platform_util.h 7.3 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185
  1. /**
  2. * \file platform_util.h
  3. *
  4. * \brief Common and shared functions used by multiple modules in the Mbed TLS
  5. * library.
  6. */
  7. /*
  8. * Copyright (C) 2018, Arm Limited, All Rights Reserved
  9. * SPDX-License-Identifier: Apache-2.0
  10. *
  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
  14. *
  15. * http://www.apache.org/licenses/LICENSE-2.0
  16. *
  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.
  22. *
  23. * This file is part of Mbed TLS (https://tls.mbed.org)
  24. */
  25. #ifndef MBEDTLS_PLATFORM_UTIL_H
  26. #define MBEDTLS_PLATFORM_UTIL_H
  27. #if !defined(MBEDTLS_CONFIG_FILE)
  28. #include "mbedtls/config.h"
  29. #else
  30. #include MBEDTLS_CONFIG_FILE
  31. #endif
  32. #include <stddef.h>
  33. #if defined(MBEDTLS_HAVE_TIME_DATE)
  34. #include "mbedtls/platform_time.h"
  35. #include <time.h>
  36. #endif /* MBEDTLS_HAVE_TIME_DATE */
  37. #ifdef __cplusplus
  38. extern "C" {
  39. #endif
  40. #if defined(MBEDTLS_CHECK_PARAMS)
  41. #if defined(MBEDTLS_PARAM_FAILED)
  42. /** An alternative definition of MBEDTLS_PARAM_FAILED has been set in config.h.
  43. *
  44. * This flag can be used to check whether it is safe to assume that
  45. * MBEDTLS_PARAM_FAILED() will expand to a call to mbedtls_param_failed().
  46. */
  47. #define MBEDTLS_PARAM_FAILED_ALT
  48. #else /* MBEDTLS_PARAM_FAILED */
  49. #define MBEDTLS_PARAM_FAILED( cond ) \
  50. mbedtls_param_failed( #cond, __FILE__, __LINE__ )
  51. /**
  52. * \brief User supplied callback function for parameter validation failure.
  53. * See #MBEDTLS_CHECK_PARAMS for context.
  54. *
  55. * This function will be called unless an alternative treatement
  56. * is defined through the #MBEDTLS_PARAM_FAILED macro.
  57. *
  58. * This function can return, and the operation will be aborted, or
  59. * alternatively, through use of setjmp()/longjmp() can resume
  60. * execution in the application code.
  61. *
  62. * \param failure_condition The assertion that didn't hold.
  63. * \param file The file where the assertion failed.
  64. * \param line The line in the file where the assertion failed.
  65. */
  66. void mbedtls_param_failed( const char *failure_condition,
  67. const char *file,
  68. int line );
  69. #endif /* MBEDTLS_PARAM_FAILED */
  70. /* Internal macro meant to be called only from within the library. */
  71. #define MBEDTLS_INTERNAL_VALIDATE_RET( cond, ret ) \
  72. do { \
  73. if( !(cond) ) \
  74. { \
  75. MBEDTLS_PARAM_FAILED( cond ); \
  76. return( ret ); \
  77. } \
  78. } while( 0 )
  79. /* Internal macro meant to be called only from within the library. */
  80. #define MBEDTLS_INTERNAL_VALIDATE( cond ) \
  81. do { \
  82. if( !(cond) ) \
  83. { \
  84. MBEDTLS_PARAM_FAILED( cond ); \
  85. return; \
  86. } \
  87. } while( 0 )
  88. #else /* MBEDTLS_CHECK_PARAMS */
  89. /* Internal macros meant to be called only from within the library. */
  90. #define MBEDTLS_INTERNAL_VALIDATE_RET( cond, ret ) do { } while( 0 )
  91. #define MBEDTLS_INTERNAL_VALIDATE( cond ) do { } while( 0 )
  92. #endif /* MBEDTLS_CHECK_PARAMS */
  93. /* Internal helper macros for deprecating API constants. */
  94. #if !defined(MBEDTLS_DEPRECATED_REMOVED)
  95. #if defined(MBEDTLS_DEPRECATED_WARNING)
  96. /* Deliberately don't (yet) export MBEDTLS_DEPRECATED here
  97. * to avoid conflict with other headers which define and use
