_ Git - rust-lightning/blob - lightning/src/util/enforcing_trait_impls.rs

   1 use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys};
   2 use chain::keysinterface::{ChannelKeys, InMemoryChannelKeys};
   3
   4 use std::cmp;
   5 use std::sync::Mutex;
   6
   7 use bitcoin::blockdata::transaction::Transaction;
   8 use bitcoin::blockdata::script::Script;
   9
  10 use secp256k1;
  11 use secp256k1::key::SecretKey;
  12 use secp256k1::{Secp256k1, Signature};
  13
  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)>,
  19 }
  20
  21 impl EnforcingChannelKeys {
  22         pub fn new(inner: InMemoryChannelKeys) -> Self {
  23                 Self {
  24                         inner,
  25                         commitment_number_obscure_and_last: Mutex::new((None, 0)),
  26                 }
  27         }
  28 }
  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() }
  36
  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);
  40
  41                 {
  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);
  45                         }
  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)
  49                 }
  50
  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())
  52         }
  53 }
  54
  55 impl_writeable!(EnforcingChannelKeys, 0, {
  56         inner,
  57         commitment_number_obscure_and_last
  58 });