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 * This file is provided under the Apache License 2.0, or the
8 * GNU General Public License v2.0 or later.
9 *
10 * **********
11 * Apache License 2.0:
12 *
13 * Licensed under the Apache License, Version 2.0 (the "License"); you may
14 * not use this file except in compliance with the License.
15 * You may obtain a copy of the License at
16 *
17 * http://www.apache.org/licenses/LICENSE-2.0
18 *
19 * Unless required by applicable law or agreed to in writing, software
20 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
21 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
22 * See the License for the specific language governing permissions and
23 * limitations under the License.
24 *
25 * **********
26 *
27 * **********
28 * GNU General Public License v2.0 or later:
29 *
30 * This program is free software; you can redistribute it and/or modify
31 * it under the terms of the GNU General Public License as published by
32 * the Free Software Foundation; either version 2 of the License, or
33 * (at your option) any later version.
34 *
35 * This program is distributed in the hope that it will be useful,
36 * but WITHOUT ANY WARRANTY; without even the implied warranty of
37 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
38 * GNU General Public License for more details.
39 *
40 * You should have received a copy of the GNU General Public License along
41 * with this program; if not, write to the Free Software Foundation, Inc.,
42 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
43 *
44 * **********
45 */
46
47 #if !defined(MBEDTLS_CONFIG_FILE)
48 #include "mbedtls/config.h"
49 #else
50 #include MBEDTLS_CONFIG_FILE
51 #endif
52
53 #if defined(MBEDTLS_PLATFORM_C)
54
55 #include "mbedtls/platform.h"
56 #include "mbedtls/platform_util.h"
57
58 /* The compile time configuration of memory allocation via the macros
59 * MBEDTLS_PLATFORM_{FREE/CALLOC}_MACRO takes precedence over the runtime
60 * configuration via mbedtls_platform_set_calloc_free(). So, omit everything
61 * related to the latter if MBEDTLS_PLATFORM_{FREE/CALLOC}_MACRO are defined. */
62 #if defined(MBEDTLS_PLATFORM_MEMORY) && \
63 !( defined(MBEDTLS_PLATFORM_CALLOC_MACRO) && \
64 defined(MBEDTLS_PLATFORM_FREE_MACRO) )
65
66 #if !defined(MBEDTLS_PLATFORM_STD_CALLOC)
platform_calloc_uninit(size_t n,size_t size)67 static void *platform_calloc_uninit( size_t n, size_t size )
68 {
69 ((void) n);
70 ((void) size);
71 return( NULL );
72 }
73
74 #define MBEDTLS_PLATFORM_STD_CALLOC platform_calloc_uninit
75 #endif /* !MBEDTLS_PLATFORM_STD_CALLOC */
76
77 #if !defined(MBEDTLS_PLATFORM_STD_FREE)
platform_free_uninit(void * ptr)78 static void platform_free_uninit( void *ptr )
79 {
80 ((void) ptr);
81 }
82
83 #define MBEDTLS_PLATFORM_STD_FREE platform_free_uninit
84 #endif /* !MBEDTLS_PLATFORM_STD_FREE */
85
86 static void * (*mbedtls_calloc_func)( size_t, size_t ) = MBEDTLS_PLATFORM_STD_CALLOC;
87 static void (*mbedtls_free_func)( void * ) = MBEDTLS_PLATFORM_STD_FREE;
88
mbedtls_calloc(size_t nmemb,size_t size)89 void * mbedtls_calloc( size_t nmemb, size_t size )
