platform.c 11 KB

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  1. /*
  2. * Platform abstraction layer
  3. *
  4. * Copyright The Mbed TLS Contributors
  5. * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
  6. */
  7. #include "common.h"
  8. #if defined(MBEDTLS_PLATFORM_C)
  9. #include "mbedtls/platform.h"
  10. #include "mbedtls/platform_util.h"
  11. #include "mbedtls/error.h"
  12. /* The compile time configuration of memory allocation via the macros
  13. * MBEDTLS_PLATFORM_{FREE/CALLOC}_MACRO takes precedence over the runtime
  14. * configuration via mbedtls_platform_set_calloc_free(). So, omit everything
  15. * related to the latter if MBEDTLS_PLATFORM_{FREE/CALLOC}_MACRO are defined. */
  16. #if defined(MBEDTLS_PLATFORM_MEMORY) && \
  17. !(defined(MBEDTLS_PLATFORM_CALLOC_MACRO) && \
  18. defined(MBEDTLS_PLATFORM_FREE_MACRO))
  19. #if !defined(MBEDTLS_PLATFORM_STD_CALLOC)
  20. static void *platform_calloc_uninit(size_t n, size_t size)
  21. {
  22. ((void) n);
  23. ((void) size);
  24. return NULL;
  25. }
  26. #define MBEDTLS_PLATFORM_STD_CALLOC platform_calloc_uninit
  27. #endif /* !MBEDTLS_PLATFORM_STD_CALLOC */
  28. #if !defined(MBEDTLS_PLATFORM_STD_FREE)
  29. static void platform_free_uninit(void *ptr)
  30. {
  31. ((void) ptr);
  32. }
  33. #define MBEDTLS_PLATFORM_STD_FREE platform_free_uninit
  34. #endif /* !MBEDTLS_PLATFORM_STD_FREE */
  35. static void * (*mbedtls_calloc_func)(size_t, size_t) = MBEDTLS_PLATFORM_STD_CALLOC;
  36. static void (*mbedtls_free_func)(void *) = MBEDTLS_PLATFORM_STD_FREE;
  37. void *mbedtls_calloc(size_t nmemb, size_t size)
  38. {
  39. return (*mbedtls_calloc_func)(nmemb, size);
  40. }
  41. void mbedtls_free(void *ptr)
  42. {
  43. (*mbedtls_free_func)(ptr);
  44. }
  45. int mbedtls_platform_set_calloc_free(void *(*calloc_func)(size_t, size_t),
  46. void (*free_func)(void *))
  47. {
  48. mbedtls_calloc_func = calloc_func;
  49. mbedtls_free_func = free_func;
  50. return 0;
  51. }
  52. #endif /* MBEDTLS_PLATFORM_MEMORY &&
  53. !( defined(MBEDTLS_PLATFORM_CALLOC_MACRO) &&
  54. defined(MBEDTLS_PLATFORM_FREE_MACRO) ) */
  55. #if defined(MBEDTLS_PLATFORM_HAS_NON_CONFORMING_SNPRINTF)
  56. #include <stdarg.h>
  57. int mbedtls_platform_win32_snprintf(char *s, size_t n, const char *fmt, ...)
  58. {
  59. int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
  60. va_list argp;
  61. va_start(argp, fmt);
  62. ret = mbedtls_vsnprintf(s, n, fmt, argp);
  63. va_end(argp);
  64. return ret;
  65. }
  66. #endif
  67. #if defined(MBEDTLS_PLATFORM_SNPRINTF_ALT)
  68. #if !defined(MBEDTLS_PLATFORM_STD_SNPRINTF)
  69. /*
  70. * Make dummy function to prevent NULL pointer dereferences
  71. */
  72. static int platform_snprintf_uninit(char *s, size_t n,
  73. const char *format, ...)
