X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fkeysinterface.rs;h=9de35f0ef43d78b2a5c9f63c7fa47d8ecd856bb1;hb=2087032e7a823f6c63a64dac951e0f4843bc4667;hp=5f1a307bf27dc9f7bba705961b8b3646b4393b12;hpb=5101d2086c0cf2134ce9d729cfdf69b0a21d564e;p=rust-lightning diff --git a/lightning/src/chain/keysinterface.rs b/lightning/src/chain/keysinterface.rs index 5f1a307b..9de35f0e 100644 --- a/lightning/src/chain/keysinterface.rs +++ b/lightning/src/chain/keysinterface.rs @@ -9,25 +9,23 @@ use bitcoin::network::constants::Network; use bitcoin::util::bip32::{ExtendedPrivKey, ExtendedPubKey, ChildNumber}; use bitcoin::util::bip143; -use bitcoin_hashes::{Hash, HashEngine}; -use bitcoin_hashes::sha256::HashEngine as Sha256State; -use bitcoin_hashes::sha256::Hash as Sha256; -use bitcoin_hashes::sha256d::Hash as Sha256dHash; -use bitcoin_hashes::hash160::Hash as Hash160; +use bitcoin::hashes::{Hash, HashEngine}; +use bitcoin::hashes::sha256::HashEngine as Sha256State; +use bitcoin::hashes::sha256::Hash as Sha256; +use bitcoin::hashes::sha256d::Hash as Sha256dHash; +use bitcoin::hash_types::WPubkeyHash; -use secp256k1::key::{SecretKey, PublicKey}; -use secp256k1::{Secp256k1, Signature, Signing}; -use secp256k1; +use bitcoin::secp256k1::key::{SecretKey, PublicKey}; +use bitcoin::secp256k1::{Secp256k1, Signature, Signing}; +use bitcoin::secp256k1; use util::byte_utils; -use util::logger::Logger; use util::ser::{Writeable, Writer, Readable}; use ln::chan_utils; use ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, LocalCommitmentTransaction}; use ln::msgs; -use std::sync::Arc; use std::sync::atomic::{AtomicUsize, Ordering}; use std::io::Error; use ln::msgs::DecodeError; @@ -51,41 +49,66 @@ pub enum SpendableOutputDescriptor { output: TxOut, }, /// An output to a P2WSH script which can be spent with a single signature after a CSV delay. - /// The private key which should be used to sign the transaction is provided, as well as the - /// full witness redeemScript which is hashed in the output script_pubkey. + /// /// The witness in the spending input should be: - /// (MINIMALIF standard rule) - /// - /// Note that the nSequence field in the input must be set to_self_delay (which corresponds to - /// the transaction not being broadcastable until at least to_self_delay blocks after the input - /// confirms). + /// (MINIMALIF standard rule) + /// + /// Note that the nSequence field in the spending input must be set to to_self_delay + /// (which means the transaction is not broadcastable until at least to_self_delay + /// blocks after the outpoint confirms). + /// /// These are generally the result of a "revocable" output to us, spendable only by us unless - /// it is an output from us having broadcast an old state (which should never happen). + /// 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 + /// 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 chan_utils::derive_public_revocation_key. + /// + /// The witness script which is hashed and included in the output script_pubkey may be + /// regenerated by passing the revocation_pubkey (derived as above), our delayed_payment pubkey + /// (derived as above), and the to_self_delay contained here to + /// chan_utils::get_revokeable_redeemscript. + // + // TODO: we need to expose utility methods in KeyManager to do all the relevant derivation. DynamicOutputP2WSH { /// The outpoint which is spendable outpoint: OutPoint, - /// The secret key which must be used to sign the spending transaction - key: SecretKey, - /// The witness redeemScript which is hashed to create the script_pubkey in the given output - witness_script: Script, + /// Per commitment point to derive delayed_payment_key by key holder + per_commitment_point: PublicKey, /// The nSequence value which must be set in the spending input to satisfy the OP_CSV in /// the witness_script. to_self_delay: u16, /// The output which is referenced by the given outpoint output: TxOut, + /// 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 }, - /// An output to a P2WPKH, spendable exclusively by the given private key. + /// 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). /// The witness in the spending input, is, thus, simply: - /// + /// + /// /// These are generally the result of our counterparty having broadcast the current state, /// allowing us to claim the