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[RRG-proxmark3.git] / common / mbedtls / x509write_crt.c
blob80797578b96babafa4468e55934e869e9e6a5e8f
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 void mbedtls_x509write_crt_init(mbedtls_x509write_cert *ctx) {
44 memset(ctx, 0, sizeof(mbedtls_x509write_cert));
45
46 mbedtls_mpi_init(&ctx->serial);
47 ctx->version = MBEDTLS_X509_CRT_VERSION_3;
48 }
49
50 void mbedtls_x509write_crt_free(mbedtls_x509write_cert *ctx) {
51 mbedtls_mpi_free(&ctx->serial);
52
53 mbedtls_asn1_free_named_data_list(&ctx->subject);
54 mbedtls_asn1_free_named_data_list(&ctx->issuer);
55 mbedtls_asn1_free_named_data_list(&ctx->extensions);
56
57 mbedtls_platform_zeroize(ctx, sizeof(mbedtls_x509write_cert));
58 }
59
60 void mbedtls_x509write_crt_set_version(mbedtls_x509write_cert *ctx,
61 int version) {
62 ctx->version = version;
63 }
64
65 void mbedtls_x509write_crt_set_md_alg(mbedtls_x509write_cert *ctx,
66 mbedtls_md_type_t md_alg) {
67 ctx->md_alg = md_alg;
68 }
69
70 void mbedtls_x509write_crt_set_subject_key(mbedtls_x509write_cert *ctx,
71 mbedtls_pk_context *key) {
72 ctx->subject_key = key;
73 }
74
75 void mbedtls_x509write_crt_set_issuer_key(mbedtls_x509write_cert *ctx,
76 mbedtls_pk_context *key) {
77 ctx->issuer_key = key;
78 }
79
80 int mbedtls_x509write_crt_set_subject_name(mbedtls_x509write_cert *ctx,
81 const char *subject_name) {
82 return mbedtls_x509_string_to_names(&ctx->subject, subject_name);
83 }
84
85 int mbedtls_x509write_crt_set_issuer_name(mbedtls_x509write_cert *ctx,
86 const char *issuer_name) {
87 return mbedtls_x509_string_to_names(&ctx->issuer, issuer_name);
88 }
89
90 int mbedtls_x509write_crt_set_serial(mbedtls_x509write_cert *ctx,
91 const mbedtls_mpi *serial) {
92 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
93
94 if ((ret = mbedtls_mpi_copy(&ctx->serial, serial)) != 0)
95 return (ret);
96
97 return (0);
98 }
99
100 int mbedtls_x509write_crt_set_validity(mbedtls_x509write_cert *ctx,
101 const char *not_before,
102 const char *not_after) {
103 if (strlen(not_before) != MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1 ||
104 strlen(not_after) != MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1) {
105 return (MBEDTLS_ERR_X509_BAD_INPUT_DATA);
106 }
107 strncpy(ctx->not_before, not_before, MBEDTLS_X509_RFC5280_UTC_TIME_LEN);
108 strncpy(ctx->not_after, not_after, MBEDTLS_X509_RFC5280_UTC_TIME_LEN);
109 ctx->not_before[MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
110 ctx->not_after[MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
111
112 return (0);
113 }
114
115 int mbedtls_x509write_crt_set_extension(mbedtls_x509write_cert *ctx,
116 const char *oid, size_t oid_len,
117 int critical,
118 const unsigned char *val, size_t val_len) {
119 return (mbedtls_x509_set_extension(&ctx->extensions, oid, oid_len,
120 critical, val, val_len));
121 }
122
123 int mbedtls_x509write_crt_set_basic_constraints(mbedtls_x509write_cert *ctx,
124 int is_ca, int max_pathlen) {
125 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
126 unsigned char buf[9];
127 unsigned char *c = buf + sizeof(buf);
128 size_t len = 0;
129
130 memset(buf, 0, sizeof(buf));
131
132 if (is_ca && max_pathlen > 127)
133 return (MBEDTLS_ERR_X509_BAD_INPUT_DATA);
134
135 if (is_ca) {
136 if (max_pathlen >= 0) {
137 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(&c, buf,
138 max_pathlen));
139 }
140 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_bool(&c, buf, 1));
141 }
142
143 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
144 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c, buf,
145 MBEDTLS_ASN1_CONSTRUCTED |
146 MBEDTLS_ASN1_SEQUENCE));
147
148 return (
