1 /*
2 * X.509 base functions for creating certificates / CSRs
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6 */
7
8 #include "x509_internal.h"
9
10 #if defined(MBEDTLS_X509_CREATE_C)
11
12 #include "mbedtls/asn1write.h"
13 #include "mbedtls/error.h"
14 #include "mbedtls/oid.h"
15 #include "x509_oid.h"
16
17 #include <limits.h>
18 #include <string.h>
19
20 #include "mbedtls/platform.h"
21
22 #include "mbedtls/asn1.h"
23
24 /* Structure linking OIDs for X.509 DN AttributeTypes to their
25 * string representations and default string encodings used by Mbed TLS. */
26 typedef struct {
27 const char *name; /* String representation of AttributeType, e.g.
28 * "CN" or "emailAddress". */
29 size_t name_len; /* Length of 'name', without trailing 0 byte. */
30 const char *oid; /* String representation of OID of AttributeType,
31 * as per RFC 5280, Appendix A.1. encoded as per
32 * X.690 */
33 int default_tag; /* The default character encoding used for the
34 * given attribute type, e.g.
35 * MBEDTLS_ASN1_UTF8_STRING for UTF-8. */
36 } x509_attr_descriptor_t;
37
38 #define ADD_STRLEN(s) s, sizeof(s) - 1
39
40 /* X.509 DN attributes from RFC 5280, Appendix A.1. */
41 static const x509_attr_descriptor_t x509_attrs[] =
42 {
43 { ADD_STRLEN("CN"),
44 MBEDTLS_OID_AT_CN, MBEDTLS_ASN1_UTF8_STRING },
45 { ADD_STRLEN("commonName"),
46 MBEDTLS_OID_AT_CN, MBEDTLS_ASN1_UTF8_STRING },
47 { ADD_STRLEN("C"),
48 MBEDTLS_OID_AT_COUNTRY, MBEDTLS_ASN1_PRINTABLE_STRING },
49 { ADD_STRLEN("countryName"),
50 MBEDTLS_OID_AT_COUNTRY, MBEDTLS_ASN1_PRINTABLE_STRING },
51 { ADD_STRLEN("O"),
52 MBEDTLS_OID_AT_ORGANIZATION, MBEDTLS_ASN1_UTF8_STRING },
53 { ADD_STRLEN("organizationName"),
54 MBEDTLS_OID_AT_ORGANIZATION, MBEDTLS_ASN1_UTF8_STRING },
55 { ADD_STRLEN("L"),
56 MBEDTLS_OID_AT_LOCALITY, MBEDTLS_ASN1_UTF8_STRING },
57 { ADD_STRLEN("locality"),
58 MBEDTLS_OID_AT_LOCALITY, MBEDTLS_ASN1_UTF8_STRING },
59 { ADD_STRLEN("R"),
60 MBEDTLS_OID_PKCS9_EMAIL, MBEDTLS_ASN1_IA5_STRING },
61 { ADD_STRLEN("OU"),
62 MBEDTLS_OID_AT_ORG_UNIT, MBEDTLS_ASN1_UTF8_STRING },
63 { ADD_STRLEN("organizationalUnitName"),
64 MBEDTLS_OID_AT_ORG_UNIT, MBEDTLS_ASN1_UTF8_STRING },
65 { ADD_STRLEN("ST"),
66 MBEDTLS_OID_AT_STATE, MBEDTLS_ASN1_UTF8_STRING },
67 { ADD_STRLEN("stateOrProvinceName"),
68 MBEDTLS_OID_AT_STATE, MBEDTLS_ASN1_UTF8_STRING },
69 { ADD_STRLEN("emailAddress"),
70 MBEDTLS_OID_PKCS9_EMAIL, MBEDTLS_ASN1_IA5_STRING },
71 { ADD_STRLEN("serialNumber"),
72 MBEDTLS_OID_AT_SERIAL_NUMBER, MBEDTLS_ASN1_PRINTABLE_STRING },
73 { ADD_STRLEN("postalAddress"),
74 MBEDTLS_OID_AT_POSTAL_ADDRESS, MBEDTLS_ASN1_PRINTABLE_STRING },
75 { ADD_STRLEN("postalCode"),
76 MBEDTLS_OID_AT_POSTAL_CODE, MBEDTLS_ASN1_PRINTABLE_STRING },
77 { ADD_STRLEN("dnQualifier"),
78 MBEDTLS_OID_AT_DN_QUALIFIER, MBEDTLS_ASN1_PRINTABLE_STRING },
79 { ADD_STRLEN("title"),
