//! 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, TxOut, SigHashType};
+use bitcoin::blockdata::transaction::{Transaction, TxOut, TxIn, SigHashType};
use bitcoin::blockdata::script::{Script, Builder};
use bitcoin::blockdata::opcodes;
use bitcoin::network::constants::Network;
use bitcoin::secp256k1::{Secp256k1, Signature, Signing};
use bitcoin::secp256k1;
-use util::byte_utils;
+use util::{byte_utils, transaction_utils};
use util::ser::{Writeable, Writer, Readable};
use chain::transaction::OutPoint;
use ln::chan_utils::{HTLCOutputInCommitment, make_funding_redeemscript, ChannelPublicKeys, HolderCommitmentTransaction, ChannelTransactionParameters, CommitmentTransaction};
use ln::msgs::UnsignedChannelAnnouncement;
+use std::collections::HashSet;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::io::Error;
-use ln::msgs::DecodeError;
+use ln::msgs::{DecodeError, MAX_VALUE_MSAT};
+
+/// Information about a spendable output to a P2WSH script. See
+/// SpendableOutputDescriptor::DelayedPaymentOutput for more details on how to spend this.
+#[derive(Clone, Debug, PartialEq)]
+pub struct DelayedPaymentOutputDescriptor {
+ /// The outpoint which is spendable
+ pub outpoint: OutPoint,
+ /// Per commitment point to derive delayed_payment_key by key holder
+ pub per_commitment_point: PublicKey,
+ /// The nSequence value which must be set in the spending input to satisfy the OP_CSV in
+ /// the witness_script.
+ pub to_self_delay: u16,
+ /// The output which is referenced by the given outpoint
+ pub output: TxOut,
+ /// The revocation point specific to the commitment transaction which was broadcast. Used to
+ /// derive the witnessScript for this output.
+ pub revocation_pubkey: PublicKey,
+ /// Arbitrary identification information returned by a call to
+ /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
+ /// the channel to spend the output.
+ pub channel_keys_id: [u8; 32],
+ /// The value of the channel which this output originated from, possibly indirectly.
+ pub channel_value_satoshis: u64,
+}
+impl DelayedPaymentOutputDescriptor {
+ /// The maximum length a well-formed witness spending one of these should have.
+ // Calculated as 1 byte length + 73 byte signature, 1 byte empty vec push, 1 byte length plus
+ // redeemscript push length.
+ pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 1 + chan_utils::REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH + 1;
+}
+
+/// Information about a spendable output to our "payment key". See
+/// SpendableOutputDescriptor::StaticPaymentOutput for more details on how to spend this.
+#[derive(Clone, Debug, PartialEq)]
+pub struct StaticPaymentOutputDescriptor {
+ /// The outpoint which is spendable
+ pub outpoint: OutPoint,
+ /// The output which is referenced by the given outpoint
+ pub output: TxOut,
+ /// Arbitrary identification information returned by a call to
+ /// `Sign::channel_keys_id()`. This may be useful in re-deriving keys used in
+ /// the channel to spend the output.
+ pub channel_keys_id: [u8; 32],
+ /// The value of the channel which this transactions spends.
+ pub channel_value_satoshis: u64,
+}
+impl StaticPaymentOutputDescriptor {
+ /// The maximum length a well-formed witness spending one of these should have.
+ // Calculated as 1 byte legnth + 73 byte signature, 1 byte empty vec push, 1 byte length plus
+ // redeemscript push length.
+ pub const MAX_WITNESS_LENGTH: usize = 1 + 73 + 34;
+}
/// When on-chain outputs are created by rust-lightning (which our counterparty is not able to
/// claim at any point in the future) an event is generated which you must track and be able to
/// 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 derive the delayed_payment key which is used to sign for this input, you must pass the
/// 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
+ /// Sign::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().
+ /// Sign::pubkeys().
///
/// 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
+ /// call to Sign::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
/// 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,
- /// 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 revocation_pubkey used to derive witnessScript
- revocation_pubkey: PublicKey
- },
+ DelayedPaymentOutput(DelayedPaymentOutputDescriptor),
/// 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).
+ /// corresponds to the public key in Sign::pubkeys().payment_point).
/// The witness in the spending input, is, thus, simply:
/// <BIP 143 signature> <payment key>
///
/// These are generally the result of our counterparty having broadcast the current state,
/// allowing us to claim the non-HTLC-encumbered outputs immediately.
