Merge #18455: tests: Add fuzzing harness for functions/classes in flatfile.h, merkleblock.h, random.h, serialize.h and span.h

11a520f6793e21e0a8a9301f5ec4c28a48131b85 tests: Add fuzzing harness for functions/classes in random.h (practicalswift)
64d277bbbcbd464b2a795bae011ee808298a42ca tests: Add fuzzing harness for LimitedString (serialize.h) (practicalswift)
f205cf7fef5618aaa96f016fda168eedfd9da437 tests: Add fuzzing harness for functions/classes in span.h (practicalswift)
9718f38f54357f15b8a27e060aed56f91015112d tests: Add fuzzing harness for functions/classes in merkleblock.h (practicalswift)
a16ea051f915eb4c975fe06f89470aa99d99d7e4 tests: Add fuzzing harness for functions/classes in flatfile.h (practicalswift)

Pull request description:

  * Add fuzzing harness for functions/classes in `flatfile.h`
  * Add fuzzing harness for functions/classes in `merkleblock.h`
  * Add fuzzing harness for functions/classes in `span.h`
  * Add fuzzing harness for `LimitedString` (`serialize.h`)
  * Add fuzzing harness for functions/classes in `random.h`

Top commit has no ACKs.

Tree-SHA512: 6f7e0f946f1062d51216990cde9672b4e896335152548ace3d8711e4969c3e3c8566d01d915b72adcda5c1caa9c2e34da6b7473b55a229f5b77239d3b0ba4b67

6 files changed, 171 insertions, 4 deletions

diff --git a/src/test/fuzz/flatfile.cpp b/src/test/fuzz/flatfile.cpp
new file mode 100644
index 0000000000..a55de77df7
--- /dev/null
+++ b/src/test/fuzz/flatfile.cpp
@@ -0,0 +1,30 @@
+// 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 <flatfile.h>
+#include <optional.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.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());
+    Optional<FlatFilePos> flat_file_pos = ConsumeDeserializable<FlatFilePos>(fuzzed_data_provider);
+    if (!flat_file_pos) {
+        return;
+    }
+    Optional<FlatFilePos> another_flat_file_pos = ConsumeDeserializable<FlatFilePos>(fuzzed_data_provider);
+    if (another_flat_file_pos) {
+        assert((*flat_file_pos == *another_flat_file_pos) != (*flat_file_pos != *another_flat_file_pos));
+    }
+    (void)flat_file_pos->ToString();
+    flat_file_pos->SetNull();
+    assert(flat_file_pos->IsNull());
+}
diff --git a/src/test/fuzz/merkleblock.cpp b/src/test/fuzz/merkleblock.cpp
new file mode 100644
index 0000000000..eb8fa1d421
--- /dev/null
+++ b/src/test/fuzz/merkleblock.cpp
@@ -0,0 +1,27 @@
+// 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 <merkleblock.h>
+#include <optional.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+#include <uint256.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());
+    Optional<CPartialMerkleTree> partial_merkle_tree = ConsumeDeserializable<CPartialMerkleTree>(fuzzed_data_provider);
+    if (!partial_merkle_tree) {
+        return;
+    }
+    (void)partial_merkle_tree->GetNumTransactions();
+    std::vector<uint256> matches;
+    std::vector<unsigned int> indices;
+    (void)partial_merkle_tree->ExtractMatches(matches, indices);
+}
diff --git a/src/test/fuzz/random.cpp b/src/test/fuzz/random.cpp
new file mode 100644
index 0000000000..7df6594ad6
--- /dev/null
+++ b/src/test/fuzz/random.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 <random.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <algorithm>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+    FastRandomContext fast_random_context{ConsumeUInt256(fuzzed_data_provider)};
+    (void)fast_random_context.rand64();
+    (void)fast_random_context.randbits(fuzzed_data_provider.ConsumeIntegralInRange<int>(0, 64));
+    (void)fast_random_context.randrange(fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(FastRandomContext::min() + 1, FastRandomContext::max()));
+    (void)fast_random_context.randbytes(fuzzed_data_provider.ConsumeIntegralInRange<size_t>(0, 1024));
+    (void)fast_random_context.rand32();
+    (void)fast_random_context.rand256();
+    (void)fast_random_context.randbool();
+    (void)fast_random_context();
+
+    std::vector<int64_t> integrals = ConsumeRandomLengthIntegralVector<int64_t>(fuzzed_data_provider);
+    Shuffle(integrals.begin(), integrals.end(), fast_random_context);
+    std::shuffle(integrals.begin(), integrals.end(), fast_random_context);
+}
diff --git a/src/test/fuzz/span.cpp b/src/test/fuzz/span.cpp
new file mode 100644
index 0000000000..4aea530ef2
--- /dev/null
+++ b/src/test/fuzz/span.cpp
@@ -0,0 +1,39 @@
+// 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 <span.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+
+    std::string str = fuzzed_data_provider.ConsumeBytesAsString(32);
+    const Span<const char> span = MakeSpan(str);
+    (void)span.data();
+    (void)span.begin();
+    (void)span.end();
+    if (span.size() > 0) {
+        const std::ptrdiff_t idx = fuzzed_data_provider.ConsumeIntegralInRange<std::ptrdiff_t>(0U, span.size() - 1U);
+        (void)span.first(idx);
+        (void)span.last(idx);
+        (void)span.subspan(idx);
+        (void)span.subspan(idx, span.size() - idx);
+        (void)span[idx];
+    }
+
+    std::string another_str = fuzzed_data_provider.ConsumeBytesAsString(32);
+    const Span<const char> another_span = MakeSpan(another_str);
+    assert((span <= another_span) != (span > another_span));
+    assert((span == another_span) != (span != another_span));
+    assert((span >= another_span) != (span < another_span));
+}
diff --git a/src/test/fuzz/string.cpp b/src/test/fuzz/string.cpp
index bb583885ba..3de0cf8db7 100644
--- a/src/test/fuzz/string.cpp
+++ b/src/test/fuzz/string.cpp
@@ -12,6 +12,8 @@
 #include <rpc/server.h>
 #include <rpc/util.h>
 #include <script/descriptor.h>
+#include <serialize.h>
+#include <streams.h>
 #include <test/fuzz/FuzzedDataProvider.h>
 #include <test/fuzz/fuzz.h>
 #include <test/fuzz/util.h>
@@ -24,6 +26,7 @@
 #include <util/system.h>
 #include <util/translation.h>
 #include <util/url.h>
+#include <version.h>
 
