corresponds to the public key in ChannelKeys::pubkeys().payment_point). @@ -101,7 +111,7 @@ pub enum SpendableOutputDescriptor { /// /// These are generally the result of our counterparty having broadcast the current state, /// allowing us to claim the non-HTLC-encumbered outputs immediately. - StaticOutputRemotePayment { + StaticOutputCounterpartyPayment { /// The outpoint which is spendable outpoint: OutPoint, /// The output which is reference by the given outpoint @@ -120,7 +130,7 @@ impl Writeable for SpendableOutputDescriptor { outpoint.write(writer)?; output.write(writer)?; }, - &SpendableOutputDescriptor::DynamicOutputP2WSH { ref outpoint, ref per_commitment_point, ref to_self_delay, ref output, ref key_derivation_params, ref remote_revocation_pubkey } => { + &SpendableOutputDescriptor::DynamicOutputP2WSH { ref outpoint, ref per_commitment_point, ref to_self_delay, ref output, ref key_derivation_params, ref revocation_pubkey } => { 1u8.write(writer)?; outpoint.write(writer)?; per_commitment_point.write(writer)?; @@ -128,9 +138,9 @@ impl Writeable for SpendableOutputDescriptor { output.write(writer)?; key_derivation_params.0.write(writer)?; key_derivation_params.1.write(writer)?; - remote_revocation_pubkey.write(writer)?; + revocation_pubkey.write(writer)?; }, - &SpendableOutputDescriptor::StaticOutputRemotePayment { ref outpoint, ref output, ref key_derivation_params } => { + &SpendableOutputDescriptor::StaticOutputCounterpartyPayment { ref outpoint, ref output, ref key_derivation_params } => { 2u8.write(writer)?; outpoint.write(writer)?; output.write(writer)?; @@ -155,9 +165,9 @@ impl Readable for SpendableOutputDescriptor { to_self_delay: Readable::read(reader)?, output: Readable::read(reader)?, key_derivation_params: (Readable::read(reader)?, Readable::read(reader)?), - remote_revocation_pubkey: Readable::read(reader)?, + revocation_pubkey: Readable::read(reader)?, }), - 2u8 => Ok(SpendableOutputDescriptor::StaticOutputRemotePayment { + 2u8 => Ok(SpendableOutputDescriptor::StaticOutputCounterpartyPayment { outpoint: Readable::read(reader)?, output: Readable::read(reader)?, key_derivation_params: (Readable::read(reader)?, Readable::read(reader)?), @@ -194,7 +204,7 @@ impl Readable for SpendableOutputDescriptor { // routine). // TODO: We should remove Clone by instead requesting a new ChannelKeys copy when we create // ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors. -pub trait ChannelKeys : Send+Clone { +pub trait ChannelKeys : Send+Clone + Writeable { /// Gets the per-commitment point for a specific commitment number /// /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards. @@ -209,52 +219,42 @@ pub trait ChannelKeys : Send+Clone { /// Note that the commitment number starts at (1 << 48) - 1 and counts backwards. /// TODO: return a Result so we can signal a validation error fn release_commitment_secret(&self, idx: u64) -> [u8; 32]; - /// Gets the local channel public keys and basepoints + /// Gets the holder's channel public keys and basepoints fn pubkeys(&self) -> &ChannelPublicKeys; /// Gets arbitrary identifiers describing the set of keys which are provided back to you in /// some SpendableOutputDescriptor types. These should be sufficient to identify this /// ChannelKeys object uniquely and lookup or re-derive its keys. fn key_derivation_params(&self) -> (u64, u64); - /// Create a signature for a remote commitment transaction and associated HTLC transactions. + /// Create a signature for a counterparty's commitment transaction and associated HTLC transactions. /// /// Note that if signing fails or is rejected, the channel will be force-closed. // // TODO: Document the things someone using this interface should enforce before signing. - // TODO: Add more input vars to enable better checking (preferably removing commitment_tx and - // making the callee generate it via some util function we expose)! - fn sign_remote_commitment(&self, feerate_per_kw: u32, commitment_tx: &Transaction, keys: &TxCreationKeys, htlcs: &[&HTLCOutputInCommitment], to_self_delay: u16, secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()>; - - /// Create a signature for a local commitment transaction. This will only ever be called with - /// the same local_commitment_tx (or a copy thereof), though there are currently no guarantees - /// that it will not be called multiple times. + fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()>; + + /// Create a signatures for a holder's commitment transaction and its claiming HTLC transactions. + /// This will only ever be called with a non-revoked commitment_tx. This will be called with the + /// latest commitment_tx when we initiate a