  74. {
  75. ((void) s);
  76. ((void) n);
  77. ((void) format);
  78. return 0;
  79. }
  80. #define MBEDTLS_PLATFORM_STD_SNPRINTF platform_snprintf_uninit
  81. #endif /* !MBEDTLS_PLATFORM_STD_SNPRINTF */
  82. int (*mbedtls_snprintf)(char *s, size_t n,
  83. const char *format,
  84. ...) = MBEDTLS_PLATFORM_STD_SNPRINTF;
  85. int mbedtls_platform_set_snprintf(int (*snprintf_func)(char *s, size_t n,
  86. const char *format,
  87. ...))
  88. {
  89. mbedtls_snprintf = snprintf_func;
  90. return 0;
  91. }
  92. #endif /* MBEDTLS_PLATFORM_SNPRINTF_ALT */
  93. #if defined(MBEDTLS_PLATFORM_HAS_NON_CONFORMING_VSNPRINTF)
  94. #include <stdarg.h>
  95. int mbedtls_platform_win32_vsnprintf(char *s, size_t n, const char *fmt, va_list arg)
  96. {
  97. int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
  98. /* Avoid calling the invalid parameter handler by checking ourselves */
  99. if (s == NULL || n == 0 || fmt == NULL) {
  100. return -1;
  101. }
  102. #if defined(_TRUNCATE)
  103. ret = vsnprintf_s(s, n, _TRUNCATE, fmt, arg);
  104. #else
  105. ret = vsnprintf(s, n, fmt, arg);
  106. if (ret < 0 || (size_t) ret == n) {
  107. s[n-1] = '\0';
  108. ret = -1;
  109. }
  110. #endif
  111. return ret;
  112. }
  113. #endif
  114. #if defined(MBEDTLS_PLATFORM_VSNPRINTF_ALT)
  115. #if !defined(MBEDTLS_PLATFORM_STD_VSNPRINTF)
  116. /*
  117. * Make dummy function to prevent NULL pointer dereferences
  118. */
  119. static int platform_vsnprintf_uninit(char *s, size_t n,
  120. const char *format, va_list arg)
  121. {
  122. ((void) s);
  123. ((void) n);
  124. ((void) format);
  125. ((void) arg);
  126. return -1;
  127. }
  128. #define MBEDTLS_PLATFORM_STD_VSNPRINTF platform_vsnprintf_uninit
  129. #endif /* !MBEDTLS_PLATFORM_STD_VSNPRINTF */
  130. int (*mbedtls_vsnprintf)(char *s, size_t n,
  131. const char *format,
  132. va_list arg) = MBEDTLS_PLATFORM_STD_VSNPRINTF;
  133. int mbedtls_platform_set_vsnprintf(int (*vsnprintf_func)(char *s, size_t n,
  134. const char *format,
  135. va_list arg))
  136. {
  137. mbedtls_vsnprintf = vsnprintf_func;
  138. return 0;
  139. }
  140. #endif /* MBEDTLS_PLATFORM_VSNPRINTF_ALT */
  141. #if defined(MBEDTLS_PLATFORM_PRINTF_ALT)
  142. #if !defined(MBEDTLS_PLATFORM_STD_PRINTF)
  143. /*
  144. * Make dummy function to prevent NULL pointer dereferences
  145. */
  146. static int platform_printf_uninit(const char *format, ...)
  147. {
  148. ((void) format);
  149. return 0;
  150. }
  151. #define MBEDTLS_PLATFORM_STD_PRINTF platform_printf_uninit
  152. #endif /* !MBEDTLS_PLATFORM_STD_PRINTF */
  153. int (*mbedtls_printf)(const char *, ...) = MBEDTLS_PLATFORM_STD_PRINTF;
  154. int mbedtls_platform_set_printf(int (*printf_func)(const char *, ...))
  155. {
  156. mbedtls_printf = printf_func;
  157. return 0;
  158. }
  159. #endif /* MBEDTLS_PLATFORM_PRINTF_ALT */
  160. #if defined(MBEDTLS_PLATFORM_FPRINTF_ALT)
  161. #if !defined(MBEDTLS_PLATFORM_STD_FPRINTF)
  162. /*
  163. * Make dummy function to prevent NULL pointer dereferences
  164. */
  165. static int platform_fprintf_uninit(FILE *stream, const char *format, ...)
