Bench test for ECDH

Author: dhruv

src/Makefile.bench.include

@@ -18,6 +18,7 @@ bench_bench_bitcoin_SOURCES = \
   bench/bench.cpp \
   bench/bench.h \
   bench/bench_bitcoin.cpp \
+  bench/bip324_ecdh.cpp \
   bench/bip324_suite.cpp \
   bench/block_assemble.cpp \
   bench/ccoins_caching.cpp \

src/bench/bip324_ecdh.cpp

@@ -0,0 +1,57 @@
+// Copyright (c) 2022 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <bench/bench.h>
+
+#include <key.h>
+#include <pubkey.h>
+#include <random.h>
+#include <secp256k1.h>
+#include <secp256k1_ellswift.h>
+
+#include <cstddef>
+
+CKey GetRandomKey()
+{
+    CKey key;
+    key.MakeNewKey(true);
+    return key;
+}
+
+int GetEll64(const CKey& key, unsigned char* ell64, secp256k1_context* ctx)
+{
+    std::array<unsigned char, 32> rnd32;
+    GetRandBytes(rnd32);
+    return secp256k1_ellswift_create(ctx, ell64, reinterpret_cast<const unsigned char*>(key.data()), rnd32.data());
+}
+
+static void BIP324_ECDH(benchmark::Bench& bench)
+{
+    ECC_Start();
+    secp256k1_context* ctx = secp256k1_context_create(SECP256K1_CONTEXT_NONE);
+    assert(ctx != nullptr);
+    assert(secp256k1_context_randomize(ctx, nullptr));
+    auto our_key = GetRandomKey();
+    auto their_key = GetRandomKey();
+
+    unsigned char our_ell64[64], their_ell64[64];
+    if (!GetEll64(our_key, our_ell64, ctx)) {
+        assert(false);
+    }
+
+    if (!GetEll64(their_key, their_ell64, ctx)) {
+        assert(false);
+    }
+
+    bench.batch(1).unit("ecdh").run([&] {
+        assert(our_key.ComputeBIP324ECDHSecret({reinterpret_cast<std::byte*>(their_ell64), 64},
+                                               {reinterpret_cast<std::byte*>(our_ell64), 64},
+                                               true)
+                   .has_value());
+    });
+    secp256k1_context_destroy(ctx);
+    ECC_Stop();
+}
+
+BENCHMARK(BIP324_ECDH, benchmark::PriorityLevel::HIGH);