1 /*
2 * Platform abstraction layer
3 *
4 * Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
5 * SPDX-License-Identifier: Apache-2.0
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 *
19 * This file is part of mbed TLS (https://tls.mbed.org)
20 */
21
22 #if !defined(MBEDTLS_CONFIG_FILE)
23 #include "mbedtls/config.h"
24 #else
25 #include MBEDTLS_CONFIG_FILE
26 #endif
27
28 #if defined(MBEDTLS_PLATFORM_C)
29
30 #include "mbedtls/platform.h"
31 #include "mbedtls/platform_util.h"
32
33 /* The compile time configuration of memory allocation via the macros
34 * MBEDTLS_PLATFORM_{FREE/CALLOC}_MACRO takes precedence over the runtime
35 * configuration via mbedtls_platform_set_calloc_free(). So, omit everything
36 * related to the latter if MBEDTLS_PLATFORM_{FREE/CALLOC}_MACRO are defined. */
37 #if defined(MBEDTLS_PLATFORM_MEMORY) && \
38 !( defined(MBEDTLS_PLATFORM_CALLOC_MACRO) && \
39 defined(MBEDTLS_PLATFORM_FREE_MACRO) )
40
41 #if !defined(MBEDTLS_PLATFORM_STD_CALLOC)
platform_calloc_uninit(size_t n,size_t size)42 static void *platform_calloc_uninit( size_t n, size_t size )
43 {
44 ((void) n);
45 ((void) size);
46 return( NULL );
47 }
48
49 #define MBEDTLS_PLATFORM_STD_CALLOC platform_calloc_uninit
50 #endif /* !MBEDTLS_PLATFORM_STD_CALLOC */
51
52 #if !defined(MBEDTLS_PLATFORM_STD_FREE)
platform_free_uninit(void * ptr)53 static void platform_free_uninit( void *ptr )
54 {
55 ((void) ptr);
56 }
57
58 #define MBEDTLS_PLATFORM_STD_FREE platform_free_uninit
59 #endif /* !MBEDTLS_PLATFORM_STD_FREE */
60
61 static void * (*mbedtls_calloc_func)( size_t, size_t ) = MBEDTLS_PLATFORM_STD_CALLOC;
62 static void (*mbedtls_free_func)( void * ) = MBEDTLS_PLATFORM_STD_FREE;
63
mbedtls_calloc(size_t nmemb,size_t size)64 void * mbedtls_calloc( size_t nmemb, size_t size )
65 {
66 return (*mbedtls_calloc_func)( nmemb, size );
67 }
68
mbedtls_free(void * ptr)69 void mbedtls_free( void * ptr )
70 {
71 (*mbedtls_free_func)( ptr );
72 }
73
mbedtls_platform_set_calloc_free(void * (* calloc_func)(size_t,size_t),void (* free_func)(void *))74 int mbedtls_platform_set_calloc_free( void * (*calloc_func)( size_t, size_t ),
75 void (*free_func)( void * ) )
76 {
77 mbedtls_calloc_func = calloc_func;
78 mbedtls_free_func = free_func;
79 return( 0 );
80 }
81 #endif /* MBEDTLS_PLATFORM_MEMORY &&
82 !( defined(MBEDTLS_PLATFORM_CALLOC_MACRO) &&
83 defined(MBEDTLS_PLATFORM_FREE_MACRO) ) */
84
85 #if defined(_WIN32)
86 #include <stdarg.h>
mbedtls_platform_win32_snprintf(char * s,size_t n,const char * fmt,...)87 int mbedtls_platform_win32_snprintf( char *s, size_t n, const char *fmt, ... )
88 {
89 int ret;
90 va_list argp;
91
92 /* Avoid calling the invalid parameter handler by checking ourselves */
93 if( s == NULL || n == 0 || fmt == NULL )
94 return( -1 );
95
96 va_start( argp, fmt );
97 #if defined(_TRUNCATE) && !defined(__MINGW32__)
98 ret = _vsnprintf_s( s, n, _TRUNCATE, fmt, argp );
99 #else
100 ret = _vsnprintf( s, n, fmt, argp );
101 if( ret < 0 || (size_t) ret == n )
102 {
103 s[n-1] = '\0';
104 ret = -1;
105 }
106 #endif
107 va_end( argp );
108
109 return( ret );
110 }
111 #endif
112
113 #if defined(MBEDTLS_PLATFORM_SNPRINTF_ALT)
114 #if !defined(MBEDTLS_PLATFORM_STD_SNPRINTF)
115 /*
116 * Make dummy function to prevent NULL pointer dereferences
117 */
platform_snprintf_uninit(char * s,size_t n,const char * format,...)118 static int platform_snprintf_uninit( char * s, size_t n,
119 const char * format, ... )
120 {
121 ((void) s);
122 ((void) n);
123 ((void) format);
124 return( 0 );
125 }
126
127 #define MBEDTLS_PLATFORM_STD_SNPRINTF platform_snprintf_uninit
128 #endif /* !MBEDTLS_PLATFORM_STD_SNPRINTF */
129
130 int (*mbedtls_snprintf)( char * s, size_t n,
