1 /*
2 * X.509 certificate writing
3 *
4 * Copyright The Mbed TLS Contributors
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 /*
20 * References:
21 * - certificates: RFC 5280, updated by RFC 6818
22 * - CSRs: PKCS#10 v1.7 aka RFC 2986
23 * - attributes: PKCS#9 v2.0 aka RFC 2985
24 */
25
26 #include "common.h"
27
28 #if defined(MBEDTLS_X509_CRT_WRITE_C)
29
30 #include "mbedtls/x509_crt.h"
31 #include "mbedtls/asn1write.h"
32 #include "mbedtls/error.h"
33 #include "mbedtls/oid.h"
34 #include "mbedtls/platform_util.h"
35 #include "mbedtls/sha1.h"
36
37 #include <string.h>
38
39 #if defined(MBEDTLS_PEM_WRITE_C)
40 #include "mbedtls/pem.h"
41 #endif /* MBEDTLS_PEM_WRITE_C */
42
mbedtls_x509write_crt_init(mbedtls_x509write_cert * ctx)43 void mbedtls_x509write_crt_init( mbedtls_x509write_cert *ctx )
44 {
45 memset( ctx, 0, sizeof( mbedtls_x509write_cert ) );
46
47 mbedtls_mpi_init( &ctx->serial );
48 ctx->version = MBEDTLS_X509_CRT_VERSION_3;
49 }
50
mbedtls_x509write_crt_free(mbedtls_x509write_cert * ctx)51 void mbedtls_x509write_crt_free( mbedtls_x509write_cert *ctx )
52 {
53 mbedtls_mpi_free( &ctx->serial );
54
55 mbedtls_asn1_free_named_data_list( &ctx->subject );
56 mbedtls_asn1_free_named_data_list( &ctx->issuer );
57 mbedtls_asn1_free_named_data_list( &ctx->extensions );
58
59 mbedtls_platform_zeroize( ctx, sizeof( mbedtls_x509write_cert ) );
60 }
61
mbedtls_x509write_crt_set_version(mbedtls_x509write_cert * ctx,int version)62 void mbedtls_x509write_crt_set_version( mbedtls_x509write_cert *ctx,
63 int version )
64 {
65 ctx->version = version;
66 }
67
mbedtls_x509write_crt_set_md_alg(mbedtls_x509write_cert * ctx,mbedtls_md_type_t md_alg)68 void mbedtls_x509write_crt_set_md_alg( mbedtls_x509write_cert *ctx,
69 mbedtls_md_type_t md_alg )
70 {
71 ctx->md_alg = md_alg;
72 }
73
mbedtls_x509write_crt_set_subject_key(mbedtls_x509write_cert * ctx,mbedtls_pk_context * key)74 void mbedtls_x509write_crt_set_subject_key( mbedtls_x509write_cert *ctx,
75 mbedtls_pk_context *key )
76 {
77 ctx->subject_key = key;
78 }
79
mbedtls_x509write_crt_set_issuer_key(mbedtls_x509write_cert * ctx,mbedtls_pk_context * key)80 void mbedtls_x509write_crt_set_issuer_key( mbedtls_x509write_cert *ctx,
81 mbedtls_pk_context *key )
82 {
83 ctx->issuer_key = key;
84 }
85
mbedtls_x509write_crt_set_subject_name(mbedtls_x509write_cert * ctx,const char * subject_name)86 int mbedtls_x509write_crt_set_subject_name( mbedtls_x509write_cert *ctx,
87 const char *subject_name )
88 {
89 return mbedtls_x509_string_to_names( &ctx->subject, subject_name );
90 }
91
mbedtls_x509write_crt_set_issuer_name(mbedtls_x509write_cert * ctx,const char * issuer_name)92 int mbedtls_x509write_crt_set_issuer_name( mbedtls_x509write_cert *ctx,
93 const char *issuer_name )
94 {
95 return mbedtls_x509_string_to_names( &ctx->issuer, issuer_name );
96 }
97
mbedtls_x509write_crt_set_serial(mbedtls_x509write_cert * ctx,const mbedtls_mpi * serial)98 int mbedtls_x509write_crt_set_serial( mbedtls_x509write_cert *ctx,
99 const mbedtls_mpi *serial )
100 {
101 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
102
103 if( ( ret = mbedtls_mpi_copy( &ctx->serial, serial ) ) != 0 )
104 return( ret );
105
106 return( 0 );
107 }
108
mbedtls_x509write_crt_set_validity(mbedtls_x509write_cert * ctx,const char * not_before,const char * not_after)109 int mbedtls_x509write_crt_set_validity( mbedtls_x509write_cert *ctx,
110 const char *not_before,
111 const char *not_after )
112 {
