/// that txid/index, and any keys or other information required to sign.
#[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
- /// script_pubkey as it appears in the output.
+ /// An output to a script which was provided via KeysInterface directly, either from
+ /// `get_destination_script()` or `get_shutdown_pubkey()`, thus you should already know how to
+ /// spend it. No secret keys are provided as rust-lightning was never given any key.
/// These may include outputs from a transaction punishing our counterparty or claiming an HTLC
/// on-chain using the payment preimage or after it has timed out.
StaticOutput {
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 revocation_pubkey used to derive witnessScript
- revocation_pubkey: PublicKey
+ revocation_pubkey: PublicKey,
+ /// Arbitrary identification information returned by a call to
+ /// `ChannelKeys::channel_keys_id()`. This may be useful in re-deriving keys used in
+ /// the channel to spend the output.
+ channel_keys_id: [u8; 32],
+ /// The value of the channel which this output originated from, possibly indirectly.
+ channel_value_satoshis: u64,
},
/// 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).
outpoint: OutPoint,
/// 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),
+ /// Arbitrary identification information returned by a call to
+ /// `ChannelKeys::channel_keys_id()`. This may be useful in re-deriving keys used in
+ /// the channel to spend the output.
+ channel_keys_id: [u8; 32],
+ /// The value of the channel which this transactions spends.
+ channel_value_satoshis: u64,
}
}
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 revocation_pubkey } => {
+ &SpendableOutputDescriptor::DynamicOutputP2WSH { ref outpoint, ref per_commitment_point, ref to_self_delay, ref output, ref revocation_pubkey, ref channel_keys_id, channel_value_satoshis } => {
1u8.write(writer)?;
outpoint.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)?;
revocation_pubkey.write(writer)?;
+ channel_keys_id.write(writer)?;
+ channel_value_satoshis.write(writer)?;
},
- &SpendableOutputDescriptor::StaticOutputCounterpartyPayment { ref outpoint, ref output, ref key_derivation_params } => {
+ &SpendableOutputDescriptor::StaticOutputCounterpartyPayment { ref outpoint, ref output, ref channel_keys_id, channel_value_satoshis } => {
2u8.write(writer)?;
outpoint.write(writer)?;
output.write(writer)?;
- key_derivation_params.0.write(writer)?;
- key_derivation_params.1.write(writer)?;
+ channel_keys_id.write(writer)?;
+ channel_value_satoshis.write(writer)?;
},
}
Ok(())
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)?),
revocation_pubkey: Readable::read(reader)?,
+ channel_keys_id: Readable::read(reader)?,
+ channel_value_satoshis: Readable::read(reader)?,
}),
2u8 => Ok(SpendableOutputDescriptor::StaticOutputCounterpartyPayment {
outpoint: Readable::read(reader)?,
output: Readable::read(reader)?,
- key_derivation_params: (Readable::read(reader)?, Readable::read(reader)?),
+ channel_keys_id: Readable::read(reader)?,
+ channel_value_satoshis: Readable::read(reader)?,
}),
_ => Err(DecodeError::InvalidValue),
}
// 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.
fn release_commitment_secret(&self, idx: u64) -> [u8; 32];
/// 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
+ /// Gets an arbitrary identifier describing the set of keys which are provided back to you in
+ /// some SpendableOutputDescriptor types. This should be sufficient to identify this
/// ChannelKeys object uniquely and lookup or re-derive its keys.
- fn key_derivation_params(&self) -> (u64, u64);
+ fn channel_keys_id(&self) -> [u8; 32];
/// Create a signature for a counterparty's commitment transaction and associated HTLC transactions.
///
// TODO: Document the things someone using this interface should enforce before signing.
fn sign_counterparty_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
- /// Create a signature for a holder's commitment transaction. This will only ever be called with
- /// the same commitment_tx (or a copy thereof), though there are currently no guarantees
- /// that it will not be called multiple times.
+ /// 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.
- fn sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
+ // TODO: Key derivation failure should panic rather than Err
+ fn sign_holder_commitment_and_htlcs<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
/// 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_holder_commitment may enforce that we only ever
/// get called once.
#[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
- fn unsafe_sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()>;
-
- /// Create a signature for each HTLC transaction spending a holder's commitment transaction.
- ///
- /// Unlike sign_holder_commitment, this may be called multiple times with *different*
- /// commitment_tx values. While this will never be called with a revoked
- /// commitment_tx, it is possible that it is called with the second-latest
- /// 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
- /// commitment_tx.
- fn sign_holder_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Vec<Signature>, ()>;
+ fn unsafe_sign_holder_commitment_and_htlcs<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()>;
/// 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 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)
+ /// Get node secret key (aka node_id or network_key).
+ ///
+ /// This method must return the same value each time it is called.
fn get_node_secret(&self) -> SecretKey;
- /// Get destination redeemScript to encumber static protocol exit points.
+ /// Get a script pubkey which we send funds to when claiming on-chain contestable outputs.
+ ///
+ /// This method should return a different value each time it is called, to avoid linking
+ /// on-chain funds across channels as controlled to the same user.
fn get_destination_script(&self) -> Script;
- /// Get shutdown_pubkey to use as PublicKey at channel closure
+ /// Get a public key which we will send funds to (in the form of a P2WPKH output) when closing
+ /// a channel.