90 {
91 return (*mbedtls_calloc_func)( nmemb, size );
92 }
93
mbedtls_free(void * ptr)94 void mbedtls_free( void * ptr )
95 {
96 (*mbedtls_free_func)( ptr );
97 }
98
mbedtls_platform_set_calloc_free(void * (* calloc_func)(size_t,size_t),void (* free_func)(void *))99 int mbedtls_platform_set_calloc_free( void * (*calloc_func)( size_t, size_t ),
100 void (*free_func)( void * ) )
101 {
102 mbedtls_calloc_func = calloc_func;
103 mbedtls_free_func = free_func;
104 return( 0 );
105 }
106 #endif /* MBEDTLS_PLATFORM_MEMORY &&
107 !( defined(MBEDTLS_PLATFORM_CALLOC_MACRO) &&
108 defined(MBEDTLS_PLATFORM_FREE_MACRO) ) */
109
110 #if defined(_WIN32)
111 #include <stdarg.h>
mbedtls_platform_win32_snprintf(char * s,size_t n,const char * fmt,...)112 int mbedtls_platform_win32_snprintf( char *s, size_t n, const char *fmt, ... )
113 {
114 int ret;
115 va_list argp;
116
117 /* Avoid calling the invalid parameter handler by checking ourselves */
118 if( s == NULL || n == 0 || fmt == NULL )
119 return( -1 );
120
121 va_start( argp, fmt );
122 #if defined(_TRUNCATE) && !defined(__MINGW32__)
123 ret = _vsnprintf_s( s, n, _TRUNCATE, fmt, argp );
124 #else
125 ret = _vsnprintf( s, n, fmt, argp );
126 if( ret < 0 || (size_t) ret == n )
127 {
128 s[n-1] = '\0';
129 ret = -1;
130 }
131 #endif
132 va_end( argp );
133
134 return( ret );
135 }
136 #endif
137
138 #if defined(MBEDTLS_PLATFORM_SNPRINTF_ALT)
139 #if !defined(MBEDTLS_PLATFORM_STD_SNPRINTF)
140 /*
141 * Make dummy function to prevent NULL pointer dereferences
142 */
platform_snprintf_uninit(char * s,size_t n,const char * format,...)143 static int platform_snprintf_uninit( char * s, size_t n,
144 const char * format, ... )
145 {
146 ((void) s);
147 ((void) n);
148 ((void) format);
149 return( 0 );
150 }
151
152 #define MBEDTLS_PLATFORM_STD_SNPRINTF platform_snprintf_uninit
153 #endif /* !MBEDTLS_PLATFORM_STD_SNPRINTF */
154
155 int (*mbedtls_snprintf)( char * s, size_t n,
156 const char * format,
157 ... ) = MBEDTLS_PLATFORM_STD_SNPRINTF;
158
mbedtls_platform_set_snprintf(int (* snprintf_func)(char * s,size_t n,const char * format,...))159 int mbedtls_platform_set_snprintf( int (*snprintf_func)( char * s, size_t n,
160 const char * format,
161 ... ) )
162 {
163 mbedtls_snprintf = snprintf_func;
164 return( 0 );
165 }
166 #endif /* MBEDTLS_PLATFORM_SNPRINTF_ALT */
167
168 #if defined(MBEDTLS_PLATFORM_PRINTF_ALT)
169 #if !defined(MBEDTLS_PLATFORM_STD_PRINTF)
170 /*
171 * Make dummy function to prevent NULL pointer dereferences
172 */
platform_printf_uninit(const char * format,...)173 static int platform_printf_uninit( const char *format, ... )
174 {
175 ((void) format);
176 return( 0 );
177 }
178
179 #define MBEDTLS_PLATFORM_STD_PRINTF platform_printf_uninit
180 #endif /* !MBEDTLS_PLATFORM_STD_PRINTF */
181
182 int (*mbedtls_printf)( const char *, ... ) = MBEDTLS_PLATFORM_STD_PRINTF;
183
mbedtls_platform_set_printf(int (* printf_func)(const char *,...))184 int mbedtls_platform_set_printf( int (*printf_func)( const char *, ... ) )
185 {
186 mbedtls_printf = printf_func;
187 return( 0 );
188 }
189 #endif /* MBEDTLS_PLATFORM_PRINTF_ALT */
190