113 if( strlen( not_before ) != MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1 ||
114 strlen( not_after ) != MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1 )
115 {
116 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
117 }
118 strncpy( ctx->not_before, not_before, MBEDTLS_X509_RFC5280_UTC_TIME_LEN );
119 strncpy( ctx->not_after , not_after , MBEDTLS_X509_RFC5280_UTC_TIME_LEN );
120 ctx->not_before[MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
121 ctx->not_after[MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
122
123 return( 0 );
124 }
125
mbedtls_x509write_crt_set_extension(mbedtls_x509write_cert * ctx,const char * oid,size_t oid_len,int critical,const unsigned char * val,size_t val_len)126 int mbedtls_x509write_crt_set_extension( mbedtls_x509write_cert *ctx,
127 const char *oid, size_t oid_len,
128 int critical,
129 const unsigned char *val, size_t val_len )
130 {
131 return( mbedtls_x509_set_extension( &ctx->extensions, oid, oid_len,
132 critical, val, val_len ) );
133 }
134
mbedtls_x509write_crt_set_basic_constraints(mbedtls_x509write_cert * ctx,int is_ca,int max_pathlen)135 int mbedtls_x509write_crt_set_basic_constraints( mbedtls_x509write_cert *ctx,
136 int is_ca, int max_pathlen )
137 {
138 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
139 unsigned char buf[9];
140 unsigned char *c = buf + sizeof(buf);
141 size_t len = 0;
142
143 memset( buf, 0, sizeof(buf) );
144
145 if( is_ca && max_pathlen > 127 )
146 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
147
148 if( is_ca )
149 {
150 if( max_pathlen >= 0 )
151 {
152 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf,
153 max_pathlen ) );
154 }
155 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_bool( &c, buf, 1 ) );
156 }
157
158 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
159 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf,
160 MBEDTLS_ASN1_CONSTRUCTED |
161 MBEDTLS_ASN1_SEQUENCE ) );
162
163 return(
164 mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_BASIC_CONSTRAINTS,
165 MBEDTLS_OID_SIZE( MBEDTLS_OID_BASIC_CONSTRAINTS ),
166 is_ca, buf + sizeof(buf) - len, len ) );
167 }
168
169 #if defined(MBEDTLS_SHA1_C)
mbedtls_x509write_crt_set_subject_key_identifier(mbedtls_x509write_cert * ctx)170 int mbedtls_x509write_crt_set_subject_key_identifier( mbedtls_x509write_cert *ctx )
171 {
172 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
173 unsigned char buf[MBEDTLS_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
174 unsigned char *c = buf + sizeof(buf);
175 size_t len = 0;
176
177 memset( buf, 0, sizeof(buf) );
178 MBEDTLS_ASN1_CHK_ADD( len,
179 mbedtls_pk_write_pubkey( &c, buf, ctx->subject_key ) );
180
181 ret = mbedtls_sha1_ret( buf + sizeof( buf ) - len, len,
182 buf + sizeof( buf ) - 20 );
183 if( ret != 0 )
184 return( ret );
185 c = buf + sizeof( buf ) - 20;
186 len = 20;
187
188 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
189 MBEDTLS_ASN1_CHK_ADD( len,
190 mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_OCTET_STRING ) );
191
192 return mbedtls_x509write_crt_set_extension( ctx,
193 MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER,
194 MBEDTLS_OID_SIZE( MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER ),
195 0, buf + sizeof(buf) - len, len );
196 }
197
mbedtls_x509write_crt_set_authority_key_identifier(mbedtls_x509write_cert * ctx)198 int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert *ctx )
199 {
200 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
