schnorr signature batch verification (#2961)

* schnorr signature batch verification

* Split the fee and lock_height verification out from the batch signature verification

* Remove the new added fee_height_verify to comply with #2859

* fix: the last n could not be leaf?

chain/src/txhashset/txhashset.rs

@@ -1373,9 +1373,11 @@ impl<'a> Extension<'a> {
 
 	fn verify_kernel_signatures(&self, status: &dyn TxHashsetWriteStatus) -> Result<(), Error> {
 		let now = Instant::now();
+		const KERNEL_BATCH_SIZE: usize = 5_000;
 
 		let mut kern_count = 0;
 		let total_kernels = pmmr::n_leaves(self.kernel_pmmr.unpruned_size());
+		let mut tx_kernels: Vec<TxKernel> = Vec::with_capacity(KERNEL_BATCH_SIZE);
 		for n in 1..self.kernel_pmmr.unpruned_size() + 1 {
 			if pmmr::is_leaf(n) {
 				let kernel = self
@@ -1383,20 +1385,20 @@ impl<'a> Extension<'a> {
 					.get_data(n)
 					.ok_or::<Error>(ErrorKind::TxKernelNotFound.into())?;
 
-				kernel.verify()?;
+				tx_kernels.push(kernel.kernel);
-				kern_count += 1;
-
-				if kern_count % 20 == 0 {
-					status.on_validation(kern_count, total_kernels, 0, 0);
 			}
-				if kern_count % 1_000 == 0 {
+
+			if tx_kernels.len() >= KERNEL_BATCH_SIZE || n >= self.kernel_pmmr.unpruned_size() {
+				TxKernel::batch_sig_verify(&tx_kernels)?;
+				kern_count += tx_kernels.len() as u64;
+				tx_kernels.clear();
+				status.on_validation(kern_count, total_kernels, 0, 0);
 				debug!(
 					"txhashset: verify_kernel_signatures: verified {} signatures",
 					kern_count,
 				);
 			}
 		}
-		}
 
 		debug!(
 			"txhashset: verified {} kernel signatures, pmmr size {}, took {}s",
@@ -1411,8 +1413,8 @@ impl<'a> Extension<'a> {
 	fn verify_rangeproofs(&self, status: &dyn TxHashsetWriteStatus) -> Result<(), Error> {
 		let now = Instant::now();
 
-		let mut commits: Vec<Commitment> = vec![];
+		let mut commits: Vec<Commitment> = Vec::with_capacity(1_000);
-		let mut proofs: Vec<RangeProof> = vec![];
+		let mut proofs: Vec<RangeProof> = Vec::with_capacity(1_000);
 
 		let mut proof_count = 0;
 		let total_rproofs = pmmr::n_leaves(self.output_pmmr.unpruned_size());
@@ -1443,7 +1445,7 @@ impl<'a> Extension<'a> {
 				);
 			}
 
-			if proof_count % 20 == 0 {
+			if proof_count % 1_000 == 0 {
 				status.on_validation(0, 0, proof_count, total_rproofs);
 			}
 		}

core/src/core/transaction.rs

@@ -391,6 +391,29 @@ impl TxKernel {
 		Ok(())
 	}
 
+	/// Batch signature verification.
+	pub fn batch_sig_verify(tx_kernels: &Vec<TxKernel>) -> Result<(), Error> {
+		let len = tx_kernels.len();
+		let mut sigs: Vec<secp::Signature> = Vec::with_capacity(len);
+		let mut pubkeys: Vec<secp::key::PublicKey> = Vec::with_capacity(len);
+		let mut msgs: Vec<secp::Message> = Vec::with_capacity(len);
+
+		let secp = static_secp_instance();
+		let secp = secp.lock();
+
+		for tx_kernel in tx_kernels {
+			sigs.push(tx_kernel.excess_sig);
+			pubkeys.push(tx_kernel.excess.to_pubkey(&secp)?);
+			msgs.push(tx_kernel.msg_to_sign()?);
+		}
+
+		if !secp::aggsig::verify_batch(&secp, &sigs, &msgs, &pubkeys) {
+			return Err(Error::IncorrectSignature);
+		}
+
+		Ok(())
+	}
+
 	/// Build an empty tx kernel with zero values.
 	pub fn empty() -> TxKernel {
 		TxKernel {
@@ -861,11 +884,7 @@ impl TransactionBody {
 		};
 
 		// Verify the unverified tx kernels.
-		// No ability to batch verify these right now
+		TxKernel::batch_sig_verify(&kernels)?;
-		// so just do them individually.
-		for x in &kernels {
-			x.verify()?;
-		}
 
 		// Cache the successful verification results for the new outputs and kernels.
 		{