source: azure_iot_hub_mbedtls/trunk/mbedtls-2.16.1/library/asn1write.c@ 398

Last change on this file since 398 was 398, checked in by coas-nagasima, 5 years ago

mbedTLS版Azure IoT Hub接続サンプルのソースコードを追加
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1/*
2 * ASN.1 buffer writing functionality
3 *
4 * Copyright (C) 2006-2015, 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_ASN1_WRITE_C)
29
30#include "mbedtls/asn1write.h"
31
32#include <string.h>
33
34#if defined(MBEDTLS_PLATFORM_C)
35#include "mbedtls/platform.h"
36#else
37#include <stdlib.h>
38#define mbedtls_calloc calloc
39#define mbedtls_free free
40#endif
41
42int mbedtls_asn1_write_len( unsigned char **p, unsigned char *start, size_t len )
43{
44 if( len < 0x80 )
45 {
46 if( *p - start < 1 )
47 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
48
49 *--(*p) = (unsigned char) len;
50 return( 1 );
51 }
52
53 if( len <= 0xFF )
54 {
55 if( *p - start < 2 )
56 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
57
58 *--(*p) = (unsigned char) len;
59 *--(*p) = 0x81;
60 return( 2 );
61 }
62
63 if( len <= 0xFFFF )
64 {
65 if( *p - start < 3 )
66 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
67
68 *--(*p) = ( len ) & 0xFF;
69 *--(*p) = ( len >> 8 ) & 0xFF;
70 *--(*p) = 0x82;
71 return( 3 );
72 }
73
74 if( len <= 0xFFFFFF )
75 {
76 if( *p - start < 4 )
77 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
78
79 *--(*p) = ( len ) & 0xFF;
80 *--(*p) = ( len >> 8 ) & 0xFF;
81 *--(*p) = ( len >> 16 ) & 0xFF;
82 *--(*p) = 0x83;
83 return( 4 );
84 }
85
86#if SIZE_MAX > 0xFFFFFFFF
87 if( len <= 0xFFFFFFFF )
88#endif
89 {
90 if( *p - start < 5 )
91 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
92
93 *--(*p) = ( len ) & 0xFF;
94 *--(*p) = ( len >> 8 ) & 0xFF;
95 *--(*p) = ( len >> 16 ) & 0xFF;
96 *--(*p) = ( len >> 24 ) & 0xFF;
97 *--(*p) = 0x84;
98 return( 5 );
99 }
100
101#if SIZE_MAX > 0xFFFFFFFF
102 return( MBEDTLS_ERR_ASN1_INVALID_LENGTH );
103#endif
104}
105
106int mbedtls_asn1_write_tag( unsigned char **p, unsigned char *start, unsigned char tag )
107{
108 if( *p - start < 1 )
109 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
110
111 *--(*p) = tag;
112
113 return( 1 );
114}
115
116int mbedtls_asn1_write_raw_buffer( unsigned char **p, unsigned char *start,
117 const unsigned char *buf, size_t size )
118{
119 size_t len = 0;
120
121 if( *p < start || (size_t)( *p - start ) < size )
122 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
123
124 len = size;
125 (*p) -= len;
126 memcpy( *p, buf, len );
127
128 return( (int) len );
129}
130
131#if defined(MBEDTLS_BIGNUM_C)
132int mbedtls_asn1_write_mpi( unsigned char **p, unsigned char *start, const mbedtls_mpi *X )
133{
134 int ret;
135 size_t len = 0;
136
137 // Write the MPI
138 //
139 len = mbedtls_mpi_size( X );
140
141 if( *p < start || (size_t)( *p - start ) < len )
142 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
143
144 (*p) -= len;
145 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( X, *p, len ) );
146
147 // DER format assumes 2s complement for numbers, so the leftmost bit
148 // should be 0 for positive numbers and 1 for negative numbers.
149 //
150 if( X->s ==1 && **p & 0x80 )
151 {
152 if( *p - start < 1 )
153 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
154
155 *--(*p) = 0x00;
156 len += 1;
157 }
158
159 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
160 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_INTEGER ) );
161
162 ret = (int) len;
163
164cleanup:
165 return( ret );
166}
167#endif /* MBEDTLS_BIGNUM_C */
168
169int mbedtls_asn1_write_null( unsigned char **p, unsigned char *start )
170{
171 int ret;
172 size_t len = 0;
173
174 // Write NULL
175 //
176 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, 0) );
177 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_NULL ) );
178
179 return( (int) len );
180}
181
182int mbedtls_asn1_write_oid( unsigned char **p, unsigned char *start,
183 const char *oid, size_t oid_len )
184{
185 int ret;
186 size_t len = 0;
187
188 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
189 (const unsigned char *) oid, oid_len ) );
190 MBEDTLS_ASN1_CHK_ADD( len , mbedtls_asn1_write_len( p, start, len ) );
191 MBEDTLS_ASN1_CHK_ADD( len , mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OID ) );
192
193 return( (int) len );
194}
195
196int mbedtls_asn1_write_algorithm_identifier( unsigned char **p, unsigned char *start,
197 const char *oid, size_t oid_len,
198 size_t par_len )
199{
200 int ret;
201 size_t len = 0;
202
203 if( par_len == 0 )
204 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_null( p, start ) );
205 else
206 len += par_len;
207
208 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid, oid_len ) );
209
210 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
211 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start,
212 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
213
214 return( (int) len );
215}
216
217int mbedtls_asn1_write_bool( unsigned char **p, unsigned char *start, int boolean )
218{
219 int ret;
220 size_t len = 0;
221
222 if( *p - start < 1 )
223 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
224
225 *--(*p) = (boolean) ? 255 : 0;
226 len++;
227