80 MBEDTLS_OID_AT_TITLE, MBEDTLS_ASN1_UTF8_STRING },
81 { ADD_STRLEN("surName"),
82 MBEDTLS_OID_AT_SUR_NAME, MBEDTLS_ASN1_UTF8_STRING },
83 { ADD_STRLEN("SN"),
84 MBEDTLS_OID_AT_SUR_NAME, MBEDTLS_ASN1_UTF8_STRING },
85 { ADD_STRLEN("givenName"),
86 MBEDTLS_OID_AT_GIVEN_NAME, MBEDTLS_ASN1_UTF8_STRING },
87 { ADD_STRLEN("GN"),
88 MBEDTLS_OID_AT_GIVEN_NAME, MBEDTLS_ASN1_UTF8_STRING },
89 { ADD_STRLEN("initials"),
90 MBEDTLS_OID_AT_INITIALS, MBEDTLS_ASN1_UTF8_STRING },
91 { ADD_STRLEN("pseudonym"),
92 MBEDTLS_OID_AT_PSEUDONYM, MBEDTLS_ASN1_UTF8_STRING },
93 { ADD_STRLEN("generationQualifier"),
94 MBEDTLS_OID_AT_GENERATION_QUALIFIER, MBEDTLS_ASN1_UTF8_STRING },
95 { ADD_STRLEN("domainComponent"),
96 MBEDTLS_OID_DOMAIN_COMPONENT, MBEDTLS_ASN1_IA5_STRING },
97 { ADD_STRLEN("DC"),
98 MBEDTLS_OID_DOMAIN_COMPONENT, MBEDTLS_ASN1_IA5_STRING },
99 { NULL, 0, NULL, MBEDTLS_ASN1_NULL }
100 };
101
x509_attr_descr_from_name(const char * name,size_t name_len)102 static const x509_attr_descriptor_t *x509_attr_descr_from_name(const char *name, size_t name_len)
103 {
104 const x509_attr_descriptor_t *cur;
105
106 for (cur = x509_attrs; cur->name != NULL; cur++) {
107 if (cur->name_len == name_len &&
108 strncmp(cur->name, name, name_len) == 0) {
109 break;
110 }
111 }
112
113 if (cur->name == NULL) {
114 return NULL;
115 }
116
117 return cur;
118 }
119
hex_to_int(char c)120 static int hex_to_int(char c)
121 {
122 return ('0' <= c && c <= '9') ? (c - '0') :
123 ('a' <= c && c <= 'f') ? (c - 'a' + 10) :
124 ('A' <= c && c <= 'F') ? (c - 'A' + 10) : -1;
125 }
126
hexpair_to_int(const char * hexpair)127 static int hexpair_to_int(const char *hexpair)
128 {
129 int n1 = hex_to_int(*hexpair);
130 int n2 = hex_to_int(*(hexpair + 1));
131
132 if (n1 != -1 && n2 != -1) {
133 return (n1 << 4) | n2;
134 } else {
135 return -1;
136 }
137 }
138
parse_attribute_value_string(const char * s,int len,unsigned char * data,size_t * data_len)139 static int parse_attribute_value_string(const char *s,
140 int len,
141 unsigned char *data,
142 size_t *data_len)
143 {
144 const char *c;
145 const char *end = s + len;
146 unsigned char *d = data;
147 int n;
148
149 for (c = s; c < end; c++) {
150 if (*c == '\\') {
151 c++;
152
153 /* Check for valid escaped characters as per RFC 4514 Section 3 */
154 if (c + 1 < end && (n = hexpair_to_int(c)) != -1) {
155 if (n == 0) {
156 return MBEDTLS_ERR_X509_INVALID_NAME;
157 }
158 *(d++) = n;
159 c++;
160 } else if (c < end && strchr(" ,=+<>#;\"\\", *c)) {
161 *(d++) = *c;
162 } else {
163 return MBEDTLS_ERR_X509_INVALID_NAME;
164 }
165 } else {
166 *(d++) = *c;
167 }
168
169 if (d - data == MBEDTLS_X509_MAX_DN_NAME_SIZE) {
170 return MBEDTLS_ERR_X509_INVALID_NAME;
171 }
172 }
173 *data_len = (size_t) (d - data);
174 return 0;
175 }
176
177 /** Parse a hexstring containing a DER-encoded string.