- StaticOutputCounterpartyPayment {
- /// The outpoint which is spendable
- 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),
- }
+ StaticPaymentOutput(StaticPaymentOutputDescriptor),
}
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 revocation_pubkey } => {
+ &SpendableOutputDescriptor::DelayedPaymentOutput(ref descriptor) => {
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)?;
+ descriptor.outpoint.write(writer)?;
+ descriptor.per_commitment_point.write(writer)?;
+ descriptor.to_self_delay.write(writer)?;
+ descriptor.output.write(writer)?;
+ descriptor.revocation_pubkey.write(writer)?;
+ descriptor.channel_keys_id.write(writer)?;
+ descriptor.channel_value_satoshis.write(writer)?;
},
- &SpendableOutputDescriptor::StaticOutputCounterpartyPayment { ref outpoint, ref output, ref key_derivation_params } => {
+ &SpendableOutputDescriptor::StaticPaymentOutput(ref descriptor) => {
2u8.write(writer)?;
- outpoint.write(writer)?;
- output.write(writer)?;
- key_derivation_params.0.write(writer)?;
- key_derivation_params.1.write(writer)?;
+ descriptor.outpoint.write(writer)?;
+ descriptor.output.write(writer)?;
+ descriptor.channel_keys_id.write(writer)?;
+ descriptor.channel_value_satoshis.write(writer)?;
},
}
Ok(())
outpoint: Readable::read(reader)?,
output: Readable::read(reader)?,
}),
- 1u8 => Ok(SpendableOutputDescriptor::DynamicOutputP2WSH {
+ 1u8 => Ok(SpendableOutputDescriptor::DelayedPaymentOutput(DelayedPaymentOutputDescriptor {
outpoint: 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)?),
revocation_pubkey: Readable::read(reader)?,
- }),
- 2u8 => Ok(SpendableOutputDescriptor::StaticOutputCounterpartyPayment {
+ channel_keys_id: Readable::read(reader)?,
+ channel_value_satoshis: Readable::read(reader)?,
+ })),
+ 2u8 => Ok(SpendableOutputDescriptor::StaticPaymentOutput(StaticPaymentOutputDescriptor {
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),
}
}
}
-/// Set of lightning keys needed to operate a channel as described in BOLT 3.
+/// A trait to sign lightning channel transactions as described in BOLT 3.
///
/// Signing services could be implemented on a hardware wallet. In this case,
-/// the current ChannelKeys would be a front-end on top of a communication
+/// the current Sign would be a front-end on top of a communication
/// channel connected to your secure device and lightning key material wouldn't
/// reside on a hot server. Nevertheless, a this deployment would still need
/// to trust the ChannelManager to avoid loss of funds as this latest component
/// In any case, ChannelMonitor or fallback watchtowers are always going to be trusted
/// to act, as liveness and breach reply correctness are always going to be hard requirements
/// of LN security model, orthogonal of key management issues.
-///
-/// If you're implementing a custom signer, you almost certainly want to implement
-/// 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
+// TODO: We should remove Clone by instead requesting a new Sign copy when we create
// ChannelMonitors instead of expecting to clone the one out of the Channel into the monitors.
-pub trait ChannelKeys : Send+Clone + Writeable {
+pub trait Sign : 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.
/// May be called more than once for the same index.
///
/// Note that the commitment number starts at (1 << 48) - 1 and counts backwards.
- /// TODO: return a Result so we can signal a validation error
+ // TODO: return a Result so we can signal a validation error
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
- /// ChannelKeys object uniquely and lookup or re-derive its keys.
- fn key_derivation_params(&self) -> (u64, u64);
+ /// 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
+ /// Sign object uniquely and lookup or re-derive its keys.
+ 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 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;
+ /// A type which implements Sign which will be returned by get_channel_signer.
+ type Signer : Sign;
- /// 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
+ /// Get a new set of Sign 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;
+ ///
+ /// This method must return a different value each time it is called.
+ fn get_channel_signer(&self, inbound: bool, channel_value_satoshis: u64) -> Self::Signer;
/// 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 `Signer` for this `KeysInterface` from the given input stream.
+ /// This is only called during deserialization of other objects which contain
+ /// `Sign`-implementing objects (ie `ChannelMonitor`s and `ChannelManager`s).
+ /// The bytes are exactly those which `<Self::Signer 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::Signer, DecodeError>;
}
#[derive(Clone)]
-/// A simple implementation of ChannelKeys that just keeps the private keys in memory.
