tests: Add fuzzing harness for TorController

src/test/fuzz/torcontrol.cpp

@@ -0,0 +1,79 @@
+// Copyright (c) 2020 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 <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+#include <torcontrol.h>
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+class DummyTorControlConnection : public TorControlConnection
+{
+public:
+    DummyTorControlConnection() : TorControlConnection{nullptr}
+    {
+    }
+
+    bool Connect(const std::string&, const ConnectionCB&, const ConnectionCB&)
+    {
+        return true;
+    }
+
+    void Disconnect()
+    {
+    }
+
+    bool Command(const std::string&, const ReplyHandlerCB&)
+    {
+        return true;
+    }
+};
+
+void initialize_torcontrol()
+{
+    static const auto testing_setup = MakeNoLogFileContext<>();
+}
+
+FUZZ_TARGET_INIT(torcontrol, initialize_torcontrol)
+{
+    FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
+
+    TorController tor_controller;
+    while (fuzzed_data_provider.ConsumeBool()) {
+        TorControlReply tor_control_reply;
+        CallOneOf(
+            fuzzed_data_provider,
+            [&] {
+                tor_control_reply.code = 250;
+            },
+            [&] {
+                tor_control_reply.code = 510;
+            },
+            [&] {
+                tor_control_reply.code = fuzzed_data_provider.ConsumeIntegral<int>();
+            });
+        tor_control_reply.lines = ConsumeRandomLengthStringVector(fuzzed_data_provider);
+        if (tor_control_reply.lines.empty()) {
+            break;
+        }
+        DummyTorControlConnection dummy_tor_control_connection;
+        CallOneOf(
+            fuzzed_data_provider,
+            [&] {
+                tor_controller.add_onion_cb(dummy_tor_control_connection, tor_control_reply);
+            },
+            [&] {
+                tor_controller.auth_cb(dummy_tor_control_connection, tor_control_reply);
+            },
+            [&] {
+                tor_controller.authchallenge_cb(dummy_tor_control_connection, tor_control_reply);
+            },
+            [&] {
+                tor_controller.protocolinfo_cb(dummy_tor_control_connection, tor_control_reply);
+            });
+    }
+}