178 *
179 * \param s A string of \p len bytes hexadecimal digits.
180 * \param len Number of bytes to read from \p s.
181 * \param data Output buffer of size \p data_size.
182 * On success, it contains the payload that's DER-encoded
183 * in the input (content without the tag and length).
184 * If the DER tag is a string tag, the payload is guaranteed
185 * not to contain null bytes.
186 * \param data_size Length of the \p data buffer.
187 * \param data_len On success, the length of the parsed string.
188 * It is guaranteed to be less than
189 * #MBEDTLS_X509_MAX_DN_NAME_SIZE.
190 * \param tag The ASN.1 tag that the payload in \p data is encoded in.
191 *
192 * \retval 0 on success.
193 * \retval #MBEDTLS_ERR_X509_INVALID_NAME if \p s does not contain
194 * a valid hexstring,
195 * or if the decoded hexstring is not valid DER,
196 * or if the payload does not fit in \p data,
197 * or if the payload is more than
198 * #MBEDTLS_X509_MAX_DN_NAME_SIZE bytes,
199 * of if \p *tag is an ASN.1 string tag and the payload
200 * contains a null byte.
201 * \retval #MBEDTLS_ERR_X509_ALLOC_FAILED on low memory.
202 */
parse_attribute_value_hex_der_encoded(const char * s,size_t len,unsigned char * data,size_t data_size,size_t * data_len,int * tag)203 static int parse_attribute_value_hex_der_encoded(const char *s,
204 size_t len,
205 unsigned char *data,
206 size_t data_size,
207 size_t *data_len,
208 int *tag)
209 {
210 /* Step 1: preliminary length checks. */
211 /* Each byte is encoded by exactly two hexadecimal digits. */
212 if (len % 2 != 0) {
213 /* Odd number of hex digits */
214 return MBEDTLS_ERR_X509_INVALID_NAME;
215 }
216 size_t const der_length = len / 2;
217 if (der_length > MBEDTLS_X509_MAX_DN_NAME_SIZE + 4) {
218 /* The payload would be more than MBEDTLS_X509_MAX_DN_NAME_SIZE
219 * (after subtracting the ASN.1 tag and length). Reject this early
220 * to avoid allocating a large intermediate buffer. */
221 return MBEDTLS_ERR_X509_INVALID_NAME;
222 }
223 if (der_length < 1) {
224 /* Avoid empty-buffer shenanigans. A valid DER encoding is never
225 * empty. */
226 return MBEDTLS_ERR_X509_INVALID_NAME;
227 }
228
229 /* Step 2: Decode the hex string into an intermediate buffer. */
230 unsigned char *der = mbedtls_calloc(1, der_length);
231 if (der == NULL) {
232 return MBEDTLS_ERR_X509_ALLOC_FAILED;
233 }
234 /* Beyond this point, der needs to be freed on exit. */
235 for (size_t i = 0; i < der_length; i++) {
236 int c = hexpair_to_int(s + 2 * i);
237 if (c < 0) {
238 goto error;
239 }
240 der[i] = c;
241 }
242
243 /* Step 3: decode the DER. */
244 /* We've checked that der_length >= 1 above. */
245 *tag = der[0];
246 {
247 unsigned char *p = der + 1;
248 if (mbedtls_asn1_get_len(&p, der + der_length, data_len) != 0) {
249 goto error;
250 }
251 /* Now p points to the first byte of the payload inside der,
252 * and *data_len is the length of the payload. */
253
254 /* Step 4: payload validation */
255 if (*data_len > MBEDTLS_X509_MAX_DN_NAME_SIZE) {
256 goto error;
257 }
