Kylin/Encrypt/mbedtls-3.4.0/library/common.h
2023-08-01 13:54:17 +08:00

168 lines
5.5 KiB
C

/**
* \file common.h
*
* \brief Utility macros for internal use in the library
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* 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 MBEDTLS_LIBRARY_COMMON_H
#define MBEDTLS_LIBRARY_COMMON_H
#include "mbedtls/build_info.h"
#include "alignment.h"
#include <assert.h>
#include <stddef.h>
#include <stdint.h>
#include <stddef.h>
/** Helper to define a function as static except when building invasive tests.
*
* If a function is only used inside its own source file and should be
* declared `static` to allow the compiler to optimize for code size,
* but that function has unit tests, define it with
* ```
* MBEDTLS_STATIC_TESTABLE int mbedtls_foo(...) { ... }
* ```
* and declare it in a header in the `library/` directory with
* ```
* #if defined(MBEDTLS_TEST_HOOKS)
* int mbedtls_foo(...);
* #endif
* ```
*/
#if defined(MBEDTLS_TEST_HOOKS)
#define MBEDTLS_STATIC_TESTABLE
#else
#define MBEDTLS_STATIC_TESTABLE static
#endif
#if defined(MBEDTLS_TEST_HOOKS)
extern void (*mbedtls_test_hook_test_fail)(const char *test, int line, const char *file);
#define MBEDTLS_TEST_HOOK_TEST_ASSERT(TEST) \
do { \
if ((!(TEST)) && ((*mbedtls_test_hook_test_fail) != NULL)) \
{ \
(*mbedtls_test_hook_test_fail)( #TEST, __LINE__, __FILE__); \
} \
} while (0)
#else
#define MBEDTLS_TEST_HOOK_TEST_ASSERT(TEST)
#endif /* defined(MBEDTLS_TEST_HOOKS) */
/** Allow library to access its structs' private members.
*
* Although structs defined in header files are publicly available,
* their members are private and should not be accessed by the user.
*/
#define MBEDTLS_ALLOW_PRIVATE_ACCESS
/** Return an offset into a buffer.
*
* This is just the addition of an offset to a pointer, except that this
* function also accepts an offset of 0 into a buffer whose pointer is null.
* (`p + n` has undefined behavior when `p` is null, even when `n == 0`.
* A null pointer is a valid buffer pointer when the size is 0, for example
* as the result of `malloc(0)` on some platforms.)
*
* \param p Pointer to a buffer of at least n bytes.
* This may be \p NULL if \p n is zero.
* \param n An offset in bytes.
* \return Pointer to offset \p n in the buffer \p p.
* Note that this is only a valid pointer if the size of the
* buffer is at least \p n + 1.
*/
static inline unsigned char *mbedtls_buffer_offset(
unsigned char *p, size_t n)
{
return p == NULL ? NULL : p + n;
}
/** Return an offset into a read-only buffer.
*
* Similar to mbedtls_buffer_offset(), but for const pointers.
*
* \param p Pointer to a buffer of at least n bytes.
* This may be \p NULL if \p n is zero.
* \param n An offset in bytes.
* \return Pointer to offset \p n in the buffer \p p.
* Note that this is only a valid pointer if the size of the
* buffer is at least \p n + 1.
*/
static inline const unsigned char *mbedtls_buffer_offset_const(
const unsigned char *p, size_t n)
{
return p == NULL ? NULL : p + n;
}
/**
* Perform a fast block XOR operation, such that
* r[i] = a[i] ^ b[i] where 0 <= i < n
*
* \param r Pointer to result (buffer of at least \p n bytes). \p r
* may be equal to either \p a or \p b, but behaviour when
* it overlaps in other ways is undefined.
* \param a Pointer to input (buffer of at least \p n bytes)
* \param b Pointer to input (buffer of at least \p n bytes)
* \param n Number of bytes to process.
*/
inline void mbedtls_xor(unsigned char *r, const unsigned char *a, const unsigned char *b, size_t n)
{
size_t i = 0;
#if defined(MBEDTLS_EFFICIENT_UNALIGNED_ACCESS)
for (; (i + 4) <= n; i += 4) {
uint32_t x = mbedtls_get_unaligned_uint32(a + i) ^ mbedtls_get_unaligned_uint32(b + i);
mbedtls_put_unaligned_uint32(r + i, x);
}
#endif
for (; i < n; i++) {
r[i] = a[i] ^ b[i];
}
}
/* Fix MSVC C99 compatible issue
* MSVC support __func__ from visual studio 2015( 1900 )
* Use MSVC predefine macro to avoid name check fail.
*/
#if (defined(_MSC_VER) && (_MSC_VER <= 1900))
#define /*no-check-names*/ __func__ __FUNCTION__
#endif
/* Define `asm` for compilers which don't define it. */
/* *INDENT-OFF* */
#ifndef asm
#define asm __asm__
#endif
/* *INDENT-ON* */
/* Always provide a static assert macro, so it can be used unconditionally.
* It will expand to nothing on some systems.
* Can be used outside functions (but don't add a trailing ';' in that case:
* the semicolon is included here to avoid triggering -Wextra-semi when
* MBEDTLS_STATIC_ASSERT() expands to nothing).
* Can't use the C11-style `defined(static_assert)` on FreeBSD, since it
* defines static_assert even with -std=c99, but then complains about it.
*/
#if defined(static_assert) && !defined(__FreeBSD__)
#define MBEDTLS_STATIC_ASSERT(expr, msg) static_assert(expr, msg);
#else
#define MBEDTLS_STATIC_ASSERT(expr, msg)
#endif
#endif /* MBEDTLS_LIBRARY_COMMON_H */