+/// A simple implementation of Sign 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 {
+pub struct InMemorySigner {
/// Private key of anchor tx
pub funding_key: SecretKey,
/// Holder secret key for blinded revocation pubkey
/// 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 {
- /// Create a new InMemoryChannelKeys
+impl InMemorySigner {
+ /// Create a new InMemorySigner
pub fn new<C: Signing>(
secp_ctx: &Secp256k1<C>,
funding_key: SecretKey,
htlc_base_key: SecretKey,
commitment_seed: [u8; 32],
channel_value_satoshis: u64,
- key_derivation_params: (u64, u64)) -> InMemoryChannelKeys {
+ channel_keys_id: [u8; 32]) -> InMemorySigner {
let holder_channel_pubkeys =
- InMemoryChannelKeys::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
+ InMemorySigner::make_holder_keys(secp_ctx, &funding_key, &revocation_base_key,
&payment_key, &delayed_payment_base_key,
&htlc_base_key);
- InMemoryChannelKeys {
+ InMemorySigner {
funding_key,
revocation_base_key,
payment_key,
channel_value_satoshis,
holder_channel_pubkeys,
channel_parameters: None,
- key_derivation_params,
+ channel_keys_id,
}
}
pub fn get_channel_parameters(&self) -> &ChannelTransactionParameters {
self.channel_parameters.as_ref().unwrap()
}
+
+ /// Sign the single input of spend_tx at index `input_idx` which spends the output
+ /// described by descriptor, returning the witness stack for the input.
+ ///
+ /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
+ /// or is not spending the outpoint described by `descriptor.outpoint`.
+ pub fn sign_counterparty_payment_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &StaticPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
+ // TODO: We really should be taking the SigHashCache as a parameter here instead of
+ // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
+ // so that we can check them. This requires upstream rust-bitcoin changes (as well as
+ // bindings updates to support SigHashCache objects).
+ if spend_tx.input.len() <= input_idx { return Err(()); }
+ if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
+ if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
+
+ let remotepubkey = self.pubkeys().payment_point;
+ let witness_script = bitcoin::Address::p2pkh(&::bitcoin::PublicKey{compressed: true, key: remotepubkey}, Network::Testnet).script_pubkey();
+ let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
+ let remotesig = secp_ctx.sign(&sighash, &self.payment_key);
+
+ let mut witness = Vec::with_capacity(2);
+ witness.push(remotesig.serialize_der().to_vec());
+ witness[0].push(SigHashType::All as u8);
+ witness.push(remotepubkey.serialize().to_vec());
+ Ok(witness)
+ }
+
+ /// Sign the single input of spend_tx at index `input_idx` which spends the output
+ /// described by descriptor, returning the witness stack for the input.
+ ///
+ /// Returns an Err if the input at input_idx does not exist, has a non-empty script_sig,
+ /// is not spending the outpoint described by `descriptor.outpoint`, or does not have a
+ /// sequence set to `descriptor.to_self_delay`.
+ pub fn sign_dynamic_p2wsh_input<C: Signing>(&self, spend_tx: &Transaction, input_idx: usize, descriptor: &DelayedPaymentOutputDescriptor, secp_ctx: &Secp256k1<C>) -> Result<Vec<Vec<u8>>, ()> {
+ // TODO: We really should be taking the SigHashCache as a parameter here instead of
+ // spend_tx, but ideally the SigHashCache would expose the transaction's inputs read-only
+ // so that we can check them. This requires upstream rust-bitcoin changes (as well as
+ // bindings updates to support SigHashCache objects).
