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