non-HTLC-encumbered outputs immediately. - DynamicOutputP2WPKH { + StaticOutputRemotePayment { /// The outpoint which is spendable outpoint: OutPoint, - /// The secret key which must be used to sign the spending transaction - key: SecretKey, /// The output which is reference by the given outpoint output: TxOut, + /// 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), } } @@ -97,19 +120,22 @@ impl Writeable for SpendableOutputDescriptor { outpoint.write(writer)?; output.write(writer)?; }, - &SpendableOutputDescriptor::DynamicOutputP2WSH { ref outpoint, ref key, ref witness_script, ref to_self_delay, ref output } => { + &SpendableOutputDescriptor::DynamicOutputP2WSH { ref outpoint, ref per_commitment_point, ref to_self_delay, ref output, ref key_derivation_params, ref remote_revocation_pubkey } => { 1u8.write(writer)?; outpoint.write(writer)?; - key.write(writer)?; - witness_script.write(writer)?; + per_commitment_point.write(writer)?; to_self_delay.write(writer)?; output.write(writer)?; + key_derivation_params.0.write(writer)?; + key_derivation_params.1.write(writer)?; + remote_revocation_pubkey.write(writer)?; }, - &SpendableOutputDescriptor::DynamicOutputP2WPKH { ref outpoint, ref key, ref output } => { + &SpendableOutputDescriptor::StaticOutputRemotePayment { ref outpoint, ref output, ref key_derivation_params } => { 2u8.write(writer)?; outpoint.write(writer)?; - key.write(writer)?; output.write(writer)?; + key_derivation_params.0.write(writer)?; + key_derivation_params.1.write(writer)?; }, } Ok(()) @@ -125,43 +151,22 @@ impl Readable for SpendableOutputDescriptor { }), 1u8 => Ok(SpendableOutputDescriptor::DynamicOutputP2WSH { outpoint: Readable::read(reader)?, - key: Readable::read(reader)?, - witness_script: Readable::read(reader)?, + per_commitment_point: Readable::read(reader)?, 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)?, }), - 2u8 => Ok(SpendableOutputDescriptor::DynamicOutputP2WPKH { + 2u8 => Ok(SpendableOutputDescriptor::StaticOutputRemotePayment { outpoint: Readable::read(reader)?, - key: Readable::read(reader)?, output: Readable::read(reader)?, + key_derivation_params: (Readable::read(reader)?, Readable::read(reader)?), }), _ => Err(DecodeError::InvalidValue), } } } -/// A trait to describe an object which can get user secrets and key material. -pub trait KeysInterface: Send + Sync { - /// A type which implements ChannelKeys which will be returned by get_channel_keys. - type ChanKeySigner : ChannelKeys; - - /// Get node secret key (aka node_id or network_key) - fn get_node_secret(&self) -> SecretKey; - /// Get destination redeemScript to encumber static protocol exit points. - fn get_destination_script(&self) -> Script; - /// Get shutdown_pubkey to use as PublicKey at channel closure - fn get_shutdown_pubkey(&self) -> PublicKey; - /// 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 construting 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]; -} - /// Set of lightning keys needed to operate a channel as described in BOLT 3. /// /// Signing services could be implemented on a hardware wallet. In this case, @@ -184,19 +189,20 @@ pub trait KeysInterface: Send + Sync { /// Readable/Writable to serialize out a unique reference to this set of keys so /// that you can serialize the full ChannelManager object. /// -/// (TODO: We shouldn't require that, and should have an API to get them at deser time, due mostly -/// to the possibility of reentrancy issues by calling the user's code during our deserialization -/// 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. +// (TODO: We shouldn't require that, and should have an API to get them at deser time, due mostly +// to the possibility of reentrancy issues by calling the user's code during our deserialization +// 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 { /// Gets the private key for the anchor tx fn funding_key<'a>(&'a self) -> &'a SecretKey; /// Gets the local secret key for blinded revocation pubkey fn revocation_base_key<'a>(&'a self) -> &'a SecretKey; - /// Gets the local secret key used in to_remote output of remote commitment tx - /// (and also as part of obscured commitment number) - fn payment_base_key<'a>(&'a self) -> &'a SecretKey; + /// Gets the local secret key used in the to_remote output of remote commitment tx (ie the + /// output to us in transactions our