1 use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys, ChannelPublicKeys};
3 use chain::keysinterface::{ChannelKeys, InMemoryChannelKeys};
8 use bitcoin::blockdata::transaction::Transaction;
11 use secp256k1::key::{SecretKey, PublicKey};
12 use secp256k1::{Secp256k1, Signature};
14 /// Enforces some rules on ChannelKeys calls. Eventually we will probably want to expose a variant
15 /// of this which would essentially be what you'd want to run on a hardware wallet.
16 pub struct EnforcingChannelKeys {
17 pub inner: InMemoryChannelKeys,
18 commitment_number_obscure_and_last: Mutex<(Option<u64>, u64)>,
21 impl EnforcingChannelKeys {
22 pub fn new(inner: InMemoryChannelKeys) -> Self {
25 commitment_number_obscure_and_last: Mutex::new((None, 0)),
30 impl EnforcingChannelKeys {
31 fn check_keys<T: secp256k1::Signing + secp256k1::Verification>(&self, secp_ctx: &Secp256k1<T>,
32 keys: &TxCreationKeys) {
33 let revocation_base = PublicKey::from_secret_key(secp_ctx, &self.inner.revocation_base_key);
34 let payment_base = PublicKey::from_secret_key(secp_ctx, &self.inner.payment_base_key);
35 let htlc_base = PublicKey::from_secret_key(secp_ctx, &self.inner.htlc_base_key);
37 let remote_points = self.inner.remote_channel_pubkeys.as_ref().unwrap();
39 let keys_expected = TxCreationKeys::new(secp_ctx,
40 &keys.per_commitment_point,
41 &remote_points.delayed_payment_basepoint,
42 &remote_points.htlc_basepoint,
46 if keys != &keys_expected { panic!("derived different per-tx keys") }
50 impl ChannelKeys for EnforcingChannelKeys {
51 fn funding_key(&self) -> &SecretKey { self.inner.funding_key() }
52 fn revocation_base_key(&self) -> &SecretKey { self.inner.revocation_base_key() }
53 fn payment_base_key(&self) -> &SecretKey { self.inner.payment_base_key() }
54 fn delayed_payment_base_key(&self) -> &SecretKey { self.inner.delayed_payment_base_key() }
55 fn htlc_base_key(&self) -> &SecretKey { self.inner.htlc_base_key() }
56 fn commitment_seed(&self) -> &[u8; 32] { self.inner.commitment_seed() }
58 fn sign_remote_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, feerate_per_kw: u64, commitment_tx: &Transaction, keys: &TxCreationKeys, htlcs: &[&HTLCOutputInCommitment], to_self_delay: u16, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
59 if commitment_tx.input.len() != 1 { panic!("lightning commitment transactions have a single input"); }
60 self.check_keys(secp_ctx, keys);
61 let obscured_commitment_transaction_number = (commitment_tx.lock_time & 0xffffff) as u64 | ((commitment_tx.input[0].sequence as u64 & 0xffffff) << 3*8);
64 let mut commitment_data = self.commitment_number_obscure_and_last.lock().unwrap();
65 if commitment_data.0.is_none() {
66 commitment_data.0 = Some(obscured_commitment_transaction_number ^ commitment_data.1);
68 let commitment_number = obscured_commitment_transaction_number ^ commitment_data.0.unwrap();
69 assert!(commitment_number == commitment_data.1 || commitment_number == commitment_data.1 + 1);
70 commitment_data.1 = cmp::max(commitment_number, commitment_data.1)
73 Ok(self.inner.sign_remote_commitment(feerate_per_kw, commitment_tx, keys, htlcs, to_self_delay, secp_ctx).unwrap())
76 fn sign_closing_transaction<T: secp256k1::Signing>(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
77 Ok(self.inner.sign_closing_transaction(closing_tx, secp_ctx).unwrap())
80 fn sign_channel_announcement<T: secp256k1::Signing>(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
81 self.inner.sign_channel_announcement(msg, secp_ctx)
84 fn set_remote_channel_pubkeys(&mut self, channel_pubkeys: &ChannelPublicKeys) {
85 self.inner.set_remote_channel_pubkeys(channel_pubkeys)
90 impl_writeable!(EnforcingChannelKeys, 0, {
92 commitment_number_obscure_and_last