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/* Copyright 2015 OpenMarket Ltd
*
* 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.
*/
#include <cstddef>
#include <cstdint>
#include <cstring>
#include <type_traits>
namespace olm {
/** Clear the memory held in the buffer */
void unset(
void volatile * buffer, std::size_t buffer_length
);
/** Clear the memory backing an object */
template<typename T>
void unset(T & value) {
unset(reinterpret_cast<void volatile *>(&value), sizeof(T));
}
/** Check if two buffers are equal in constant time. */
bool is_equal(
std::uint8_t const * buffer_a,
std::uint8_t const * buffer_b,
std::size_t length
);
/** Check if two fixed size arrays are equals */
template<typename T>
bool array_equal(
T const & array_a,
T const & array_b
) {
static_assert(
std::is_array<T>::value
&& std::is_convertible<T, std::uint8_t *>::value
&& sizeof(T) > 0,
"Arguments to array_equal must be std::uint8_t arrays[]."
);
return is_equal(array_a, array_b, sizeof(T));
}
/** Copy into a fixed size array */
template<typename T>
std::uint8_t const * load_array(
T & destination,
std::uint8_t const * source
) {
static_assert(
std::is_array<T>::value
&& std::is_convertible<T, std::uint8_t *>::value
&& sizeof(T) > 0,
"The first argument to load_array must be a std::uint8_t array[]."
);
std::memcpy(destination, source, sizeof(T));
return source + sizeof(T);
}
/** Copy from a fixed size array */
template<typename T>
std::uint8_t * store_array(
std::uint8_t * destination,
T const & source
) {
static_assert(
std::is_array<T>::value
&& std::is_convertible<T, std::uint8_t *>::value
&& sizeof(T) > 0,
"The second argument to store_array must be a std::uint8_t array[]."
);
std::memcpy(destination, source, sizeof(T));
return destination + sizeof(T);
}
} // namespace olm
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