blob: 3045e693a75f9eee407538809731a00eee9d160f [file] [log] [blame]
// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/test/fuzzed_data_provider.h"
#include <algorithm>
#include <limits>
#include "base/logging.h"
namespace base {
FuzzedDataProvider::FuzzedDataProvider(const uint8_t* data, size_t size)
: remaining_data_(reinterpret_cast<const char*>(data), size) {}
FuzzedDataProvider::~FuzzedDataProvider() {}
std::string FuzzedDataProvider::ConsumeBytes(size_t num_bytes) {
num_bytes = std::min(num_bytes, remaining_data_.length());
StringPiece result(remaining_data_.data(), num_bytes);
remaining_data_ = remaining_data_.substr(num_bytes);
return result.as_string();
}
std::string FuzzedDataProvider::ConsumeRemainingBytes() {
return ConsumeBytes(remaining_data_.length());
}
uint32_t FuzzedDataProvider::ConsumeUint32InRange(uint32_t min, uint32_t max) {
CHECK_LE(min, max);
uint32_t range = max - min;
uint32_t offset = 0;
uint32_t result = 0;
while (offset < 32 && (range >> offset) > 0 && !remaining_data_.empty()) {
// 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.
uint8_t next_byte = remaining_data_.back();
remaining_data_.remove_suffix(1);
result = (result << 8) | next_byte;
offset += 8;
}
// Avoid division by 0, in the case |range + 1| results in overflow.
if (range == std::numeric_limits<uint32_t>::max())
return result;
return min + result % (range + 1);
}
int FuzzedDataProvider::ConsumeInt32InRange(int min, int max) {
CHECK_LE(min, max);
uint32_t range = max - min;
return min + ConsumeUint32InRange(0, range);
}
bool FuzzedDataProvider::ConsumeBool() {
return (ConsumeUint8() & 0x01) == 0x01;
}
uint8_t FuzzedDataProvider::ConsumeUint8() {
return ConsumeUint32InRange(0, 0xFF);
}
uint16_t FuzzedDataProvider::ConsumeUint16() {
return ConsumeUint32InRange(0, 0xFFFF);
}
} // namespace base