149 mbedtls_x509write_crt_set_extension(ctx, MBEDTLS_OID_BASIC_CONSTRAINTS,
150 MBEDTLS_OID_SIZE(MBEDTLS_OID_BASIC_CONSTRAINTS),
151 is_ca, buf + sizeof(buf) - len, len));
152 }
153
154 #if defined(MBEDTLS_SHA1_C)
155 int mbedtls_x509write_crt_set_subject_key_identifier(mbedtls_x509write_cert *ctx) {
156 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
157 unsigned char buf[MBEDTLS_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
158 unsigned char *c = buf + sizeof(buf);
159 size_t len = 0;
160
161 memset(buf, 0, sizeof(buf));
162 MBEDTLS_ASN1_CHK_ADD(len,
163 mbedtls_pk_write_pubkey(&c, buf, ctx->subject_key));
164
165 ret = mbedtls_sha1_ret(buf + sizeof(buf) - len, len,
166 buf + sizeof(buf) - 20);
167 if (ret != 0)
168 return (ret);
169 c = buf + sizeof(buf) - 20;
170 len = 20;
171
172 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
173 MBEDTLS_ASN1_CHK_ADD(len,
174 mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_OCTET_STRING));
175
176 return mbedtls_x509write_crt_set_extension(ctx,
177 MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER,
178 MBEDTLS_OID_SIZE(MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER),
179 0, buf + sizeof(buf) - len, len);
180 }
181
182 int mbedtls_x509write_crt_set_authority_key_identifier(mbedtls_x509write_cert *ctx) {
183 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
184 unsigned char buf[MBEDTLS_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
185 unsigned char *c = buf + sizeof(buf);
186 size_t len = 0;
187
188 memset(buf, 0, sizeof(buf));
189 MBEDTLS_ASN1_CHK_ADD(len,
190 mbedtls_pk_write_pubkey(&c, buf, ctx->issuer_key));
191
192 ret = mbedtls_sha1_ret(buf + sizeof(buf) - len, len,
193 buf + sizeof(buf) - 20);
194 if (ret != 0)
195 return (ret);
196 c = buf + sizeof(buf) - 20;
197 len = 20;
198
199 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
200 MBEDTLS_ASN1_CHK_ADD(len,
201 mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | 0));
202
203 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
204 MBEDTLS_ASN1_CHK_ADD(len,
205 mbedtls_asn1_write_tag(&c, buf,
206 MBEDTLS_ASN1_CONSTRUCTED |
207 MBEDTLS_ASN1_SEQUENCE));
208
209 return mbedtls_x509write_crt_set_extension(
210 ctx, MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER,
211 MBEDTLS_OID_SIZE(MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER),
212 0, buf + sizeof(buf) - len, len);
213 }
214 #endif /* MBEDTLS_SHA1_C */
215
216 int mbedtls_x509write_crt_set_key_usage(mbedtls_x509write_cert *ctx,
217 unsigned int key_usage) {
218 unsigned char buf[5], ku[2];
219 unsigned char *c;
220 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
221 const unsigned int allowed_bits = MBEDTLS_X509_KU_DIGITAL_SIGNATURE |
222 MBEDTLS_X509_KU_NON_REPUDIATION |
223 MBEDTLS_X509_KU_KEY_ENCIPHERMENT |
224 MBEDTLS_X509_KU_DATA_ENCIPHERMENT |
225 MBEDTLS_X509_KU_KEY_AGREEMENT |
226 MBEDTLS_X509_KU_KEY_CERT_SIGN |
227 MBEDTLS_X509_KU_CRL_SIGN |
228 MBEDTLS_X509_KU_ENCIPHER_ONLY |
229 MBEDTLS_X509_KU_DECIPHER_ONLY;
230
231 /* Check that nothing other than the allowed flags is set */
232 if ((key_usage & ~allowed_bits) != 0)
233 return (MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE);
234
235 c = buf + 5;
236 ku[0] = (unsigned char)(key_usage);
237 ku[1] = (unsigned char)(key_usage >> 8);
238 ret = mbedtls_asn1_write_named_bitstring(&c, buf, ku, 9);
239
240 if (ret < 0)
241 return (ret);
242 else if (ret < 3 || ret > 5)
243 return (MBEDTLS_ERR_X509_INVALID_FORMAT);
244
245 ret = mbedtls_x509write_crt_set_extension(ctx, MBEDTLS_OID_KEY_USAGE,
246 MBEDTLS_OID_SIZE(MBEDTLS_OID_KEY_USAGE),
247 1, c, (size_t)ret);
248 if (ret != 0)
249 return (ret);
250
251 return (0);
252 }
253