258 /* Strings must not contain null bytes. */
259 if (MBEDTLS_ASN1_IS_STRING_TAG(*tag)) {
260 for (size_t i = 0; i < *data_len; i++) {
261 if (p[i] == 0) {
262 goto error;
263 }
264 }
265 }
266
267 /* Step 5: output the payload. */
268 if (*data_len > data_size) {
269 goto error;
270 }
271 memcpy(data, p, *data_len);
272 }
273 mbedtls_free(der);
274
275 return 0;
276
277 error:
278 mbedtls_free(der);
279 return MBEDTLS_ERR_X509_INVALID_NAME;
280 }
281
oid_parse_number(unsigned int * num,const char ** p,const char * bound)282 static int oid_parse_number(unsigned int *num, const char **p, const char *bound)
283 {
284 int ret = MBEDTLS_ERR_ASN1_INVALID_DATA;
285
286 *num = 0;
287
288 while (*p < bound && **p >= '0' && **p <= '9') {
289 ret = 0;
290 if (*num > (UINT_MAX / 10)) {
291 return MBEDTLS_ERR_ASN1_INVALID_DATA;
292 }
293 *num *= 10;
294 *num += **p - '0';
295 (*p)++;
296 }
297 return ret;
298 }
299
oid_subidentifier_num_bytes(unsigned int value)300 static size_t oid_subidentifier_num_bytes(unsigned int value)
301 {
302 size_t num_bytes = 0;
303
304 do {
305 value >>= 7;
306 num_bytes++;
307 } while (value != 0);
308
309 return num_bytes;
310 }
311
oid_subidentifier_encode_into(unsigned char ** p,unsigned char * bound,unsigned int value)312 static int oid_subidentifier_encode_into(unsigned char **p,
313 unsigned char *bound,
314 unsigned int value)
315 {
316 size_t num_bytes = oid_subidentifier_num_bytes(value);
317
318 if ((size_t) (bound - *p) < num_bytes) {
319 return PSA_ERROR_BUFFER_TOO_SMALL;
320 }
321 (*p)[num_bytes - 1] = (unsigned char) (value & 0x7f);
322 value >>= 7;
323
324 for (size_t i = 2; i <= num_bytes; i++) {
325 (*p)[num_bytes - i] = 0x80 | (unsigned char) (value & 0x7f);
326 value >>= 7;
327 }
328 *p += num_bytes;
329
330 return 0;
331 }
332
333 /* Return the OID for the given x.y.z.... style numeric string */
mbedtls_oid_from_numeric_string(mbedtls_asn1_buf * oid,const char * oid_str,size_t size)334 int mbedtls_oid_from_numeric_string(mbedtls_asn1_buf *oid,
335 const char *oid_str, size_t size)
336 {
337 int ret = MBEDTLS_ERR_ASN1_INVALID_DATA;
338 const char *str_ptr = oid_str;
339 const char *str_bound = oid_str + size;
340 unsigned int val = 0;
341 unsigned int component1, component2;
342 size_t encoded_len;
343 unsigned char *resized_mem;
344
345 /* Count the number of dots to get a worst-case allocation size. */
346 size_t num_dots = 0;
347 for (size_t i = 0; i < size; i++) {
348 if (oid_str[i] == '.') {
349 num_dots++;
350 }
351 }
352 /* Allocate maximum possible required memory:
353 * There are (num_dots + 1) integer components, but the first 2 share the
354 * same subidentifier, so we only need num_dots subidentifiers maximum. */
355 if (num_dots == 0 || (num_dots > MBEDTLS_OID_MAX_COMPONENTS - 1)) {
356 return MBEDTLS_ERR_ASN1_INVALID_DATA;
357 }
358 /* Each byte can store 7 bits, calculate number of bytes for a
359 * subidentifier:
360 *
361 * bytes = ceil(subidentifer_size * 8 / 7)
362 */
