Document nonzero anchors in features module.

[rust-lightning] / lightning / src / ln / chan_utils.rs

diff --git a/lightning/src/ln/chan_utils.rs b/lightning/src/ln/chan_utils.rs
index 533da9772a2c8db922794546b696e4bae32a7f94..6ca5c929f1d6eccb4306a6403313fd21d0044362 100644 (file)
--- a/lightning/src/ln/chan_utils.rs
+++ b/lightning/src/ln/chan_utils.rs
@@ -8,7 +8,7 @@
 // licenses.
 
 //! Various utilities for building scripts and deriving keys related to channels. These are
-//! largely of interest for those implementing the traits on [`chain::keysinterface`] by hand.
+//! largely of interest for those implementing the traits on [`crate::sign`] by hand.
 
 use bitcoin::blockdata::script::{Script,Builder};
 use bitcoin::blockdata::opcodes;
@@ -21,6 +21,7 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::hashes::ripemd160::Hash as Ripemd160;
 use bitcoin::hash_types::{Txid, PubkeyHash};
 
+use crate::sign::EntropySource;
 use crate::ln::{PaymentHash, PaymentPreimage};
 use crate::ln::msgs::DecodeError;
 use crate::util::ser::{Readable, Writeable, Writer};
@@ -39,7 +40,7 @@ use crate::util::transaction_utils::sort_outputs;
 use crate::ln::channel::{INITIAL_COMMITMENT_NUMBER, ANCHOR_OUTPUT_VALUE_SATOSHI};
 use core::ops::Deref;
 use crate::chain;
-use crate::util::crypto::sign;
+use crate::util::crypto::{sign, sign_with_aux_rand};
 
 /// Maximum number of one-way in-flight HTLC (protocol-level value).
 pub const MAX_HTLCS: u16 = 483;
@@ -56,6 +57,15 @@ pub(crate) const MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 136;
 /// This is the maximum post-anchor value.
 pub const MAX_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 143;
 
+/// The upper bound weight of an anchor input.
+pub const ANCHOR_INPUT_WITNESS_WEIGHT: u64 = 116;
+/// The upper bound weight of an HTLC timeout input from a commitment transaction with anchor
+/// outputs.
+pub const HTLC_TIMEOUT_INPUT_ANCHOR_WITNESS_WEIGHT: u64 = 288;
+/// The upper bound weight of an HTLC success input from a commitment transaction with anchor
+/// outputs.
+pub const HTLC_SUCCESS_INPUT_ANCHOR_WITNESS_WEIGHT: u64 = 327;
+
 /// Gets the weight for an HTLC-Success transaction.
 #[inline]
 pub fn htlc_success_tx_weight(opt_anchors: bool) -> u64 {
@@ -1081,12 +1091,20 @@ impl BuiltCommitmentTransaction {
                hash_to_message!(sighash)
        }
 
-       /// Sign a transaction, either because we are counter-signing the counterparty's transaction or
-       /// because we are about to broadcast a holder transaction.
-       pub fn sign<T: secp256k1::Signing>(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) -> Signature {
+       /// Signs the counterparty's commitment transaction.
+       pub fn sign_counterparty_commitment<T: secp256k1::Signing>(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) -> Signature {
                let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis);
                sign(secp_ctx, &sighash, funding_key)
        }
+
+       /// Signs the holder commitment transaction because we are about to broadcast it.
+       pub fn sign_holder_commitment<T: secp256k1::Signing, ES: Deref>(
+               &self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64,
+               entropy_source: &ES, secp_ctx: &Secp256k1<T>
+       ) -> Signature where ES::Target: EntropySource {
+               let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis);
+               sign_with_aux_rand(secp_ctx, &sighash, funding_key, entropy_source)
+       }
 }
 
 /// This class tracks the per-transaction information needed to build a closing transaction and will
@@ -1563,7 +1581,10 @@ impl<'a> TrustedCommitmentTransaction<'a> {
        /// The returned Vec has one entry for each HTLC, and in the same order.
        ///
        /// This function is only valid in the holder commitment context, it always uses EcdsaSighashType::All.
-       pub fn get_htlc_sigs<T: secp256k1::Signing>(&self, htlc_base_key: &SecretKey, channel_parameters: &DirectedChannelTransactionParameters, secp_ctx: &Secp256k1<T>) -> Result<Vec<Signature>, ()> {
+       pub fn get_htlc_sigs<T: secp256k1::Signing, ES: Deref>(
+               &self, htlc_base_key: &SecretKey, channel_parameters: &DirectedChannelTransactionParameters,
+               entropy_source: &ES, secp_ctx: &Secp256k1<T>,
+       ) -> Result<Vec<Signature>, ()> where ES::Target: EntropySource {
                let inner = self.inner;
                let keys = &inner.keys;
                let txid = inner.built.txid;
@@ -1577,7 +1598,7 @@ impl<'a> TrustedCommitmentTransaction<'a> {
                        let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc, self.opt_anchors(), &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key);
 
                        let sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, this_htlc.amount_msat / 1000, EcdsaSighashType::All).unwrap()[..]);
-                       ret.push(sign(secp_ctx, &sighash, &holder_htlc_key));
+                       ret.push(sign_with_aux_rand(secp_ctx, &sighash, &holder_htlc_key, entropy_source));
                }
                Ok(ret)
        }
@@ -1643,7 +1664,7 @@ mod tests {
        use crate::ln::chan_utils::{get_htlc_redeemscript, get_to_countersignatory_with_anchors_redeemscript, CommitmentTransaction, TxCreationKeys, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, HTLCOutputInCommitment};
        use bitcoin::secp256k1::{PublicKey, SecretKey, Secp256k1};
        use crate::util::test_utils;
-       use crate::chain::keysinterface::{ChannelSigner, SignerProvider};
+       use crate::sign::{ChannelSigner, SignerProvider};
        use bitcoin::{Network, Txid};
        use bitcoin::hashes::Hash;
        use crate::ln::PaymentHash;