force-close. + /// This will be called with the previous latest, just to get claiming HTLC signatures, if we are + /// reacting to a ChannelMonitor replica that decided to broadcast before it had been updated to + /// the latest. + /// This may be called multiple times for the same transaction. + /// /// An external signer implementation should check that the commitment has not been revoked. + /// + /// May return Err if key derivation fails. Callers, such as ChannelMonitor, will panic in such a case. // // TODO: Document the things someone using this interface should enforce before signing. - // TODO: Add more input vars to enable better checking (preferably removing commitment_tx and - fn sign_local_commitment(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1) -> Result; + // TODO: Key derivation failure should panic rather than Err + fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()>; - /// Same as sign_local_commitment, but exists only for tests to get access to local commitment + /// Same as sign_holder_commitment, but exists only for tests to get access to holder commitment /// transactions which will be broadcasted later, after the channel has moved on to a newer - /// state. Thus, needs its own method as sign_local_commitment may enforce that we only ever + /// state. Thus, needs its own method as sign_holder_commitment may enforce that we only ever /// get called once. - #[cfg(test)] - fn unsafe_sign_local_commitment(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1) -> Result; - - /// Create a signature for each HTLC transaction spending a local commitment transaction. - /// - /// Unlike sign_local_commitment, this may be called multiple times with *different* - /// local_commitment_tx values. While this will never be called with a revoked - /// local_commitment_tx, it is possible that it is called with the second-latest - /// local_commitment_tx (only if we haven't yet revoked it) if some watchtower/secondary - /// ChannelMonitor decided to broadcast before it had been updated to the latest. - /// - /// Either an Err should be returned, or a Vec with one entry for each HTLC which exists in - /// local_commitment_tx. For those HTLCs which have transaction_output_index set to None - /// (implying they were considered dust at the time the commitment transaction was negotiated), - /// a corresponding None should be included in the return value. All other positions in the - /// return value must contain a signature. - fn sign_local_commitment_htlc_transactions(&self, local_commitment_tx: &LocalCommitmentTransaction, local_csv: u16, secp_ctx: &Secp256k1) -> Result>, ()>; + #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))] + fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()>; /// Create a signature for the given input in a transaction spending an HTLC or commitment /// transaction output when our counterparty broadcasts an old state. @@ -267,20 +267,16 @@ pub trait ChannelKeys : Send+Clone { /// Amount is value of the output spent by this input, committed to in the BIP 143 signature. /// /// per_commitment_key is revocation secret which was provided by our counterparty when they - /// revoked the state which they eventually broadcast. It's not a _local_ secret key and does - /// not allow the spending of any funds by itself (you need our local revocation_secret to do + /// revoked the state which they eventually broadcast. It's not a _holder_ secret key and does + /// not allow the spending of any funds by itself (you need our holder revocation_secret to do /// so). /// /// htlc holds HTLC elements (hash, timelock) if the output being spent is a HTLC output, thus /// changing the format of the witness script (which is committed to in the BIP 143 /// signatures). - /// - /// on_remote_tx_csv is the relative lock-time that that our counterparty would have to set on - /// their transaction were they to spend the same output. It is included in the witness script - /// and thus committed to in the BIP 143 signature. - fn sign_justice_transaction(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option, on_remote_tx_csv: u16, secp_ctx: &Secp256k1) -> Result; + fn sign_justice_transaction(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option, secp_ctx: &Secp256k1) -> Result; - /// Create a signature for a claiming transaction for a HTLC output on a remote commitment + /// Create a signature for a claiming transaction for a HTLC output on a counterparty's commitment /// transaction, either offered or received. /// /// Such a transaction may claim multiples offered outputs at same time if we know the @@ -297,7 +293,7 @@ pub trait ChannelKeys : Send+Clone { /// detected