sm2: add SM2DSA benchmarks (#1595)

Adapted from the `ecdsa` crate (perhaps we should just put them in
`signature` since they pretty much work for any signature system which
uses its traits)

Author: tarcieri

sm2/Cargo.toml

@@ -52,6 +52,11 @@ pem = ["elliptic-curve/pem", "pkcs8"]
 pkcs8 = ["elliptic-curve/pkcs8", "der"]
 serde = ["elliptic-curve/serde", "primeorder?/serde", "serdect"]
 
+[[bench]]
+name = "dsa"
+harness = false
+required-features = ["dsa"]
+
 [[bench]]
 name = "field"
 harness = false

sm2/benches/dsa.rs

@@ -0,0 +1,45 @@
+//! SM2DSA benchmarks
+
+use core::hint::black_box;
+use criterion::{
+    BenchmarkGroup, Criterion, criterion_group, criterion_main, measurement::Measurement,
+};
+use hex_literal::hex;
+use signature::{Signer, Verifier};
+use sm2::dsa::{Signature, SigningKey};
+
+const SIGNING_KEY_BYTES: [u8; 32] =
+    hex!("1cf6bc6c7f642a84994119e206c9f0753ff100709f4fd12f2338c1be60bf4175");
+
+fn signing_key() -> SigningKey {
+    SigningKey::from_bytes("", &SIGNING_KEY_BYTES.into()).unwrap()
+}
+
+fn bench_sign<M: Measurement>(group: &mut BenchmarkGroup<'_, M>) {
+    let sk = black_box(signing_key());
+    let msg = black_box(b"example message");
+    group.bench_function("sign", |b| {
+        b.iter(|| {
+            let sig: Signature = sk.sign(msg);
+            black_box(sig)
+        })
+    });
+}
+
+fn bench_verify<M: Measurement>(group: &mut BenchmarkGroup<'_, M>) {
+    let sk = black_box(signing_key());
+    let vk = black_box(sk.verifying_key());
+    let msg = black_box(b"example message");
+    let sig: Signature = black_box(sk.sign(msg));
+    group.bench_function("verify", |b| b.iter(|| vk.verify(msg, &sig)));
+}
+
+fn bench_dsa(c: &mut Criterion) {
+    let mut group = c.benchmark_group("SM2DSA");
+    bench_sign(&mut group);
+    bench_verify(&mut group);
+    group.finish();
+}
+
+criterion_group!(benches, bench_dsa);
+criterion_main!(benches);