363 size_t bytes_per_subidentifier = (((sizeof(unsigned int) * 8) - 1) / 7)
364 + 1;
365 size_t max_possible_bytes = num_dots * bytes_per_subidentifier;
366 oid->p = mbedtls_calloc(max_possible_bytes, 1);
367 if (oid->p == NULL) {
368 return MBEDTLS_ERR_ASN1_ALLOC_FAILED;
369 }
370 unsigned char *out_ptr = oid->p;
371 unsigned char *out_bound = oid->p + max_possible_bytes;
372
373 ret = oid_parse_number(&component1, &str_ptr, str_bound);
374 if (ret != 0) {
375 goto error;
376 }
377 if (component1 > 2) {
378 /* First component can't be > 2 */
379 ret = MBEDTLS_ERR_ASN1_INVALID_DATA;
380 goto error;
381 }
382 if (str_ptr >= str_bound || *str_ptr != '.') {
383 ret = MBEDTLS_ERR_ASN1_INVALID_DATA;
384 goto error;
385 }
386 str_ptr++;
387
388 ret = oid_parse_number(&component2, &str_ptr, str_bound);
389 if (ret != 0) {
390 goto error;
391 }
392 if ((component1 < 2) && (component2 > 39)) {
393 /* Root nodes 0 and 1 may have up to 40 children, numbered 0-39 */
394 ret = MBEDTLS_ERR_ASN1_INVALID_DATA;
395 goto error;
396 }
397 if (str_ptr < str_bound) {
398 if (*str_ptr == '.') {
399 str_ptr++;
400 } else {
401 ret = MBEDTLS_ERR_ASN1_INVALID_DATA;
402 goto error;
403 }
404 }
405
406 if (component2 > (UINT_MAX - (component1 * 40))) {
407 ret = MBEDTLS_ERR_ASN1_INVALID_DATA;
408 goto error;
409 }
410 ret = oid_subidentifier_encode_into(&out_ptr, out_bound,
411 (component1 * 40) + component2);
412 if (ret != 0) {
413 goto error;
414 }
415
416 while (str_ptr < str_bound) {
417 ret = oid_parse_number(&val, &str_ptr, str_bound);
418 if (ret != 0) {
419 goto error;
420 }
421 if (str_ptr < str_bound) {
422 if (*str_ptr == '.') {
423 str_ptr++;
424 } else {
425 ret = MBEDTLS_ERR_ASN1_INVALID_DATA;
426 goto error;
427 }
428 }
429
430 ret = oid_subidentifier_encode_into(&out_ptr, out_bound, val);
431 if (ret != 0) {
432 goto error;
433 }
434 }
435
436 encoded_len = (size_t) (out_ptr - oid->p);
437 resized_mem = mbedtls_calloc(encoded_len, 1);
438 if (resized_mem == NULL) {
439 ret = MBEDTLS_ERR_ASN1_ALLOC_FAILED;
440 goto error;
441 }
442 memcpy(resized_mem, oid->p, encoded_len);
443 mbedtls_free(oid->p);
444 oid->p = resized_mem;
445 oid->len = encoded_len;
446
447 oid->tag = MBEDTLS_ASN1_OID;
448
449 return 0;
450
451 error:
452 mbedtls_free(oid->p);
453 oid->p = NULL;
454 oid->len = 0;
455 return ret;
456 }
457
mbedtls_x509_string_to_names(mbedtls_asn1_named_data ** head,const char * name)458 int mbedtls_x509_string_to_names(mbedtls_asn1_named_data **head, const char *name)
459 {
460 int ret = MBEDTLS_ERR_X509_INVALID_NAME;
461 int parse_ret = 0;
462 const char *s = name, *c = s;
463 const char *end = s + strlen(s);
464 mbedtls_asn1_buf oid = { .p = NULL, .len = 0, .tag = MBEDTLS_ASN1_NULL };
465 const x509_attr_descriptor_t *attr_descr = NULL;
466 int in_attr_type = 1;
467 int tag;
468 int numericoid = 0;
469 unsigned char data[MBEDTLS_X509_MAX_DN_NAME_SIZE];
470 size_t data_len = 0;
471
472 /* Ensure the output parameter is not already populated.
473 * (If it were, overwriting it would likely cause a memory leak.)