onchain. It has been generated by our counterparty and is used to derive /// channel state keys, which are then included in the witness script and committed to in the /// BIP 143 signature. - fn sign_remote_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1) -> Result; + fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1) -> Result; /// Create a signature for a (proposed) closing transaction. /// @@ -311,13 +307,19 @@ pub trait ChannelKeys : Send+Clone { /// Note that if this fails or is rejected, the channel will not be publicly announced and /// our counterparty may (though likely will not) close the channel on us for violating the /// protocol. - fn sign_channel_announcement(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1) -> Result; + fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1) -> Result; - /// Set the remote channel basepoints. This is done immediately on incoming channels - /// and as soon as the channel is accepted on outgoing channels. + /// Set the counterparty static channel data, including basepoints, + /// counterparty_selected/holder_selected_contest_delay and funding outpoint. + /// This is done as soon as the funding outpoint is known. Since these are static channel data, + /// they MUST NOT be allowed to change to different values once set. + /// + /// channel_parameters.is_populated() MUST be true. + /// + /// We bind holder_selected_contest_delay late here for API convenience. /// /// Will be called before any signatures are applied. - fn set_remote_channel_pubkeys(&mut self, channel_points: &ChannelPublicKeys); + fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters); } /// A trait to describe an object which can get user secrets and key material. @@ -334,33 +336,42 @@ pub trait KeysInterface: Send + Sync { /// Get a new set of ChannelKeys for per-channel secrets. These MUST be unique even if you /// restarted with some stale data! fn get_channel_keys(&self, inbound: bool, channel_value_satoshis: u64) -> Self::ChanKeySigner; - /// Get a secret and PRNG seed for constructing an onion packet - fn get_onion_rand(&self) -> (SecretKey, [u8; 32]); - /// Get a unique temporary channel id. Channels will be referred to by this until the funding - /// transaction is created, at which point they will use the outpoint in the funding - /// transaction. - fn get_channel_id(&self) -> [u8; 32]; + /// Gets a unique, cryptographically-secure, random 32 byte value. This is used for encrypting + /// onion packets and for temporary channel IDs. There is no requirement that these be + /// persisted anywhere, though they must be unique across restarts. + fn get_secure_random_bytes(&self) -> [u8; 32]; + + /// Reads a `ChanKeySigner` for this `KeysInterface` from the given input stream. + /// This is only called during deserialization of other objects which contain + /// `ChannelKeys`-implementing objects (ie `ChannelMonitor`s and `ChannelManager`s). + /// The bytes are exactly those which `::write()` writes, and + /// contain no versioning scheme. You may wish to include your own version prefix and ensure + /// you've read all of the provided bytes to ensure no corruption occurred. + fn read_chan_signer(&self, reader: &[u8]) -> Result; } #[derive(Clone)] /// A simple implementation of ChannelKeys that just keeps the private keys in memory. +/// +/// This implementation performs no policy checks and is insufficient by itself as +/// a secure external signer. pub struct InMemoryChannelKeys { /// Private key of anchor tx pub funding_key: SecretKey, - /// Local secret key for blinded revocation pubkey + /// Holder secret key for blinded revocation pubkey pub revocation_base_key: SecretKey, - /// Local secret key used for our balance in remote-broadcasted commitment transactions + /// Holder secret key used for our balance in counterparty-broadcasted commitment transactions pub payment_key: SecretKey, - /// Local secret key used in HTLC tx + /// Holder secret key used in HTLC tx pub delayed_payment_base_key: SecretKey, - /// Local htlc secret key used in commitment tx htlc outputs + /// Holder htlc secret key used in commitment tx htlc outputs pub htlc_base_key: SecretKey, /// Commitment seed pub commitment_seed: [u8; 32], - /// Local public keys and basepoints - pub(crate) local_channel_pubkeys: ChannelPublicKeys, - /// Remote public keys and base points - pub(crate) remote_channel_pubkeys: Option, + /// Holder public keys and basepoints + pub(crate) holder_channel_pubkeys: ChannelPublicKeys, + /// Counterparty public keys and counterparty/holder selected_contest_delay, populated on channel acceptance + channel_parameters: Option, /// The total value of this channel