254 int mbedtls_x509write_crt_set_ns_cert_type(mbedtls_x509write_cert *ctx,
255 unsigned char ns_cert_type) {
256 unsigned char buf[4];
257 unsigned char *c;
258 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
259
260 c = buf + 4;
261
262 ret = mbedtls_asn1_write_named_bitstring(&c, buf, &ns_cert_type, 8);
263 if (ret < 3 || ret > 4)
264 return (ret);
265
266 ret = mbedtls_x509write_crt_set_extension(ctx, MBEDTLS_OID_NS_CERT_TYPE,
267 MBEDTLS_OID_SIZE(MBEDTLS_OID_NS_CERT_TYPE),
268 0, c, (size_t)ret);
269 if (ret != 0)
270 return (ret);
271
272 return (0);
273 }
274
275 static int x509_write_time(unsigned char **p, unsigned char *start,
276 const char *t, size_t size) {
277 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
278 size_t len = 0;
279
280 /*
281 * write MBEDTLS_ASN1_UTC_TIME if year < 2050 (2 bytes shorter)
282 */
283 if (t[0] == '2' && t[1] == '0' && t[2] < '5') {
284 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start,
285 (const unsigned char *) t + 2,
286 size - 2));
287 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
288 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start,
289 MBEDTLS_ASN1_UTC_TIME));
290 } else {
291 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start,
292 (const unsigned char *) t,
293 size));
294 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
295 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start,
296 MBEDTLS_ASN1_GENERALIZED_TIME));
297 }
298
299 return ((int) len);
300 }
301
302 int mbedtls_x509write_crt_der(mbedtls_x509write_cert *ctx,
303 unsigned char *buf, size_t size,
304 int (*f_rng)(void *, unsigned char *, size_t),
305 void *p_rng) {
306 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
307 const char *sig_oid;
308 size_t sig_oid_len = 0;
309 unsigned char *c, *c2;
310 unsigned char hash[64];
311 unsigned char sig[MBEDTLS_PK_SIGNATURE_MAX_SIZE];
312 size_t sub_len = 0, pub_len = 0, sig_and_oid_len = 0, sig_len;
313 size_t len = 0;
314 mbedtls_pk_type_t pk_alg;
315
316 /*
317 * Prepare data to be signed at the end of the target buffer
318 */
319 c = buf + size;
320
321 /* Signature algorithm needed in TBS, and later for actual signature */
322
323 /* There's no direct way of extracting a signature algorithm
324 * (represented as an element of mbedtls_pk_type_t) from a PK instance. */
325 if (mbedtls_pk_can_do(ctx->issuer_key, MBEDTLS_PK_RSA))
326 pk_alg = MBEDTLS_PK_RSA;
327 else if (mbedtls_pk_can_do(ctx->issuer_key, MBEDTLS_PK_ECDSA))
328 pk_alg = MBEDTLS_PK_ECDSA;
329 else
330 return (MBEDTLS_ERR_X509_INVALID_ALG);
331
332 if ((ret = mbedtls_oid_get_oid_by_sig_alg(pk_alg, ctx->md_alg,
333 &sig_oid, &sig_oid_len)) != 0) {
334 return (ret);
335 }
336
337 /*
338 * Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension
339 */
340
341 /* Only for v3 */
342 if (ctx->version == MBEDTLS_X509_CRT_VERSION_3) {
343 MBEDTLS_ASN1_CHK_ADD(len,
344 mbedtls_x509_write_extensions(&c,
345 buf, ctx->extensions));
346 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
347 MBEDTLS_ASN1_CHK_ADD(len,
348 mbedtls_asn1_write_tag(&c, buf,
349 MBEDTLS_ASN1_CONSTRUCTED |
350 MBEDTLS_ASN1_SEQUENCE));
351 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
352 MBEDTLS_ASN1_CHK_ADD(len,
353 mbedtls_asn1_write_tag(&c, buf,
354 MBEDTLS_ASN1_CONTEXT_SPECIFIC |
355 MBEDTLS_ASN1_CONSTRUCTED | 3));
356 }
357
358 /*
359 * SubjectPublicKeyInfo
360 */
361 MBEDTLS_ASN1_CHK_ADD(pub_len,
362 mbedtls_pk_write_pubkey_der(ctx->subject_key,
363 buf, c - buf));
364 c -= pub_len;
365 len += pub_len;
366
367 /*
368 * Subject ::= Name
369 */
370 MBEDTLS_ASN1_CHK_ADD(len,
371 mbedtls_x509_write_names(&c, buf,
372 ctx->subject));
373
374 /*
375 * Validity ::= SEQUENCE {
376 * notBefore Time,
377 * notAfter Time }
