2 * \file platform_util.h
4 * \brief Common and shared functions used by multiple modules in the Mbed TLS
8 * Copyright (C) 2018, Arm Limited, All Rights Reserved
9 * SPDX-License-Identifier: Apache-2.0
11 * Licensed under the Apache License, Version 2.0 (the "License"); you may
12 * not use this file except in compliance with the License.
13 * You may obtain a copy of the License at
15 * http://www.apache.org/licenses/LICENSE-2.0
17 * Unless required by applicable law or agreed to in writing, software
18 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
19 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20 * See the License for the specific language governing permissions and
21 * limitations under the License.
23 * This file is part of Mbed TLS (https://tls.mbed.org)
25 #ifndef MBEDTLS_PLATFORM_UTIL_H
26 #define MBEDTLS_PLATFORM_UTIL_H
28 #if !defined(MBEDTLS_CONFIG_FILE)
31 #include MBEDTLS_CONFIG_FILE
35 #if defined(MBEDTLS_HAVE_TIME_DATE)
36 #include "platform_time.h"
38 #endif /* MBEDTLS_HAVE_TIME_DATE */
44 #if defined(MBEDTLS_CHECK_PARAMS)
46 #if defined(MBEDTLS_PARAM_FAILED)
47 /** An alternative definition of MBEDTLS_PARAM_FAILED has been set in config.h.
49 * This flag can be used to check whether it is safe to assume that
50 * MBEDTLS_PARAM_FAILED() will expand to a call to mbedtls_param_failed().
52 #define MBEDTLS_PARAM_FAILED_ALT
53 #else /* MBEDTLS_PARAM_FAILED */
54 #define MBEDTLS_PARAM_FAILED( cond ) \
55 mbedtls_param_failed( #cond, __FILE__, __LINE__ )
58 * \brief User supplied callback function for parameter validation failure.
59 * See #MBEDTLS_CHECK_PARAMS for context.
61 * This function will be called unless an alternative treatement
62 * is defined through the #MBEDTLS_PARAM_FAILED macro.
64 * This function can return, and the operation will be aborted, or
65 * alternatively, through use of setjmp()/longjmp() can resume
66 * execution in the application code.
68 * \param failure_condition The assertion that didn't hold.
69 * \param file The file where the assertion failed.
70 * \param line The line in the file where the assertion failed.
72 void mbedtls_param_failed( const char *failure_condition,
75 #endif /* MBEDTLS_PARAM_FAILED */
77 /* Internal macro meant to be called only from within the library. */
78 #define MBEDTLS_INTERNAL_VALIDATE_RET( cond, ret ) \
82 MBEDTLS_PARAM_FAILED( cond ); \
87 /* Internal macro meant to be called only from within the library. */
88 #define MBEDTLS_INTERNAL_VALIDATE( cond ) \
92 MBEDTLS_PARAM_FAILED( cond ); \
97 #else /* MBEDTLS_CHECK_PARAMS */
99 /* Internal macros meant to be called only from within the library. */
100 #define MBEDTLS_INTERNAL_VALIDATE_RET( cond, ret ) do { } while( 0 )
101 #define MBEDTLS_INTERNAL_VALIDATE( cond ) do { } while( 0 )
103 #endif /* MBEDTLS_CHECK_PARAMS */
105 /* Internal helper macros for deprecating API constants. */
106 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
107 #if defined(MBEDTLS_DEPRECATED_WARNING)
108 /* Deliberately don't (yet) export MBEDTLS_DEPRECATED here
109 * to avoid conflict with other headers which define and use
110 * it, too. We might want to move all these definitions here at
111 * some point for uniformity. */
112 #define MBEDTLS_DEPRECATED __attribute__((deprecated))
113 MBEDTLS_DEPRECATED typedef char const * mbedtls_deprecated_string_constant_t;
114 #define MBEDTLS_DEPRECATED_STRING_CONSTANT( VAL ) \
115 ( (mbedtls_deprecated_string_constant_t) ( VAL ) )
116 MBEDTLS_DEPRECATED typedef int mbedtls_deprecated_numeric_constant_t;
117 #define MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( VAL ) \
118 ( (mbedtls_deprecated_numeric_constant_t) ( VAL ) )
119 #undef MBEDTLS_DEPRECATED
120 #else /* MBEDTLS_DEPRECATED_WARNING */
121 #define MBEDTLS_DEPRECATED_STRING_CONSTANT( VAL ) VAL
122 #define MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( VAL ) VAL
123 #endif /* MBEDTLS_DEPRECATED_WARNING */
124 #endif /* MBEDTLS_DEPRECATED_REMOVED */
127 * \brief Securely zeroize a buffer
129 * The function is meant to wipe the data contained in a buffer so
130 * that it can no longer be recovered even if the program memory
131 * is later compromised. Call this function on sensitive data
132 * stored on the stack before returning from a function, and on
133 * sensitive data stored on the heap before freeing the heap
136 * It is extremely difficult to guarantee that calls to
137 * mbedtls_platform_zeroize() are not removed by aggressive
138 * compiler optimizations in a portable way. For this reason, Mbed
139 * TLS provides the configuration option
140 * MBEDTLS_PLATFORM_ZEROIZE_ALT, which allows users to configure
141 * mbedtls_platform_zeroize() to use a suitable implementation for
142 * their platform and needs
144 * \param buf Buffer to be zeroized
145 * \param len Length of the buffer in bytes
148 void mbedtls_platform_zeroize( void *buf, size_t len );
150 #if defined(MBEDTLS_HAVE_TIME_DATE)
152 * \brief Platform-specific implementation of gmtime_r()
154 * The function is a thread-safe abstraction that behaves
155 * similarly to the gmtime_r() function from Unix/POSIX.
157 * Mbed TLS will try to identify the underlying platform and
158 * make use of an appropriate underlying implementation (e.g.
159 * gmtime_r() for POSIX and gmtime_s() for Windows). If this is
160 * not possible, then gmtime() will be used. In this case, calls
161 * from the library to gmtime() will be guarded by the mutex
162 * mbedtls_threading_gmtime_mutex if MBEDTLS_THREADING_C is
163 * enabled. It is recommended that calls from outside the library
164 * are also guarded by this mutex.
166 * If MBEDTLS_PLATFORM_GMTIME_R_ALT is defined, then Mbed TLS will
167 * unconditionally use the alternative implementation for
168 * mbedtls_platform_gmtime_r() supplied by the user at compile time.
170 * \param tt Pointer to an object containing time (in seconds) since the
171 * epoch to be converted
172 * \param tm_buf Pointer to an object where the results will be stored
174 * \return Pointer to an object of type struct tm on success, otherwise
177 struct tm *mbedtls_platform_gmtime_r( const mbedtls_time_t *tt,
179 #endif /* MBEDTLS_HAVE_TIME_DATE */
185 #endif /* MBEDTLS_PLATFORM_UTIL_H */