| /** |
| * \file platform_util.h |
| * |
| * \brief Common and shared functions used by multiple modules in the Mbed TLS |
| * 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_PLATFORM_UTIL_H |
| #define MBEDTLS_PLATFORM_UTIL_H |
| |
| #include "mbedtls/build_info.h" |
| |
| #include <stddef.h> |
| #if defined(MBEDTLS_HAVE_TIME_DATE) |
| #include "mbedtls/platform_time.h" |
| #include <time.h> |
| #endif /* MBEDTLS_HAVE_TIME_DATE */ |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /* Internal macros meant to be called only from within the library. */ |
| #define MBEDTLS_INTERNAL_VALIDATE_RET( cond, ret ) do { } while( 0 ) |
| #define MBEDTLS_INTERNAL_VALIDATE( cond ) do { } while( 0 ) |
| |
| /* Internal helper macros for deprecating API constants. */ |
| #if !defined(MBEDTLS_DEPRECATED_REMOVED) |
| #if defined(MBEDTLS_DEPRECATED_WARNING) |
| #define MBEDTLS_DEPRECATED __attribute__((deprecated)) |
| MBEDTLS_DEPRECATED typedef char const * mbedtls_deprecated_string_constant_t; |
| #define MBEDTLS_DEPRECATED_STRING_CONSTANT( VAL ) \ |
| ( (mbedtls_deprecated_string_constant_t) ( VAL ) ) |
| MBEDTLS_DEPRECATED typedef int mbedtls_deprecated_numeric_constant_t; |
| #define MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( VAL ) \ |
| ( (mbedtls_deprecated_numeric_constant_t) ( VAL ) ) |
| #else /* MBEDTLS_DEPRECATED_WARNING */ |
| #define MBEDTLS_DEPRECATED |
| #define MBEDTLS_DEPRECATED_STRING_CONSTANT( VAL ) VAL |
| #define MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( VAL ) VAL |
| #endif /* MBEDTLS_DEPRECATED_WARNING */ |
| #endif /* MBEDTLS_DEPRECATED_REMOVED */ |
| |
| /* Implementation of the check-return facility. |
| * See the user documentation in mbedtls_config.h. |
| * |
| * Do not use this macro directly to annotate function: instead, |
| * use one of MBEDTLS_CHECK_RETURN_CRITICAL or MBEDTLS_CHECK_RETURN_TYPICAL |
| * depending on how important it is to check the return value. |
| */ |
| #if !defined(MBEDTLS_CHECK_RETURN) |
| #if defined(__GNUC__) |
| #define MBEDTLS_CHECK_RETURN __attribute__((__warn_unused_result__)) |
| #elif defined(_MSC_VER) && _MSC_VER >= 1700 |
| #include <sal.h> |
| #define MBEDTLS_CHECK_RETURN _Check_return_ |
| #else |
| #define MBEDTLS_CHECK_RETURN |
| #endif |
| #endif |
| |
| /** Critical-failure function |
| * |
| * This macro appearing at the beginning of the declaration of a function |
| * indicates that its return value should be checked in all applications. |
| * Omitting the check is very likely to indicate a bug in the application |
| * and will result in a compile-time warning if #MBEDTLS_CHECK_RETURN |
| * is implemented for the compiler in use. |
| * |
| * \note The use of this macro is a work in progress. |
| * This macro may be added to more functions in the future. |
| * Such an extension is not considered an API break, provided that |
| * there are near-unavoidable circumstances under which the function |
| * can fail. For example, signature/MAC/AEAD verification functions, |
| * and functions that require a random generator, are considered |
| * return-check-critical. |
| */ |
| #define MBEDTLS_CHECK_RETURN_CRITICAL MBEDTLS_CHECK_RETURN |
| |
| /** Ordinary-failure function |
| * |
| * This macro appearing at the beginning of the declaration of a function |
| * indicates that its return value should be generally be checked in portable |
| * applications. Omitting the check will result in a compile-time warning if |
| * #MBEDTLS_CHECK_RETURN is implemented for the compiler in use and |
| * #MBEDTLS_CHECK_RETURN_WARNING is enabled in the compile-time configuration. |
| * |
| * You can use #MBEDTLS_IGNORE_RETURN to explicitly ignore the return value |
| * of a function that is annotated with #MBEDTLS_CHECK_RETURN. |
| * |
| * \note The use of this macro is a work in progress. |
| * This macro will be added to more functions in the future. |
| * Eventually this should appear before most functions returning |
| * an error code (as \c int in the \c mbedtls_xxx API or |