474 */
475 if (*head != NULL) {
476 return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
477 }
478
479 while (c <= end) {
480 if (in_attr_type && *c == '=') {
481 if ((attr_descr = x509_attr_descr_from_name(s, (size_t) (c - s))) == NULL) {
482 if ((mbedtls_oid_from_numeric_string(&oid, s, (size_t) (c - s))) != 0) {
483 return MBEDTLS_ERR_X509_INVALID_NAME;
484 } else {
485 numericoid = 1;
486 }
487 } else {
488 oid.len = strlen(attr_descr->oid);
489 oid.p = mbedtls_calloc(1, oid.len);
490 memcpy(oid.p, attr_descr->oid, oid.len);
491 numericoid = 0;
492 }
493
494 s = c + 1;
495 in_attr_type = 0;
496 }
497
498 if (!in_attr_type && ((*c == ',' && *(c-1) != '\\') || c == end)) {
499 if (s == c) {
500 mbedtls_free(oid.p);
501 return MBEDTLS_ERR_X509_INVALID_NAME;
502 } else if (*s == '#') {
503 /* We know that c >= s (loop invariant) and c != s (in this
504 * else branch), hence c - s - 1 >= 0. */
505 parse_ret = parse_attribute_value_hex_der_encoded(
506 s + 1, (size_t) (c - s) - 1,
507 data, sizeof(data), &data_len, &tag);
508 if (parse_ret != 0) {
509 mbedtls_free(oid.p);
510 return parse_ret;
511 }
512 } else {
513 if (numericoid) {
514 mbedtls_free(oid.p);
515 return MBEDTLS_ERR_X509_INVALID_NAME;
516 } else {
517 if ((parse_ret =
518 parse_attribute_value_string(s, (int) (c - s), data,
519 &data_len)) != 0) {
520 mbedtls_free(oid.p);
521 return parse_ret;
522 }
523 tag = attr_descr->default_tag;
524 }
525 }
526
527 mbedtls_asn1_named_data *cur =
528 mbedtls_asn1_store_named_data(head, (char *) oid.p, oid.len,
529 (unsigned char *) data,
530 data_len);
531 mbedtls_free(oid.p);
532 oid.p = NULL;
533 if (cur == NULL) {
534 return MBEDTLS_ERR_X509_ALLOC_FAILED;
535 }
536
537 // set tagType
538 cur->val.tag = tag;
539
540 while (c < end && *(c + 1) == ' ') {
541 c++;
542 }
543
544 s = c + 1;
545 in_attr_type = 1;
546
547 /* Successfully parsed one name, update ret to success */
548 ret = 0;
549 }
550 c++;
551 }
552 if (oid.p != NULL) {
553 mbedtls_free(oid.p);
554 }
555 return ret;
556 }
557
558 /* The first byte of the value in the mbedtls_asn1_named_data structure is reserved
559 * to store the critical boolean for us
560 */
mbedtls_x509_set_extension(mbedtls_asn1_named_data ** head,const char * oid,size_t oid_len,int critical,const unsigned char * val,size_t val_len)561 int mbedtls_x509_set_extension(mbedtls_asn1_named_data **head, const char *oid, size_t oid_len,
562 int critical, const unsigned char *val, size_t val_len)
563 {
564 mbedtls_asn1_named_data *cur;
565
566 if (val_len > (SIZE_MAX - 1)) {
567 return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
568 }
569
570 if ((cur = mbedtls_asn1_store_named_data(head, oid, oid_len,
571 NULL, val_len + 1)) == NULL) {
572 return MBEDTLS_ERR_X509_ALLOC_FAILED;
573 }
574
575 cur->val.p[0] = critical;
576 memcpy(cur->val.p + 1, val, val_len);
577
578 return 0;
579 }
580
581 /*
582 * RelativeDistinguishedName ::=
583 * SET OF AttributeTypeAndValue
584 *
585 * AttributeTypeAndValue ::= SEQUENCE {
586 * type AttributeType,
587 * value AttributeValue }
588 *
589 * AttributeType ::= OBJECT IDENTIFIER
590 *
591 * AttributeValue ::= ANY DEFINED BY AttributeType
592 */
x509_write_name(unsigned char ** p,unsigned char * start,mbedtls_asn1_named_data * cur_name)593 static int x509_write_name(unsigned char **p,
594 unsigned char *start,
595 mbedtls_asn1_named_data *cur_name)
596 {
597 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
598 size_t len = 0;
599 const char *oid = (const char *) cur_name->oid.p;
600 size_t oid_len = cur_name->oid.len;
601 const unsigned char *name = cur_name->val.p;
602 size_t name_len = cur_name->val.len;
603
604 // Write correct string tag and value
605 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tagged_string(p, start,
606 cur_name->val.tag,
607 (const char *) name,
608 name_len));
609 // Write OID
610 //
611 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid,
612 oid_len));
613
614 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
615 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start,
616 MBEDTLS_ASN1_CONSTRUCTED |
617 MBEDTLS_ASN1_SEQUENCE));
618
619 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