+ if spend_tx.input.len() <= input_idx { return Err(()); }
+ if !spend_tx.input[input_idx].script_sig.is_empty() { return Err(()); }
+ if spend_tx.input[input_idx].previous_output != descriptor.outpoint.into_bitcoin_outpoint() { return Err(()); }
+ if spend_tx.input[input_idx].sequence != descriptor.to_self_delay as u32 { return Err(()); }
+
+ let delayed_payment_key = chan_utils::derive_private_key(&secp_ctx, &descriptor.per_commitment_point, &self.delayed_payment_base_key)
+ .expect("We constructed the payment_base_key, so we can only fail here if the RNG is busted.");
+ let delayed_payment_pubkey = PublicKey::from_secret_key(&secp_ctx, &delayed_payment_key);
+ let witness_script = chan_utils::get_revokeable_redeemscript(&descriptor.revocation_pubkey, descriptor.to_self_delay, &delayed_payment_pubkey);
+ let sighash = hash_to_message!(&bip143::SigHashCache::new(spend_tx).signature_hash(input_idx, &witness_script, descriptor.output.value, SigHashType::All)[..]);
+ let local_delayedsig = secp_ctx.sign(&sighash, &delayed_payment_key);
+
+ let mut witness = Vec::with_capacity(3);
+ witness.push(local_delayedsig.serialize_der().to_vec());
+ witness[0].push(SigHashType::All as u8);
+ witness.push(vec!()); //MINIMALIF
+ witness.push(witness_script.clone().into_bytes());
+ Ok(witness)
+ }
}
-impl ChannelKeys for InMemoryChannelKeys {
+impl Sign for InMemorySigner {
fn get_per_commitment_point<T: secp256k1::Signing + secp256k1::Verification>(&self, idx: u64, secp_ctx: &Secp256k1<T>) -> PublicKey {
let commitment_secret = SecretKey::from_slice(&chan_utils::build_commitment_secret(&self.commitment_seed, idx)).unwrap();
PublicKey::from_secret_key(secp_ctx, &commitment_secret)
}
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, ()> {
}
}
-impl Writeable for InMemoryChannelKeys {
+impl Writeable for InMemorySigner {
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
self.funding_key.write(writer)?;
self.revocation_base_key.write(writer)?;
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(())
}
}
-impl Readable for InMemoryChannelKeys {
+impl Readable for InMemorySigner {
fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
let funding_key = Readable::read(reader)?;
let revocation_base_key = Readable::read(reader)?;
let channel_value_satoshis = Readable::read(reader)?;
let secp_ctx = Secp256k1::signing_only();
let holder_channel_pubkeys =
- InMemoryChannelKeys::make_holder_keys(&secp_ctx, &funding_key, &revocation_base_key,
+ InMemorySigner::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 {
+ Ok(InMemorySigner {
funding_key,
revocation_base_key,
payment_key,
channel_value_satoshis,
holder_channel_pubkeys,
channel_parameters: counterparty_channel_data,
- key_derivation_params: (params_1, params_2),
+ channel_keys_id: keys_id,
})
}
}
/// 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, starting_time_secs: u64, starting_time_nanos: u32) -> Self {
+ pub fn new(seed: &[u8; 32], starting_time_secs: u64, starting_time_nanos: u32) -> Self {
let secp_ctx = Secp256k1::signing_only();
- match ExtendedPrivKey::new_master(network.clone(), seed) {
+ // Note that when we aren't serializing the key, network doesn't matter
+ match ExtendedPrivKey::new_master(Network::Testnet, 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()) {
unique_start.input(&self.seed);
unique_start
}
- /// Derive an old set of ChannelKeys for per-channel secrets based on a key derivation
+ /// Derive an old set of Sign 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
+ /// Sign::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]) -> InMemorySigner {
+ 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();
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(
+ InMemorySigner::new(
&self.secp_ctx,
funding_key,
revocation_base_key,
htlc_base_key,
commitment_seed,
channel_value_satoshis,
- (params_1, params_2),
+ params.clone()
)
}
+
+ /// Creates a Transaction which spends the given descriptors to the given outputs, plus an
+ /// output to the given change destination (if sufficient change value remains). The
+ /// transaction will have a feerate, at least, of the given value.
+ ///
+ /// Returns `Err(())` if the output value is greater than the input value minus required fee or
+ /// if a descriptor was duplicated.
+ ///
+ /// We do not enforce that outputs meet the dust limit or that any output scripts are standard.
+ ///
+ /// May panic if the `SpendableOutputDescriptor`s were not generated by Channels which used
+ /// this KeysManager or one of the `InMemorySigner` created by this KeysManager.