378 */
379 sub_len = 0;
380
381 MBEDTLS_ASN1_CHK_ADD(sub_len,
382 x509_write_time(&c, buf, ctx->not_after,
383 MBEDTLS_X509_RFC5280_UTC_TIME_LEN));
384
385 MBEDTLS_ASN1_CHK_ADD(sub_len,
386 x509_write_time(&c, buf, ctx->not_before,
387 MBEDTLS_X509_RFC5280_UTC_TIME_LEN));
388
389 len += sub_len;
390 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, sub_len));
391 MBEDTLS_ASN1_CHK_ADD(len,
392 mbedtls_asn1_write_tag(&c, buf,
393 MBEDTLS_ASN1_CONSTRUCTED |
394 MBEDTLS_ASN1_SEQUENCE));
395
396 /*
397 * Issuer ::= Name
398 */
399 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_x509_write_names(&c, buf,
400 ctx->issuer));
401
402 /*
403 * Signature ::= AlgorithmIdentifier
404 */
405 MBEDTLS_ASN1_CHK_ADD(len,
406 mbedtls_asn1_write_algorithm_identifier(&c, buf,
407 sig_oid, strlen(sig_oid), 0));
408
409 /*
410 * Serial ::= INTEGER
411 */
412 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_mpi(&c, buf,
413 &ctx->serial));
414
415 /*
416 * Version ::= INTEGER { v1(0), v2(1), v3(2) }
417 */
418
419 /* Can be omitted for v1 */
420 if (ctx->version != MBEDTLS_X509_CRT_VERSION_1) {
421 sub_len = 0;
422 MBEDTLS_ASN1_CHK_ADD(sub_len,
423 mbedtls_asn1_write_int(&c, buf, ctx->version));
424 len += sub_len;
425 MBEDTLS_ASN1_CHK_ADD(len,
426 mbedtls_asn1_write_len(&c, buf, sub_len));
427 MBEDTLS_ASN1_CHK_ADD(len,
428 mbedtls_asn1_write_tag(&c, buf,
429 MBEDTLS_ASN1_CONTEXT_SPECIFIC |
430 MBEDTLS_ASN1_CONSTRUCTED | 0));
431 }
432
433 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
434 MBEDTLS_ASN1_CHK_ADD(len,
435 mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_CONSTRUCTED |
436 MBEDTLS_ASN1_SEQUENCE));
437
438 /*
439 * Make signature
440 */
441
442 /* Compute hash of CRT. */
443 if ((ret = mbedtls_md(mbedtls_md_info_from_type(ctx->md_alg), c,
444 len, hash)) != 0) {
445 return (ret);
446 }
447
448 if ((ret = mbedtls_pk_sign(ctx->issuer_key, ctx->md_alg,
449 hash, 0, sig, &sig_len,
450 f_rng, p_rng)) != 0) {
451 return (ret);
452 }
453
454 /* Move CRT to the front of the buffer to have space
455 * for the signature. */
456 memmove(buf, c, len);
457 c = buf + len;
458
459 /* Add signature at the end of the buffer,
460 * making sure that it doesn't underflow
461 * into the CRT buffer. */
462 c2 = buf + size;
463 MBEDTLS_ASN1_CHK_ADD(sig_and_oid_len, mbedtls_x509_write_sig(&c2, c,
464 sig_oid, sig_oid_len, sig, sig_len));
465
466 /*
467 * Memory layout after this step:
468 *
469 * buf c=buf+len c2 buf+size
470 * [CRT0,...,CRTn, UNUSED, ..., UNUSED, SIG0, ..., SIGm]
471 */
472
473 /* Move raw CRT to just before the signature. */
474 c = c2 - len;
475 memmove(c, buf, len);
476
477 len += sig_and_oid_len;
478 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
479 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c, buf,
480 MBEDTLS_ASN1_CONSTRUCTED |
481 MBEDTLS_ASN1_SEQUENCE));
482
483 return ((int) len);
484 }
485
486 #define PEM_BEGIN_CRT "-----BEGIN CERTIFICATE-----\n"
487 #define PEM_END_CRT "-----END CERTIFICATE-----\n"
488
489 #if defined(MBEDTLS_PEM_WRITE_C)
490 int mbedtls_x509write_crt_pem(mbedtls_x509write_cert *crt,
491 unsigned char *buf, size_t size,
492 int (*f_rng)(void *, unsigned char *, size_t),
493 void *p_rng) {
494 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
495 size_t olen;
496
497 if ((ret = mbedtls_x509write_crt_der(crt, buf, size,
498 f_rng, p_rng)) < 0) {
499 return (ret);
500 }
501
502 if ((ret = mbedtls_pem_write_buffer(PEM_BEGIN_CRT, PEM_END_CRT,
503 buf + size - ret, ret,
504 buf, size, &olen)) != 0) {
505 return (ret);
506 }
507
508 return (0);
509 }
510 #endif /* MBEDTLS_PEM_WRITE_C */
511
512 #endif /* MBEDTLS_X509_CRT_WRITE_C */
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