X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Futil%2Fenforcing_trait_impls.rs;h=a4bfdf8800a398594b64f2f771fa68e28abad1c1;hb=eff8af21103e43f763cb10ae6a75c1543a2d4068;hp=728caed098f277d67ab3d958452951e593824130;hpb=f2a2fd0d48be78972ed81481c2dfbfb68ecda44e;p=rust-lightning diff --git a/lightning/src/util/enforcing_trait_impls.rs b/lightning/src/util/enforcing_trait_impls.rs index 728caed0..a4bfdf88 100644 --- a/lightning/src/util/enforcing_trait_impls.rs +++ b/lightning/src/util/enforcing_trait_impls.rs @@ -1,20 +1,57 @@ +use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys, ChannelPublicKeys, LocalCommitmentTransaction}; +use ln::{chan_utils, msgs}; use chain::keysinterface::{ChannelKeys, InMemoryChannelKeys}; -use secp256k1::key::SecretKey; +use std::cmp; +use std::sync::{Mutex, Arc}; + +use bitcoin::blockdata::transaction::Transaction; +use bitcoin::util::bip143; + +use bitcoin::secp256k1; +use bitcoin::secp256k1::key::{SecretKey, PublicKey}; +use bitcoin::secp256k1::{Secp256k1, Signature}; +use util::ser::{Writeable, Writer, Readable}; +use std::io::Error; +use ln::msgs::DecodeError; /// Enforces some rules on ChannelKeys calls. Eventually we will probably want to expose a variant /// of this which would essentially be what you'd want to run on a hardware wallet. +#[derive(Clone)] pub struct EnforcingChannelKeys { pub inner: InMemoryChannelKeys, + commitment_number_obscure_and_last: Arc, u64)>>, } impl EnforcingChannelKeys { pub fn new(inner: InMemoryChannelKeys) -> Self { Self { inner, + commitment_number_obscure_and_last: Arc::new(Mutex::new((None, 0))), } } } + +impl EnforcingChannelKeys { + fn check_keys(&self, secp_ctx: &Secp256k1, + keys: &TxCreationKeys) { + let revocation_base = PublicKey::from_secret_key(secp_ctx, &self.inner.revocation_base_key()); + let payment_base = PublicKey::from_secret_key(secp_ctx, &self.inner.payment_base_key()); + let htlc_base = PublicKey::from_secret_key(secp_ctx, &self.inner.htlc_base_key()); + + let remote_points = self.inner.remote_channel_pubkeys.as_ref().unwrap(); + + let keys_expected = TxCreationKeys::new(secp_ctx, + &keys.per_commitment_point, + &remote_points.delayed_payment_basepoint, + &remote_points.htlc_basepoint, + &revocation_base, + &payment_base, + &htlc_base).unwrap(); + if keys != &keys_expected { panic!("derived different per-tx keys") } + } +} + impl ChannelKeys for EnforcingChannelKeys { fn funding_key(&self) -> &SecretKey { self.inner.funding_key() } fn revocation_base_key(&self) -> &SecretKey { self.inner.revocation_base_key() } @@ -22,8 +59,82 @@ impl ChannelKeys for EnforcingChannelKeys { fn delayed_payment_base_key(&self) -> &SecretKey { self.inner.delayed_payment_base_key() } fn htlc_base_key(&self) -> &SecretKey { self.inner.htlc_base_key() } fn commitment_seed(&self) -> &[u8; 32] { self.inner.commitment_seed() } + fn pubkeys<'a>(&'a self) -> &'a ChannelPublicKeys { self.inner.pubkeys() } + + 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 { panic!("lightning commitment transactions have a single input"); } + self.check_keys(secp_ctx, keys); + let obscured_commitment_transaction_number = (commitment_tx.lock_time & 0xffffff) as u64 | ((commitment_tx.input[0].sequence as u64 & 0xffffff) << 3*8); + + { + let mut commitment_data = self.commitment_number_obscure_and_last.lock().unwrap(); + if commitment_data.0.is_none() { + commitment_data.0 = Some(obscured_commitment_transaction_number ^ commitment_data.1); + } + let commitment_number = obscured_commitment_transaction_number ^ commitment_data.0.unwrap(); + assert!(commitment_number == commitment_data.1 || commitment_number == commitment_data.1 + 1); + commitment_data.1 = cmp::max(commitment_number, commitment_data.1) + } + + Ok(self.inner.sign_remote_commitment(feerate_per_kw, commitment_tx, keys, htlcs, to_self_delay, secp_ctx).unwrap()) + } + + fn sign_local_commitment(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1) -> Result { + Ok(self.inner.sign_local_commitment(local_commitment_tx, secp_ctx).unwrap()) + } + + #[cfg(test)] + fn unsafe_sign_local_commitment(&self, local_commitment_tx: &LocalCommitmentTransaction, secp_ctx: &Secp256k1) -> Result { + Ok(self.inner.unsafe_sign_local_commitment(local_commitment_tx, secp_ctx).unwrap()) + } + + fn sign_local_commitment_htlc_transactions(&self, local_commitment_tx: &LocalCommitmentTransaction, local_csv: u16, secp_ctx: &Secp256k1) -> Result>, ()> { + let commitment_txid = local_commitment_tx.txid(); + + for this_htlc in local_commitment_tx.per_htlc.iter() { + if this_htlc.0.transaction_output_index.is_some() { + let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, local_commitment_tx.feerate_per_kw, local_csv, &this_htlc.0, &local_commitment_tx.local_keys.a_delayed_payment_key, &local_commitment_tx.local_keys.revocation_key); + + let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&this_htlc.0, &local_commitment_tx.local_keys); + + let sighash = hash_to_message!(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, this_htlc.0.amount_msat / 1000)[..]); + secp_ctx.verify(&sighash, this_htlc.1.as_ref().unwrap(), &local_commitment_tx.local_keys.b_htlc_key).unwrap(); + } + } + + Ok(self.inner.sign_local_commitment_htlc_transactions(local_commitment_tx, local_csv, secp_ctx).unwrap()) + } + + fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1) -> Result { + Ok(self.inner.sign_closing_transaction(closing_tx, secp_ctx).unwrap()) + } + + fn sign_channel_announcement(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1) -> Result { + self.inner.sign_channel_announcement(msg, secp_ctx) + } + + fn set_remote_channel_pubkeys(&mut self, channel_pubkeys: &ChannelPublicKeys) { + self.inner.set_remote_channel_pubkeys(channel_pubkeys) + } } -impl_writeable!(EnforcingChannelKeys, 0, { - inner -}); +impl Writeable for EnforcingChannelKeys { + fn write(&self, writer: &mut W) -> Result<(), Error> { + self.inner.write(writer)?; + let (obscure, last) = *self.commitment_number_obscure_and_last.lock().unwrap(); + obscure.write(writer)?; + last.write(writer)?; + Ok(()) + } +} + +impl Readable for EnforcingChannelKeys { + fn read(reader: &mut R) -> Result { + let inner = Readable::read(reader)?; + let obscure_and_last = Readable::read(reader)?; + Ok(EnforcingChannelKeys { + inner: inner, + commitment_number_obscure_and_last: Arc::new(Mutex::new(obscure_and_last)) + }) + } +}