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Diffstat (limited to 'crypto/ext4crypt/KeyBuffer.h')
-rw-r--r-- | crypto/ext4crypt/KeyBuffer.h | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/crypto/ext4crypt/KeyBuffer.h b/crypto/ext4crypt/KeyBuffer.h new file mode 100644 index 000000000..2087187df --- /dev/null +++ b/crypto/ext4crypt/KeyBuffer.h @@ -0,0 +1,63 @@ +/* + * 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 + |