1 use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys};
2 use chain::keysinterface::{ChannelKeys, InMemoryChannelKeys};
7 use bitcoin::blockdata::transaction::Transaction;
8 use bitcoin::blockdata::script::Script;
11 use secp256k1::key::SecretKey;
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)),
29 impl ChannelKeys for EnforcingChannelKeys {
30 fn funding_key(&self) -> &SecretKey { self.inner.funding_key() }
31 fn revocation_base_key(&self) -> &SecretKey { self.inner.revocation_base_key() }
32 fn payment_base_key(&self) -> &SecretKey { self.inner.payment_base_key() }
33 fn delayed_payment_base_key(&self) -> &SecretKey { self.inner.delayed_payment_base_key() }
34 fn htlc_base_key(&self) -> &SecretKey { self.inner.htlc_base_key() }
35 fn commitment_seed(&self) -> &[u8; 32] { self.inner.commitment_seed() }
37 fn sign_remote_commitment<T: secp256k1::Signing>(&self, channel_value_satoshis: u64, channel_funding_script: &Script, feerate_per_kw: u64, commitment_tx: &Transaction, keys: &TxCreationKeys, htlcs: &[&HTLCOutputInCommitment], to_self_delay: u16, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
38 if commitment_tx.input.len() != 1 { panic!(); }
39 let obscured_commitment_transaction_number = (commitment_tx.lock_time & 0xffffff) as u64 | ((commitment_tx.input[0].sequence as u64 & 0xffffff) << 3*8);
42 let mut commitment_data = self.commitment_number_obscure_and_last.lock().unwrap();
43 if commitment_data.0.is_none() {
44 commitment_data.0 = Some(obscured_commitment_transaction_number ^ commitment_data.1);
46 let commitment_number = obscured_commitment_transaction_number ^ commitment_data.0.unwrap();
47 assert!(commitment_number == commitment_data.1 || commitment_number == commitment_data.1 + 1);
48 commitment_data.1 = cmp::max(commitment_number, commitment_data.1)
51 Ok(self.inner.sign_remote_commitment(channel_value_satoshis, channel_funding_script, feerate_per_kw, commitment_tx, keys, htlcs, to_self_delay, secp_ctx).unwrap())
55 impl_writeable!(EnforcingChannelKeys, 0, {
57 commitment_number_obscure_and_last