1 /* 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 24 namespace android { 25 namespace 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__ 35 inline 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. 43 class 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. 53 using KeyBuffer = std::vector<char, ZeroingAllocator>; 54 55 // Convenience methods to concatenate key buffers. 56 KeyBuffer operator+(KeyBuffer&& lhs, const KeyBuffer& rhs); 57 KeyBuffer operator+(KeyBuffer&& lhs, const char* rhs); 58 59 } // namespace vold 60 } // namespace android 61 62 #endif 63 64
