tests: Add fuzzing harness for functions in script/bitcoinconsensus.h

Author: practicalswift

src/Makefile.test.include

@@ -110,6 +110,7 @@ FUZZ_TARGETS = \
   test/fuzz/rbf \
   test/fuzz/rolling_bloom_filter \
   test/fuzz/script \
+  test/fuzz/script_bitcoin_consensus \
   test/fuzz/script_deserialize \
   test/fuzz/script_flags \
   test/fuzz/script_ops \
@@ -941,6 +942,12 @@ test_fuzz_script_LDADD = $(FUZZ_SUITE_LD_COMMON)
 test_fuzz_script_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 test_fuzz_script_SOURCES = test/fuzz/script.cpp
 
+test_fuzz_script_bitcoin_consensus_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
+test_fuzz_script_bitcoin_consensus_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
+test_fuzz_script_bitcoin_consensus_LDADD = $(FUZZ_SUITE_LD_COMMON)
+test_fuzz_script_bitcoin_consensus_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
+test_fuzz_script_bitcoin_consensus_SOURCES = test/fuzz/script_bitcoin_consensus.cpp
+
 test_fuzz_script_deserialize_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) -DSCRIPT_DESERIALIZE=1
 test_fuzz_script_deserialize_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 test_fuzz_script_deserialize_LDADD = $(FUZZ_SUITE_LD_COMMON)

src/test/fuzz/script_bitcoin_consensus.cpp

@@ -0,0 +1,31 @@
+// 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 <script/bitcoinconsensus.h>
+#include <script/interpreter.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+    const std::vector<uint8_t> random_bytes_1 = ConsumeRandomLengthByteVector(fuzzed_data_provider);
+    const std::vector<uint8_t> random_bytes_2 = ConsumeRandomLengthByteVector(fuzzed_data_provider);
+    const CAmount money = ConsumeMoney(fuzzed_data_provider);
+    bitcoinconsensus_error err;
+    bitcoinconsensus_error* err_p = fuzzed_data_provider.ConsumeBool() ? &err : nullptr;
+    const unsigned int n_in = fuzzed_data_provider.ConsumeIntegral<unsigned int>();
+    const unsigned int flags = fuzzed_data_provider.ConsumeIntegral<unsigned int>();
+    assert(bitcoinconsensus_version() == BITCOINCONSENSUS_API_VER);
+    if ((flags & SCRIPT_VERIFY_WITNESS) != 0 && (flags & SCRIPT_VERIFY_P2SH) == 0) {
+        return;
+    }
+    (void)bitcoinconsensus_verify_script(random_bytes_1.data(), random_bytes_1.size(), random_bytes_2.data(), random_bytes_2.size(), n_in, flags, err_p);
+    (void)bitcoinconsensus_verify_script_with_amount(random_bytes_1.data(), random_bytes_1.size(), money, random_bytes_2.data(), random_bytes_2.size(), n_in, flags, err_p);
+}