  98. * it, too. We might want to move all these definitions here at
  99. * some point for uniformity. */
  100. #define MBEDTLS_DEPRECATED __attribute__((deprecated))
  101. MBEDTLS_DEPRECATED typedef char const * mbedtls_deprecated_string_constant_t;
  102. #define MBEDTLS_DEPRECATED_STRING_CONSTANT( VAL ) \
  103. ( (mbedtls_deprecated_string_constant_t) ( VAL ) )
  104. MBEDTLS_DEPRECATED typedef int mbedtls_deprecated_numeric_constant_t;
  105. #define MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( VAL ) \
  106. ( (mbedtls_deprecated_numeric_constant_t) ( VAL ) )
  107. #undef MBEDTLS_DEPRECATED
  108. #else /* MBEDTLS_DEPRECATED_WARNING */
  109. #define MBEDTLS_DEPRECATED_STRING_CONSTANT( VAL ) VAL
  110. #define MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( VAL ) VAL
  111. #endif /* MBEDTLS_DEPRECATED_WARNING */
  112. #endif /* MBEDTLS_DEPRECATED_REMOVED */
  113. /**
  114. * \brief Securely zeroize a buffer
  115. *
  116. * The function is meant to wipe the data contained in a buffer so
  117. * that it can no longer be recovered even if the program memory
  118. * is later compromised. Call this function on sensitive data
  119. * stored on the stack before returning from a function, and on
  120. * sensitive data stored on the heap before freeing the heap
  121. * object.
  122. *
  123. * It is extremely difficult to guarantee that calls to
  124. * mbedtls_platform_zeroize() are not removed by aggressive
  125. * compiler optimizations in a portable way. For this reason, Mbed
  126. * TLS provides the configuration option
  127. * MBEDTLS_PLATFORM_ZEROIZE_ALT, which allows users to configure
  128. * mbedtls_platform_zeroize() to use a suitable implementation for
  129. * their platform and needs
  130. *
  131. * \param buf Buffer to be zeroized
  132. * \param len Length of the buffer in bytes
  133. *
  134. */
  135. void mbedtls_platform_zeroize( void *buf, size_t len );
  136. #if defined(MBEDTLS_HAVE_TIME_DATE)
  137. /**
  138. * \brief Platform-specific implementation of gmtime_r()
  139. *
  140. * The function is a thread-safe abstraction that behaves
  141. * similarly to the gmtime_r() function from Unix/POSIX.
  142. *
  143. * Mbed TLS will try to identify the underlying platform and
  144. * make use of an appropriate underlying implementation (e.g.
  145. * gmtime_r() for POSIX and gmtime_s() for Windows). If this is
  146. * not possible, then gmtime() will be used. In this case, calls
  147. * from the library to gmtime() will be guarded by the mutex
  148. * mbedtls_threading_gmtime_mutex if MBEDTLS_THREADING_C is
  149. * enabled. It is recommended that calls from outside the library
  150. * are also guarded by this mutex.
  151. *
  152. * If MBEDTLS_PLATFORM_GMTIME_R_ALT is defined, then Mbed TLS will
  153. * unconditionally use the alternative implementation for
  154. * mbedtls_platform_gmtime_r() supplied by the user at compile time.
  155. *
  156. * \param tt Pointer to an object containing time (in seconds) since the
  157. * epoch to be converted
  158. * \param tm_buf Pointer to an object where the results will be stored
  159. *
  160. * \return Pointer to an object of type struct tm on success, otherwise
  161. * NULL
  162. */
  163. struct tm *mbedtls_platform_gmtime_r( const mbedtls_time_t *tt,
  164. struct tm *tm_buf );
  165. #endif /* MBEDTLS_HAVE_TIME_DATE */
  166. #ifdef __cplusplus
  167. }
  168. #endif
  169. #endif /* MBEDTLS_PLATFORM_UTIL_H */