counterparty broadcasts). + /// Also as part of obscured commitment number. + fn payment_key<'a>(&'a self) -> &'a SecretKey; /// Gets the local secret key used in HTLC-Success/HTLC-Timeout txn and to_local output fn delayed_payment_base_key<'a>(&'a self) -> &'a SecretKey; /// Gets the local htlc secret key used in commitment tx htlc outputs @@ -205,31 +211,92 @@ pub trait ChannelKeys : Send+Clone { fn commitment_seed<'a>(&'a self) -> &'a [u8; 32]; /// Gets the local channel public keys and basepoints fn pubkeys<'a>(&'a self) -> &'a 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. /// /// 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)! + // + // 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: u64, 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 + /// 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. + // + // 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; + + /// Same as sign_local_commitment, but exists only for tests to get access to local 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 + /// 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. /// - /// 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 - /// TODO: Ensure test-only version doesn't enforce uniqueness of signature when it's enforced in this method - /// making the callee generate it via some util function we expose)! - fn sign_local_commitment(&self, local_commitment_tx: &mut LocalCommitmentTransaction, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1); + /// 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>, ()>; + + /// Create a signature for the given input in a transaction spending an HTLC or commitment + /// transaction output when our counterparty broadcasts an old state. + /// + /// A justice transaction may claim multiples outputs at the same time if timelocks are + /// similar, but only a signature for the input at index `input` should be signed for here. + /// It may be called multiples time for same output(s) if a fee-bump is needed with regards + /// to an upcoming timelock expiration. + /// + /// 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 + /// 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; - /// Create a signature for a local commitment transaction without enforcing one-time signing. + /// Create a signature for a claiming transaction for a HTLC output on a remote commitment + /// transaction, either offered or received. /// - /// Testing revocation logic by our test framework needs to sign multiple local commitment - /// transactions. This unsafe test-only version doesn't enforce one-time signing security - /// requirement. - #[cfg(test)] - fn unsafe_sign_local_commitment(&self, local_commitment_tx: &mut LocalCommitmentTransaction, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1); + /// Such a transaction may claim multiples offered outputs at same time if we know the + /// preimage for each when we create it, but only the input at index `input` should be + /// signed for here. It may be called multiple times for same output(s) if a fee-bump is + /// needed with regards to an upcoming timelock expiration. + /// + /// Witness_script is either a offered or received script as defined in BOLT3 for HTLC + /// outputs. + /// + /// Amount is value of the output spent by this input, committed to in the BIP 143 signature. + /// + /// Per_commitment_point is the dynamic point corresponding to the channel state + /// 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; /// Create a signature for a (proposed) closing transaction. /// @@ -252,6 +319,28 @@ pub trait ChannelKeys : Send+Clone { fn set_remote_channel_pubkeys(&mut self, channel_points: &ChannelPublicKeys); } +/// A trait to describe an object which can get user secrets and key material. +pub trait KeysInterface: Send + Sync { + /// A type which implements ChannelKeys which will be returned by get_channel_keys. + type ChanKeySigner : ChannelKeys; + + /// Get node secret key (aka node_id or network_key) + fn get_node_secret(&self) -> SecretKey; + /// Get destination redeemScript to encumber static protocol exit points. + fn get_destination_script(&self) -> Script; + /// Get shutdown_pubkey to use as PublicKey at channel closure + fn get_shutdown_pubkey(&self) -> PublicKey; + /// 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]; +} + #[derive(Clone)] /// A