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
43 #if defined(MBEDTLS_USE_PSA_CRYPTO)
44 #include "psa/crypto.h"
45 #include "mbedtls/psa_util.h"
46 #endif /* MBEDTLS_USE_PSA_CRYPTO */
47
48 #include "hash_info.h"
49 #include "mbedtls/legacy_or_psa.h"
50
mbedtls_x509write_crt_init(mbedtls_x509write_cert * ctx)51 void mbedtls_x509write_crt_init( mbedtls_x509write_cert *ctx )
52 {
53 memset( ctx, 0, sizeof( mbedtls_x509write_cert ) );
54
55 mbedtls_mpi_init( &ctx->serial );
56 ctx->version = MBEDTLS_X509_CRT_VERSION_3;
57 }
58
mbedtls_x509write_crt_free(mbedtls_x509write_cert * ctx)59 void mbedtls_x509write_crt_free( mbedtls_x509write_cert *ctx )
60 {
61 mbedtls_mpi_free( &ctx->serial );
62
63 mbedtls_asn1_free_named_data_list( &ctx->subject );
64 mbedtls_asn1_free_named_data_list( &ctx->issuer );
65 mbedtls_asn1_free_named_data_list( &ctx->extensions );
66
67 mbedtls_platform_zeroize( ctx, sizeof( mbedtls_x509write_cert ) );
68 }
69
mbedtls_x509write_crt_set_version(mbedtls_x509write_cert * ctx,int version)70 void mbedtls_x509write_crt_set_version( mbedtls_x509write_cert *ctx,
71 int version )
72 {
73 ctx->version = version;
74 }
75
mbedtls_x509write_crt_set_md_alg(mbedtls_x509write_cert * ctx,mbedtls_md_type_t md_alg)76 void mbedtls_x509write_crt_set_md_alg( mbedtls_x509write_cert *ctx,
77 mbedtls_md_type_t md_alg )
78 {
79 ctx->md_alg = md_alg;
80 }
81
mbedtls_x509write_crt_set_subject_key(mbedtls_x509write_cert * ctx,mbedtls_pk_context * key)82 void mbedtls_x509write_crt_set_subject_key( mbedtls_x509write_cert *ctx,
83 mbedtls_pk_context *key )
84 {
85 ctx->subject_key = key;
86 }
87
mbedtls_x509write_crt_set_issuer_key(mbedtls_x509write_cert * ctx,mbedtls_pk_context * key)88 void mbedtls_x509write_crt_set_issuer_key( mbedtls_x509write_cert *ctx,
89 mbedtls_pk_context *key )
90 {
91 ctx->issuer_key = key;
92 }
93
mbedtls_x509write_crt_set_subject_name(mbedtls_x509write_cert * ctx,const char * subject_name)94 int mbedtls_x509write_crt_set_subject_name( mbedtls_x509write_cert *ctx,
95 const char *subject_name )
96 {
97 return mbedtls_x509_string_to_names( &ctx->subject, subject_name );
98 }
99
mbedtls_x509write_crt_set_issuer_name(mbedtls_x509write_cert * ctx,const char * issuer_name)100 int mbedtls_x509write_crt_set_issuer_name( mbedtls_x509write_cert *ctx,
101 const char *issuer_name )
102 {
103 return mbedtls_x509_string_to_names( &ctx->issuer, issuer_name );
104 }
105
mbedtls_x509write_crt_set_serial(mbedtls_x509write_cert * ctx,const mbedtls_mpi * serial)106 int mbedtls_x509write_crt_set_serial( mbedtls_x509write_cert *ctx,
107 const mbedtls_mpi *serial )
108 {
109 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
110
111 if( ( ret = mbedtls_mpi_copy( &ctx->serial, serial ) ) != 0 )
112 return( ret );
113
114 return( 0 );
115 }
116
mbedtls_x509write_crt_set_validity(mbedtls_x509write_cert * ctx,const char * not_before,const char * not_after)117 int mbedtls_x509write_crt_set_validity( mbedtls_x509write_cert *ctx,
