X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fkeysinterface.rs;h=05e24d8c1b220556c2d43e57aa566a6670a302ef;hb=d77e40fa76d7f6f9ab5c5ae91d686ac8b8226b3f;hp=654ba71ef7d644245f3604ded5ab6975e94282bf;hpb=06445b61893ab74ec09765a10c091415e877a82c;p=rust-lightning diff --git a/lightning/src/chain/keysinterface.rs b/lightning/src/chain/keysinterface.rs index 654ba71e..05e24d8c 100644 --- a/lightning/src/chain/keysinterface.rs +++ b/lightning/src/chain/keysinterface.rs @@ -54,19 +54,30 @@ pub enum SpendableOutputDescriptor { /// (MINIMALIF standard rule) /// /// Note that the nSequence field in the spending input must be set to to_self_delay - /// (which means the transaction not being broadcastable until at least 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). /// - /// WitnessScript may be regenerated by passing the revocation_pubkey, to_self_delay and - /// delayed_payment_pubkey to chan_utils::get_revokeable_redeemscript. + /// 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 delayed_payment key corresponding to the channel state, you must pass the - /// channel's delayed_payment_key and the provided per_commitment_point to - /// chan_utils::derive_private_key. The resulting key should be used to sign the spending - /// transaction. + /// 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, @@ -83,20 +94,14 @@ pub enum SpendableOutputDescriptor { /// The remote_revocation_pubkey used to derive witnessScript remote_revocation_pubkey: PublicKey }, - // TODO: Note that because key is now static and exactly what is provided by us, we should drop - // this in favor of StaticOutput: - /// 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. - /// - /// To derive the payment key corresponding to the channel state, you must pass the - /// channel's payment_base_key and the provided per_commitment_point to - /// chan_utils::derive_private_key. The resulting key should be used to sign the spending - /// transaction. - DynamicOutputP2WPKH { + StaticOutputRemotePayment { /// The outpoint which is spendable outpoint: OutPoint, /// The output which is reference by the given outpoint @@ -125,7 +130,7 @@ impl Writeable for SpendableOutputDescriptor { key_derivation_params.1.write(writer)?; remote_revocation_pubkey.write(writer)?; }, - &SpendableOutputDescriptor::DynamicOutputP2WPKH { ref outpoint, ref output, ref key_derivation_params } => { + &SpendableOutputDescriptor::StaticOutputRemotePayment { ref outpoint, ref output, ref key_derivation_params } => { 2u8.write(writer)?; outpoint.write(writer)?; output.write(writer)?; @@ -152,7 +157,7 @@ impl Readable for SpendableOutputDescriptor { 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)?, output: Readable::read(reader)?, key_derivation_params: (Readable::read(reader)?, Readable::read(reader)?), @@ -162,28 +167,6 @@ impl Readable for SpendableOutputDescriptor { } } -/// 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, @@ -212,16 +195,6 @@ pub trait KeysInterface: Send + Sync { // 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 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 fn htlc_base_key<'a>(&'a self) -> &'a SecretKey; /// Gets the commitment seed @@ -272,47 +245,47 @@ pub trait ChannelKeys : Send+Clone { /// 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 a transaction spending an HTLC or commitment transaction output - /// when our counterparty broadcast an old state. + /// Create a signature for the given input in a transaction spending an HTLC or commitment + /// transaction output when our counterparty broadcasts an old state. /// - /// Justice transaction may claim multiples outputs at same time if timelock are similar. + /// 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. /// - /// Input index is a pointer towards outpoint spent, commited by sigs (BIP 143). - /// - /// Amount is value of the output spent by this input, committed by sigs (BIP 143). + /// Amount is value of the output spent by this input, committed to in the BIP 143 signature. /// - /// Per_commitment key is revocation secret such as provided by remote party while - /// revocating detected onchain transaction. It's not a _local_ secret key, therefore - /// it may cross interfaces, a node compromise won't allow to spend revoked output without - /// also compromissing revocation key. + /// 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 output spent is a HTLC one, committed as - /// part of witnessScript by sigs (BIP 143). + /// 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 challenge if output spent is on remote - /// balance or 2nd-stage HTLC transactions, committed as part of witnessScript by sigs - /// (BIP 143). + /// 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 claiming transaction for a HTLC output on a remote commitment /// transaction, either offered or received. /// - /// HTLC transaction may claim multiples offered outputs at same time if we know preimage - /// for each at detection. It may be called multtiples time for same output(s) if a fee-bump - /// is needed with regards to an upcoming timelock expiration. + /// 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. /// - /// Input index is a pointer towards outpoint spent, commited by sigs (BIP 143). - /// - /// Amount is value of the output spent by this input, committed by sigs (BIP 143). + /// 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 remote party and is used to derive - /// channel state keys, committed as part of witnessScript by sigs (BIP 143). + /// 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. @@ -336,21 +309,43 @@ 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 { /// Private key of anchor tx - funding_key: SecretKey, + pub funding_key: SecretKey, /// Local secret key for blinded revocation pubkey - revocation_base_key: SecretKey, + pub revocation_base_key: SecretKey, /// Local secret key used for our balance in remote-broadcasted commitment transactions - payment_key: SecretKey, + pub payment_key: SecretKey, /// Local secret key used in HTLC tx - delayed_payment_base_key: SecretKey, + pub delayed_payment_base_key: SecretKey, /// Local htlc secret key used in commitment tx htlc outputs - htlc_base_key: SecretKey, + pub htlc_base_key: SecretKey, /// Commitment seed - commitment_seed: [u8; 32], + pub commitment_seed: [u8; 32], /// Local public keys and basepoints pub(crate) local_channel_pubkeys: ChannelPublicKeys, /// Remote public keys and base points @@ -411,10 +406,6 @@ impl InMemoryChannelKeys { } impl ChannelKeys for InMemoryChannelKeys { - fn funding_key(&self) -> &SecretKey { &self.funding_key } - fn revocation_base_key(&self) -> &SecretKey { &self.revocation_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 } @@ -637,7 +628,7 @@ 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, 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) => {