131 const char * format,
132 ... ) = MBEDTLS_PLATFORM_STD_SNPRINTF;
133
mbedtls_platform_set_snprintf(int (* snprintf_func)(char * s,size_t n,const char * format,...))134 int mbedtls_platform_set_snprintf( int (*snprintf_func)( char * s, size_t n,
135 const char * format,
136 ... ) )
137 {
138 mbedtls_snprintf = snprintf_func;
139 return( 0 );
140 }
141 #endif /* MBEDTLS_PLATFORM_SNPRINTF_ALT */
142
143 #if defined(MBEDTLS_PLATFORM_PRINTF_ALT)
144 #if !defined(MBEDTLS_PLATFORM_STD_PRINTF)
145 /*
146 * Make dummy function to prevent NULL pointer dereferences
147 */
platform_printf_uninit(const char * format,...)148 static int platform_printf_uninit( const char *format, ... )
149 {
150 ((void) format);
151 return( 0 );
152 }
153
154 #define MBEDTLS_PLATFORM_STD_PRINTF platform_printf_uninit
155 #endif /* !MBEDTLS_PLATFORM_STD_PRINTF */
156
157 int (*mbedtls_printf)( const char *, ... ) = MBEDTLS_PLATFORM_STD_PRINTF;
158
mbedtls_platform_set_printf(int (* printf_func)(const char *,...))159 int mbedtls_platform_set_printf( int (*printf_func)( const char *, ... ) )
160 {
161 mbedtls_printf = printf_func;
162 return( 0 );
163 }
164 #endif /* MBEDTLS_PLATFORM_PRINTF_ALT */
165
166 #if defined(MBEDTLS_PLATFORM_FPRINTF_ALT)
167 #if !defined(MBEDTLS_PLATFORM_STD_FPRINTF)
168 /*
169 * Make dummy function to prevent NULL pointer dereferences
170 */
platform_fprintf_uninit(FILE * stream,const char * format,...)171 static int platform_fprintf_uninit( FILE *stream, const char *format, ... )
172 {
173 ((void) stream);
174 ((void) format);
175 return( 0 );
176 }
177
178 #define MBEDTLS_PLATFORM_STD_FPRINTF platform_fprintf_uninit
179 #endif /* !MBEDTLS_PLATFORM_STD_FPRINTF */
180
181 int (*mbedtls_fprintf)( FILE *, const char *, ... ) =
182 MBEDTLS_PLATFORM_STD_FPRINTF;
183
mbedtls_platform_set_fprintf(int (* fprintf_func)(FILE *,const char *,...))184 int mbedtls_platform_set_fprintf( int (*fprintf_func)( FILE *, const char *, ... ) )
185 {
186 mbedtls_fprintf = fprintf_func;
187 return( 0 );
188 }
189 #endif /* MBEDTLS_PLATFORM_FPRINTF_ALT */
190
191 #if defined(MBEDTLS_PLATFORM_EXIT_ALT)
192 #if !defined(MBEDTLS_PLATFORM_STD_EXIT)
193 /*
194 * Make dummy function to prevent NULL pointer dereferences
195 */
platform_exit_uninit(int status)196 static void platform_exit_uninit( int status )
197 {
198 ((void) status);
199 }
200
201 #define MBEDTLS_PLATFORM_STD_EXIT platform_exit_uninit
202 #endif /* !MBEDTLS_PLATFORM_STD_EXIT */
203
204 void (*mbedtls_exit)( int status ) = MBEDTLS_PLATFORM_STD_EXIT;
205
mbedtls_platform_set_exit(void (* exit_func)(int status))206 int mbedtls_platform_set_exit( void (*exit_func)( int status ) )
207 {
208 mbedtls_exit = exit_func;
209 return( 0 );
210 }
211 #endif /* MBEDTLS_PLATFORM_EXIT_ALT */
212
213 #if defined(MBEDTLS_HAVE_TIME)
214
215 #if defined(MBEDTLS_PLATFORM_TIME_ALT)
216 #if !defined(MBEDTLS_PLATFORM_STD_TIME)
217 /*
218 * Make dummy function to prevent NULL pointer dereferences
219 */
platform_time_uninit(mbedtls_time_t * timer)220 static mbedtls_time_t platform_time_uninit( mbedtls_time_t* timer )
221 {
222 ((void) timer);
223 return( 0 );
224 }
225
226 #define MBEDTLS_PLATFORM_STD_TIME platform_time_uninit
227 #endif /* !MBEDTLS_PLATFORM_STD_TIME */
228
229 mbedtls_time_t (*mbedtls_time)( mbedtls_time_t* timer ) = MBEDTLS_PLATFORM_STD_TIME;
230
mbedtls_platform_set_time(mbedtls_time_t (* time_func)(mbedtls_time_t * timer))231 int mbedtls_platform_set_time( mbedtls_time_t (*time_func)( mbedtls_time_t* timer ) )
232 {
233 mbedtls_time = time_func;
234 return( 0 );
235 }
236 #endif /* MBEDTLS_PLATFORM_TIME_ALT */
237
238 #endif /* MBEDTLS_HAVE_TIME */
239
