use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, HolderCommitmentTransaction, CommitmentTransaction, ChannelTransactionParameters, TrustedCommitmentTransaction};
use ln::{chan_utils, msgs};
-use chain::keysinterface::{ChannelKeys, InMemoryChannelKeys};
+use chain::keysinterface::{Sign, InMemorySigner, BaseSign};
-use std::cmp;
-use std::sync::{Mutex, Arc};
+use prelude::*;
+use core::cmp;
+use sync::{Mutex, Arc};
use bitcoin::blockdata::transaction::{Transaction, SigHashType};
use bitcoin::util::bip143;
use std::io::Error;
use ln::msgs::DecodeError;
-/// An implementation of ChannelKeys that enforces some policy checks.
+/// Initial value for revoked commitment downward counter
+pub const INITIAL_REVOKED_COMMITMENT_NUMBER: u64 = 1 << 48;
+
+/// An implementation of Sign that enforces some policy checks. The current checks
+/// are an incomplete set. They include:
+///
+/// - When signing, the holder transaction has not been revoked
+/// - When revoking, the holder transaction has not been signed
+/// - The holder commitment number is monotonic and without gaps
+/// - The counterparty commitment number is monotonic and without gaps
+/// - The pre-derived keys and pre-built transaction in CommitmentTransaction were correctly built
///
/// Eventually we will probably want to expose a variant of this which would essentially
/// be what you'd want to run on a hardware wallet.
+///
+/// Note that before we do so we should ensure its serialization format has backwards- and
+/// forwards-compatibility prefix/suffixes!
#[derive(Clone)]
-pub struct EnforcingChannelKeys {
- pub inner: InMemoryChannelKeys,
- last_commitment_number: Arc<Mutex<Option<u64>>>,
+pub struct EnforcingSigner {
+ pub inner: InMemorySigner,
+ /// The last counterparty commitment number we signed, backwards counting
+ pub last_commitment_number: Arc<Mutex<Option<u64>>>,
+ /// The last holder commitment number we revoked, backwards counting
+ pub revoked_commitment: Arc<Mutex<u64>>,
+ pub disable_revocation_policy_check: bool,
}
-impl EnforcingChannelKeys {
- pub fn new(inner: InMemoryChannelKeys) -> Self {
+impl EnforcingSigner {
+ /// Construct an EnforcingSigner
+ pub fn new(inner: InMemorySigner) -> Self {
+ Self {
+ inner,
+ last_commitment_number: Arc::new(Mutex::new(None)),
+ revoked_commitment: Arc::new(Mutex::new(INITIAL_REVOKED_COMMITMENT_NUMBER)),
+ disable_revocation_policy_check: false
+ }
+ }
+
+ /// Construct an EnforcingSigner with externally managed storage
+ ///
+ /// Since there are multiple copies of this struct for each channel, some coordination is needed
+ /// so that all copies are aware of revocations. A pointer to this state is provided here, usually
+ /// by an implementation of KeysInterface.
+ pub fn new_with_revoked(inner: InMemorySigner, revoked_commitment: Arc<Mutex<u64>>, disable_revocation_policy_check: bool) -> Self {
Self {
inner,
last_commitment_number: Arc::new(Mutex::new(None)),
+ revoked_commitment,
+ disable_revocation_policy_check
}
}
}
-impl ChannelKeys for EnforcingChannelKeys {
- fn get_per_commitment_point<T: secp256k1::Signing + secp256k1::Verification>(&self, idx: u64, secp_ctx: &Secp256k1<T>) -> PublicKey {
+impl BaseSign for EnforcingSigner {
+ fn get_per_commitment_point(&self, idx: u64, secp_ctx: &Secp256k1<secp256k1::All>) -> PublicKey {
self.inner.get_per_commitment_point(idx, secp_ctx)
}
fn release_commitment_secret(&self, idx: u64) -> [u8; 32] {
- // TODO: enforce the ChannelKeys contract - error here if we already signed this commitment
+ {
+ let mut revoked = self.revoked_commitment.lock().unwrap();
+ assert!(idx == *revoked || idx == *revoked - 1, "can only revoke the current or next unrevoked commitment - trying {}, revoked {}", idx, *revoked);
+ *revoked = idx;
+ }
self.inner.release_commitment_secret(idx)
}
fn pubkeys(&self) -> &ChannelPublicKeys { self.inner.pubkeys() }
- fn key_derivation_params(&self) -> (u64, u64) { self.inner.key_derivation_params() }
+ fn channel_keys_id(&self) -> [u8; 32] { self.inner.channel_keys_id() }
- fn sign_counterparty_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<(Signature, Vec<Signature>), ()> {
+ fn sign_counterparty_commitment(&self, commitment_tx: &CommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
self.verify_counterparty_commitment_tx(commitment_tx, secp_ctx);
{
Ok(self.inner.sign_counterparty_commitment(commitment_tx, secp_ctx).unwrap())
}
- fn sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
- self.verify_holder_commitment_tx(commitment_tx, secp_ctx);
-
- // TODO: enforce the ChannelKeys contract - error if this commitment was already revoked
- // TODO: need the commitment number
- Ok(self.inner.sign_holder_commitment(commitment_tx, secp_ctx).unwrap())
- }
-
- #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
- fn unsafe_sign_holder_commitment<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