118 const char *not_before,
119 const char *not_after )
120 {
121 if( strlen( not_before ) != MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1 ||
122 strlen( not_after ) != MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1 )
123 {
124 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
125 }
126 strncpy( ctx->not_before, not_before, MBEDTLS_X509_RFC5280_UTC_TIME_LEN );
127 strncpy( ctx->not_after , not_after , MBEDTLS_X509_RFC5280_UTC_TIME_LEN );
128 ctx->not_before[MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
129 ctx->not_after[MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
130
131 return( 0 );
132 }
133
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)134 int mbedtls_x509write_crt_set_extension( mbedtls_x509write_cert *ctx,
135 const char *oid, size_t oid_len,
136 int critical,
137 const unsigned char *val, size_t val_len )
138 {
139 return( mbedtls_x509_set_extension( &ctx->extensions, oid, oid_len,
140 critical, val, val_len ) );
141 }
142
mbedtls_x509write_crt_set_basic_constraints(mbedtls_x509write_cert * ctx,int is_ca,int max_pathlen)143 int mbedtls_x509write_crt_set_basic_constraints( mbedtls_x509write_cert *ctx,
144 int is_ca, int max_pathlen )
145 {
146 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
147 unsigned char buf[9];
148 unsigned char *c = buf + sizeof(buf);
149 size_t len = 0;
150
151 memset( buf, 0, sizeof(buf) );
152
153 if( is_ca && max_pathlen > 127 )
154 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
155
156 if( is_ca )
157 {
158 if( max_pathlen >= 0 )
159 {
160 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf,
161 max_pathlen ) );
162 }
163 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_bool( &c, buf, 1 ) );
164 }
165
166 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
167 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf,
168 MBEDTLS_ASN1_CONSTRUCTED |
169 MBEDTLS_ASN1_SEQUENCE ) );
170
171 return(
172 mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_BASIC_CONSTRAINTS,
173 MBEDTLS_OID_SIZE( MBEDTLS_OID_BASIC_CONSTRAINTS ),
174 is_ca, buf + sizeof(buf) - len, len ) );
175 }
176
177 #if defined(MBEDTLS_HAS_ALG_SHA_1_VIA_MD_OR_PSA_BASED_ON_USE_PSA)
mbedtls_x509write_crt_set_key_identifier(mbedtls_x509write_cert * ctx,int is_ca,unsigned char tag)178 static int mbedtls_x509write_crt_set_key_identifier( mbedtls_x509write_cert *ctx,
179 int is_ca,
180 unsigned char tag )
181 {
182 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
183 unsigned char buf[MBEDTLS_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
184 unsigned char *c = buf + sizeof(buf);
185 size_t len = 0;
186 #if defined(MBEDTLS_USE_PSA_CRYPTO)
187 psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
188 size_t hash_length;
189 #endif /* MBEDTLS_USE_PSA_CRYPTO */
190
191 memset( buf, 0, sizeof(buf) );
192 MBEDTLS_ASN1_CHK_ADD( len,
193 mbedtls_pk_write_pubkey( &c,
194 buf,
195 is_ca ?