| * as ::psa_status_t in the \c psa_xxx API). |
| */ |
| #if defined(MBEDTLS_CHECK_RETURN_WARNING) |
| #define MBEDTLS_CHECK_RETURN_TYPICAL MBEDTLS_CHECK_RETURN |
| #else |
| #define MBEDTLS_CHECK_RETURN_TYPICAL |
| #endif |
| |
| /** Benign-failure function |
| * |
| * This macro appearing at the beginning of the declaration of a function |
| * indicates that it is rarely useful to check its return value. |
| * |
| * This macro has an empty expansion. It exists for documentation purposes: |
| * a #MBEDTLS_CHECK_RETURN_OPTIONAL annotation indicates that the function |
| * has been analyzed for return-check usefulness, whereas the lack of |
| * an annotation indicates that the function has not been analyzed and its |
| * return-check usefulness is unknown. |
| */ |
| #define MBEDTLS_CHECK_RETURN_OPTIONAL |
| |
| /** \def MBEDTLS_IGNORE_RETURN |
| * |
| * Call this macro with one argument, a function call, to suppress a warning |
| * from #MBEDTLS_CHECK_RETURN due to that function call. |
| */ |
| #if !defined(MBEDTLS_IGNORE_RETURN) |
| /* GCC doesn't silence the warning with just (void)(result). |
| * (void)!(result) is known to work up at least up to GCC 10, as well |
| * as with Clang and MSVC. |
| * |
| * https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Non_002dbugs.html |
| * https://stackoverflow.com/questions/40576003/ignoring-warning-wunused-result |
| * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66425#c34 |
| */ |
| #define MBEDTLS_IGNORE_RETURN(result) ( (void) !( result ) ) |
| #endif |
| |
| /** |
| * \brief Securely zeroize a buffer |
| * |
| * The function is meant to wipe the data contained in a buffer so |
| * that it can no longer be recovered even if the program memory |
| * is later compromised. Call this function on sensitive data |
| * stored on the stack before returning from a function, and on |
| * sensitive data stored on the heap before freeing the heap |
| * object. |
| * |
| * It is extremely difficult to guarantee that calls to |
| * mbedtls_platform_zeroize() are not removed by aggressive |
| * compiler optimizations in a portable way. For this reason, Mbed |
| * TLS provides the configuration option |
| * MBEDTLS_PLATFORM_ZEROIZE_ALT, which allows users to configure |
| * mbedtls_platform_zeroize() to use a suitable implementation for |
| * their platform and needs |
| * |
| * \param buf Buffer to be zeroized |
| * \param len Length of the buffer in bytes |
| * |
| */ |
| void mbedtls_platform_zeroize( void *buf, size_t len ); |
| |
| #if defined(MBEDTLS_HAVE_TIME_DATE) |
| /** |
| * \brief Platform-specific implementation of gmtime_r() |
| * |
| * The function is a thread-safe abstraction that behaves |
| * similarly to the gmtime_r() function from Unix/POSIX. |
| * |
| * Mbed TLS will try to identify the underlying platform and |
| * make use of an appropriate underlying implementation (e.g. |
| * gmtime_r() for POSIX and gmtime_s() for Windows). If this is |
| * not possible, then gmtime() will be used. In this case, calls |
| * from the library to gmtime() will be guarded by the mutex |
| * mbedtls_threading_gmtime_mutex if MBEDTLS_THREADING_C is |
| * enabled. It is recommended that calls from outside the library |
| * are also guarded by this mutex. |
| * |
| * If MBEDTLS_PLATFORM_GMTIME_R_ALT is defined, then Mbed TLS will |
| * unconditionally use the alternative implementation for |
| * mbedtls_platform_gmtime_r() supplied by the user at compile time. |
| * |
| * \param tt Pointer to an object containing time (in seconds) since the |
| * epoch to be converted |
| * \param tm_buf Pointer to an object where the results will be stored |
| * |
| * \return Pointer to an object of type struct tm on success, otherwise |
| * NULL |
| */ |
| struct tm *mbedtls_platform_gmtime_r( const mbedtls_time_t *tt, |
| struct tm *tm_buf ); |
| #endif /* MBEDTLS_HAVE_TIME_DATE */ |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* MBEDTLS_PLATFORM_UTIL_H */ |