simple implementation of ChannelKeys that just keeps the private keys in memory. pub struct InMemoryChannelKeys { @@ -259,8 +348,8 @@ pub struct InMemoryChannelKeys { funding_key: SecretKey, /// Local secret key for blinded revocation pubkey revocation_base_key: SecretKey, - /// Local secret key used in commitment tx htlc outputs - payment_base_key: SecretKey, + /// Local secret key used for our balance in remote-broadcasted commitment transactions + payment_key: SecretKey, /// Local secret key used in HTLC tx delayed_payment_base_key: SecretKey, /// Local htlc secret key used in commitment tx htlc outputs @@ -273,6 +362,8 @@ pub struct InMemoryChannelKeys { pub(crate) remote_channel_pubkeys: Option, /// The total value of this channel channel_value_satoshis: u64, + /// Key derivation parameters + key_derivation_params: (u64, u64), } impl InMemoryChannelKeys { @@ -281,53 +372,58 @@ impl InMemoryChannelKeys { secp_ctx: &Secp256k1, funding_key: SecretKey, revocation_base_key: SecretKey, - payment_base_key: SecretKey, + payment_key: SecretKey, delayed_payment_base_key: SecretKey, htlc_base_key: SecretKey, commitment_seed: [u8; 32], - channel_value_satoshis: u64) -> InMemoryChannelKeys { + 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, - &payment_base_key, &delayed_payment_base_key, + &payment_key, &delayed_payment_base_key, &htlc_base_key); InMemoryChannelKeys { funding_key, revocation_base_key, - payment_base_key, + payment_key, delayed_payment_base_key, htlc_base_key, commitment_seed, channel_value_satoshis, local_channel_pubkeys, remote_channel_pubkeys: None, + key_derivation_params, } } fn make_local_keys(secp_ctx: &Secp256k1, funding_key: &SecretKey, revocation_base_key: &SecretKey, - payment_base_key: &SecretKey, + payment_key: &SecretKey, delayed_payment_base_key: &SecretKey, htlc_base_key: &SecretKey) -> ChannelPublicKeys { let from_secret = |s: &SecretKey| PublicKey::from_secret_key(secp_ctx, s); ChannelPublicKeys { funding_pubkey: from_secret(&funding_key), revocation_basepoint: from_secret(&revocation_base_key), - payment_basepoint: from_secret(&payment_base_key), + payment_point: from_secret(&payment_key), delayed_payment_basepoint: from_secret(&delayed_payment_base_key), htlc_basepoint: from_secret(&htlc_base_key), } } + + fn remote_pubkeys<'a>(&'a self) -> &'a ChannelPublicKeys { self.remote_channel_pubkeys.as_ref().unwrap() } } impl ChannelKeys for InMemoryChannelKeys { fn funding_key(&self) -> &SecretKey { &self.funding_key } fn revocation_base_key(&self) -> &SecretKey { &self.revocation_base_key } - fn payment_base_key(&self) -> &SecretKey { &self.payment_base_key } + fn payment_key(&self) -> &SecretKey { &self.payment_key } fn delayed_payment_base_key(&self) -> &SecretKey { &self.delayed_payment_base_key } fn htlc_base_key(&self) -> &SecretKey { &self.htlc_base_key } fn commitment_seed(&self) -> &[u8; 32] { &self.commitment_seed } fn pubkeys<'a>(&'a self) -> &'a ChannelPublicKeys { &self.local_channel_pubkeys } + fn key_derivation_params(&self) -> (u64, u64) { self.key_derivation_params } fn sign_remote_commitment(&self, feerate_per_kw: u64, 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(()); } @@ -358,13 +454,73 @@ impl ChannelKeys for InMemoryChannelKeys { Ok((commitment_sig, htlc_sigs)) } - fn sign_local_commitment(&self, local_commitment_tx: &mut LocalCommitmentTransaction, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1) { - local_commitment_tx.add_local_sig(&self.funding_key, funding_redeemscript, channel_value_satoshis, secp_ctx); + fn sign_local_commitment(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1) -> Result { + 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)) } #[cfg(test)] - fn unsafe_sign_local_commitment(&self, local_commitment_tx: &mut LocalCommitmentTransaction, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1) { - local_commitment_tx.add_local_sig(&self.funding_key, funding_redeemscript, channel_value_satoshis, secp_ctx); + fn unsafe_sign_local_commitment(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1) -> Result { + 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)) + } + + 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 { + 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(()) + }; + let per_commitment_point = PublicKey::from_secret_key(secp_ctx, &per_commitment_key); + let