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// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <fuzzer/FuzzedDataProvider.h>
#include <stddef.h>
#include <stdint.h>
#include <string_view>
#include <tuple>
#include "base/strings/utf_string_conversions.h"
#include "content/browser/indexed_db/indexed_db_leveldb_coding.h"
#include "third_party/blink/public/common/indexeddb/indexeddb_key.h"
using blink::IndexedDBKey;
using blink::mojom::IDBKeyType;
// IDBKeyType has 7 possible values, so the lower 3 bits of |data| are used to
// determine the IDBKeyType to return.
IDBKeyType GetIDBKeyType(uint8_t data) {
auto enum_mask = data & 0x7;
switch (enum_mask) {
case 0:
return IDBKeyType::Invalid;
case 1:
return IDBKeyType::Array;
case 2:
return IDBKeyType::Binary;
case 3:
return IDBKeyType::String;
case 4:
return IDBKeyType::Date;
case 5:
return IDBKeyType::Number;
case 6:
return IDBKeyType::None;
case 7:
return IDBKeyType::Min;
default:
return IDBKeyType::Invalid;
}
}
// Parse |fuzzed_data| to create an IndexedDBKey. This method takes uses the
// first byte to determine the type of key to create. The remaining bytes in
// |fuzzed_data| will be consumed differently depending on the type of key.
IndexedDBKey CreateKey(FuzzedDataProvider* fuzzed_data,
size_t recursion_level = 0) {
// Avoid a stack overflow by enforcing this limit. The added buffer here is to
// allow this fuzzer to verify behavior for when the generated key is too
// deep.
if (recursion_level > IndexedDBKey::kMaximumDepth + 5) {
fuzzed_data->ConsumeRemainingBytes<uint8_t>();
}
// If there is no more data to use, return a made-up key.
if (fuzzed_data->remaining_bytes() < 1) {
return IndexedDBKey(1.0, IDBKeyType::Number);
}
auto key_type = GetIDBKeyType(fuzzed_data->ConsumeIntegral<uint8_t>());
switch (key_type) {
case IDBKeyType::Array: {
// Recursively create and add keys to |key_array| until there are no more
// bytes to consume. Then, create the final key to return with this array.
IndexedDBKey::KeyArray key_array;
while (fuzzed_data->remaining_bytes() > 0) {
key_array.push_back(CreateKey(fuzzed_data, 1 + recursion_level));
}
return IndexedDBKey(std::move(key_array));
}
// For keys of type |Binary| and |String|, consume sizeof(size_t) bytes to
// determine the maximum length of the string to create.
case IDBKeyType::Binary: {
if (fuzzed_data->remaining_bytes() < 1)
return IndexedDBKey("");
auto str_size = fuzzed_data->ConsumeIntegral<size_t>();
return IndexedDBKey(fuzzed_data->ConsumeBytesAsString(str_size));
}
case IDBKeyType::String: {
if (fuzzed_data->remaining_bytes() < 1)
return IndexedDBKey(base::UTF8ToUTF16(std::string()));
auto str_size = fuzzed_data->ConsumeIntegral<size_t>();
std::u16string data_str =
base::UTF8ToUTF16(fuzzed_data->ConsumeBytesAsString(str_size));
return IndexedDBKey(data_str);
}
case IDBKeyType::Date:
case IDBKeyType::Number: {
return IndexedDBKey(fuzzed_data->ConsumeFloatingPoint<double>(),
key_type);
}
case IDBKeyType::Invalid:
case IDBKeyType::None:
case IDBKeyType::Min:
default:
return IndexedDBKey(key_type);
}
}
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
FuzzedDataProvider fuzzed_data(data, size);
auto key = CreateKey(&fuzzed_data);
// Encoding fails if the key is invalid or if the recursion depth is too much.
// In prod, either of these cases will CHECK, but here we fail gracefully.
std::string result;
if (!content::indexed_db::MaybeEncodeIDBKey(key, &result)) {
return 0;
}
// Ensure that |result| can be decoded back into the original key.
auto decoded_key = std::make_unique<IndexedDBKey>();
auto result_str_view = std::string_view(result);
std::ignore =
content::indexed_db::DecodeIDBKey(&result_str_view, &decoded_key);
assert(decoded_key->Equals(key));
return 0;
}
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