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

   1 use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys};
   2 use ln::msgs;
   3 use chain::keysinterface::{ChannelKeys, InMemoryChannelKeys};
   4
   5 use std::cmp;
   6 use std::sync::Mutex;
   7
   8 use bitcoin::blockdata::transaction::Transaction;
   9 use bitcoin::blockdata::script::Script;
  10
  11 use secp256k1;
  12 use secp256k1::key::SecretKey;
  13 use secp256k1::{Secp256k1, Signature};
  14
  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)>,
  20 }
  21
  22 impl EnforcingChannelKeys {
  23         pub fn new(inner: InMemoryChannelKeys) -> Self {
  24                 Self {
  25                         inner,
  26                         commitment_number_obscure_and_last: Mutex::new((None, 0)),
  27                 }
  28         }
  29 }
  30 impl ChannelKeys for EnforcingChannelKeys {
  31         fn funding_key(&self) -> &SecretKey { self.inner.funding_key() }
  32         fn revocation_base_key(&self) -> &SecretKey { self.inner.revocation_base_key() }
  33         fn payment_base_key(&self) -> &SecretKey { self.inner.payment_base_key() }
  34         fn delayed_payment_base_key(&self) -> &SecretKey { self.inner.delayed_payment_base_key() }
  35         fn htlc_base_key(&self) -> &SecretKey { self.inner.htlc_base_key() }
  36         fn commitment_seed(&self) -> &[u8; 32] { self.inner.commitment_seed() }
  37
  38         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>), ()> {
  39                 if commitment_tx.input.len() != 1 { panic!(); }
  40                 let obscured_commitment_transaction_number = (commitment_tx.lock_time & 0xffffff) as u64 | ((commitment_tx.input[0].sequence as u64 & 0xffffff) << 3*8);
  41
  42                 {
  43                         let mut commitment_data = self.commitment_number_obscure_and_last.lock().unwrap();
  44                         if commitment_data.0.is_none() {
  45                                 commitment_data.0 = Some(obscured_commitment_transaction_number ^ commitment_data.1);
  46                         }
  47                         let commitment_number = obscured_commitment_transaction_number ^ commitment_data.0.unwrap();
  48                         assert!(commitment_number == commitment_data.1 || commitment_number == commitment_data.1 + 1);
  49                         commitment_data.1 = cmp::max(commitment_number, commitment_data.1)
  50                 }
  51
  52                 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())
  53         }
  54
  55         fn sign_channel_announcement<T: secp256k1::Signing>(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
  56                 self.inner.sign_channel_announcement(msg, secp_ctx)
  57         }
  58 }
  59
  60 impl_writeable!(EnforcingChannelKeys, 0, {
  61         inner,
  62         commitment_number_obscure_and_last
  63 });