  166. {
  167. ((void) stream);
  168. ((void) format);
  169. return 0;
  170. }
  171. #define MBEDTLS_PLATFORM_STD_FPRINTF platform_fprintf_uninit
  172. #endif /* !MBEDTLS_PLATFORM_STD_FPRINTF */
  173. int (*mbedtls_fprintf)(FILE *, const char *, ...) =
  174. MBEDTLS_PLATFORM_STD_FPRINTF;
  175. int mbedtls_platform_set_fprintf(int (*fprintf_func)(FILE *, const char *, ...))
  176. {
  177. mbedtls_fprintf = fprintf_func;
  178. return 0;
  179. }
  180. #endif /* MBEDTLS_PLATFORM_FPRINTF_ALT */
  181. #if defined(MBEDTLS_PLATFORM_SETBUF_ALT)
  182. #if !defined(MBEDTLS_PLATFORM_STD_SETBUF)
  183. /*
  184. * Make dummy function to prevent NULL pointer dereferences
  185. */
  186. static void platform_setbuf_uninit(FILE *stream, char *buf)
  187. {
  188. ((void) stream);
  189. ((void) buf);
  190. }
  191. #define MBEDTLS_PLATFORM_STD_SETBUF platform_setbuf_uninit
  192. #endif /* !MBEDTLS_PLATFORM_STD_SETBUF */
  193. void (*mbedtls_setbuf)(FILE *stream, char *buf) = MBEDTLS_PLATFORM_STD_SETBUF;
  194. int mbedtls_platform_set_setbuf(void (*setbuf_func)(FILE *stream, char *buf))
  195. {
  196. mbedtls_setbuf = setbuf_func;
  197. return 0;
  198. }
  199. #endif /* MBEDTLS_PLATFORM_SETBUF_ALT */
  200. #if defined(MBEDTLS_PLATFORM_EXIT_ALT)
  201. #if !defined(MBEDTLS_PLATFORM_STD_EXIT)
  202. /*
  203. * Make dummy function to prevent NULL pointer dereferences
  204. */
  205. static void platform_exit_uninit(int status)
  206. {
  207. ((void) status);
  208. }
  209. #define MBEDTLS_PLATFORM_STD_EXIT platform_exit_uninit
  210. #endif /* !MBEDTLS_PLATFORM_STD_EXIT */
  211. void (*mbedtls_exit)(int status) = MBEDTLS_PLATFORM_STD_EXIT;
  212. int mbedtls_platform_set_exit(void (*exit_func)(int status))
  213. {
  214. mbedtls_exit = exit_func;
  215. return 0;
  216. }
  217. #endif /* MBEDTLS_PLATFORM_EXIT_ALT */
  218. #if defined(MBEDTLS_HAVE_TIME)
  219. #if defined(MBEDTLS_PLATFORM_TIME_ALT)
  220. #if !defined(MBEDTLS_PLATFORM_STD_TIME)
  221. /*
  222. * Make dummy function to prevent NULL pointer dereferences
  223. */
  224. static mbedtls_time_t platform_time_uninit(mbedtls_time_t *timer)
  225. {
  226. ((void) timer);
  227. return 0;
  228. }
  229. #define MBEDTLS_PLATFORM_STD_TIME platform_time_uninit
  230. #endif /* !MBEDTLS_PLATFORM_STD_TIME */
  231. mbedtls_time_t (*mbedtls_time)(mbedtls_time_t *timer) = MBEDTLS_PLATFORM_STD_TIME;
  232. int mbedtls_platform_set_time(mbedtls_time_t (*time_func)(mbedtls_time_t *timer))
  233. {
  234. mbedtls_time = time_func;
  235. return 0;
  236. }
  237. #endif /* MBEDTLS_PLATFORM_TIME_ALT */
  238. #endif /* MBEDTLS_HAVE_TIME */
  239. #if defined(MBEDTLS_ENTROPY_NV_SEED)
  240. #if !defined(MBEDTLS_PLATFORM_NO_STD_FUNCTIONS) && defined(MBEDTLS_FS_IO)
  241. /* Default implementations for the platform independent seed functions use
  242. * standard libc file functions to read from and write to a pre-defined filename
  243. */
  244. int mbedtls_platform_std_nv_seed_read(unsigned char *buf, size_t buf_len)
  245. {
  246. FILE *file;
  247. size_t n;
  248. if ((file = fopen(MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "rb")) == NULL) {