196 ctx->issuer_key :
197 ctx->subject_key ) );
198
199
200 #if defined(MBEDTLS_USE_PSA_CRYPTO)
201 status = psa_hash_compute( PSA_ALG_SHA_1,
202 buf + sizeof(buf) - len,
203 len,
204 buf + sizeof(buf) - 20,
205 20,
206 &hash_length );
207 if( status != PSA_SUCCESS )
208 {
209 return( MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED );
210 }
211 #else
212 ret = mbedtls_sha1( buf + sizeof( buf ) - len, len,
213 buf + sizeof( buf ) - 20 );
214 if( ret != 0 )
215 return( ret );
216 #endif /* MBEDTLS_USE_PSA_CRYPTO */
217
218 c = buf + sizeof( buf ) - 20;
219 len = 20;
220
221 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
222 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, tag ) );
223
224 if( is_ca ) // writes AuthorityKeyIdentifier sequence
225 {
226 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ));
227 MBEDTLS_ASN1_CHK_ADD( len,
228 mbedtls_asn1_write_tag( &c,
229 buf,
230 MBEDTLS_ASN1_CONSTRUCTED |
231 MBEDTLS_ASN1_SEQUENCE ) );
232 }
233
234 if( is_ca )
235 return( mbedtls_x509write_crt_set_extension( ctx,
236 MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER,
237 MBEDTLS_OID_SIZE( MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER ),
238 0, buf + sizeof(buf) - len, len ) );
239 else
240 return( mbedtls_x509write_crt_set_extension( ctx,
241 MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER,
242 MBEDTLS_OID_SIZE( MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER ),
243 0, buf + sizeof(buf) - len, len ) );
244 }
245
mbedtls_x509write_crt_set_subject_key_identifier(mbedtls_x509write_cert * ctx)246 int mbedtls_x509write_crt_set_subject_key_identifier( mbedtls_x509write_cert *ctx )
247 {
248 return mbedtls_x509write_crt_set_key_identifier( ctx,
249 0,
250 MBEDTLS_ASN1_OCTET_STRING );
251 }
252
mbedtls_x509write_crt_set_authority_key_identifier(mbedtls_x509write_cert * ctx)253 int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert *ctx )
254 {
255 return mbedtls_x509write_crt_set_key_identifier( ctx,
256 1,
257 (MBEDTLS_ASN1_CONTEXT_SPECIFIC | 0) );
258 }
259 #endif /* MBEDTLS_HAS_ALG_SHA_1_VIA_MD_OR_PSA_BASED_ON_USE_PSA */
260
mbedtls_x509write_crt_set_key_usage(mbedtls_x509write_cert * ctx,unsigned int key_usage)261 int mbedtls_x509write_crt_set_key_usage( mbedtls_x509write_cert *ctx,
262 unsigned int key_usage )
263 {
264 unsigned char buf[5] = {0}, ku[2] = {0};
265 unsigned char *c;
266 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
267 const unsigned int allowed_bits = MBEDTLS_X509_KU_DIGITAL_SIGNATURE |
268 MBEDTLS_X509_KU_NON_REPUDIATION |
269 MBEDTLS_X509_KU_KEY_ENCIPHERMENT |
270 MBEDTLS_X509_KU_DATA_ENCIPHERMENT |
271 MBEDTLS_X509_KU_KEY_AGREEMENT |
272 MBEDTLS_X509_KU_KEY_CERT_SIGN |
273 MBEDTLS_X509_KU_CRL_SIGN |
274 MBEDTLS_X509_KU_ENCIPHER_ONLY |
275 MBEDTLS_X509_KU_DECIPHER_ONLY;
276
277 /* Check that nothing other than the allowed flags is set */
278 if( ( key_usage & ~allowed_bits ) != 0 )
279 return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
280
281 c = buf + 5;
282 MBEDTLS_PUT_UINT16_LE( key_usage, ku, 0 );
283 ret = mbedtls_asn1_write_named_bitstring( &c, buf, ku, 9 );
284
285 if( ret < 0 )
286 return( ret );
287 else if( ret < 3 || ret > 5 )
288 return( MBEDTLS_ERR_X509_INVALID_FORMAT );
289
290 ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_KEY_USAGE,
291 MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ),
