blob: 2087187df6f1a7ee843d21121fff156f2551a0f2 [file] [log] [blame]
bigbiff7ba75002020-04-11 20:47:09 -04001/*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ANDROID_VOLD_KEYBUFFER_H
18#define ANDROID_VOLD_KEYBUFFER_H
19
20#include <cstring>
21#include <memory>
22#include <vector>
23
24namespace android {
25namespace vold {
26
27/**
28 * Variant of memset() that should never be optimized away. Borrowed from keymaster code.
29 */
30#ifdef __clang__
31#define OPTNONE __attribute__((optnone))
32#else // not __clang__
33#define OPTNONE __attribute__((optimize("O0")))
34#endif // not __clang__
35inline OPTNONE void* memset_s(void* s, int c, size_t n) {
36 if (!s)
37 return s;
38 return memset(s, c, n);
39}
40#undef OPTNONE
41
42// Allocator that delegates useful work to standard one but zeroes data before deallocating.
43class ZeroingAllocator : public std::allocator<char> {
44 public:
45 void deallocate(pointer p, size_type n)
46 {
47 memset_s(p, 0, n);
48 std::allocator<char>::deallocate(p, n);
49 }
50};
51
52// Char vector that zeroes memory when deallocating.
53using KeyBuffer = std::vector<char, ZeroingAllocator>;
54
55// Convenience methods to concatenate key buffers.
56KeyBuffer operator+(KeyBuffer&& lhs, const KeyBuffer& rhs);
57KeyBuffer operator+(KeyBuffer&& lhs, const char* rhs);
58
59} // namespace vold
60} // namespace android
61
62#endif
63