191 #if defined(MBEDTLS_PLATFORM_FPRINTF_ALT)
192 #if !defined(MBEDTLS_PLATFORM_STD_FPRINTF)
193 /*
194 * Make dummy function to prevent NULL pointer dereferences
195 */
platform_fprintf_uninit(FILE * stream,const char * format,...)196 static int platform_fprintf_uninit( FILE *stream, const char *format, ... )
197 {
198 ((void) stream);
199 ((void) format);
200 return( 0 );
201 }
202
203 #define MBEDTLS_PLATFORM_STD_FPRINTF platform_fprintf_uninit
204 #endif /* !MBEDTLS_PLATFORM_STD_FPRINTF */
205
206 int (*mbedtls_fprintf)( FILE *, const char *, ... ) =
207 MBEDTLS_PLATFORM_STD_FPRINTF;
208
mbedtls_platform_set_fprintf(int (* fprintf_func)(FILE *,const char *,...))209 int mbedtls_platform_set_fprintf( int (*fprintf_func)( FILE *, const char *, ... ) )
210 {
211 mbedtls_fprintf = fprintf_func;
212 return( 0 );
213 }
214 #endif /* MBEDTLS_PLATFORM_FPRINTF_ALT */
215
216 #if defined(MBEDTLS_PLATFORM_EXIT_ALT)
217 #if !defined(MBEDTLS_PLATFORM_STD_EXIT)
218 /*
219 * Make dummy function to prevent NULL pointer dereferences
220 */
platform_exit_uninit(int status)221 static void platform_exit_uninit( int status )
222 {
223 ((void) status);
224 }
225
226 #define MBEDTLS_PLATFORM_STD_EXIT platform_exit_uninit
227 #endif /* !MBEDTLS_PLATFORM_STD_EXIT */
228
229 void (*mbedtls_exit)( int status ) = MBEDTLS_PLATFORM_STD_EXIT;
230
mbedtls_platform_set_exit(void (* exit_func)(int status))231 int mbedtls_platform_set_exit( void (*exit_func)( int status ) )
232 {
233 mbedtls_exit = exit_func;
234 return( 0 );
235 }
236 #endif /* MBEDTLS_PLATFORM_EXIT_ALT */
237
238 #if defined(MBEDTLS_HAVE_TIME)
239
240 #if defined(MBEDTLS_PLATFORM_TIME_ALT)
241 #if !defined(MBEDTLS_PLATFORM_STD_TIME)
242 /*
243 * Make dummy function to prevent NULL pointer dereferences
244 */
platform_time_uninit(mbedtls_time_t * timer)245 static mbedtls_time_t platform_time_uninit( mbedtls_time_t* timer )
246 {
247 ((void) timer);
248 return( 0 );
249 }
250
251 #define MBEDTLS_PLATFORM_STD_TIME platform_time_uninit
252 #endif /* !MBEDTLS_PLATFORM_STD_TIME */
253
254 mbedtls_time_t (*mbedtls_time)( mbedtls_time_t* timer ) = MBEDTLS_PLATFORM_STD_TIME;
255
mbedtls_platform_set_time(mbedtls_time_t (* time_func)(mbedtls_time_t * timer))256 int mbedtls_platform_set_time( mbedtls_time_t (*time_func)( mbedtls_time_t* timer ) )
257 {
258 mbedtls_time = time_func;
259 return( 0 );
260 }
261 #endif /* MBEDTLS_PLATFORM_TIME_ALT */
262
263 #endif /* MBEDTLS_HAVE_TIME */
264
265 #if defined(MBEDTLS_ENTROPY_NV_SEED)
266 #if !defined(MBEDTLS_PLATFORM_NO_STD_FUNCTIONS) && defined(MBEDTLS_FS_IO)
267 /* Default implementations for the platform independent seed functions use
268 * standard libc file functions to read from and write to a pre-defined filename
269 */
mbedtls_platform_std_nv_seed_read(unsigned char * buf,size_t buf_len)270 int mbedtls_platform_std_nv_seed_read( unsigned char *buf, size_t buf_len )
271 {
272 FILE *file;
273 size_t n;
274
275 if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "rb" ) ) == NULL )
276 return( -1 );
277
278 if( ( n = fread( buf, 1, buf_len, file ) ) != buf_len )
279 {
280 fclose( file );