201 unsigned char buf[MBEDTLS_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
202 unsigned char *c = buf + sizeof( buf );
203 size_t len = 0;
204
205 memset( buf, 0, sizeof(buf) );
206 MBEDTLS_ASN1_CHK_ADD( len,
207 mbedtls_pk_write_pubkey( &c, buf, ctx->issuer_key ) );
208
209 ret = mbedtls_sha1_ret( buf + sizeof( buf ) - len, len,
210 buf + sizeof( buf ) - 20 );
211 if( ret != 0 )
212 return( ret );
213 c = buf + sizeof( buf ) - 20;
214 len = 20;
215
216 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
217 MBEDTLS_ASN1_CHK_ADD( len,
218 mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | 0 ) );
219
220 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
221 MBEDTLS_ASN1_CHK_ADD( len,
222 mbedtls_asn1_write_tag( &c, buf,
223 MBEDTLS_ASN1_CONSTRUCTED |
224 MBEDTLS_ASN1_SEQUENCE ) );
225
226 return mbedtls_x509write_crt_set_extension(
227 ctx, MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER,
228 MBEDTLS_OID_SIZE( MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER ),
229 0, buf + sizeof( buf ) - len, len );
230 }
231 #endif /* MBEDTLS_SHA1_C */
232
mbedtls_x509write_crt_set_key_usage(mbedtls_x509write_cert * ctx,unsigned int key_usage)233 int mbedtls_x509write_crt_set_key_usage( mbedtls_x509write_cert *ctx,
234 unsigned int key_usage )
235 {
236 unsigned char buf[5] = {0}, ku[2] = {0};
237 unsigned char *c;
238 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
239 const unsigned int allowed_bits = MBEDTLS_X509_KU_DIGITAL_SIGNATURE |
240 MBEDTLS_X509_KU_NON_REPUDIATION |
241 MBEDTLS_X509_KU_KEY_ENCIPHERMENT |
242 MBEDTLS_X509_KU_DATA_ENCIPHERMENT |
243 MBEDTLS_X509_KU_KEY_AGREEMENT |
244 MBEDTLS_X509_KU_KEY_CERT_SIGN |
245 MBEDTLS_X509_KU_CRL_SIGN |
246 MBEDTLS_X509_KU_ENCIPHER_ONLY |
247 MBEDTLS_X509_KU_DECIPHER_ONLY;
248
249 /* Check that nothing other than the allowed flags is set */
250 if( ( key_usage & ~allowed_bits ) != 0 )
251 return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
252
253 c = buf + 5;
254 MBEDTLS_PUT_UINT16_LE( key_usage, ku, 0 );
255 ret = mbedtls_asn1_write_named_bitstring( &c, buf, ku, 9 );
256
257 if( ret < 0 )
258 return( ret );
259 else if( ret < 3 || ret > 5 )
260 return( MBEDTLS_ERR_X509_INVALID_FORMAT );
261
262 ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_KEY_USAGE,
263 MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ),
264 1, c, (size_t)ret );
265 if( ret != 0 )
266 return( ret );
267
268 return( 0 );
269 }
270
mbedtls_x509write_crt_set_ns_cert_type(mbedtls_x509write_cert * ctx,unsigned char ns_cert_type)271 int mbedtls_x509write_crt_set_ns_cert_type( mbedtls_x509write_cert *ctx,
272 unsigned char ns_cert_type )
273 {
274 unsigned char buf[4] = {0};
275 unsigned char *c;
276 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
277
278 c = buf + 4;
279
280 ret = mbedtls_asn1_write_named_bitstring( &c, buf, &ns_cert_type, 8 );
281 if( ret < 3 || ret > 4 )
282 return( ret );
283
284 ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_NS_CERT_TYPE,
285 MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ),
286 0, c, (size_t)ret );
287 if( ret != 0 )
288 return( ret );
289
290 return( 0 );
291 }
292
x509_write_time(unsigned char ** p,unsigned char * start,const char * t,size_t size)293 static int x509_write_time( unsigned char **p, unsigned char *start,
294 const char *t, size_t size )
295 {
296 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
297 size_t len = 0;
298
299 /*
300 * write MBEDTLS_ASN1_UTC_TIME if year < 2050 (2 bytes shorter)
301 */