228 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
229 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BOOLEAN ) );
230
231 return( (int) len );
232}
233
234int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val )
235{
236 int ret;
237 size_t len = 0;
238
239 if( *p - start < 1 )
240 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
241
242 len += 1;
243 *--(*p) = val;
244
245 if( val > 0 && **p & 0x80 )
246 {
247 if( *p - start < 1 )
248 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
249
250 *--(*p) = 0x00;
251 len += 1;
252 }
253
254 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
255 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_INTEGER ) );
256
257 return( (int) len );
258}
259
260int mbedtls_asn1_write_tagged_string( unsigned char **p, unsigned char *start, int tag,
261 const char *text, size_t text_len )
262{
263 int ret;
264 size_t len = 0;
265
266 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
267 (const unsigned char *) text, text_len ) );
268
269 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
270 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, tag ) );
271
272 return( (int) len );
273}
274
275int mbedtls_asn1_write_utf8_string( unsigned char **p, unsigned char *start,
276 const char *text, size_t text_len )
277{
278 return( mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_UTF8_STRING, text, text_len) );
279}
280
281int mbedtls_asn1_write_printable_string( unsigned char **p, unsigned char *start,
282 const char *text, size_t text_len )
283{
284 return( mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_PRINTABLE_STRING, text, text_len) );
285}
286
287int mbedtls_asn1_write_ia5_string( unsigned char **p, unsigned char *start,
288 const char *text, size_t text_len )
289{
290 return( mbedtls_asn1_write_tagged_string(p, start, MBEDTLS_ASN1_IA5_STRING, text, text_len) );
291}
292
293int mbedtls_asn1_write_bitstring( unsigned char **p, unsigned char *start,
294 const unsigned char *buf, size_t bits )
295{
296 int ret;
297 size_t len = 0;
298 size_t unused_bits, byte_len;
299
300 byte_len = ( bits + 7 ) / 8;
301 unused_bits = ( byte_len * 8 ) - bits;
302
303 if( *p < start || (size_t)( *p - start ) < byte_len + 1 )
304 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
305
306 len = byte_len + 1;
307
308 /* Write the bitstring. Ensure the unused bits are zeroed */
309 if( byte_len > 0 )
310 {
311 byte_len--;
312 *--( *p ) = buf[byte_len] & ~( ( 0x1 << unused_bits ) - 1 );
313 ( *p ) -= byte_len;
314 memcpy( *p, buf, byte_len );
315 }
316
317 /* Write unused bits */
318 *--( *p ) = (unsigned char)unused_bits;
319
320 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
321 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BIT_STRING ) );
322
323 return( (int) len );
324}
325
326int mbedtls_asn1_write_octet_string( unsigned char **p, unsigned char *start,
327 const unsigned char *buf, size_t size )
328{
329 int ret;
330 size_t len = 0;
331
332 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, buf, size ) );
333
334 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
335 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OCTET_STRING ) );
336
337 return( (int) len );
338}
339
340
341/* This is a copy of the ASN.1 parsing function mbedtls_asn1_find_named_data(),
342 * which is replicated to avoid a dependency ASN1_WRITE_C on ASN1_PARSE_C. */
343static mbedtls_asn1_named_data *asn1_find_named_data(
344 mbedtls_asn1_named_data *list,
345 const char *oid, size_t len )
346{
347 while( list != NULL )
348 {
349 if( list->oid.len == len &&
350 memcmp( list->oid.p, oid, len ) == 0 )
351 {
352 break;
353 }
354
355 list = list->next;
356 }
357
358 return( list );
359}
360
361mbedtls_asn1_named_data *mbedtls_asn1_store_named_data(
362 mbedtls_asn1_named_data **head,
363 const char *oid, size_t oid_len,
364 const unsigned char *val,
365 size_t val_len )
366{
367 mbedtls_asn1_named_data *cur;
368
369 if( ( cur = asn1_find_named_data( *head, oid, oid_len ) ) == NULL )
370 {
371 // Add new entry if not present yet based on OID
372 //
373 cur = (mbedtls_asn1_named_data*)mbedtls_calloc( 1,
374 sizeof(mbedtls_asn1_named_data) );
375 if( cur == NULL )
376 return( NULL );
377
378 cur->oid.len = oid_len;
379 cur->oid.p = mbedtls_calloc( 1, oid_len );
380 if( cur->oid.p == NULL )
381 {
382 mbedtls_free( cur );
383 return( NULL );
384 }
385
386 memcpy( cur->oid.p, oid, oid_len );
387
388 cur->val.len = val_len;
389 cur->val.p = mbedtls_calloc( 1, val_len );
390 if( cur->val.p == NULL )
391 {
392 mbedtls_free( cur->oid.p );
393 mbedtls_free( cur );
394 return( NULL );
395 }
396
397 cur->next = *head;
398 *head = cur;
399 }
400 else if( cur->val.len < val_len )
401 {
402 /*
403 * Enlarge existing value buffer if needed
404 * Preserve old data until the allocation succeeded, to leave list in
405 * a consistent state in case allocation fails.
406 */
407 void *p = mbedtls_calloc( 1, val_len );
408 if( p == NULL )
409 return( NULL );
410
411 mbedtls_free( cur->val.p );
412 cur->val.p = p;
413 cur->val.len = val_len;
414 }
415
416 if( val != NULL )
417 memcpy( cur->val.p, val, val_len );
418
419 return( cur );
420}
421#endif /* MBEDTLS_ASN1_WRITE_C */
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