diff --git a/arcanist/linter/FileNameLinter.php b/arcanist/linter/FileNameLinter.php --- a/arcanist/linter/FileNameLinter.php +++ b/arcanist/linter/FileNameLinter.php @@ -8,7 +8,7 @@ const INVALID_FILENAME_FOUND = 1; const EXCEPTIONS = array( - // None so far + "src/test/fuzz/FuzzedDataProvider.h" ); public function getInfoName() { diff --git a/arcanist/linter/IncludeGuardLinter.php b/arcanist/linter/IncludeGuardLinter.php --- a/arcanist/linter/IncludeGuardLinter.php +++ b/arcanist/linter/IncludeGuardLinter.php @@ -11,7 +11,7 @@ const INCLUDE_GUARD_INVALID = 1; const EXCEPTIONS = array( - // none yet + "src/test/fuzz/FuzzedDataProvider.h" ); public function getInfoName() { diff --git a/src/Makefile.test.include b/src/Makefile.test.include --- a/src/Makefile.test.include +++ b/src/Makefile.test.include @@ -17,6 +17,7 @@ test/fuzz/bloomfilter_deserialize \ test/fuzz/coins_deserialize \ test/fuzz/diskblockindex_deserialize \ + test/fuzz/eval_script \ test/fuzz/inv_deserialize \ test/fuzz/messageheader_deserialize \ test/fuzz/netaddr_deserialize \ @@ -59,7 +60,8 @@ FUZZ_SUITE = \ test/fuzz/fuzz.cpp \ - test/fuzz/fuzz.h + test/fuzz/fuzz.h \ + test/fuzz/FuzzedDataProvider.h FUZZ_SUITE_LD_COMMON = \ $(LIBBITCOIN_SERVER) \ @@ -337,6 +339,12 @@ test_fuzz_diskblockindex_deserialize_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) test_fuzz_diskblockindex_deserialize_LDADD = $(FUZZ_SUITE_LD_COMMON) +test_fuzz_eval_script_SOURCES = $(FUZZ_SUITE) test/fuzz/eval_script.cpp +test_fuzz_eval_script_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) +test_fuzz_eval_script_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS) +test_fuzz_eval_script_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) +test_fuzz_eval_script_LDADD = $(FUZZ_SUITE_LD_COMMON) + test_fuzz_txoutcompressor_deserialize_SOURCES = $(FUZZ_SUITE) test/fuzz/deserialize.cpp test_fuzz_txoutcompressor_deserialize_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) -DTXOUTCOMPRESSOR_DESERIALIZE=1 test_fuzz_txoutcompressor_deserialize_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS) diff --git a/src/test/fuzz/CMakeLists.txt b/src/test/fuzz/CMakeLists.txt --- a/src/test/fuzz/CMakeLists.txt +++ b/src/test/fuzz/CMakeLists.txt @@ -45,6 +45,7 @@ endfunction() add_regular_fuzz_targets( + eval_script script_flags transaction ) diff --git a/src/test/fuzz/FuzzedDataProvider.h b/src/test/fuzz/FuzzedDataProvider.h new file mode 100644 --- /dev/null +++ b/src/test/fuzz/FuzzedDataProvider.h @@ -0,0 +1,249 @@ +//===- FuzzedDataProvider.h - Utility header for fuzz targets ---*- C++ -* ===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// A single header library providing an utility class to break up an array of +// bytes. Whenever run on the same input, provides the same output, as long as +// its methods are called in the same order, with the same arguments. +//===----------------------------------------------------------------------===// + +#ifndef LLVM_FUZZER_FUZZED_DATA_PROVIDER_H_ +#define LLVM_FUZZER_FUZZED_DATA_PROVIDER_H_ + +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include + +class FuzzedDataProvider { +public: + // |data| is an array of length |size| that the FuzzedDataProvider wraps to + // provide more granular access. |data| must outlive the FuzzedDataProvider. + FuzzedDataProvider(const uint8_t *data, size_t size) + : data_ptr_(data), remaining_bytes_(size) {} + ~FuzzedDataProvider() = default; + + // Returns a std::vector containing |num_bytes| of input data. If fewer than + // |num_bytes| of data remain, returns a shorter std::vector containing all + // of the data that's left. Can be used with any byte sized type, such as + // char, uint8_t, uint8_t, etc. + template std::vector ConsumeBytes(size_t num_bytes) { + num_bytes = std::min(num_bytes, remaining_bytes_); + return ConsumeBytes(num_bytes, num_bytes); + } + + // Similar to |ConsumeBytes|, but also appends the terminator value at the + // end of the resulting vector. Useful, when a mutable null-terminated + // C-string