 #include <cstdint>
 #include <string>
@@ -86,4 +89,30 @@ void test_one_input(const std::vector<uint8_t>& buffer)
     (void)urlDecode(random_string_1);
     (void)ValidAsCString(random_string_1);
     (void)_(random_string_1.c_str());
+
+    {
+        CDataStream data_stream{SER_NETWORK, INIT_PROTO_VERSION};
+        std::string s;
+        LimitedString<10> limited_string = LIMITED_STRING(s, 10);
+        data_stream << random_string_1;
+        try {
+            data_stream >> limited_string;
+            assert(data_stream.empty());
+            assert(s.size() <= random_string_1.size());
+            assert(s.size() <= 10);
+            if (!random_string_1.empty()) {
+                assert(!s.empty());
+            }
+        } catch (const std::ios_base::failure&) {
+        }
+    }
+    {
+        CDataStream data_stream{SER_NETWORK, INIT_PROTO_VERSION};
+        const LimitedString<10> limited_string = LIMITED_STRING(random_string_1, 10);
+        data_stream << limited_string;
+        std::string deserialized_string;
+        data_stream >> deserialized_string;
+        assert(data_stream.empty());
+        assert(deserialized_string == random_string_1);
+    }
 }
diff --git a/src/test/fuzz/util.h b/src/test/fuzz/util.h
index 10be2ebaf7..7004aff420 100644
--- a/src/test/fuzz/util.h
+++ b/src/test/fuzz/util.h
@@ -20,13 +20,13 @@
 #include <string>
 #include <vector>
 
-NODISCARD inline std::vector<uint8_t> ConsumeRandomLengthByteVector(FuzzedDataProvider& fuzzed_data_provider, size_t max_length = 4096) noexcept
+NODISCARD inline std::vector<uint8_t> ConsumeRandomLengthByteVector(FuzzedDataProvider& fuzzed_data_provider, const size_t max_length = 4096) noexcept
 {
     const std::string s = fuzzed_data_provider.ConsumeRandomLengthString(max_length);
     return {s.begin(), s.end()};
 }
 
-NODISCARD inline std::vector<std::string> ConsumeRandomLengthStringVector(FuzzedDataProvider& fuzzed_data_provider, size_t max_vector_size = 16, size_t max_string_length = 16) noexcept
+NODISCARD inline std::vector<std::string> ConsumeRandomLengthStringVector(FuzzedDataProvider& fuzzed_data_provider, const size_t max_vector_size = 16, const size_t max_string_length = 16) noexcept
 {
     const size_t n_elements = fuzzed_data_provider.ConsumeIntegralInRange<size_t>(0, max_vector_size);
     std::vector<std::string> r;
@@ -37,7 +37,18 @@ NODISCARD inline std::vector<std::string> ConsumeRandomLengthStringVector(Fuzzed
 }
 
 template <typename T>
-NODISCARD inline Optional<T> ConsumeDeserializable(FuzzedDataProvider& fuzzed_data_provider, size_t max_length = 4096) noexcept
+NODISCARD inline std::vector<T> ConsumeRandomLengthIntegralVector(FuzzedDataProvider& fuzzed_data_provider, const size_t max_vector_size = 16) noexcept
+{
+    const size_t n_elements = fuzzed_data_provider.ConsumeIntegralInRange<size_t>(0, max_vector_size);
+    std::vector<T> r;
+    for (size_t i = 0; i < n_elements; ++i) {
+        r.push_back(fuzzed_data_provider.ConsumeIntegral<T>());
+    }
+    return r;
+}
+
+template <typename T>
+NODISCARD inline Optional<T> ConsumeDeserializable(FuzzedDataProvider& fuzzed_data_provider, const 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};
@@ -81,7 +92,7 @@ NODISCARD inline uint256 ConsumeUInt256(FuzzedDataProvider& fuzzed_data_provider
 }
 
 template <typename T>
-bool MultiplicationOverflow(T i, T j)
+NODISCARD bool MultiplicationOverflow(const T i, const T j) noexcept
 {
     static_assert(std::is_integral<T>::value, "Integral required.");
     if (std::numeric_limits<T>::is_signed) {