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/*-
* Copyright (c) 2021 Ribose Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef CRYPTO_MEM_H_
#define CRYPTO_MEM_H_
#include "config.h"
#include <array>
#include <vector>
#if defined(CRYPTO_BACKEND_BOTAN)
#include <botan/secmem.h>
#include <botan/ffi.h>
#elif defined(CRYPTO_BACKEND_OPENSSL)
#include <openssl/crypto.h>
#endif
namespace rnp {
#if defined(CRYPTO_BACKEND_BOTAN)
template <typename T> using secure_vector = Botan::secure_vector<T>;
#elif defined(CRYPTO_BACKEND_OPENSSL)
template <typename T> class ossl_allocator {
public:
static_assert(std::is_integral<T>::value, "T must be integral type");
typedef T value_type;
typedef std::size_t size_type;
ossl_allocator() noexcept = default;
ossl_allocator(const ossl_allocator &) noexcept = default;
ossl_allocator &operator=(const ossl_allocator &) noexcept = default;
~ossl_allocator() noexcept = default;
template <typename U> ossl_allocator(const ossl_allocator<U> &) noexcept
{
}
T *
allocate(std::size_t n)
{
if (!n) {
return nullptr;
}
/* attempt to use OpenSSL secure alloc */
T *ptr = static_cast<T *>(OPENSSL_secure_zalloc(n * sizeof(T)));
if (ptr) {
return ptr;
}
/* fallback to std::alloc if failed */
ptr = static_cast<T *>(std::calloc(n, sizeof(T)));
if (!ptr)
throw std::bad_alloc();
return ptr;
}
void
deallocate(T *p, std::size_t n)
{
if (!p) {
return;
}
if (CRYPTO_secure_allocated(p)) {
OPENSSL_secure_clear_free(p, n * sizeof(T));
return;
}
OPENSSL_cleanse(p, n * sizeof(T));
std::free(p);
}
};
template <typename T> using secure_vector = std::vector<T, ossl_allocator<T> >;
#else
#error Unsupported backend.
#endif
template <typename T, std::size_t N> struct secure_array {
private:
static_assert(std::is_integral<T>::value, "T must be integer type");
std::array<T, N> data_;
public:
secure_array() : data_({0})
{
}
T *
data()
{
return &data_[0];
}
std::size_t
size() const
{
return data_.size();
}
T
operator[](size_t idx) const
{
return data_[idx];
}
T &
operator[](size_t idx)
{
return data_[idx];
}
~secure_array()
{
#if defined(CRYPTO_BACKEND_BOTAN)
botan_scrub_mem(&data_[0], sizeof(data_));
#elif defined(CRYPTO_BACKEND_OPENSSL)
OPENSSL_cleanse(&data_[0], sizeof(data_));
#else
#error "Unsupported crypto backend."
#endif
}
};
typedef enum { HEX_LOWERCASE, HEX_UPPERCASE } hex_format_t;
bool hex_encode(const uint8_t *buf,
size_t buf_len,
char * hex,
size_t hex_len,
hex_format_t format = HEX_UPPERCASE);
size_t hex_decode(const char *hex, uint8_t *buf, size_t buf_len);
} // namespace rnp
void secure_clear(void *vp, size_t size);
#endif // CRYPTO_MEM_H_