- Ok(self.inner.unsafe_sign_holder_commitment(commitment_tx, secp_ctx).unwrap())
- }
-
- fn sign_holder_commitment_htlc_transactions<T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<T>) -> Result<Vec<Signature>, ()> {
+ fn sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
let trusted_tx = self.verify_holder_commitment_tx(commitment_tx, secp_ctx);
let commitment_txid = trusted_tx.txid();
let holder_csv = self.inner.counterparty_selected_contest_delay();
+ let revoked = self.revoked_commitment.lock().unwrap();
+ let commitment_number = trusted_tx.commitment_number();
+ if *revoked - 1 != commitment_number && *revoked - 2 != commitment_number {
+ if !self.disable_revocation_policy_check {
+ panic!("can only sign the next two unrevoked commitment numbers, revoked={} vs requested={} for {}",
+ *revoked, commitment_number, self.inner.commitment_seed[0])
+ }
+ }
+
for (this_htlc, sig) in trusted_tx.htlcs().iter().zip(&commitment_tx.counterparty_htlc_sigs) {
assert!(this_htlc.transaction_output_index.is_some());
let keys = trusted_tx.keys();
secp_ctx.verify(&sighash, sig, &keys.countersignatory_htlc_key).unwrap();
}
- Ok(self.inner.sign_holder_commitment_htlc_transactions(commitment_tx, secp_ctx).unwrap())
+ Ok(self.inner.sign_holder_commitment_and_htlcs(commitment_tx, secp_ctx).unwrap())
+ }
+
+ #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
+ fn unsafe_sign_holder_commitment_and_htlcs(&self, commitment_tx: &HolderCommitmentTransaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<(Signature, Vec<Signature>), ()> {
+ Ok(self.inner.unsafe_sign_holder_commitment_and_htlcs(commitment_tx, secp_ctx).unwrap())
+ }
+
+ fn sign_justice_revoked_output(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
+ Ok(self.inner.sign_justice_revoked_output(justice_tx, input, amount, per_commitment_key, secp_ctx).unwrap())
}
- fn sign_justice_transaction<T: secp256k1::Signing + secp256k1::Verification>(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &Option<HTLCOutputInCommitment>, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
- Ok(self.inner.sign_justice_transaction(justice_tx, input, amount, per_commitment_key, htlc, secp_ctx).unwrap())
+ fn sign_justice_revoked_htlc(&self, justice_tx: &Transaction, input: usize, amount: u64, per_commitment_key: &SecretKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
+ Ok(self.inner.sign_justice_revoked_htlc(justice_tx, input, amount, per_commitment_key, htlc, secp_ctx).unwrap())
}
- fn sign_counterparty_htlc_transaction<T: secp256k1::Signing + secp256k1::Verification>(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
+ fn sign_counterparty_htlc_transaction(&self, htlc_tx: &Transaction, input: usize, amount: u64, per_commitment_point: &PublicKey, htlc: &HTLCOutputInCommitment, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
Ok(self.inner.sign_counterparty_htlc_transaction(htlc_tx, input, amount, per_commitment_point, htlc, secp_ctx).unwrap())
}
- fn sign_closing_transaction<T: secp256k1::Signing>(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
+ fn sign_closing_transaction(&self, closing_tx: &Transaction, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
Ok(self.inner.sign_closing_transaction(closing_tx, secp_ctx).unwrap())
}
- fn sign_channel_announcement<T: secp256k1::Signing>(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<Signature, ()> {
+ fn sign_channel_announcement(&self, msg: &msgs::UnsignedChannelAnnouncement, secp_ctx: &Secp256k1<secp256k1::All>) -> Result<Signature, ()> {
self.inner.sign_channel_announcement(msg, secp_ctx)
}
}
}
+impl Sign for EnforcingSigner {}
-impl Writeable for EnforcingChannelKeys {
+impl Writeable for EnforcingSigner {
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
self.inner.write(writer)?;
let last = *self.last_commitment_number.lock().unwrap();
}
}
-impl Readable for EnforcingChannelKeys {
+impl Readable for EnforcingSigner {
fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
let inner = Readable::read(reader)?;
let last_commitment_number = Readable::read(reader)?;
- Ok(EnforcingChannelKeys {
+ Ok(EnforcingSigner {
inner,
- last_commitment_number: Arc::new(Mutex::new(last_commitment_number))
+ last_commitment_number: Arc::new(Mutex::new(last_commitment_number)),
+ revoked_commitment: Arc::new(Mutex::new(INITIAL_REVOKED_COMMITMENT_NUMBER)),
+ disable_revocation_policy_check: false,
})
}
}
-impl EnforcingChannelKeys {
+impl EnforcingSigner {
fn verify_counterparty_commitment_tx<'a, T: secp256k1::Signing + secp256k1::Verification>(&self, commitment_tx: &'a CommitmentTransaction, secp_ctx: &Secp256k1<T>) -> TrustedCommitmentTransaction<'a> {
commitment_tx.verify(&self.inner.get_channel_parameters().as_counterparty_broadcastable(),
self.inner.counterparty_pubkeys(), self.inner.pubkeys(), secp_ctx)
projects / rust-lightning / blobdiff