+ pub fn spend_spendable_outputs<C: Signing>(&self, descriptors: &[&SpendableOutputDescriptor], outputs: Vec<TxOut>, change_destination_script: Script, feerate_sat_per_1000_weight: u32, secp_ctx: &Secp256k1<C>) -> Result<Transaction, ()> {
+ let mut input = Vec::new();
+ let mut input_value = 0;
+ let mut witness_weight = 0;
+ let mut output_set = HashSet::with_capacity(descriptors.len());
+ for outp in descriptors {
+ match outp {
+ SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
+ input.push(TxIn {
+ previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
+ script_sig: Script::new(),
+ sequence: 0,
+ witness: Vec::new(),
+ });
+ witness_weight += StaticPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
+ input_value += descriptor.output.value;
+ if !output_set.insert(descriptor.outpoint) { return Err(()); }
+ },
+ SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
+ input.push(TxIn {
+ previous_output: descriptor.outpoint.into_bitcoin_outpoint(),
+ script_sig: Script::new(),
+ sequence: descriptor.to_self_delay as u32,
+ witness: Vec::new(),
+ });
+ witness_weight += DelayedPaymentOutputDescriptor::MAX_WITNESS_LENGTH;
+ input_value += descriptor.output.value;
+ if !output_set.insert(descriptor.outpoint) { return Err(()); }
+ },
+ SpendableOutputDescriptor::StaticOutput { ref outpoint, ref output } => {
+ input.push(TxIn {
+ previous_output: outpoint.into_bitcoin_outpoint(),
+ script_sig: Script::new(),
+ sequence: 0,
+ witness: Vec::new(),
+ });
+ witness_weight += 1 + 73 + 34;
+ input_value += output.value;
+ if !output_set.insert(*outpoint) { return Err(()); }
+ }
+ }
+ if input_value > MAX_VALUE_MSAT / 1000 { return Err(()); }
+ }
+ let mut spend_tx = Transaction {
+ version: 2,
+ lock_time: 0,
+ input,
+ output: outputs,
+ };
+ transaction_utils::maybe_add_change_output(&mut spend_tx, input_value, witness_weight, feerate_sat_per_1000_weight, change_destination_script)?;
+
+ let mut keys_cache: Option<(InMemorySigner, [u8; 32])> = None;
+ let mut input_idx = 0;
+ for outp in descriptors {
+ match outp {
+ SpendableOutputDescriptor::StaticPaymentOutput(descriptor) => {
+ if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
+ keys_cache = Some((
+ self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
+ descriptor.channel_keys_id));
+ }
+ spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_counterparty_payment_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
+ },
+ SpendableOutputDescriptor::DelayedPaymentOutput(descriptor) => {
+ if keys_cache.is_none() || keys_cache.as_ref().unwrap().1 != descriptor.channel_keys_id {
+ keys_cache = Some((
+ self.derive_channel_keys(descriptor.channel_value_satoshis, &descriptor.channel_keys_id),
+ descriptor.channel_keys_id));
+ }
+ spend_tx.input[input_idx].witness = keys_cache.as_ref().unwrap().0.sign_dynamic_p2wsh_input(&spend_tx, input_idx, &descriptor, &secp_ctx).unwrap();
+ },
+ SpendableOutputDescriptor::StaticOutput { ref output, .. } => {
+ let derivation_idx = if output.script_pubkey == self.destination_script {
+ 1
+ } else {
+ 2
+ };
+ let secret = {
+ // Note that when we aren't serializing the key, network doesn't matter
+ match ExtendedPrivKey::new_master(Network::Testnet, &self.seed) {
+ Ok(master_key) => {
+ match master_key.ckd_priv(&secp_ctx, ChildNumber::from_hardened_idx(derivation_idx).expect("key space exhausted")) {
+ Ok(key) => key,
+ Err(_) => panic!("Your RNG is busted"),
+ }
+ }
+ Err(_) => panic!("Your rng is busted"),
+ }
+ };
+ let pubkey = ExtendedPubKey::from_private(&secp_ctx, &secret).public_key;
+ if derivation_idx == 2 {
+ assert_eq!(pubkey.key, self.shutdown_pubkey);
+ }
+ let witness_script = bitcoin::Address::p2pkh(&pubkey, Network::Testnet).script_pubkey();
+ let sighash = hash_to_message!(&bip143::SigHashCache::new(&spend_tx).signature_hash(input_idx, &witness_script, output.value, SigHashType::All)[..]);
+ let sig = secp_ctx.sign(&sighash, &secret.private_key.key);
+ spend_tx.input[input_idx].witness.push(sig.serialize_der().to_vec());
+ spend_tx.input[input_idx].witness[0].push(SigHashType::All as u8);
+ spend_tx.input[input_idx].witness.push(pubkey.key.serialize().to_vec());
+ },
+ }
+ input_idx += 1;
+ }
+ Ok(spend_tx)
+ }
}
impl KeysInterface for KeysManager {
- type ChanKeySigner = InMemoryChannelKeys;
+ type Signer = InMemorySigner;
fn get_node_secret(&self) -> SecretKey {
self.node_secret.clone()
self.shutdown_pubkey.clone()
}
- fn get_channel_keys(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::ChanKeySigner {
+ fn get_channel_signer(&self, _inbound: bool, channel_value_satoshis: u64) -> Self::Signer {
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::Signer, DecodeError> {
+ InMemorySigner::read(&mut std::io::Cursor::new(reader))
+ }
}