tests: Add fuzzing harness for bloom filter class CBloomFilter

2 files changed, 119 insertions, 0 deletions

diff --git a/src/test/fuzz/bloom_filter.cpp b/src/test/fuzz/bloom_filter.cpp
new file mode 100644
index 0000000000..b78744d9df
--- /dev/null
+++ b/src/test/fuzz/bloom_filter.cpp
@@ -0,0 +1,80 @@
+// 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 <bloom.h>
+#include <optional.h>
+#include <primitives/transaction.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+#include <uint256.h>
+
+#include <cassert>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+
+    CBloomFilter bloom_filter{
+        fuzzed_data_provider.ConsumeIntegralInRange<unsigned int>(1, 10000000),
+        1.0 / fuzzed_data_provider.ConsumeIntegralInRange<unsigned int>(1, std::numeric_limits<unsigned int>::max()),
+        fuzzed_data_provider.ConsumeIntegral<unsigned int>(),
+        static_cast<unsigned char>(fuzzed_data_provider.PickValueInArray({BLOOM_UPDATE_NONE, BLOOM_UPDATE_ALL, BLOOM_UPDATE_P2PUBKEY_ONLY, BLOOM_UPDATE_MASK}))};
+    while (fuzzed_data_provider.remaining_bytes() > 0) {
+        switch (fuzzed_data_provider.ConsumeIntegralInRange(0, 6)) {
+        case 0: {
+            const std::vector<unsigned char>& b = ConsumeRandomLengthByteVector(fuzzed_data_provider);
+            (void)bloom_filter.contains(b);
+            bloom_filter.insert(b);
+            const bool present = bloom_filter.contains(b);
+            assert(present);
+            break;
+        }
+        case 1: {
+            const Optional<COutPoint> out_point = ConsumeDeserializable<COutPoint>(fuzzed_data_provider);
+            if (!out_point) {
+                break;
+            }
+            (void)bloom_filter.contains(*out_point);
+            bloom_filter.insert(*out_point);
+            const bool present = bloom_filter.contains(*out_point);
+            assert(present);
+            break;
+        }
+        case 2: {
+            const Optional<uint256> u256 = ConsumeDeserializable<uint256>(fuzzed_data_provider);
+            if (!u256) {
+                break;
+            }
+            (void)bloom_filter.contains(*u256);
+            bloom_filter.insert(*u256);
+            const bool present = bloom_filter.contains(*u256);
+            assert(present);
+            break;
+        }
+        case 3:
+            bloom_filter.clear();
+            break;
+        case 4:
+            bloom_filter.reset(fuzzed_data_provider.ConsumeIntegral<unsigned int>());
+            break;
+        case 5: {
+            const Optional<CMutableTransaction> mut_tx = ConsumeDeserializable<CMutableTransaction>(fuzzed_data_provider);
+            if (!mut_tx) {
+                break;
+            }
+            const CTransaction tx{*mut_tx};
+            (void)bloom_filter.IsRelevantAndUpdate(tx);
+            break;
+        }
+        case 6:
+            bloom_filter.UpdateEmptyFull();
+            break;
+        }
+        (void)bloom_filter.IsWithinSizeConstraints();
+    }
+}
diff --git a/src/test/fuzz/util.h b/src/test/fuzz/util.h
new file mode 100644
index 0000000000..62907c7e0b
--- /dev/null
+++ b/src/test/fuzz/util.h
@@ -0,0 +1,39 @@
+// Copyright (c) 2009-2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_TEST_FUZZ_UTIL_H
+#define BITCOIN_TEST_FUZZ_UTIL_H
+
+#include <attributes.h>
+#include <optional.h>
+#include <serialize.h>
+#include <streams.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <version.h>
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+NODISCARD inline std::vector<uint8_t> ConsumeRandomLengthByteVector(FuzzedDataProvider& fuzzed_data_provider, size_t max_length = 4096) noexcept
+{
+    const std::string s = fuzzed_data_provider.ConsumeRandomLengthString(max_length);
+    return {s.begin(), s.end()};
+}
+
+template <typename T>
+NODISCARD inline Optional<T> ConsumeDeserializable(FuzzedDataProvider& fuzzed_data_provider, size_t max_length = 4096) noexcept
+{
+    const std::vector<uint8_t>& buffer = ConsumeRandomLengthByteVector(fuzzed_data_provider, max_length);
+    CDataStream ds{buffer, SER_NETWORK, INIT_PROTO_VERSION};
+    T obj;
+    try {
+        ds >> obj;
+    } catch (const std::ios_base::failure&) {
+        return nullopt;
+    }
+    return obj;
+}
+
+#endif // BITCOIN_TEST_FUZZ_UTIL_H