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/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_VOLD_KEYBUFFER_H
#define ANDROID_VOLD_KEYBUFFER_H
#include <cstring>
#include <memory>
#include <vector>
namespace android {
namespace vold {
/**
* Variant of memset() that should never be optimized away. Borrowed from keymaster code.
*/
#ifdef __clang__
#define OPTNONE __attribute__((optnone))
#else // not __clang__
#define OPTNONE __attribute__((optimize("O0")))
#endif // not __clang__
inline OPTNONE void* memset_s(void* s, int c, size_t n) {
if (!s)
return s;
return memset(s, c, n);
}
#undef OPTNONE
// Allocator that delegates useful work to standard one but zeroes data before deallocating.
class ZeroingAllocator : public std::allocator<char> {
public:
void deallocate(pointer p, size_type n)
{
memset_s(p, 0, n);
std::allocator<char>::deallocate(p, n);
}
};
// Char vector that zeroes memory when deallocating.
using KeyBuffer = std::vector<char, ZeroingAllocator>;
// Convenience methods to concatenate key buffers.
KeyBuffer operator+(KeyBuffer&& lhs, const KeyBuffer& rhs);
KeyBuffer operator+(KeyBuffer&& lhs, const char* rhs);
} // namespace vold
} // namespace android
#endif
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