channel_value_satoshis: u64, /// Key derivation parameters @@ -379,8 +390,8 @@ impl InMemoryChannelKeys { commitment_seed: [u8; 32], channel_value_satoshis: u64, key_derivation_params: (u64, u64)) -> InMemoryChannelKeys { - let local_channel_pubkeys = - InMemoryChannelKeys::make_local_keys(secp_ctx, &funding_key, &revocation_base_key, + let holder_channel_pubkeys = + InMemoryChannelKeys::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key, &payment_key, &delayed_payment_base_key, &htlc_base_key); InMemoryChannelKeys { @@ -391,13 +402,13 @@ impl InMemoryChannelKeys { htlc_base_key, commitment_seed, channel_value_satoshis, - local_channel_pubkeys, - remote_channel_pubkeys: None, + holder_channel_pubkeys, + channel_parameters: None, key_derivation_params, } } - fn make_local_keys(secp_ctx: &Secp256k1, + fn make_holder_keys(secp_ctx: &Secp256k1, funding_key: &SecretKey, revocation_base_key: &SecretKey, payment_key: &SecretKey, @@ -413,7 +424,37 @@ impl InMemoryChannelKeys { } } - fn remote_pubkeys<'a>(&'a self) -> &'a ChannelPublicKeys { self.remote_channel_pubkeys.as_ref().unwrap() } + /// Counterparty pubkeys. + /// Will panic if ready_channel wasn't called. + pub fn counterparty_pubkeys(&self) -> &ChannelPublicKeys { &self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().pubkeys } + + /// The contest_delay value specified by our counterparty and applied on holder-broadcastable + /// transactions, ie the amount of time that we have to wait to recover our funds if we + /// broadcast a transaction. + /// Will panic if ready_channel wasn't called. + pub fn counterparty_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().counterparty_parameters.as_ref().unwrap().selected_contest_delay } + + /// The contest_delay value specified by us and applied on transactions broadcastable + /// by our counterparty, ie the amount of time that they have to wait to recover their funds + /// if they broadcast a transaction. + /// Will panic if ready_channel wasn't called. + pub fn holder_selected_contest_delay(&self) -> u16 { self.get_channel_parameters().holder_selected_contest_delay } + + /// Whether the holder is the initiator + /// Will panic if ready_channel wasn't called. + pub fn is_outbound(&self) -> bool { self.get_channel_parameters().is_outbound_from_holder } + + /// Funding outpoint + /// Will panic if ready_channel wasn't called. + pub fn funding_outpoint(&self) -> &OutPoint { self.get_channel_parameters().funding_outpoint.as_ref().unwrap() } + + /// Obtain a ChannelTransactionParameters for this channel, to be used when verifying or + /// building transactions. + /// + /// Will panic if ready_channel wasn't called. + pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters { + self.channel_parameters.as_ref().unwrap() + } } impl ChannelKeys for InMemoryChannelKeys { @@ -426,60 +467,57 @@ impl ChannelKeys for InMemoryChannelKeys { chan_utils::build_commitment_secret(&self.commitment_seed, idx) } - fn pubkeys(&self) -> &ChannelPublicKeys { &self.local_channel_pubkeys } + fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys } fn key_derivation_params(&self) -> (u64, u64) { self.key_derivation_params } - fn sign_remote_commitment(&self, feerate_per_kw: u32, commitment_tx: &Transaction, keys: &TxCreationKeys, htlcs: &[&HTLCOutputInCommitment], to_self_delay: u16, secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()> { - if commitment_tx.input.len() != 1 { return Err(()); } + fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()> { + let trusted_tx = commitment_tx.trust(); + let keys = trusted_tx.keys(); let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key); - let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing"); - let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey); - - let commitment_sighash = hash_to_message!(&bip143::SighashComponents::new(&commitment_tx).sighash_all(&commitment_tx.input[0], &channel_funding_redeemscript, self.channel_value_satoshis)[..]); - let commitment_sig = secp_ctx.sign(&commitment_sighash, &self.funding_key); - - let commitment_txid = commitment_tx.txid(); - - let mut htlc_sigs = Vec::with_capacity(htlcs.len()); - for ref htlc in htlcs { - if let Some(_) = htlc.transaction_output_index { - let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, feerate_per_kw, to_self_delay, htlc, &keys.a_delayed_payment_key, &keys.revocation_key); - let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys); - let htlc_sighash = hash_to_message!