platform.c

00001 /*
00002  *  Platform abstraction layer
00003  *
00004  *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
00005  *  SPDX-License-Identifier: Apache-2.0
00006  *
00007  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00008  *  not use this file except in compliance with the License.
00009  *  You may obtain a copy of the License at
00010  *
00011  *  http://www.apache.org/licenses/LICENSE-2.0
00012  *
00013  *  Unless required by applicable law or agreed to in writing, software
00014  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00015  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00016  *  See the License for the specific language governing permissions and
00017  *  limitations under the License.
00018  *
00019  *  This file is part of mbed TLS (https://tls.mbed.org)
00020  */
00021 
00022 #if !defined(MBEDTLS_CONFIG_FILE)
00023 #include "mbedtls/config.h"
00024 #else
00025 #include MBEDTLS_CONFIG_FILE
00026 #endif
00027 
00028 #if defined(MBEDTLS_PLATFORM_C)
00029 
00030 #include "mbedtls/platform.h"
00031 
00032 #if defined(MBEDTLS_PLATFORM_MEMORY)
00033 #if !defined(MBEDTLS_PLATFORM_STD_CALLOC)
00034 static void *platform_calloc_uninit( size_t n, size_t size )
00035 {
00036     ((void) n);
00037     ((void) size);
00038     return( NULL );
00039 }
00040 
00041 #define MBEDTLS_PLATFORM_STD_CALLOC   platform_calloc_uninit
00042 #endif /* !MBEDTLS_PLATFORM_STD_CALLOC */
00043 
00044 #if !defined(MBEDTLS_PLATFORM_STD_FREE)
00045 static void platform_free_uninit( void *ptr )
00046 {
00047     ((void) ptr);
00048 }
00049 
00050 #define MBEDTLS_PLATFORM_STD_FREE     platform_free_uninit
00051 #endif /* !MBEDTLS_PLATFORM_STD_FREE */
00052 
00053 void * (*mbedtls_calloc)( size_t, size_t ) = MBEDTLS_PLATFORM_STD_CALLOC;
00054 void (*mbedtls_free)( void * )     = MBEDTLS_PLATFORM_STD_FREE;
00055 
00056 int mbedtls_platform_set_calloc_free( void * (*calloc_func)( size_t, size_t ),
00057                               void (*free_func)( void * ) )
00058 {
00059     mbedtls_calloc = calloc_func;
00060     mbedtls_free = free_func;
00061     return( 0 );
00062 }
00063 #endif /* MBEDTLS_PLATFORM_MEMORY */
00064 
00065 #if defined(_WIN32)
00066 #include <stdarg.h>
00067 int mbedtls_platform_win32_snprintf( char *s, size_t n, const char *fmt, ... )
00068 {
00069     int ret;
00070     va_list argp;
00071 
00072     /* Avoid calling the invalid parameter handler by checking ourselves */
00073     if( s == NULL || n == 0 || fmt == NULL )
00074         return( -1 );
00075 
00076     va_start( argp, fmt );
00077 #if defined(_TRUNCATE)
00078     ret = _vsnprintf_s( s, n, _TRUNCATE, fmt, argp );
00079 #else
00080     ret = _vsnprintf( s, n, fmt, argp );
00081     if( ret < 0 || (size_t) ret == n )
00082     {
00083         s[n-1] = '\0';
00084         ret = -1;
00085     }
00086 #endif
00087     va_end( argp );
00088 
00089     return( ret );
00090 }
00091 #endif
00092 
00093 #if defined(MBEDTLS_PLATFORM_SNPRINTF_ALT)
00094 #if !defined(MBEDTLS_PLATFORM_STD_SNPRINTF)
00095 /*
00096  * Make dummy function to prevent NULL pointer dereferences
00097  */
00098 static int platform_snprintf_uninit( char * s, size_t n,
00099                                      const char * format, ... )
00100 {
00101     ((void) s);
00102     ((void) n);
00103     ((void) format);
00104     return( 0 );
00105 }
00106 
00107 #define MBEDTLS_PLATFORM_STD_SNPRINTF    platform_snprintf_uninit
00108 #endif /* !MBEDTLS_PLATFORM_STD_SNPRINTF */
00109 
00110 int (*mbedtls_snprintf)( char * s, size_t n,
00111                           const char * format,