281 mbedtls_platform_zeroize( buf, buf_len );
282 return( -1 );
283 }
284
285 fclose( file );
286 return( (int)n );
287 }
288
mbedtls_platform_std_nv_seed_write(unsigned char * buf,size_t buf_len)289 int mbedtls_platform_std_nv_seed_write( unsigned char *buf, size_t buf_len )
290 {
291 FILE *file;
292 size_t n;
293
294 if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "w" ) ) == NULL )
295 return -1;
296
297 if( ( n = fwrite( buf, 1, buf_len, file ) ) != buf_len )
298 {
299 fclose( file );
300 return -1;
301 }
302
303 fclose( file );
304 return( (int)n );
305 }
306 #endif /* MBEDTLS_PLATFORM_NO_STD_FUNCTIONS */
307
308 #if defined(MBEDTLS_PLATFORM_NV_SEED_ALT)
309 #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_READ)
310 /*
311 * Make dummy function to prevent NULL pointer dereferences
312 */
platform_nv_seed_read_uninit(unsigned char * buf,size_t buf_len)313 static int platform_nv_seed_read_uninit( unsigned char *buf, size_t buf_len )
314 {
315 ((void) buf);
316 ((void) buf_len);
317 return( -1 );
318 }
319
320 #define MBEDTLS_PLATFORM_STD_NV_SEED_READ platform_nv_seed_read_uninit
321 #endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_READ */
322
323 #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_WRITE)
324 /*
325 * Make dummy function to prevent NULL pointer dereferences
326 */
platform_nv_seed_write_uninit(unsigned char * buf,size_t buf_len)327 static int platform_nv_seed_write_uninit( unsigned char *buf, size_t buf_len )
328 {
329 ((void) buf);
330 ((void) buf_len);
331 return( -1 );
332 }
333
334 #define MBEDTLS_PLATFORM_STD_NV_SEED_WRITE platform_nv_seed_write_uninit
335 #endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_WRITE */
336
337 int (*mbedtls_nv_seed_read)( unsigned char *buf, size_t buf_len ) =
338 MBEDTLS_PLATFORM_STD_NV_SEED_READ;
339 int (*mbedtls_nv_seed_write)( unsigned char *buf, size_t buf_len ) =
340 MBEDTLS_PLATFORM_STD_NV_SEED_WRITE;
341
mbedtls_platform_set_nv_seed(int (* nv_seed_read_func)(unsigned char * buf,size_t buf_len),int (* nv_seed_write_func)(unsigned char * buf,size_t buf_len))342 int mbedtls_platform_set_nv_seed(
343 int (*nv_seed_read_func)( unsigned char *buf, size_t buf_len ),
344 int (*nv_seed_write_func)( unsigned char *buf, size_t buf_len ) )
345 {
346 mbedtls_nv_seed_read = nv_seed_read_func;
347 mbedtls_nv_seed_write = nv_seed_write_func;
348 return( 0 );
349 }
350 #endif /* MBEDTLS_PLATFORM_NV_SEED_ALT */
351 #endif /* MBEDTLS_ENTROPY_NV_SEED */
352
353 #if !defined(MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT)
354 /*
355 * Placeholder platform setup that does nothing by default
356 */
mbedtls_platform_setup(mbedtls_platform_context * ctx)357 int mbedtls_platform_setup( mbedtls_platform_context *ctx )
358 {
359 (void)ctx;
360
361 return( 0 );
362 }
363
364 /*
365 * Placeholder platform teardown that does nothing by default
366 */
mbedtls_platform_teardown(mbedtls_platform_context * ctx)367 void mbedtls_platform_teardown( mbedtls_platform_context *ctx )
368 {
369 (void)ctx;
370 }
371 #endif /* MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT */
372
373 #endif /* MBEDTLS_PLATFORM_C */
374