is needed, for example. But that is a rare case. Better avoid + // it, if possible, and prefer using |ConsumeBytes| or + // |ConsumeBytesAsString| methods. + template + std::vector ConsumeBytesWithTerminator(size_t num_bytes, + T terminator = 0) { + num_bytes = std::min(num_bytes, remaining_bytes_); + std::vector result = ConsumeBytes(num_bytes + 1, num_bytes); + result.back() = terminator; + return result; + } + + // Returns a std::string containing |num_bytes| of input data. Using this + // and + // |.c_str()| on the resulting string is the best way to get an immutable + // null-terminated C string. If fewer than |num_bytes| of data remain, + // returns a shorter std::string containing all of the data that's left. + std::string ConsumeBytesAsString(size_t num_bytes) { + static_assert( + sizeof(std::string::value_type) == sizeof(uint8_t), + "ConsumeBytesAsString cannot convert the data to a string."); + + num_bytes = std::min(num_bytes, remaining_bytes_); + std::string result( + reinterpret_cast(data_ptr_), + num_bytes); + Advance(num_bytes); + return result; + } + + // Returns a number in the range [min, max] by consuming bytes from the + // input data. The value might not be uniformly distributed in the given + // range. If there's no input data left, always returns |min|. |min| must + // be less than or equal to |max|. + template T ConsumeIntegralInRange(T min, T max) { + static_assert(std::is_integral::value, + "An integral type is required."); + static_assert(sizeof(T) <= sizeof(uint64_t), + "Unsupported integral type."); + + if (min > max) abort(); + + // Use the biggest type possible to hold the range and the result. + uint64_t range = static_cast(max) - min; + uint64_t result = 0; + size_t offset = 0; + + while (offset < sizeof(T) * CHAR_BIT && (range >> offset) > 0 && + remaining_bytes_ != 0) { + // Pull bytes off the end of the seed data. Experimentally, this + // seems to allow the fuzzer to more easily explore the input space. + // This makes sense, since it works by modifying inputs that caused + // new code to run, and this data is often used to encode length of + // data read by |ConsumeBytes|. Separating out read lengths makes it + // easier modify the contents of the data that is actually read. + --remaining_bytes_; + result = (result << CHAR_BIT) | data_ptr_[remaining_bytes_]; + offset += CHAR_BIT; + } + + // Avoid division by 0, in case |range + 1| results in overflow. + if (range != std::numeric_limits::max()) + result = result % (range + 1); + + return static_cast(min + result); + } + + // Returns a std::string of length from 0 to |max_length|. When it runs out + // of input data, returns what remains of the input. Designed to be more + // stable with respect to a fuzzer inserting characters than just picking a + // random length and then consuming that many bytes with |ConsumeBytes|. + std::string ConsumeRandomLengthString(size_t max_length) { + // Reads bytes from the start of |data_ptr_|. Maps "\\" to "\", and maps + // "\" followed by anything else to the end of the string. As a result + // of this logic, a fuzzer can insert characters into the string, and + // the string will be lengthened to include those new characters, + // resulting in a more stable fuzzer than picking the length of a string + // independently from picking its contents. + std::string result; + + // Reserve the anticipated capaticity to prevent several reallocations. + result.reserve(std::min(max_length, remaining_bytes_)); + for (size_t i = 0; i < max_length && remaining_bytes_ != 0; ++i) { + char next = ConvertUnsignedToSigned(data_ptr_[0]); + Advance(1); + if (next == '\\' && remaining_bytes_ != 0) { + next = ConvertUnsignedToSigned(data_ptr_[0]); + Advance(1); + if (next != '\\') break; + } + result += next; + } + + result.shrink_to_fit(); + return result; + } + + // Returns a std::vector containing all remaining bytes of the input data. + template std::vector ConsumeRemainingBytes() { + return ConsumeBytes(remaining_bytes_); + } + + // Prefer using |ConsumeRemainingBytes| unless you actually need a + // std::string object. Returns a std::vector containing all remaining bytes + // of the input data. + std::string ConsumeRemainingBytesAsString() { + return ConsumeBytesAsString(remaining_bytes_); + } + + // Returns a number in the range [Type's min, Type's max]. The value might + // not be uniformly distributed in the given range. If there's no input data + // left, always returns |min|. + template T ConsumeIntegral() { + return ConsumeIntegralInRange(std::numeric_limits::min(), + std::numeric_limits::max()); + } + + // Reads one byte and returns a bool, or false when no data remains. + bool ConsumeBool() { return 1 & ConsumeIntegral(); } + + // Returns a copy of a value selected from a fixed-size |array|. + template + T PickValueInArray(const T (&array)[size]) { + static_assert(size > 0, "The array must be non empty."); + return array[ConsumeIntegralInRange(0, size - 1)]; + } + + template + T PickValueInArray(std::initializer_list list) { + // static_assert(list.size() > 0, "The array must be non empty."); + return *(list.begin() + + ConsumeIntegralInRange(0, list.size() - 1)); + } + + // Return an enum value. The enum must start at 0 and be contiguous. It must + // also contain |kMaxValue| aliased to its largest (inclusive) value. Such + // as: enum class Foo { SomeValue, OtherValue, kMaxValue = OtherValue }; + template T ConsumeEnum() { + static_assert(std::is_enum::value, "|T| must be an enum type."); + return static_cast(ConsumeIntegralInRange( + 0, static_cast(T::kMaxValue))); + } + + // Reports the remaining bytes available for fuzzed input. + size_t remaining_bytes() { return remaining_bytes_; } + +private: + FuzzedDataProvider(const FuzzedDataProvider &) = delete; + FuzzedDataProvider &operator=(const FuzzedDataProvider &) = delete; + + void Advance(size_t num_bytes) { + if (num_bytes > remaining_bytes_) abort(); + + data_ptr_ += num_bytes; + remaining_bytes_ -= num_bytes; + } + + template + std::vector ConsumeBytes(size_t size, size_t num_bytes_to_consume) { + static_assert(sizeof(T) == sizeof(uint8_t), "Incompatible data type."); + + // The point of using the size-based constructor below is to increase + // the odds of having a vector object with capacity being equal to the + // length. That part is always implementation specific, but at least + // both libc++ and libstdc++ allocate the requested number of bytes in + // that constructor, which seems to be a natural choice for other + // implementations as well. To increase the odds even more, we also call + // |shrink_to_fit| below. + std::vector result(size); + std::memcpy(result.data(), data_ptr_, num_bytes_to_consume); + Advance(num_bytes_to_consume); + + // Even though |shrink_to_fit| is also implementation specific, we + // expect it to provide an additional assurance in case vector's + // constructor allocated a buffer which is larger than the actual amount + // of data we put inside it. + result.shrink_to_fit(); + return result; + } + + template TS ConvertUnsignedToSigned(TU value) { + static_assert(sizeof(TS) == sizeof(TU), "Incompatible data types."); + static_assert(!std::numeric_limits::is_signed, + "Source type must be unsigned."); + + // TODO(Dor1s): change to `if constexpr` once C++17 becomes mainstream. + if (std::numeric_limits::is_modulo) return static_cast(value); + + // Avoid using implementation-defined unsigned to signer conversions. + // To learn more, see https://stackoverflow.com/questions/13150449. + if (value <= std::numeric_limits::max()) + return static_cast(value); + else { + constexpr auto TS_min = std::numeric_limits::min(); + return TS_min + static_cast(value - TS_min); + } + } + + const uint8_t *data_ptr_; + size_t remaining_bytes_; +}; + +#endif // LLVM_FUZZER_FUZZED_DATA_PROVIDER_H_ diff --git a/src/test/fuzz/eval_script.cpp b/src/test/fuzz/eval_script.cpp new file mode 100644 --- /dev/null +++ b/src/test/fuzz/eval_script.cpp @@ -0,0 +1,31 @@ +// 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. + +#include