302 if( t[0] == '2' && t[1] == '0' && t[2] < '5' )
303 {
304 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
305 (const unsigned char *) t + 2,
306 size - 2 ) );
307 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
308 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start,
309 MBEDTLS_ASN1_UTC_TIME ) );
310 }
311 else
312 {
313 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
314 (const unsigned char *) t,
315 size ) );
316 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
317 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start,
318 MBEDTLS_ASN1_GENERALIZED_TIME ) );
319 }
320
321 return( (int) len );
322 }
323
mbedtls_x509write_crt_der(mbedtls_x509write_cert * ctx,unsigned char * buf,size_t size,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)324 int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx,
325 unsigned char *buf, size_t size,
326 int (*f_rng)(void *, unsigned char *, size_t),
327 void *p_rng )
328 {
329 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
330 const char *sig_oid;
331 size_t sig_oid_len = 0;
332 unsigned char *c, *c2;
333 unsigned char hash[64];
334 unsigned char sig[MBEDTLS_PK_SIGNATURE_MAX_SIZE];
335 size_t sub_len = 0, pub_len = 0, sig_and_oid_len = 0, sig_len;
336 size_t len = 0;
337 mbedtls_pk_type_t pk_alg;
338
339 /*
340 * Prepare data to be signed at the end of the target buffer
341 */
342 c = buf + size;
343
344 /* Signature algorithm needed in TBS, and later for actual signature */
345
346 /* There's no direct way of extracting a signature algorithm
347 * (represented as an element of mbedtls_pk_type_t) from a PK instance. */
348 if( mbedtls_pk_can_do( ctx->issuer_key, MBEDTLS_PK_RSA ) )
349 pk_alg = MBEDTLS_PK_RSA;
350 else if( mbedtls_pk_can_do( ctx->issuer_key, MBEDTLS_PK_ECDSA ) )
351 pk_alg = MBEDTLS_PK_ECDSA;
352 else
353 return( MBEDTLS_ERR_X509_INVALID_ALG );
354
355 if( ( ret = mbedtls_oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg,
356 &sig_oid, &sig_oid_len ) ) != 0 )
357 {
358 return( ret );
359 }
360
361 /*
362 * Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension
363 */
364
365 /* Only for v3 */
366 if( ctx->version == MBEDTLS_X509_CRT_VERSION_3 )
367 {
368 MBEDTLS_ASN1_CHK_ADD( len,
369 mbedtls_x509_write_extensions( &c,
370 buf, ctx->extensions ) );
371 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
372 MBEDTLS_ASN1_CHK_ADD( len,
373 mbedtls_asn1_write_tag( &c, buf,
374 MBEDTLS_ASN1_CONSTRUCTED |
375 MBEDTLS_ASN1_SEQUENCE ) );
376 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
377 MBEDTLS_ASN1_CHK_ADD( len,
378 mbedtls_asn1_write_tag( &c, buf,
379 MBEDTLS_ASN1_CONTEXT_SPECIFIC |
380 MBEDTLS_ASN1_CONSTRUCTED | 3 ) );
381 }
382
383 /*
384 * SubjectPublicKeyInfo
385 */
386 MBEDTLS_ASN1_CHK_ADD( pub_len,
387 mbedtls_pk_write_pubkey_der( ctx->subject_key,
388 buf, c - buf ) );
389 c -= pub_len;
390 len += pub_len;
391
392 /*
393 * Subject ::= Name
394 */
395 MBEDTLS_ASN1_CHK_ADD( len,
396 mbedtls_x509_write_names( &c, buf,
397 ctx->subject ) );
398
399 /*
400 * Validity ::= SEQUENCE {
401 * notBefore Time,
402 * notAfter Time }
403 */
404 sub_len = 0;
405
406 MBEDTLS_ASN1_CHK_ADD( sub_len,
407 x509_write_time( &c, buf, ctx->not_after,
408 MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) );
409
410 MBEDTLS_ASN1_CHK_ADD( sub_len,
411 x509_write_time( &c, buf, ctx->not_before,
412 MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) );
413
414 len += sub_len;
415 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, sub_len ) );