(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]); - let our_htlc_key = match chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key) { - Ok(s) => s, - Err(_) => return Err(()), - }; - htlc_sigs.push(secp_ctx.sign(&htlc_sighash, &our_htlc_key)); - } + let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey); + + let built_tx = trusted_tx.built_transaction(); + let commitment_sig = built_tx.sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx); + let commitment_txid = built_tx.txid; + + let mut htlc_sigs = Vec::with_capacity(commitment_tx.htlcs().len()); + for htlc in commitment_tx.htlcs() { + let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_tx.feerate_per_kw(), self.holder_selected_contest_delay(), htlc, &keys.broadcaster_delayed_payment_key, &keys.revocation_key); + let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys); + let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]); + let holder_htlc_key = match chan_utils::derive_private_key(&secp_ctx, &keys.per_commitment_point, &self.htlc_base_key) { + Ok(s) => s, + Err(_) => return Err(()), + }; + htlc_sigs.push(secp_ctx.sign(&htlc_sighash, &holder_htlc_key)); } Ok((commitment_sig, htlc_sigs)) } - fn sign_local_commitment(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1) -> Result { + fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()> { let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key); - let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing"); - let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey); - - Ok(local_commitment_tx.get_local_sig(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx)) + let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey); + let trusted_tx = commitment_tx.trust(); + let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx); + let channel_parameters = self.get_channel_parameters(); + let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?; + Ok((sig, htlc_sigs)) } - #[cfg(test)] - fn unsafe_sign_local_commitment(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1) -> Result { + #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))] + fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1) -> Result<(Signature, Vec), ()> { let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key); - let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing"); - let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey); - - Ok(local_commitment_tx.get_local_sig(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx)) + let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey); + let trusted_tx = commitment_tx.trust(); + let sig = trusted_tx.built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx); + let channel_parameters = self.get_channel_parameters(); + let htlc_sigs = trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)?; + Ok((sig, htlc_sigs)) } - fn sign_local_commitment_htlc_transactions(&self, local_commitment_tx: &LocalCommitmentTransaction, local_csv: u16, secp_ctx: &Secp256k1) -> Result>, ()> { - local_commitment_tx.get_htlc_sigs(&self.htlc_base_key, local_csv, secp_ctx) - } - - fn sign_justice_transaction(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option, on_remote_tx_csv: u16, secp_ctx: &Secp256k1) -> Result { + fn sign_justice_transaction(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option, secp_ctx: &Secp256k1) -> Result { let revocation_key = match chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_key, &self.revocation_base_key) { Ok(revocation_key) => revocation_key, Err(_) => return Err(()) @@ -490,38 +528,38 @@ impl ChannelKeys for InMemoryChannelKeys { Err(_) => return Err(()) }; let witness_script = if let &Some(ref htlc) = htlc { - let remote_htlcpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.remote_pubkeys().htlc_basepoint) { - Ok(remote_htlcpubkey) => remote_htlcpubkey, + let counterparty_htlcpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) { + Ok(counterparty_htlcpubkey) => counterparty_htlcpubkey, Err(_) => return Err(()) }; - let local_htlcpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) { - Ok(local_htlcpubkey) => local_htlcpubkey, + let holder_htlcpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) { + Ok(holder_htlcpubkey) => holder_htlcpubkey, Err(_) => return Err(()) }; - chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &remote_htlcpubkey, &local_htlcpubkey, &revocation_pubkey) + chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &holder_htlcpubkey, &revocation_pubkey) } else { - let remote_delayedpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.remote_pubkeys().delayed_payment_basepoint) { - Ok(remote_delayedpubkey) => remote_delayedpubkey, + let counterparty_delayedpubkey = match chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().delayed_payment_basepoint) { + Ok(counterparty_delayedpubkey) => counterparty_delayedpubkey, Err(_) => return Err(()) }; - chan_utils::get_revokeable_redeemscript(&revocation_pubkey, on_remote_tx_csv, &remote_delayedpubkey) + chan_utils::get_revokeable_redeemscript(&revocation_pubkey, self.holder_selected_contest_delay(), &counterparty_delayedpubkey) }; - let sighash_parts = bip143::SighashComponents::new(&justice_tx); - let sighash = hash_to_message!