  249. return -1;
  250. }
  251. /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
  252. mbedtls_setbuf(file, NULL);
  253. if ((n = fread(buf, 1, buf_len, file)) != buf_len) {
  254. fclose(file);
  255. mbedtls_platform_zeroize(buf, buf_len);
  256. return -1;
  257. }
  258. fclose(file);
  259. return (int) n;
  260. }
  261. int mbedtls_platform_std_nv_seed_write(unsigned char *buf, size_t buf_len)
  262. {
  263. FILE *file;
  264. size_t n;
  265. if ((file = fopen(MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "w")) == NULL) {
  266. return -1;
  267. }
  268. /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
  269. mbedtls_setbuf(file, NULL);
  270. if ((n = fwrite(buf, 1, buf_len, file)) != buf_len) {
  271. fclose(file);
  272. return -1;
  273. }
  274. fclose(file);
  275. return (int) n;
  276. }
  277. #endif /* MBEDTLS_PLATFORM_NO_STD_FUNCTIONS */
  278. #if defined(MBEDTLS_PLATFORM_NV_SEED_ALT)
  279. #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_READ)
  280. /*
  281. * Make dummy function to prevent NULL pointer dereferences
  282. */
  283. static int platform_nv_seed_read_uninit(unsigned char *buf, size_t buf_len)
  284. {
  285. ((void) buf);
  286. ((void) buf_len);
  287. return -1;
  288. }
  289. #define MBEDTLS_PLATFORM_STD_NV_SEED_READ platform_nv_seed_read_uninit
  290. #endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_READ */
  291. #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_WRITE)
  292. /*
  293. * Make dummy function to prevent NULL pointer dereferences
  294. */
  295. static int platform_nv_seed_write_uninit(unsigned char *buf, size_t buf_len)
  296. {
  297. ((void) buf);
  298. ((void) buf_len);
  299. return -1;
  300. }
  301. #define MBEDTLS_PLATFORM_STD_NV_SEED_WRITE platform_nv_seed_write_uninit
  302. #endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_WRITE */
  303. int (*mbedtls_nv_seed_read)(unsigned char *buf, size_t buf_len) =
  304. MBEDTLS_PLATFORM_STD_NV_SEED_READ;
  305. int (*mbedtls_nv_seed_write)(unsigned char *buf, size_t buf_len) =
  306. MBEDTLS_PLATFORM_STD_NV_SEED_WRITE;
  307. int mbedtls_platform_set_nv_seed(
  308. int (*nv_seed_read_func)(unsigned char *buf, size_t buf_len),
  309. int (*nv_seed_write_func)(unsigned char *buf, size_t buf_len))
  310. {
  311. mbedtls_nv_seed_read = nv_seed_read_func;
  312. mbedtls_nv_seed_write = nv_seed_write_func;
  313. return 0;
  314. }
  315. #endif /* MBEDTLS_PLATFORM_NV_SEED_ALT */
  316. #endif /* MBEDTLS_ENTROPY_NV_SEED */
  317. #if !defined(MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT)
  318. /*
  319. * Placeholder platform setup that does nothing by default
  320. */
  321. int mbedtls_platform_setup(mbedtls_platform_context *ctx)
  322. {
  323. (void) ctx;
  324. return 0;
  325. }
  326. /*
  327. * Placeholder platform teardown that does nothing by default
  328. */
  329. void mbedtls_platform_teardown(mbedtls_platform_context *ctx)
  330. {
  331. (void) ctx;
  332. }
  333. #endif /* MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT */
  334. #endif /* MBEDTLS_PLATFORM_C */