292 1, c, (size_t)ret );
293 if( ret != 0 )
294 return( ret );
295
296 return( 0 );
297 }
298
mbedtls_x509write_crt_set_ext_key_usage(mbedtls_x509write_cert * ctx,const mbedtls_asn1_sequence * exts)299 int mbedtls_x509write_crt_set_ext_key_usage( mbedtls_x509write_cert *ctx,
300 const mbedtls_asn1_sequence *exts )
301 {
302 unsigned char buf[256];
303 unsigned char *c = buf + sizeof(buf);
304 int ret;
305 size_t len = 0;
306 const mbedtls_asn1_sequence *last_ext = NULL;
307 const mbedtls_asn1_sequence *ext;
308
309 memset( buf, 0, sizeof(buf) );
310
311 /* We need at least one extension: SEQUENCE SIZE (1..MAX) OF KeyPurposeId */
312 if( exts == NULL )
313 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
314
315 /* Iterate over exts backwards, so we write them out in the requested order */
316 while( last_ext != exts )
317 {
318 for( ext = exts; ext->next != last_ext; ext = ext->next ) {}
319 if( ext->buf.tag != MBEDTLS_ASN1_OID )
320 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
321 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( &c, buf, ext->buf.p, ext->buf.len ) );
322 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, ext->buf.len ) );
323 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_OID ) );
324 last_ext = ext;
325 }
326
327 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
328 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
329
330 return mbedtls_x509write_crt_set_extension( ctx,
331 MBEDTLS_OID_EXTENDED_KEY_USAGE,
332 MBEDTLS_OID_SIZE( MBEDTLS_OID_EXTENDED_KEY_USAGE ),
333 1, c, len );
334 }
335
mbedtls_x509write_crt_set_ns_cert_type(mbedtls_x509write_cert * ctx,unsigned char ns_cert_type)336 int mbedtls_x509write_crt_set_ns_cert_type( mbedtls_x509write_cert *ctx,
337 unsigned char ns_cert_type )
338 {
339 unsigned char buf[4] = {0};
340 unsigned char *c;
341 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
342
343 c = buf + 4;
344
345 ret = mbedtls_asn1_write_named_bitstring( &c, buf, &ns_cert_type, 8 );
346 if( ret < 3 || ret > 4 )
347 return( ret );
348
349 ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_NS_CERT_TYPE,
350 MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ),
351 0, c, (size_t)ret );
352 if( ret != 0 )
353 return( ret );
354
355 return( 0 );
356 }
357
x509_write_time(unsigned char ** p,unsigned char * start,const char * t,size_t size)358 static int x509_write_time( unsigned char **p, unsigned char *start,
359 const char *t, size_t size )
360 {
361 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
362 size_t len = 0;
363
364 /*
365 * write MBEDTLS_ASN1_UTC_TIME if year < 2050 (2 bytes shorter)
366 */
367 if( t[0] < '2' || ( t[0] == '2' && t[1] == '0' && t[2] < '5' ) )
368 {
369 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
370 (const unsigned char *) t + 2,
371 size - 2 ) );
372 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
373 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start,
374 MBEDTLS_ASN1_UTC_TIME ) );
375 }
376 else
377 {
378 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
379 (const unsigned char *) t,
380 size ) );
381 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
382 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start,
383 MBEDTLS_ASN1_GENERALIZED_TIME ) );
384 }
385
386 return( (int) len );
387 }
388