revocation_pubkey = match chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &self.pubkeys().revocation_basepoint) { + Ok(revocation_pubkey) => revocation_pubkey, + 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, + 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, + Err(_) => return Err(()) + }; + chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &remote_htlcpubkey, &local_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, + Err(_) => return Err(()) + }; + chan_utils::get_revokeable_redeemscript(&revocation_pubkey, on_remote_tx_csv, &remote_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)[..]); + 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 { + 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) + } 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)[..]); + return Ok(secp_ctx.sign(&sighash, &htlc_key)) + } + Err(()) } fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1) -> Result { @@ -396,12 +552,14 @@ impl Writeable for InMemoryChannelKeys { fn write(&self, writer: &mut W) -> Result<(), Error> { self.funding_key.write(writer)?; self.revocation_base_key.write(writer)?; - self.payment_base_key.write(writer)?; + self.payment_key.write(writer)?; 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_value_satoshis.write(writer)?; + self.key_derivation_params.0.write(writer)?; + self.key_derivation_params.1.write(writer)?; Ok(()) } @@ -411,7 +569,7 @@ impl Readable for InMemoryChannelKeys { fn read(reader: &mut R) -> Result { let funding_key = Readable::read(reader)?; let revocation_base_key = Readable::read(reader)?; - let payment_base_key = Readable::read(reader)?; + let payment_key = Readable::read(reader)?; let delayed_payment_base_key = Readable::read(reader)?; let htlc_base_key = Readable::read(reader)?; let commitment_seed = Readable::read(reader)?; @@ -420,19 +578,22 @@ impl Readable for InMemoryChannelKeys { let secp_ctx = Secp256k1::signing_only(); let local_channel_pubkeys = InMemoryChannelKeys::make_local_keys(&secp_ctx, &funding_key, &revocation_base_key, - &payment_base_key, &delayed_payment_base_key, + &payment_key, &delayed_payment_base_key, &htlc_base_key); + let params_1 = Readable::read(reader)?; + let params_2 = Readable::read(reader)?; Ok(InMemoryChannelKeys { funding_key, revocation_base_key, - payment_base_key, + payment_key, delayed_payment_base_key, htlc_base_key, commitment_seed, channel_value_satoshis, local_channel_pubkeys, - remote_channel_pubkeys + remote_channel_pubkeys, + key_derivation_params: (params_1, params_2), }) } } @@ -456,8 +617,9 @@ pub struct KeysManager { channel_id_master_key: ExtendedPrivKey, channel_id_child_index: AtomicUsize, - unique_start: Sha256State, - logger: Arc, + seed: [u8; 32], + starting_time_secs: u64, + starting_time_nanos: u32, } impl KeysManager { @@ -480,16 +642,16 @@ impl KeysManager { /// Note that until the 0.1 release there is no guarantee of backward compatibility between /// versions. Once the library is more fully supported, the docs will be updated to include a /// detailed description of the guarantee. - pub fn new(seed: &[u8; 32], network: Network, logger: Arc, starting_time_secs: u64, starting_time_nanos: u32) -> KeysManager { + pub fn new(seed: &[u8; 32], network: Network, starting_time_secs: u64, starting_time_nanos: u32) -> Self { let secp_ctx = Secp256k1::signing_only(); match ExtendedPrivKey::new_master(network.clone(), seed) { Ok(master_key) => { let node_secret = master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(0).unwrap()).expect("Your RNG is busted").private_key.key; let destination_script = match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(1).unwrap()) { Ok(destination_key) => { - let pubkey_hash160 = Hash160::hash(&ExtendedPubKey::from_private(&secp_ctx, &destination_key).public_key.key.serialize()[..]); + let wpubkey_hash = WPubkeyHash::hash(&ExtendedPubKey::from_private(&secp_ctx, &destination_key).public_key.to_bytes()); Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0) - .push_slice(&pubkey_hash160.into_inner()) + .push_slice(&wpubkey_hash.into_inner()) .into_script() }, Err(_) => panic!