Add fuzzing target for consensus

Signed-off-by: Konstantin Munichev <toobwn@gmail.com>

test/fuzzing/CMakeLists.txt

@@ -61,3 +61,11 @@ target_link_libraries(request_proposal_fuzz
   on_demand_ordering_service_transport_grpc
   protobuf-mutator
   )
+
+add_executable(consensus_fuzz consensus_fuzz.cpp)
+target_link_libraries(consensus_fuzz
+  gtest::gtest
+  gmock::gmock
+  yac_transport
+  protobuf-mutator
+  )

test/fuzzing/consensus_fuzz.cpp

@@ -0,0 +1,54 @@
+/**
+ * Copyright Soramitsu Co., Ltd. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <memory>
+
+#include <gtest/gtest.h>
+#include <libfuzzer/libfuzzer_macro.h>
+
+#include "consensus/yac/transport/impl/network_impl.hpp"
+#include "module/irohad/consensus/yac/yac_mocks.hpp"
+
+using namespace testing;
+
+namespace fuzzing {
+  struct ConsensusFixture {
+    std::shared_ptr<
+        NiceMock<iroha::consensus::yac::MockYacNetworkNotifications>>
+        notifications_;
+    std::shared_ptr<iroha::network::AsyncGrpcClient<google::protobuf::Empty>>
+        async_call_;
+    std::shared_ptr<iroha::consensus::yac::NetworkImpl> network_;
+
+    ConsensusFixture() {
+      spdlog::set_level(spdlog::level::critical);
+
+      notifications_ = std::make_shared<
+          NiceMock<iroha::consensus::yac::MockYacNetworkNotifications>>();
+      async_call_ = std::make_shared<
+          iroha::network::AsyncGrpcClient<google::protobuf::Empty>>();
+      network_ =
+          std::make_shared<iroha::consensus::yac::NetworkImpl>(async_call_);
+      network_->subscribe(notifications_);
+    }
+  };
+}  // namespace fuzzing
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, std::size_t size) {
+  static fuzzing::ConsensusFixture fixture;
+
+  if (size < 1) {
+    return 0;
+  }
+
+  iroha::consensus::yac::proto::State request;
+  if (protobuf_mutator::libfuzzer::LoadProtoInput(true, data, size, &request)) {
+    grpc::ServerContext context;
+    google::protobuf::Empty response;
+    fixture.network_->SendState(&context, &request, &response);
+  }
+
+  return 0;
+}