X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fchain%2Fkeysinterface.rs;h=f5a919bc22528c76caa9603e10ceec6ba42abb1a;hb=ebb55ff2aae55146239ff8fecd79c02ea4c3580f;hp=f46fe7da85ffbb2898804350c162ff05ec9b8a74;hpb=d14ece4ac0d36409c306bf42f316c12d7028855b;p=rust-lightning diff --git a/lightning/src/chain/keysinterface.rs b/lightning/src/chain/keysinterface.rs index f46fe7da..f5a919bc 100644 --- a/lightning/src/chain/keysinterface.rs +++ b/lightning/src/chain/keysinterface.rs @@ -30,43 +30,56 @@ use ln::msgs; use std::sync::Arc; use std::sync::atomic::{AtomicUsize, Ordering}; -/// When on-chain outputs are created by rust-lightning an event is generated which informs the -/// user thereof. This enum describes the format of the output and provides the OutPoint. +/// 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 +/// spend on-chain. The information needed to do this is provided in this enum, including the +/// outpoint describing which txid and output index is available, the full output which exists at +/// that txid/index, and any keys or other information required to sign. pub enum SpendableOutputDescriptor { - /// Outpoint with an output to a script which was provided via KeysInterface, thus you should - /// have stored somewhere how to spend script_pubkey! - /// Outputs from a justice tx, claim tx or preimage tx + /// 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. + /// 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 { - /// The outpoint spendable by user wallet + /// The outpoint which is spendable outpoint: OutPoint, - /// The output which is referenced by the given outpoint + /// The output which is referenced by the given outpoint. output: TxOut, }, - /// Outpoint commits to a P2WSH - /// P2WSH should be spend by the following witness : - /// 0 - /// With input nSequence set to_self_delay. - /// Outputs from a HTLC-Success/Timeout tx/commitment tx + /// 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: + /// + /// + /// 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). + /// 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). DynamicOutputP2WSH { - /// Outpoint spendable by user wallet + /// The outpoint which is spendable outpoint: OutPoint, - /// local_delayedkey = delayed_payment_basepoint_secret + SHA256(per_commitment_point || delayed_payment_basepoint) OR + /// The secret key which must be used to sign the spending transaction key: SecretKey, - /// witness redeemScript encumbering output. + /// The witness redeemScript which is hashed to create the script_pubkey in the given output witness_script: Script, - /// nSequence input must commit to self_delay to satisfy script's OP_CSV + /// 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, }, - /// Outpoint commits to a P2WPKH - /// P2WPKH should be spend by the following witness : - /// - /// Outputs to_remote from a commitment tx + /// An output to a P2WPKH, spendable exclusively by the given private key. + /// 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 { - /// Outpoint spendable by user wallet + /// The outpoint which is spendable outpoint: OutPoint, - /// localkey = payment_basepoint_secret + SHA256(per_commitment_point || payment_basepoint + /// 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, @@ -148,7 +161,7 @@ pub trait ChannelKeys : Send { /// /// Note that, due to rounding, there may be one "missing" satoshi, and either party may have /// chosen to forgo their output as dust. - fn sign_closing_transaction(&self, channel_funding_redeemscript: &Script, closing_tx: &Transaction, secp_ctx: &Secp256k1) -> Result; + fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1) -> Result; /// Signs a channel announcement message with our funding key, proving it comes from one /// of the channel participants. @@ -223,11 +236,15 @@ impl ChannelKeys for InMemoryChannelKeys { Ok((commitment_sig, htlc_sigs)) } - fn sign_closing_transaction(&self, channel_funding_redeemscript: &Script, closing_tx: &Transaction, secp_ctx: &Secp256k1) -> Result { + fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1) -> Result { if closing_tx.input.len() != 1 { return Err(()); } if closing_tx.input[0].witness.len() != 0 { return Err(()); } if closing_tx.output.len() > 2 { return Err(()); } + let remote_channel_pubkeys = self.remote_channel_pubkeys.as_ref().expect("must set remote channel pubkeys before signing"); + let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key); + let channel_funding_redeemscript = make_funding_redeemscript(&funding_pubkey, &remote_channel_pubkeys.funding_pubkey); + let sighash = hash_to_message!(&bip143::SighashComponents::new(closing_tx) .sighash_all(&closing_tx.input[0], &channel_funding_redeemscript, self.channel_value_satoshis)[..]); Ok(secp_ctx.sign(&sighash, &self.funding_key))