("Your RNG is busted"), @@ -502,11 +664,6 @@ impl KeysManager { 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 mut unique_start = Sha256::engine(); - unique_start.input(&byte_utils::be64_to_array(starting_time_secs)); - unique_start.input(&byte_utils::be32_to_array(starting_time_nanos)); - unique_start.input(seed); - KeysManager { secp_ctx, node_secret, @@ -519,41 +676,40 @@ impl KeysManager { channel_id_master_key, channel_id_child_index: AtomicUsize::new(0), - unique_start, - logger, + seed: *seed, + starting_time_secs, + starting_time_nanos, } }, Err(_) => panic!("Your rng is busted"), } } -} - -impl KeysInterface for KeysManager { - type ChanKeySigner = InMemoryChannelKeys; - - fn get_node_secret(&self) -> SecretKey { - self.node_secret.clone() + fn derive_unique_start(&self) -> Sha256State { + let mut unique_start = Sha256::engine(); + unique_start.input(&byte_utils::be64_to_array(self.starting_time_secs)); + unique_start.input(&byte_utils::be32_to_array(self.starting_time_nanos)); + unique_start.input(&self.seed); + unique_start } + /// Derive an old set of ChannelKeys for per-channel secrets based on a key derivation + /// parameters. + /// Key derivation parameters are accessible through a per-channel secrets + /// ChannelKeys::key_derivation_params and is provided inside DynamicOuputP2WSH in case of + /// onchain output detection for which a corresponding delayed_payment_key must be derived. + pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params_1: u64, params_2: u64) -> InMemoryChannelKeys { + let chan_id = ((params_1 & 0xFFFF_FFFF_0000_0000) >> 32) as u32; + let mut unique_start = Sha256::engine(); + unique_start.input(&byte_utils::be64_to_array(params_2)); + unique_start.input(&byte_utils::be32_to_array(params_1 as u32)); + unique_start.input(&self.seed); - fn get_destination_script(&self) -> Script { - self.destination_script.clone() - } - - fn get_shutdown_pubkey(&self) -> PublicKey { - self.shutdown_pubkey.clone() - } - - fn get_channel_keys(&self, _inbound: bool, channel_value_satoshis: u64) -> InMemoryChannelKeys { // We only seriously intend to rely on the channel_master_key for true secure // entropy, everything else just ensures uniqueness. We rely on the unique_start (ie // starting_time provided in the constructor) to be unique. - let mut sha = self.unique_start.clone(); + let child_privkey = self.channel_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(chan_id).expect("key space exhausted")).expect("Your RNG is busted"); + unique_start.input(&child_privkey.private_key.key[..]); - let child_ix = self.channel_child_index.fetch_add(1, Ordering::AcqRel); - let child_privkey = self.channel_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 seed = Sha256::from_engine(sha).into_inner(); + let seed = Sha256::from_engine(unique_start).into_inner(); let commitment_seed = { let mut sha = Sha256::engine(); @@ -572,24 +728,47 @@ impl KeysInterface for KeysManager { } let funding_key = key_step!(b"funding key", commitment_seed); let revocation_base_key = key_step!(b"revocation base key", funding_key); - let payment_base_key = key_step!(b"payment base key", revocation_base_key); - let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_base_key); + let payment_key = key_step!(b"payment key", revocation_base_key); + let delayed_payment_base_key = key_step!(b"delayed payment base key", payment_key); let htlc_base_key = key_step!(b"HTLC base key", delayed_payment_base_key); InMemoryChannelKeys::new( &self.secp_ctx, funding_key, revocation_base_key, - payment_base_key, + payment_key, delayed_payment_base_key, htlc_base_key, commitment_seed, - channel_value_satoshis + channel_value_satoshis, + (params_1, params_2), ) } +} + +impl KeysInterface for KeysManager { + type ChanKeySigner = InMemoryChannelKeys; + + fn get_node_secret(&self) -> SecretKey { + self.node_secret.clone() + } + + fn get_destination_script(&self) -> Script { + self.destination_script.clone() + } + + fn get_shutdown_pubkey(&self) -> PublicKey { + self.shutdown_pubkey.clone() + } + + fn get_channel_keys(&self, _inbound: bool, channel_value_satoshis: u64) -> InMemoryChannelKeys { + 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]) { - let mut sha = self.unique_start.clone(); + 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"); @@ -605,12 +784,12 @@ impl KeysInterface for KeysManager { } fn get_channel_id(&self) -> [u8; 32] { - let mut sha = self.unique_start.clone(); + 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()) + Sha256::from_engine(sha).into_inner() } }