/** * \file platform_util.h * * \brief Common and shared functions used by multiple modules in the Mbed TLS * library. */ /* * Copyright (C) 2018, Arm Limited, All Rights Reserved * 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. * * This file is part of Mbed TLS (https://tls.mbed.org) */ #ifndef MBEDTLS_PLATFORM_UTIL_H #define MBEDTLS_PLATFORM_UTIL_H #if !defined(MBEDTLS_CONFIG_FILE) #include "mbedtls/config.h" #else #include MBEDTLS_CONFIG_FILE #endif #include #if defined(MBEDTLS_HAVE_TIME_DATE) #include "mbedtls/platform_time.h" #include #endif /* MBEDTLS_HAVE_TIME_DATE */ #ifdef __cplusplus extern "C" { #endif #if defined(MBEDTLS_CHECK_PARAMS) #if defined(MBEDTLS_CHECK_PARAMS_ASSERT) /* Allow the user to define MBEDTLS_PARAM_FAILED to something like assert * (which is what our config.h suggests). */ #include #endif /* MBEDTLS_CHECK_PARAMS_ASSERT */ #if defined(MBEDTLS_PARAM_FAILED) /** An alternative definition of MBEDTLS_PARAM_FAILED has been set in config.h. * * This flag can be used to check whether it is safe to assume that * MBEDTLS_PARAM_FAILED() will expand to a call to mbedtls_param_failed(). */ #define MBEDTLS_PARAM_FAILED_ALT #elif defined(MBEDTLS_CHECK_PARAMS_ASSERT) #define MBEDTLS_PARAM_FAILED( cond ) assert( cond ) #define MBEDTLS_PARAM_FAILED_ALT #else /* MBEDTLS_PARAM_FAILED */ #define MBEDTLS_PARAM_FAILED( cond ) \ mbedtls_param_failed( #cond, __FILE__, __LINE__ ) /** * \brief User supplied callback function for parameter validation failure. * See #MBEDTLS_CHECK_PARAMS for context. * * This function will be called unless an alternative treatement * is defined through the #MBEDTLS_PARAM_FAILED macro. * * This function can return, and the operation will be aborted, or * alternatively, through use of setjmp()/longjmp() can resume * execution in the application code. * * \param failure_condition The assertion that didn't hold. * \param file The file where the assertion failed. * \param line The line in the file where the assertion failed. */ void mbedtls_param_failed( const char *failure_condition, const char *file, int line ); #endif /* MBEDTLS_PARAM_FAILED */ /* Internal macro meant to be called only from within the library. */ #define MBEDTLS_INTERNAL_VALIDATE_RET( cond, ret ) \ do { \ if( !(cond) ) \ { \ MBEDTLS_PARAM_FAILED( cond ); \ return( ret ); \ } \ } while( 0 ) /* Internal macro meant to be called only from within the library. */ #define MBEDTLS_INTERNAL_VALIDATE( cond ) \ do { \ if( !(cond) ) \ { \ MBEDTLS_PARAM_FAILED( cond ); \ return; \ } \ } while( 0 ) #else /* MBEDTLS_CHECK_PARAMS */ /* 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 ) #endif /* MBEDTLS_CHECK_PARAMS */ /* Internal helper macros for deprecating API constants. */ #if !defined(MBEDTLS_DEPRECATED_REMOVED) #if defined(MBEDTLS_DEPRECATED_WARNING) /* Deliberately don't (yet) export MBEDTLS_DEPRECATED here * to avoid conflict with other headers which define and use * it, too. We might want to move all these definitions here at * some point for uniformity. */ #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 ) ) #undef MBEDTLS_DEPRECATED #else /* MBEDTLS_DEPRECATED_WARNING */ #define MBEDTLS_DEPRECATED_STRING_CONSTANT( VAL ) VAL #define MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( VAL ) VAL #endif /* MBEDTLS_DEPRECATED_WARNING */ #endif /* MBEDTLS_DEPRECATED_REMOVED */ /** * \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 */