620 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start,
621 MBEDTLS_ASN1_CONSTRUCTED |
622 MBEDTLS_ASN1_SET));
623
624 return (int) len;
625 }
626
mbedtls_x509_write_names(unsigned char ** p,unsigned char * start,mbedtls_asn1_named_data * first)627 int mbedtls_x509_write_names(unsigned char **p, unsigned char *start,
628 mbedtls_asn1_named_data *first)
629 {
630 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
631 size_t len = 0;
632 mbedtls_asn1_named_data *cur = first;
633
634 while (cur != NULL) {
635 MBEDTLS_ASN1_CHK_ADD(len, x509_write_name(p, start, cur));
636 cur = cur->next;
637 }
638
639 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
640 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED |
641 MBEDTLS_ASN1_SEQUENCE));
642
643 return (int) len;
644 }
645
mbedtls_x509_write_sig(unsigned char ** p,unsigned char * start,const char * oid,size_t oid_len,unsigned char * sig,size_t size,mbedtls_pk_sigalg_t pk_alg)646 int mbedtls_x509_write_sig(unsigned char **p, unsigned char *start,
647 const char *oid, size_t oid_len,
648 unsigned char *sig, size_t size,
649 mbedtls_pk_sigalg_t pk_alg)
650 {
651 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
652 int write_null_par;
653 size_t len = 0;
654
655 if (*p < start || (size_t) (*p - start) < size) {
656 return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
657 }
658
659 len = size;
660 (*p) -= len;
661 memcpy(*p, sig, len);
662
663 if (*p - start < 1) {
664 return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
665 }
666
667 *--(*p) = 0;
668 len += 1;
669
670 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
671 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_BIT_STRING));
672
673 // Write OID
674 //
675 if (pk_alg == MBEDTLS_PK_SIGALG_ECDSA) {
676 /*
677 * The AlgorithmIdentifier's parameters field must be absent for DSA/ECDSA signature
678 * algorithms, see https://www.rfc-editor.org/rfc/rfc5480#page-17 and
679 * https://www.rfc-editor.org/rfc/rfc5758#section-3.
680 */
681 write_null_par = 0;
682 } else {
683 write_null_par = 1;
684 }
685 MBEDTLS_ASN1_CHK_ADD(len,
686 mbedtls_asn1_write_algorithm_identifier_ext(p, start, oid, oid_len,
687 0, write_null_par));
688
689 return (int) len;
690 }
691
x509_write_extension(unsigned char ** p,unsigned char * start,mbedtls_asn1_named_data * ext)692 static int x509_write_extension(unsigned char **p, unsigned char *start,
693 mbedtls_asn1_named_data *ext)
694 {
695 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
696 size_t len = 0;
697
698 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, ext->val.p + 1,
699 ext->val.len - 1));
700 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, ext->val.len - 1));
701 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OCTET_STRING));
702
703 if (ext->val.p[0] != 0) {
704 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_bool(p, start, 1));
705 }
706
707 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, ext->oid.p,
708 ext->oid.len));
709 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, ext->oid.len));
710 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OID));
711
712 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
713 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED |
714 MBEDTLS_ASN1_SEQUENCE));
715
716 return (int) len;
717 }
718
719 /*
720 * Extension ::= SEQUENCE {
721 * extnID OBJECT IDENTIFIER,
722 * critical BOOLEAN DEFAULT FALSE,
723 * extnValue OCTET STRING
724 * -- contains the DER encoding of an ASN.1 value
725 * -- corresponding to the extension type identified
726 * -- by extnID
727 * }
728 */
mbedtls_x509_write_extensions(unsigned char ** p,unsigned char * start,mbedtls_asn1_named_data * first)729 int mbedtls_x509_write_extensions(unsigned char **p, unsigned char *start,
730 mbedtls_asn1_named_data *first)
731 {
732 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
733 size_t len = 0;
734 mbedtls_asn1_named_data *cur_ext = first;
735
736 while (cur_ext != NULL) {
737 MBEDTLS_ASN1_CHK_ADD(len, x509_write_extension(p, start, cur_ext));
738 cur_ext = cur_ext->next;
739 }
740
741 return (int) len;
742 }
743
744 #endif /* MBEDTLS_X509_CREATE_C */
745