416 MBEDTLS_ASN1_CHK_ADD( len,
417 mbedtls_asn1_write_tag( &c, buf,
418 MBEDTLS_ASN1_CONSTRUCTED |
419 MBEDTLS_ASN1_SEQUENCE ) );
420
421 /*
422 * Issuer ::= Name
423 */
424 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, buf,
425 ctx->issuer ) );
426
427 /*
428 * Signature ::= AlgorithmIdentifier
429 */
430 MBEDTLS_ASN1_CHK_ADD( len,
431 mbedtls_asn1_write_algorithm_identifier( &c, buf,
432 sig_oid, strlen( sig_oid ), 0 ) );
433
434 /*
435 * Serial ::= INTEGER
436 */
437 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf,
438 &ctx->serial ) );
439
440 /*
441 * Version ::= INTEGER { v1(0), v2(1), v3(2) }
442 */
443
444 /* Can be omitted for v1 */
445 if( ctx->version != MBEDTLS_X509_CRT_VERSION_1 )
446 {
447 sub_len = 0;
448 MBEDTLS_ASN1_CHK_ADD( sub_len,
449 mbedtls_asn1_write_int( &c, buf, ctx->version ) );
450 len += sub_len;
451 MBEDTLS_ASN1_CHK_ADD( len,
452 mbedtls_asn1_write_len( &c, buf, sub_len ) );
453 MBEDTLS_ASN1_CHK_ADD( len,
454 mbedtls_asn1_write_tag( &c, buf,
455 MBEDTLS_ASN1_CONTEXT_SPECIFIC |
456 MBEDTLS_ASN1_CONSTRUCTED | 0 ) );
457 }
458
459 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
460 MBEDTLS_ASN1_CHK_ADD( len,
461 mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED |
462 MBEDTLS_ASN1_SEQUENCE ) );
463
464 /*
465 * Make signature
466 */
467
468 /* Compute hash of CRT. */
469 if( ( ret = mbedtls_md( mbedtls_md_info_from_type( ctx->md_alg ), c,
470 len, hash ) ) != 0 )
471 {
472 return( ret );
473 }
474
475 if( ( ret = mbedtls_pk_sign( ctx->issuer_key, ctx->md_alg,
476 hash, 0, sig, &sig_len,
477 f_rng, p_rng ) ) != 0 )
478 {
479 return( ret );
480 }
481
482 /* Move CRT to the front of the buffer to have space
483 * for the signature. */
484 memmove( buf, c, len );
485 c = buf + len;
486
487 /* Add signature at the end of the buffer,
488 * making sure that it doesn't underflow
489 * into the CRT buffer. */
490 c2 = buf + size;
491 MBEDTLS_ASN1_CHK_ADD( sig_and_oid_len, mbedtls_x509_write_sig( &c2, c,
492 sig_oid, sig_oid_len, sig, sig_len ) );
493
494 /*
495 * Memory layout after this step:
496 *
497 * buf c=buf+len c2 buf+size
498 * [CRT0,...,CRTn, UNUSED, ..., UNUSED, SIG0, ..., SIGm]
499 */
500
501 /* Move raw CRT to just before the signature. */
502 c = c2 - len;
503 memmove( c, buf, len );
504
505 len += sig_and_oid_len;
506 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
507 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf,
508 MBEDTLS_ASN1_CONSTRUCTED |
509 MBEDTLS_ASN1_SEQUENCE ) );
510
511 return( (int) len );
512 }
513
514 #define PEM_BEGIN_CRT "-----BEGIN CERTIFICATE-----\n"
515 #define PEM_END_CRT "-----END CERTIFICATE-----\n"
516
517 #if defined(MBEDTLS_PEM_WRITE_C)
mbedtls_x509write_crt_pem(mbedtls_x509write_cert * crt,unsigned char * buf,size_t size,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)518 int mbedtls_x509write_crt_pem( mbedtls_x509write_cert *crt,
519 unsigned char *buf, size_t size,
520 int (*f_rng)(void *, unsigned char *, size_t),
521 void *p_rng )
522 {
523 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
524 size_t olen;
525
526 if( ( ret = mbedtls_x509write_crt_der( crt, buf, size,
527 f_rng, p_rng ) ) < 0 )
528 {
529 return( ret );
530 }
531
532 if( ( ret = mbedtls_pem_write_buffer( PEM_BEGIN_CRT, PEM_END_CRT,
533 buf + size - ret, ret,
534 buf, size, &olen ) ) != 0 )
535 {
536 return( ret );
537 }
538
539 return( 0 );
540 }
541 #endif /* MBEDTLS_PEM_WRITE_C */
542
543 #endif /* MBEDTLS_X509_CRT_WRITE_C */
544