00112                           ... ) = MBEDTLS_PLATFORM_STD_SNPRINTF;
00113 
00114 int mbedtls_platform_set_snprintf( int (*snprintf_func)( char * s, size_t n,
00115                                                  const char * format,
00116                                                  ... ) )
00117 {
00118     mbedtls_snprintf = snprintf_func;
00119     return( 0 );
00120 }
00121 #endif /* MBEDTLS_PLATFORM_SNPRINTF_ALT */
00122 
00123 #if defined(MBEDTLS_PLATFORM_PRINTF_ALT)
00124 #if !defined(MBEDTLS_PLATFORM_STD_PRINTF)
00125 /*
00126  * Make dummy function to prevent NULL pointer dereferences
00127  */
00128 static int platform_printf_uninit( const char *format, ... )
00129 {
00130     ((void) format);
00131     return( 0 );
00132 }
00133 
00134 #define MBEDTLS_PLATFORM_STD_PRINTF    platform_printf_uninit
00135 #endif /* !MBEDTLS_PLATFORM_STD_PRINTF */
00136 
00137 int (*mbedtls_printf)( const char *, ... ) = MBEDTLS_PLATFORM_STD_PRINTF;
00138 
00139 int mbedtls_platform_set_printf( int (*printf_func)( const char *, ... ) )
00140 {
00141     mbedtls_printf = printf_func;
00142     return( 0 );
00143 }
00144 #endif /* MBEDTLS_PLATFORM_PRINTF_ALT */
00145 
00146 #if defined(MBEDTLS_PLATFORM_FPRINTF_ALT)
00147 #if !defined(MBEDTLS_PLATFORM_STD_FPRINTF)
00148 /*
00149  * Make dummy function to prevent NULL pointer dereferences
00150  */
00151 static int platform_fprintf_uninit( FILE *stream, const char *format, ... )
00152 {
00153     ((void) stream);
00154     ((void) format);
00155     return( 0 );
00156 }
00157 
00158 #define MBEDTLS_PLATFORM_STD_FPRINTF   platform_fprintf_uninit
00159 #endif /* !MBEDTLS_PLATFORM_STD_FPRINTF */
00160 
00161 int (*mbedtls_fprintf)( FILE *, const char *, ... ) =
00162                                         MBEDTLS_PLATFORM_STD_FPRINTF;
00163 
00164 int mbedtls_platform_set_fprintf( int (*fprintf_func)( FILE *, const char *, ... ) )
00165 {
00166     mbedtls_fprintf = fprintf_func;
00167     return( 0 );
00168 }
00169 #endif /* MBEDTLS_PLATFORM_FPRINTF_ALT */
00170 
00171 #if defined(MBEDTLS_PLATFORM_EXIT_ALT)
00172 #if !defined(MBEDTLS_PLATFORM_STD_EXIT)
00173 /*
00174  * Make dummy function to prevent NULL pointer dereferences
00175  */
00176 static void platform_exit_uninit( int status )
00177 {
00178     ((void) status);
00179 }
00180 
00181 #define MBEDTLS_PLATFORM_STD_EXIT   platform_exit_uninit
00182 #endif /* !MBEDTLS_PLATFORM_STD_EXIT */
00183 
00184 void (*mbedtls_exit)( int status ) = MBEDTLS_PLATFORM_STD_EXIT;
00185 
00186 int mbedtls_platform_set_exit( void (*exit_func)( int status ) )
00187 {
00188     mbedtls_exit = exit_func;
00189     return( 0 );
00190 }
00191 #endif /* MBEDTLS_PLATFORM_EXIT_ALT */
00192 
00193 #if defined(MBEDTLS_HAVE_TIME)
00194 
00195 #if defined(MBEDTLS_PLATFORM_TIME_ALT)
00196 #if !defined(MBEDTLS_PLATFORM_STD_TIME)
00197 /*
00198  * Make dummy function to prevent NULL pointer dereferences
00199  */
00200 static mbedtls_time_t platform_time_uninit( mbedtls_time_t* timer )
00201 {
00202     ((void) timer);
00203     return( 0 );
00204 }
00205 
00206 #define MBEDTLS_PLATFORM_STD_TIME   platform_time_uninit
00207 #endif /* !MBEDTLS_PLATFORM_STD_TIME */
00208 
00209 mbedtls_time_t (*mbedtls_time)( mbedtls_time_t* timer ) = MBEDTLS_PLATFORM_STD_TIME;
00210 
00211 int mbedtls_platform_set_time( mbedtls_time_t (*time_func)( mbedtls_time_t* timer ) )
00212 {
00213     mbedtls_time = time_func;
00214     return( 0 );
00215 }
00216 #endif /* MBEDTLS_PLATFORM_TIME_ALT */
00217 
00218 #endif /* MBEDTLS_HAVE_TIME */
00219 
00220 #if defined(MBEDTLS_ENTROPY_NV_SEED)