+ ///
+ /// This method should return a different value each time it is called, to avoid linking
+ /// on-chain funds across channels as controlled to the same user.
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!
+ ///
+ /// This method must return a different value each time it is called.
fn get_channel_keys(&self, inbound: bool, channel_value_satoshis: u64) -> Self::ChanKeySigner;
/// 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.
+ ///
+ /// This method must return a different value each time it is called.
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 `<Self::ChanKeySigner as Writeable>::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<Self::ChanKeySigner, DecodeError>;
}
#[derive(Clone)]
/// The total value of this channel
channel_value_satoshis: u64,
/// Key derivation parameters
- key_derivation_params: (u64, u64),
+ channel_keys_id: [u8; 32],
}
impl InMemoryChannelKeys {
htlc_base_key: SecretKey,
commitment_seed: [u8; 32],
channel_value_satoshis: u64,
- key_derivation_params: (u64, u64)) -> InMemoryChannelKeys {
+ channel_keys_id: [u8; 32]) -> InMemoryChannelKeys {
let holder_channel_pubkeys =
InMemoryChannelKeys::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
&payment_key, &delayed_payment_base_key,
channel_value_satoshis,
holder_channel_pubkeys,
channel_parameters: None,
- key_derivation_params,
+ channel_keys_id,
}
}
}
fn pubkeys(&self) -> &ChannelPublicKeys { &self.holder_channel_pubkeys }
- fn key_derivation_params(&self) -> (u64, u64) { self.key_derivation_params }
+ fn channel_keys_id(&self) -> [u8; 32] { self.channel_keys_id }
fn sign_counterparty_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
let trusted_tx = commitment_tx.trust();
Ok((commitment_sig, htlc_sigs))
}
- fn sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
+ fn sign_holder_commitment_and_htlcs<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
- let sig = commitment_tx.trust().built_transaction().sign(&self.funding_key, &funding_redeemscript, self.channel_value_satoshis, secp_ctx);
- Ok(sig)
+ 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(any(test,feature = "unsafe_revoked_tx_signing"))]
- fn unsafe_sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
+ fn unsafe_sign_holder_commitment_and_htlcs<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
- let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
- Ok(commitment_tx.trust().built_transaction().sign(&self.funding_key, &channel_funding_redeemscript, self.channel_value_satoshis, secp_ctx))
- }
-
- fn sign_holder_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Vec<Signature>, ()> {
- let channel_parameters = self.get_channel_parameters();
+ let funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &self.counterparty_pubkeys().funding_pubkey);
let trusted_tx = commitment_tx.trust();
- trusted_tx.get_htlc_sigs(&self.htlc_base_key, &channel_parameters.as_holder_broadcastable(), secp_ctx)
+ 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_justice_transaction<T: secp256k1::Signing + secp256k1::Verification>(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option<HTLCOutputInCommitment>, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
self.commitment_seed.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)?;
+ self.channel_keys_id.write(writer)?;
Ok(())
}
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)?;
- let params_2 = Readable::read(reader)?;
+ let keys_id = Readable::read(reader)?;
Ok(InMemoryChannelKeys {
funding_key,
channel_value_satoshis,
holder_channel_pubkeys,
channel_parameters: counterparty_channel_data,
- key_derivation_params: (params_1, params_2),
+ channel_keys_id: keys_id,
})
}
}
/// 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
+ /// ChannelKeys::channel_keys_id 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;
+ pub fn derive_channel_keys(&self, channel_value_satoshis: u64, params: &[u8; 32]) -> InMemoryChannelKeys {
+ let chan_id = byte_utils::slice_to_be64(¶ms[0..8]);
+ assert!(chan_id <= std::u32::MAX as u64); // Otherwise the params field wasn't created by us
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(params);
unique_start.input(&self.seed);
// 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 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");
+ let child_privkey = self.channel_master_key.ckd_priv(&self.secp_ctx, ChildNumber::from_hardened_idx(chan_id as u32).expect("key space exhausted")).expect("Your RNG is busted");
unique_start.input(&child_privkey.private_key.key[..]);
let seed = Sha256::from_engine(unique_start).into_inner();
htlc_base_key,
commitment_seed,
channel_value_satoshis,
- (params_1, params_2),
+ params.clone()
)
}
}
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)
+ assert!(child_ix <= std::u32::MAX as usize);
+ let mut id = [0; 32];
+ id[0..8].copy_from_slice(&byte_utils::be64_to_array(child_ix as u64));
+ id[8..16].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_nanos as u64));
+ id[16..24].copy_from_slice(&byte_utils::be64_to_array(self.starting_time_secs));
+ self.derive_channel_keys(channel_value_satoshis, &id)
}
fn get_secure_random_bytes(&self) -> [u8; 32] {
sha.input(b"Unique Secure Random Bytes Salt");
Sha256::from_engine(sha).into_inner()
}
+
+ fn read_chan_signer(&self, reader: &[u8]) -> Result<Self::ChanKeySigner, DecodeError> {
+ InMemoryChannelKeys::read(&mut std::io::Cursor::new(reader))
+ }
}