240 #if defined(MBEDTLS_ENTROPY_NV_SEED)
241 #if !defined(MBEDTLS_PLATFORM_NO_STD_FUNCTIONS) && defined(MBEDTLS_FS_IO)
242 /* Default implementations for the platform independent seed functions use
243 * standard libc file functions to read from and write to a pre-defined filename
244 */
mbedtls_platform_std_nv_seed_read(unsigned char * buf,size_t buf_len)245 int mbedtls_platform_std_nv_seed_read( unsigned char *buf, size_t buf_len )
246 {
247 FILE *file;
248 size_t n;
249
250 if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "rb" ) ) == NULL )
251 return( -1 );
252
253 if( ( n = fread( buf, 1, buf_len, file ) ) != buf_len )
254 {
255 fclose( file );
256 mbedtls_platform_zeroize( buf, buf_len );
257 return( -1 );
258 }
259
260 fclose( file );
261 return( (int)n );
262 }
263
mbedtls_platform_std_nv_seed_write(unsigned char * buf,size_t buf_len)264 int mbedtls_platform_std_nv_seed_write( unsigned char *buf, size_t buf_len )
265 {
266 FILE *file;
267 size_t n;
268
269 if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "w" ) ) == NULL )
270 return -1;
271
272 if( ( n = fwrite( buf, 1, buf_len, file ) ) != buf_len )
273 {
274 fclose( file );
275 return -1;
276 }
277
278 fclose( file );
279 return( (int)n );
280 }
281 #endif /* MBEDTLS_PLATFORM_NO_STD_FUNCTIONS */
282
283 #if defined(MBEDTLS_PLATFORM_NV_SEED_ALT)
284 #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_READ)
285 /*
286 * Make dummy function to prevent NULL pointer dereferences
287 */
platform_nv_seed_read_uninit(unsigned char * buf,size_t buf_len)288 static int platform_nv_seed_read_uninit( unsigned char *buf, size_t buf_len )
289 {
290 ((void) buf);
291 ((void) buf_len);
292 return( -1 );
293 }
294
295 #define MBEDTLS_PLATFORM_STD_NV_SEED_READ platform_nv_seed_read_uninit
296 #endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_READ */
297
298 #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_WRITE)
299 /*
300 * Make dummy function to prevent NULL pointer dereferences
301 */
platform_nv_seed_write_uninit(unsigned char * buf,size_t buf_len)302 static int platform_nv_seed_write_uninit( unsigned char *buf, size_t buf_len )
303 {
304 ((void) buf);
305 ((void) buf_len);
306 return( -1 );
307 }
308
309 #define MBEDTLS_PLATFORM_STD_NV_SEED_WRITE platform_nv_seed_write_uninit
310 #endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_WRITE */
311
312 int (*mbedtls_nv_seed_read)( unsigned char *buf, size_t buf_len ) =
313 MBEDTLS_PLATFORM_STD_NV_SEED_READ;
314 int (*mbedtls_nv_seed_write)( unsigned char *buf, size_t buf_len ) =
315 MBEDTLS_PLATFORM_STD_NV_SEED_WRITE;
316
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))317 int mbedtls_platform_set_nv_seed(
318 int (*nv_seed_read_func)( unsigned char *buf, size_t buf_len ),
319 int (*nv_seed_write_func)( unsigned char *buf, size_t buf_len ) )
320 {
321 mbedtls_nv_seed_read = nv_seed_read_func;
322 mbedtls_nv_seed_write = nv_seed_write_func;
323 return( 0 );
324 }
325 #endif /* MBEDTLS_PLATFORM_NV_SEED_ALT */
326 #endif /* MBEDTLS_ENTROPY_NV_SEED */
327
328 #if !defined(MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT)
329 /*
330 * Placeholder platform setup that does nothing by default
331 */
mbedtls_platform_setup(mbedtls_platform_context * ctx)332 int mbedtls_platform_setup( mbedtls_platform_context *ctx )
333 {
334 (void)ctx;
335
336 return( 0 );
337 }
338
339 /*
340 * Placeholder platform teardown that does nothing by default
341 */
mbedtls_platform_teardown(mbedtls_platform_context * ctx)342 void mbedtls_platform_teardown( mbedtls_platform_context *ctx )
343 {
344 (void)ctx;
345 }
346 #endif /* MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT */
347
348 #endif /* MBEDTLS_PLATFORM_C */
349