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)389 int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx,
390 unsigned char *buf, size_t size,
391 int (*f_rng)(void *, unsigned char *, size_t),
392 void *p_rng )
393 {
394 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
395 const char *sig_oid;
396 size_t sig_oid_len = 0;
397 unsigned char *c, *c2;
398 unsigned char sig[MBEDTLS_PK_SIGNATURE_MAX_SIZE];
399 size_t hash_length = 0;
400 unsigned char hash[MBEDTLS_HASH_MAX_SIZE];
401 #if defined(MBEDTLS_USE_PSA_CRYPTO)
402 psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
403 psa_algorithm_t psa_algorithm;
404 #endif /* MBEDTLS_USE_PSA_CRYPTO */
405
406 size_t sub_len = 0, pub_len = 0, sig_and_oid_len = 0, sig_len;
407 size_t len = 0;
408 mbedtls_pk_type_t pk_alg;
409
410 /*
411 * Prepare data to be signed at the end of the target buffer
412 */
413 c = buf + size;
414
415 /* Signature algorithm needed in TBS, and later for actual signature */
416
417 /* There's no direct way of extracting a signature algorithm
418 * (represented as an element of mbedtls_pk_type_t) from a PK instance. */
419 if( mbedtls_pk_can_do( ctx->issuer_key, MBEDTLS_PK_RSA ) )
420 pk_alg = MBEDTLS_PK_RSA;
421 else if( mbedtls_pk_can_do( ctx->issuer_key, MBEDTLS_PK_ECDSA ) )
422 pk_alg = MBEDTLS_PK_ECDSA;
423 else
424 return( MBEDTLS_ERR_X509_INVALID_ALG );
425
426 if( ( ret = mbedtls_oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg,
427 &sig_oid, &sig_oid_len ) ) != 0 )
428 {
429 return( ret );
430 }
431
432 /*
433 * Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension
434 */
435
436 /* Only for v3 */
437 if( ctx->version == MBEDTLS_X509_CRT_VERSION_3 )
438 {
439 MBEDTLS_ASN1_CHK_ADD( len,
440 mbedtls_x509_write_extensions( &c,
441 buf, ctx->extensions ) );
442 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
443 MBEDTLS_ASN1_CHK_ADD( len,
444 mbedtls_asn1_write_tag( &c, buf,
445 MBEDTLS_ASN1_CONSTRUCTED |
446 MBEDTLS_ASN1_SEQUENCE ) );
447 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
448 MBEDTLS_ASN1_CHK_ADD( len,
449 mbedtls_asn1_write_tag( &c, buf,
450 MBEDTLS_ASN1_CONTEXT_SPECIFIC |
451 MBEDTLS_ASN1_CONSTRUCTED | 3 ) );
452 }
453
454 /*
455 * SubjectPublicKeyInfo
456 */
457 MBEDTLS_ASN1_CHK_ADD( pub_len,
458 mbedtls_pk_write_pubkey_der( ctx->subject_key,
459 buf, c - buf ) );
460 c -= pub_len;
461 len += pub_len;
462
463 /*
464 * Subject ::= Name
465 */
466 MBEDTLS_ASN1_CHK_ADD( len,
467 mbedtls_x509_write_names( &c, buf,
468 ctx->subject ) );
469
470 /*
471 * Validity ::= SEQUENCE {
472 * notBefore Time,
473 * notAfter Time }
474 */
475 sub_len = 0;
476
477 MBEDTLS_ASN1_CHK_ADD( sub_len,
478 x509_write_time( &c, buf, ctx->not_after,
479 MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) );
480
481 MBEDTLS_ASN1_CHK_ADD( sub_len,
482 x509_write_time( &c, buf, ctx->not_before,
483 MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) );
484
485 len += sub_len;
486 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, sub_len ) );
487 MBEDTLS_ASN1_CHK_ADD( len,
488 mbedtls_asn1_write_tag( &c, buf,
489 MBEDTLS_ASN1_CONSTRUCTED |
490 MBEDTLS_ASN1_SEQUENCE ) );
491
492 /*
493 * Issuer ::= Name
494 */
495 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, buf,
496 ctx->issuer ) );
497
498 /*
499 * Signature ::= AlgorithmIdentifier
500 */
501 MBEDTLS_ASN1_CHK_ADD( len,
502 mbedtls_asn1_write_algorithm_identifier( &c, buf,
