1 /* 2 * Platform abstraction layer 3 * 4 * Copyright (C) 2006-2016, ARM Limited, All Rights Reserved 5 * SPDX-License-Identifier: GPL-2.0 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License along 18 * with this program; if not, write to the Free Software Foundation, Inc., 19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * This file is part of mbed TLS (https://tls.mbed.org) 22 */ 23 24 #if !defined(MBEDTLS_CONFIG_FILE) 25 #include "mbedtls/config.h" 26 #else 27 #include MBEDTLS_CONFIG_FILE 28 #endif 29 30 #if defined(MBEDTLS_PLATFORM_C) 31 32 #include "mbedtls/platform.h" 33 34 #if defined(MBEDTLS_ENTROPY_NV_SEED) && \ 35 !defined(MBEDTLS_PLATFORM_NO_STD_FUNCTIONS) && defined(MBEDTLS_FS_IO) 36 /* Implementation that should never be optimized out by the compiler */ 37 static void mbedtls_zeroize( void *v, size_t n ) { 38 volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0; 39 } 40 #endif 41 42 /* The compile time configuration of memory allocation via the macros 43 * MBEDTLS_PLATFORM_{FREE/CALLOC}_MACRO takes precedence over the runtime 44 * configuration via mbedtls_platform_set_calloc_free(). So, omit everything 45 * related to the latter if MBEDTLS_PLATFORM_{FREE/CALLOC}_MACRO are defined. */ 46 #if defined(MBEDTLS_PLATFORM_MEMORY) && \ 47 !( defined(MBEDTLS_PLATFORM_CALLOC_MACRO) && \ 48 defined(MBEDTLS_PLATFORM_FREE_MACRO) ) 49 50 #if !defined(MBEDTLS_PLATFORM_STD_CALLOC) 51 static void *platform_calloc_uninit( size_t n, size_t size ) 52 { 53 ((void) n); 54 ((void) size); 55 return( NULL ); 56 } 57 58 #define MBEDTLS_PLATFORM_STD_CALLOC platform_calloc_uninit 59 #endif /* !MBEDTLS_PLATFORM_STD_CALLOC */ 60 61 #if !defined(MBEDTLS_PLATFORM_STD_FREE) 62 static void platform_free_uninit( void *ptr ) 63 { 64 ((void) ptr); 65 } 66 67 #define MBEDTLS_PLATFORM_STD_FREE platform_free_uninit 68 #endif /* !MBEDTLS_PLATFORM_STD_FREE */ 69 70 void * (*mbedtls_calloc)( size_t, size_t ) = MBEDTLS_PLATFORM_STD_CALLOC; 71 void (*mbedtls_free)( void * ) = MBEDTLS_PLATFORM_STD_FREE; 72 73 int mbedtls_platform_set_calloc_free( void * (*calloc_func)( size_t, size_t ), 74 void (*free_func)( void * ) ) 75 { 76 mbedtls_calloc = calloc_func; 77 mbedtls_free = free_func; 78 return( 0 ); 79 } 80 #endif /* MBEDTLS_PLATFORM_MEMORY && 81 !( defined(MBEDTLS_PLATFORM_CALLOC_MACRO) && 82 defined(MBEDTLS_PLATFORM_FREE_MACRO) ) */ 83 84 #if defined(_WIN32) 85 #include <stdarg.h> 86 int mbedtls_platform_win32_snprintf( char *s, size_t n, const char *fmt, ... ) 87 { 88 int ret; 89 va_list argp; 90 91 /* Avoid calling the invalid parameter handler by checking ourselves */ 92 if( s == NULL || n == 0 || fmt == NULL ) 93 return( -1 ); 94 95 va_start( argp, fmt ); 96 #if defined(_TRUNCATE) && !defined(__MINGW32__) 97 ret = _vsnprintf_s( s, n, _TRUNCATE, fmt, argp ); 98 #else 99 ret = _vsnprintf( s, n, fmt, argp ); 100 if( ret < 0 || (size_t) ret == n ) 101 { 102 s[n-1] = '\0'; 103 ret = -1; 104 } 105 #endif 106 va_end( argp ); 107 108 return( ret ); 109 } 110 #endif 111 112 #if defined(MBEDTLS_PLATFORM_SNPRINTF_ALT) 113 #if !defined(MBEDTLS_PLATFORM_STD_SNPRINTF) 114 /* 115 * Make dummy function to prevent NULL pointer dereferences 116 */ 117 static int platform_snprintf_uninit( char * s, size_t n, 118 const char * format, ... ) 119 { 120 ((void) s); 121 ((void) n); 122 ((void) format); 123 return( 0 ); 124 } 125 126 #define MBEDTLS_PLATFORM_STD_SNPRINTF platform_snprintf_uninit 127 #endif /* !MBEDTLS_PLATFORM_STD_SNPRINTF */ 128 129 int (*mbedtls_snprintf)( char * s, size_t n, 130 const char * format, 131 ... ) = MBEDTLS_PLATFORM_STD_SNPRINTF; 132 133 int mbedtls_platform_set_snprintf( int (*snprintf_func)( char * s, size_t n, 134 const char * format, 135 ... ) ) 136 { 137 mbedtls_snprintf = snprintf_func; 138 return( 0 ); 139 } 140 #endif /* MBEDTLS_PLATFORM_SNPRINTF_ALT */ 141 142 #if defined(MBEDTLS_PLATFORM_PRINTF_ALT) 143 #if !defined(MBEDTLS_PLATFORM_STD_PRINTF) 144 /* 145 * Make dummy function to prevent NULL pointer dereferences 146 */ 147 static int platform_printf_uninit( const char *format, ... ) 148 { 149 ((void) format); 150 return( 0 ); 151 } 152 153 #define MBEDTLS_PLATFORM_STD_PRINTF platform_printf_uninit 154 #endif /* !MBEDTLS_PLATFORM_STD_PRINTF */ 155 156 int (*mbedtls_printf)( const char *, ... ) = MBEDTLS_PLATFORM_STD_PRINTF; 157 158 int mbedtls_platform_set_printf( int (*printf_func)( const char *, ... ) ) 159 { 160 mbedtls_printf = printf_func; 161 return( 0 ); 162 } 163 #endif /* MBEDTLS_PLATFORM_PRINTF_ALT */ 164 165 #if defined(MBEDTLS_PLATFORM_FPRINTF_ALT) 166 #if !defined(MBEDTLS_PLATFORM_STD_FPRINTF) 167 /* 168 * Make dummy function to prevent NULL pointer dereferences 169 */ 170 static int platform_fprintf_uninit( FILE *stream, const char *format, ... ) 171 { 172 ((void) stream); 173 ((void) format); 174 return( 0 ); 175 } 176 177 #define MBEDTLS_PLATFORM_STD_FPRINTF platform_fprintf_uninit 178 #endif /* !MBEDTLS_PLATFORM_STD_FPRINTF */ 179 180 int (*mbedtls_fprintf)( FILE *, const char *, ... ) = 181 MBEDTLS_PLATFORM_STD_FPRINTF; 182 183 int mbedtls_platform_set_fprintf( int (*fprintf_func)( FILE *, const char *, ... ) ) 184 { 185 mbedtls_fprintf = fprintf_func; 186 return( 0 ); 187 } 188 #endif /* MBEDTLS_PLATFORM_FPRINTF_ALT */ 189 190 #if defined(MBEDTLS_PLATFORM_EXIT_ALT) 191 #if !defined(MBEDTLS_PLATFORM_STD_EXIT) 192 /* 193 * Make dummy function to prevent NULL pointer dereferences 194 */ 195 static void platform_exit_uninit( int status ) 196 { 197 ((void) status); 198 } 199 200 #define MBEDTLS_PLATFORM_STD_EXIT platform_exit_uninit 201 #endif /* !MBEDTLS_PLATFORM_STD_EXIT */ 202 203 void (*mbedtls_exit)( int status ) = MBEDTLS_PLATFORM_STD_EXIT; 204 205 int mbedtls_platform_set_exit( void (*exit_func)( int status ) ) 206 { 207 mbedtls_exit = exit_func; 208 return( 0 ); 209 } 210 #endif /* MBEDTLS_PLATFORM_EXIT_ALT */ 211 212 #if defined(MBEDTLS_HAVE_TIME) 213 214 #if defined(MBEDTLS_PLATFORM_TIME_ALT) 215 #if !defined(MBEDTLS_PLATFORM_STD_TIME) 216 /* 217 * Make dummy function to prevent NULL pointer dereferences 218 */ 219 static mbedtls_time_t platform_time_uninit( mbedtls_time_t* timer ) 220 { 221 ((void) timer); 222 return( 0 ); 223 } 224 225 #define MBEDTLS_PLATFORM_STD_TIME platform_time_uninit 226 #endif /* !MBEDTLS_PLATFORM_STD_TIME */ 227 228 mbedtls_time_t (*mbedtls_time)( mbedtls_time_t* timer ) = MBEDTLS_PLATFORM_STD_TIME; 229 230 int mbedtls_platform_set_time( mbedtls_time_t (*time_func)( mbedtls_time_t* timer ) ) 231 { 232 mbedtls_time = time_func; 233 return( 0 ); 234 } 235 #endif /* MBEDTLS_PLATFORM_TIME_ALT */ 236 237 #endif /* MBEDTLS_HAVE_TIME */ 238 239 #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; 248 249 if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "rb" ) ) == NULL ) 250 return( -1 ); 251 252 if( ( n = fread( buf, 1, buf_len, file ) ) != buf_len ) 253 { 254 fclose( file ); 255 mbedtls_zeroize( buf, buf_len ); 256 return( -1 ); 257 } 258 259 fclose( file ); 260 return( (int)n ); 261 } 262 263 int mbedtls_platform_std_nv_seed_write( unsigned char *buf, size_t buf_len ) 264 { 265 FILE *file; 266 size_t n; 267 268 if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "w" ) ) == NULL ) 269 return -1; 270 271 if( ( n = fwrite( buf, 1, buf_len, file ) ) != buf_len ) 272 { 273 fclose( file ); 274 return -1; 275 } 276 277 fclose( file ); 278 return( (int)n ); 279 } 280 #endif /* MBEDTLS_PLATFORM_NO_STD_FUNCTIONS */ 281 282 #if defined(MBEDTLS_PLATFORM_NV_SEED_ALT) 283 #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_READ) 284 /* 285 * Make dummy function to prevent NULL pointer dereferences 286 */ 287 static int platform_nv_seed_read_uninit( unsigned char *buf, size_t buf_len ) 288 { 289 ((void) buf); 290 ((void) buf_len); 291 return( -1 ); 292 } 293 294 #define MBEDTLS_PLATFORM_STD_NV_SEED_READ platform_nv_seed_read_uninit 295 #endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_READ */ 296 297 #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_WRITE) 298 /* 299 * Make dummy function to prevent NULL pointer dereferences 300 */ 301 static int platform_nv_seed_write_uninit( unsigned char *buf, size_t buf_len ) 302 { 303 ((void) buf); 304 ((void) buf_len); 305 return( -1 ); 306 } 307 308 #define MBEDTLS_PLATFORM_STD_NV_SEED_WRITE platform_nv_seed_write_uninit 309 #endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_WRITE */ 310 311 int (*mbedtls_nv_seed_read)( unsigned char *buf, size_t buf_len ) = 312 MBEDTLS_PLATFORM_STD_NV_SEED_READ; 313 int (*mbedtls_nv_seed_write)( unsigned char *buf, size_t buf_len ) = 314 MBEDTLS_PLATFORM_STD_NV_SEED_WRITE; 315 316 int mbedtls_platform_set_nv_seed( 317 int (*nv_seed_read_func)( unsigned char *buf, size_t buf_len ), 318 int (*nv_seed_write_func)( unsigned char *buf, size_t buf_len ) ) 319 { 320 mbedtls_nv_seed_read = nv_seed_read_func; 321 mbedtls_nv_seed_write = nv_seed_write_func; 322 return( 0 ); 323 } 324 #endif /* MBEDTLS_PLATFORM_NV_SEED_ALT */ 325 #endif /* MBEDTLS_ENTROPY_NV_SEED */ 326 327 #if !defined(MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT) 328 /* 329 * Placeholder platform setup that does nothing by default 330 */ 331 int mbedtls_platform_setup( mbedtls_platform_context *ctx ) 332 { 333 (void)ctx; 334 335 return( 0 ); 336 } 337 338 /* 339 * Placeholder platform teardown that does nothing by default 340 */ 341 void mbedtls_platform_teardown( mbedtls_platform_context *ctx ) 342 { 343 (void)ctx; 344 } 345 #endif /* MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT */ 346 347 #endif /* MBEDTLS_PLATFORM_C */ 348