(&sighash_parts.sighash_all(&justice_tx.input[input], &witness_script, amount)[..]); + let mut sighash_parts = bip143::SigHashCache::new(justice_tx); + let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]); return Ok(secp_ctx.sign(&sighash, &revocation_key)) } - fn sign_remote_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1) -> Result { + fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1) -> Result { if let Ok(htlc_key) = chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &self.htlc_base_key) { let witness_script = if let Ok(revocation_pubkey) = chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) { - if let Ok(remote_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.remote_pubkeys().htlc_basepoint) { - if let Ok(local_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) { - chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &remote_htlcpubkey, &local_htlcpubkey, &revocation_pubkey) + if let Ok(counterparty_htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.counterparty_pubkeys().htlc_basepoint) { + if let Ok(htlcpubkey) = chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &self.pubkeys().htlc_basepoint) { + chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &counterparty_htlcpubkey, &htlcpubkey, &revocation_pubkey) } else { return Err(()) } } else { return Err(()) } } else { return Err(()) }; - let sighash_parts = bip143::SighashComponents::new(&htlc_tx); - let sighash = hash_to_message!(&sighash_parts.sighash_all(&htlc_tx.input[input], &witness_script, amount)[..]); + let mut sighash_parts = bip143::SigHashCache::new(htlc_tx); + let sighash = hash_to_message!(&sighash_parts.signature_hash(input, &witness_script, amount, SigHashType::All)[..]); return Ok(secp_ctx.sign(&sighash, &htlc_key)) } Err(()) @@ -532,23 +570,23 @@ impl ChannelKeys for InMemoryChannelKeys { if closing_tx.input[0].witness.len() != 0 { return Err(()); } if closing_tx.output.len() > 2 { return Err(()); } - let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing"); let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key); - let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey); + let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey); - let sighash = hash_to_message!(&bip143::SighashComponents::new(closing_tx) - .sighash_all(&closing_tx.input[0], &channel_funding_redeemscript, self.channel_value_satoshis)[..]); + let sighash = hash_to_message!(&bip143::SigHashCache::new(closing_tx) + .signature_hash(0, &channel_funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]); Ok(secp_ctx.sign(&sighash, &self.funding_key)) } - fn sign_channel_announcement(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1) -> Result { + fn sign_channel_announcement(&self, msg: &UnsignedChannelAnnouncement, secp_ctx: &Secp256k1) -> Result { let msghash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]); Ok(secp_ctx.sign(&msghash, &self.funding_key)) } - fn set_remote_channel_pubkeys(&mut self, channel_pubkeys: &ChannelPublicKeys) { - assert!(self.remote_channel_pubkeys.is_none(), "Already set remote channel pubkeys"); - self.remote_channel_pubkeys = Some(channel_pubkeys.clone()); + fn ready_channel(&mut self, channel_parameters: &ChannelTransactionParameters) { + assert!(self.channel_parameters.is_none(), "Acceptance already noted"); + assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated"); + self.channel_parameters = Some(channel_parameters.clone()); } } @@ -560,7 +598,7 @@ impl Writeable for InMemoryChannelKeys { self.delayed_payment_base_key.write(writer)?; self.htlc_base_key.write(writer)?; self.commitment_seed.write(writer)?; - self.remote_channel_pubkeys.write(writer)?; + self.channel_parameters.write(writer)?; self.channel_value_satoshis.write(writer)?; self.key_derivation_params.0.write(writer)?; self.key_derivation_params.1.write(writer)?; @@ -577,11 +615,11 @@ impl Readable for InMemoryChannelKeys { let delayed_payment_base_key = Readable::read(reader)?; let htlc_base_key = Readable::read(reader)?; let commitment_seed = Readable::read(reader)?; - let remote_channel_pubkeys = Readable::read(reader)?; + let counterparty_channel_data = Readable::read(reader)?; let channel_value_satoshis = Readable::read(reader)?; let secp_ctx = Secp256k1::signing_only(); - let local_channel_pubkeys = - InMemoryChannelKeys::make_local_keys(&secp_ctx, &funding_key, &revocation_base_key, + let holder_channel_pubkeys = + InMemoryChannelKeys::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key, &payment_key, &delayed_payment_base_key, &htlc_base_key); let params_1 = Readable::read(reader)?; @@ -595,8 +633,8 @@ impl Readable for InMemoryChannelKeys { htlc_base_key, commitment_seed, channel_value_satoshis, - local_channel_pubkeys, - remote_channel_pubkeys, + holder_channel_pubkeys, + channel_parameters: counterparty_channel_data, key_derivation_params: (params_1, params_2), }) } @@ -616,10 +654,8 @@ pub struct KeysManager { shutdown_pubkey: PublicKey, channel_master_key: ExtendedPrivKey, channel_child_index: AtomicUsize, - session_master_key: ExtendedPrivKey, - session_child_index: AtomicUsize, - channel_id_master_key: ExtendedPrivKey, - channel_id_child_index: AtomicUsize, + rand_bytes_master_key: ExtendedPrivKey, + rand_bytes_child_index: AtomicUsize, seed: [u8; 32], starting_time_secs: u64, @@ -628,7 +664,7 @@ pub struct KeysManager { impl KeysManager { /// Constructs a KeysManager from a 32-byte seed. If the seed is in some way biased (eg your - /// RNG is busted) this may panic (but more importantly, you will possibly lose funds). + /// CSRNG is busted) this may panic (but more importantly, you will possibly lose funds). /// starting_time isn't strictly required to actually be a time, but it must absolutely, /// without a doubt, be unique to this instance. ie if you start multiple times with the same /// seed, starting_time must be unique to each run. Thus, the easiest way to achieve this is to @@ -665,8 +701,7 @@ impl KeysManager { Err(_) => panic!("Your RNG is busted"), }; let channel_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(3).unwrap()).expect("Your RNG is busted"); - let session_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted"); - let channel_id_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(5).unwrap()).expect("Your RNG is busted"); + let rand_bytes_master_key = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(4).unwrap()).expect("Your RNG is busted"); KeysManager { secp_ctx, @@ -675,10 +710,8 @@ impl KeysManager { shutdown_pubkey, channel_master_key, channel_child_index: AtomicUsize::new(0), - session_master_key, - session_child_index: AtomicUsize::new(0), - channel_id_master_key, - channel_id_child_index: AtomicUsize::new(0), + rand_bytes_master_key, + rand_bytes_child_index: AtomicUsize::new(0), seed: *seed, starting_time_secs, @@ -765,35 +798,24 @@ impl KeysInterface for KeysManager { self.shutdown_pubkey.clone() } - fn get_channel_keys(&self, _inbound: bool, channel_value_satoshis: u64) -> InMemoryChannelKeys { + fn get_channel_keys(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::ChanKeySigner { let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel); let ix_and_nanos: u64 = (child_ix as u64) << 32 | (self.starting_time_nanos as u64); self.derive_channel_keys(channel_value_satoshis, ix_and_nanos, self.starting_time_secs) } - fn get_onion_rand(&self) -> (SecretKey, [u8; 32]) { + fn get_secure_random_bytes(&self) -> [u8; 32] { let mut sha = self.derive_unique_start(); - let child_ix = self.session_child_index.fetch_add(1, Ordering::AcqRel); - let child_privkey = self.session_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32).expect("key space exhausted")).expect("Your RNG is busted"); + let child_ix = self.rand_bytes_child_index.fetch_add(1, Ordering::AcqRel); + let child_privkey = self.rand_bytes_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32).expect("key space exhausted")).expect("Your RNG is busted"); sha.input(&child_privkey.private_key.key[..]); - let mut rng_seed = sha.clone(); - // Not exactly the most ideal construction, but the second value will get fed into - // ChaCha so it is another step harder to break. - rng_seed.input(b"RNG Seed Salt"); - sha.input(b"Session Key Salt"); - (SecretKey::from_slice(&Sha256::from_engine(sha).into_inner()).expect("Your RNG is busted"), - Sha256::from_engine(rng_seed).into_inner()) + sha.input(b"Unique Secure Random Bytes Salt"); + Sha256::from_engine(sha).into_inner() } - fn get_channel_id(&self) -> [u8; 32] { - let mut sha = self.derive_unique_start(); - - let child_ix = self.channel_id_child_index.fetch_add(1, Ordering::AcqRel); - let child_privkey = self.channel_id_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(child_ix as u32).expect("key space exhausted")).expect("Your RNG is busted"); - sha.input(&child_privkey.private_key.key[..]); - - Sha256::from_engine(sha).into_inner() + fn read_chan_signer(&self, reader: &[u8]) -> Result { + InMemoryChannelKeys::read(&mut std::io::Cursor::new(reader)) } }