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