00221 #if !defined(MBEDTLS_PLATFORM_NO_STD_FUNCTIONS) && defined(MBEDTLS_FS_IO)
00222 /* Default implementations for the platform independent seed functions use
00223  * standard libc file functions to read from and write to a pre-defined filename
00224  */
00225 int mbedtls_platform_std_nv_seed_read( unsigned char *buf, size_t buf_len )
00226 {
00227     FILE *file;
00228     size_t n;
00229 
00230     if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "rb" ) ) == NULL )
00231         return -1;
00232 
00233     if( ( n = fread( buf, 1, buf_len, file ) ) != buf_len )
00234     {
00235         fclose( file );
00236         return -1;
00237     }
00238 
00239     fclose( file );
00240     return( (int)n );
00241 }
00242 
00243 int mbedtls_platform_std_nv_seed_write( unsigned char *buf, size_t buf_len )
00244 {
00245     FILE *file;
00246     size_t n;
00247 
00248     if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "w" ) ) == NULL )
00249         return -1;
00250 
00251     if( ( n = fwrite( buf, 1, buf_len, file ) ) != buf_len )
00252     {
00253         fclose( file );
00254         return -1;
00255     }
00256 
00257     fclose( file );
00258     return( (int)n );
00259 }
00260 #endif /* MBEDTLS_PLATFORM_NO_STD_FUNCTIONS */
00261 
00262 #if defined(MBEDTLS_PLATFORM_NV_SEED_ALT)
00263 #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_READ)
00264 /*
00265  * Make dummy function to prevent NULL pointer dereferences
00266  */
00267 static int platform_nv_seed_read_uninit( unsigned char *buf, size_t buf_len )
00268 {
00269     ((void) buf);
00270     ((void) buf_len);
00271     return( -1 );
00272 }
00273 
00274 #define MBEDTLS_PLATFORM_STD_NV_SEED_READ   platform_nv_seed_read_uninit
00275 #endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_READ */
00276 
00277 #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_WRITE)
00278 /*
00279  * Make dummy function to prevent NULL pointer dereferences
00280  */
00281 static int platform_nv_seed_write_uninit( unsigned char *buf, size_t buf_len )
00282 {
00283     ((void) buf);
00284     ((void) buf_len);
00285     return( -1 );
00286 }
00287 
00288 #define MBEDTLS_PLATFORM_STD_NV_SEED_WRITE   platform_nv_seed_write_uninit
00289 #endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_WRITE */
00290 
00291 int (*mbedtls_nv_seed_read)( unsigned char *buf, size_t buf_len ) =
00292             MBEDTLS_PLATFORM_STD_NV_SEED_READ;
00293 int (*mbedtls_nv_seed_write)( unsigned char *buf, size_t buf_len ) =
00294             MBEDTLS_PLATFORM_STD_NV_SEED_WRITE;
00295 
00296 int mbedtls_platform_set_nv_seed(
00297         int (*nv_seed_read_func)( unsigned char *buf, size_t buf_len ),
00298         int (*nv_seed_write_func)( unsigned char *buf, size_t buf_len ) )
00299 {
00300     mbedtls_nv_seed_read = nv_seed_read_func;
00301     mbedtls_nv_seed_write = nv_seed_write_func;
00302     return( 0 );
00303 }
00304 #endif /* MBEDTLS_PLATFORM_NV_SEED_ALT */
00305 #endif /* MBEDTLS_ENTROPY_NV_SEED */
00306 
00307 #if !defined(MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT)
00308 /*
00309  * Placeholder platform setup that does nothing by default
00310  */
00311 int mbedtls_platform_setup( mbedtls_platform_context *ctx )
00312 {
00313     (void)ctx;
00314 
00315     return( 0 );
00316 }
00317 
00318 /*
00319  * Placeholder platform teardown that does nothing by default
00320  */
00321 void mbedtls_platform_teardown( mbedtls_platform_context *ctx )
00322 {
00323     (void)ctx;
00324 }
00325 #endif /* MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT */
00326 
00327 #endif /* MBEDTLS_PLATFORM_C */