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

   1 use ln::chan_utils::{HTLCOutputInCommitment, TxCreationKeys, ChannelPublicKeys};
   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
  10 use secp256k1;
  11 use secp256k1::key::{SecretKey, PublicKey};
  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
  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);
  36
  37                 let remote_points = self.inner.remote_channel_pubkeys.as_ref().unwrap();
  38
  39                 let keys_expected = TxCreationKeys::new(secp_ctx,
  40                                                         &keys.per_commitment_point,
  41                                                         &remote_points.delayed_payment_basepoint,
  42                                                         &remote_points.htlc_basepoint,
  43                                                         &revocation_base,
  44                                                         &payment_base,
  45                                                         &htlc_base).unwrap();
  46                 if keys != &keys_expected { panic!("derived different per-tx keys") }
  47         }
  48 }
  49
  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() }
  57
  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);
  62
  63                 {
  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);
  67                         }
  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)
  71                 }
  72
  73                 Ok(self.inner.sign_remote_commitment(feerate_per_kw, commitment_tx, keys, htlcs, to_self_delay, secp_ctx).unwrap())
  74         }
  75
  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())
  78         }
  79
  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)
  82         }
  83
  84         fn set_remote_channel_pubkeys(&mut self, channel_pubkeys: &ChannelPublicKeys) {
  85                 self.inner.set_remote_channel_pubkeys(channel_pubkeys)
  86         }
  87 }
  88
  89
  90 impl_writeable!(EnforcingChannelKeys, 0, {
  91         inner,
  92         commitment_number_obscure_and_last
  93 });