503 sig_oid, strlen( sig_oid ), 0 ) );
504
505 /*
506 * Serial ::= INTEGER
507 */
508 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf,
509 &ctx->serial ) );
510
511 /*
512 * Version ::= INTEGER { v1(0), v2(1), v3(2) }
513 */
514
515 /* Can be omitted for v1 */
516 if( ctx->version != MBEDTLS_X509_CRT_VERSION_1 )
517 {
518 sub_len = 0;
519 MBEDTLS_ASN1_CHK_ADD( sub_len,
520 mbedtls_asn1_write_int( &c, buf, ctx->version ) );
521 len += sub_len;
522 MBEDTLS_ASN1_CHK_ADD( len,
523 mbedtls_asn1_write_len( &c, buf, sub_len ) );
524 MBEDTLS_ASN1_CHK_ADD( len,
525 mbedtls_asn1_write_tag( &c, buf,
526 MBEDTLS_ASN1_CONTEXT_SPECIFIC |
527 MBEDTLS_ASN1_CONSTRUCTED | 0 ) );
528 }
529
530 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
531 MBEDTLS_ASN1_CHK_ADD( len,
532 mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED |
533 MBEDTLS_ASN1_SEQUENCE ) );
534
535 /*
536 * Make signature
537 */
538
539 /* Compute hash of CRT. */
540 #if defined(MBEDTLS_USE_PSA_CRYPTO)
541 psa_algorithm = mbedtls_hash_info_psa_from_md( ctx->md_alg );
542
543 status = psa_hash_compute( psa_algorithm,
544 c,
545 len,
546 hash,
547 sizeof( hash ),
548 &hash_length );
549 if( status != PSA_SUCCESS )
550 {
551 return( MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED );
552 }
553 #else
554 if( ( ret = mbedtls_md( mbedtls_md_info_from_type( ctx->md_alg ), c,
555 len, hash ) ) != 0 )
556 {
557 return( ret );
558 }
559 #endif /* MBEDTLS_USE_PSA_CRYPTO */
560
561
562 if( ( ret = mbedtls_pk_sign( ctx->issuer_key, ctx->md_alg,
563 hash, hash_length, sig, sizeof( sig ), &sig_len,
564 f_rng, p_rng ) ) != 0 )
565 {
566 return( ret );
567 }
568
569 /* Move CRT to the front of the buffer to have space
570 * for the signature. */
571 memmove( buf, c, len );
572 c = buf + len;
573
574 /* Add signature at the end of the buffer,
575 * making sure that it doesn't underflow
576 * into the CRT buffer. */
577 c2 = buf + size;
578 MBEDTLS_ASN1_CHK_ADD( sig_and_oid_len, mbedtls_x509_write_sig( &c2, c,
579 sig_oid, sig_oid_len, sig, sig_len ) );
580
581 /*
582 * Memory layout after this step:
583 *
584 * buf c=buf+len c2 buf+size
585 * [CRT0,...,CRTn, UNUSED, ..., UNUSED, SIG0, ..., SIGm]
586 */
587
588 /* Move raw CRT to just before the signature. */
589 c = c2 - len;
590 memmove( c, buf, len );
591
592 len += sig_and_oid_len;
593 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
594 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf,
595 MBEDTLS_ASN1_CONSTRUCTED |
596 MBEDTLS_ASN1_SEQUENCE ) );
597
598 return( (int) len );
599 }
600
601 #define PEM_BEGIN_CRT "-----BEGIN CERTIFICATE-----\n"
602 #define PEM_END_CRT "-----END CERTIFICATE-----\n"
603
604 #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)605 int mbedtls_x509write_crt_pem( mbedtls_x509write_cert *crt,
606 unsigned char *buf, size_t size,
607 int (*f_rng)(void *, unsigned char *, size_t),
608 void *p_rng )
609 {
610 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
611 size_t olen;
612
613 if( ( ret = mbedtls_x509write_crt_der( crt, buf, size,
614 f_rng, p_rng ) ) < 0 )
615 {
616 return( ret );
617 }
618
619 if( ( ret = mbedtls_pem_write_buffer( PEM_BEGIN_CRT, PEM_END_CRT,
620 buf + size - ret, ret,
621 buf, size, &olen ) ) != 0 )
622 {
623 return( ret );
624 }
625
626 return( 0 );
627 }
628 #endif /* MBEDTLS_PEM_WRITE_C */
629
630 #endif /* MBEDTLS_X509_CRT_WRITE_C */
631
