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// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <stddef.h>
#include <stdint.h>
#include "base/compiler_specific.h"
#include "base/containers/buffer_iterator.h"
#include "base/containers/span.h"
#include "base/numerics/safe_conversions.h"
#include "media/base/bit_reader.h"
#include "media/base/test_random.h"
// Entry point for LibFuzzer.
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
UNSAFE_TODO(base::BufferIterator<const uint8_t> iterator(data, size));
const uint32_t* random_seed = iterator.Object<uint32_t>();
if (!random_seed) {
return 0;
}
// Need a simple random number generator to generate the number of bits to
// read/skip in a reproducible way (given the same |data|).
media::TestRandom rnd(*random_seed);
base::span<const uint8_t> remaining =
iterator.Span<uint8_t>(iterator.total_size() - iterator.position());
media::BitReader reader(remaining);
// Read and skip through the data in |reader|.
while (reader.bits_available() > 0) {
if (rnd.Rand() & 1) {
// Read up to 64 bits. This may fail if there is not enough bits
// remaining, but it doesn't matter (testing for failures is also good).
uint64_t value;
if (!reader.ReadBits(rnd.Rand() % 64 + 1, &value)) {
break;
}
} else {
// Skip up to 128 bits. As above, this may fail.
if (!reader.SkipBits(rnd.Rand() % 128 + 1)) {
break;
}
}
}
return 0;
}
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