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

Author: practicalswift

src/Makefile.test.include

@@ -114,6 +114,7 @@ FUZZ_TARGETS = \
   test/fuzz/script_descriptor_cache \
   test/fuzz/script_deserialize \
   test/fuzz/script_flags \
+  test/fuzz/script_interpreter \
   test/fuzz/script_ops \
   test/fuzz/scriptnum_ops \
   test/fuzz/service_deserialize \
@@ -967,6 +968,12 @@ test_fuzz_script_flags_LDADD = $(FUZZ_SUITE_LD_COMMON)
 test_fuzz_script_flags_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 test_fuzz_script_flags_SOURCES = test/fuzz/script_flags.cpp
 
+test_fuzz_script_interpreter_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
+test_fuzz_script_interpreter_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
+test_fuzz_script_interpreter_LDADD = $(FUZZ_SUITE_LD_COMMON)
+test_fuzz_script_interpreter_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
+test_fuzz_script_interpreter_SOURCES = test/fuzz/script_interpreter.cpp
+
 test_fuzz_script_ops_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 test_fuzz_script_ops_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 test_fuzz_script_ops_LDADD = $(FUZZ_SUITE_LD_COMMON)

src/test/fuzz/script_interpreter.cpp

@@ -0,0 +1,41 @@
+// 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 <primitives/transaction.h>
+#include <script/interpreter.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <cstdint>
+#include <optional>
+#include <string>
+#include <vector>
+
+bool CastToBool(const std::vector<unsigned char>& vch);
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+    {
+        const CScript script_code = ConsumeScript(fuzzed_data_provider);
+        const std::optional<CMutableTransaction> mtx = ConsumeDeserializable<CMutableTransaction>(fuzzed_data_provider);
+        if (mtx) {
+            const CTransaction tx_to{*mtx};
+            const unsigned int in = fuzzed_data_provider.ConsumeIntegral<unsigned int>();
+            if (in < tx_to.vin.size()) {
+                (void)SignatureHash(script_code, tx_to, in, fuzzed_data_provider.ConsumeIntegral<int>(), ConsumeMoney(fuzzed_data_provider), fuzzed_data_provider.PickValueInArray({SigVersion::BASE, SigVersion::WITNESS_V0}), nullptr);
+                const std::optional<CMutableTransaction> mtx_precomputed = ConsumeDeserializable<CMutableTransaction>(fuzzed_data_provider);
+                if (mtx_precomputed) {
+                    const CTransaction tx_precomputed{*mtx_precomputed};
+                    const PrecomputedTransactionData precomputed_transaction_data{tx_precomputed};
+                    (void)SignatureHash(script_code, tx_to, in, fuzzed_data_provider.ConsumeIntegral<int>(), ConsumeMoney(fuzzed_data_provider), fuzzed_data_provider.PickValueInArray({SigVersion::BASE, SigVersion::WITNESS_V0}), &precomputed_transaction_data);
+                }
+            }
+        }
+    }
+    {
+        (void)CastToBool(ConsumeRandomLengthByteVector(fuzzed_data_provider));
+    }
+}