xref: /freebsd/contrib/wpa/src/tls/x509v3.c (revision 0957b409)
1 /*
2  * X.509v3 certificate parsing and processing (RFC 3280 profile)
3  * Copyright (c) 2006-2015, Jouni Malinen <j@w1.fi>
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #include "includes.h"
10 
11 #include "common.h"
12 #include "crypto/crypto.h"
13 #include "asn1.h"
14 #include "x509v3.h"
15 
16 
17 void x509_free_name(struct x509_name *name)
18 {
19 	size_t i;
20 
21 	for (i = 0; i < name->num_attr; i++) {
22 		os_free(name->attr[i].value);
23 		name->attr[i].value = NULL;
24 		name->attr[i].type = X509_NAME_ATTR_NOT_USED;
25 	}
26 	name->num_attr = 0;
27 	os_free(name->email);
28 	name->email = NULL;
29 
30 	os_free(name->alt_email);
31 	os_free(name->dns);
32 	os_free(name->uri);
33 	os_free(name->ip);
34 	name->alt_email = name->dns = name->uri = NULL;
35 	name->ip = NULL;
36 	name->ip_len = 0;
37 	os_memset(&name->rid, 0, sizeof(name->rid));
38 }
39 
40 
41 /**
42  * x509_certificate_free - Free an X.509 certificate
43  * @cert: Certificate to be freed
44  */
45 void x509_certificate_free(struct x509_certificate *cert)
46 {
47 	if (cert == NULL)
48 		return;
49 	if (cert->next) {
50 		wpa_printf(MSG_DEBUG, "X509: x509_certificate_free: cer=%p "
51 			   "was still on a list (next=%p)\n",
52 			   cert, cert->next);
53 	}
54 	x509_free_name(&cert->issuer);
55 	x509_free_name(&cert->subject);
56 	os_free(cert->public_key);
57 	os_free(cert->sign_value);
58 	os_free(cert->subject_dn);
59 	os_free(cert);
60 }
61 
62 
63 /**
64  * x509_certificate_free - Free an X.509 certificate chain
65  * @cert: Pointer to the first certificate in the chain
66  */
67 void x509_certificate_chain_free(struct x509_certificate *cert)
68 {
69 	struct x509_certificate *next;
70 
71 	while (cert) {
72 		next = cert->next;
73 		cert->next = NULL;
74 		x509_certificate_free(cert);
75 		cert = next;
76 	}
77 }
78 
79 
80 static int x509_whitespace(char c)
81 {
82 	return c == ' ' || c == '\t';
83 }
84 
85 
86 static void x509_str_strip_whitespace(char *a)
87 {
88 	char *ipos, *opos;
89 	int remove_whitespace = 1;
90 
91 	ipos = opos = a;
92 
93 	while (*ipos) {
94 		if (remove_whitespace && x509_whitespace(*ipos))
95 			ipos++;
96 		else {
97 			remove_whitespace = x509_whitespace(*ipos);
98 			*opos++ = *ipos++;
99 		}
100 	}
101 
102 	*opos-- = '\0';
103 	if (opos > a && x509_whitespace(*opos))
104 		*opos = '\0';
105 }
106 
107 
108 static int x509_str_compare(const char *a, const char *b)
109 {
110 	char *aa, *bb;
111 	int ret;
112 
113 	if (!a && b)
114 		return -1;
115 	if (a && !b)
116 		return 1;
117 	if (!a && !b)
118 		return 0;
119 
120 	aa = os_strdup(a);
121 	bb = os_strdup(b);
122 
123 	if (aa == NULL || bb == NULL) {
124 		os_free(aa);
125 		os_free(bb);
126 		return os_strcasecmp(a, b);
127 	}
128 
129 	x509_str_strip_whitespace(aa);
130 	x509_str_strip_whitespace(bb);
131 
132 	ret = os_strcasecmp(aa, bb);
133 
134 	os_free(aa);
135 	os_free(bb);
136 
137 	return ret;
138 }
139 
140 
141 /**
142  * x509_name_compare - Compare X.509 certificate names
143  * @a: Certificate name
144  * @b: Certificate name
145  * Returns: <0, 0, or >0 based on whether a is less than, equal to, or
146  * greater than b
147  */
148 int x509_name_compare(struct x509_name *a, struct x509_name *b)
149 {
150 	int res;
151 	size_t i;
152 
153 	if (!a && b)
154 		return -1;
155 	if (a && !b)
156 		return 1;
157 	if (!a && !b)
158 		return 0;
159 	if (a->num_attr < b->num_attr)
160 		return -1;
161 	if (a->num_attr > b->num_attr)
162 		return 1;
163 
164 	for (i = 0; i < a->num_attr; i++) {
165 		if (a->attr[i].type < b->attr[i].type)
166 			return -1;
167 		if (a->attr[i].type > b->attr[i].type)
168 			return -1;
169 		res = x509_str_compare(a->attr[i].value, b->attr[i].value);
170 		if (res)
171 			return res;
172 	}
173 	res = x509_str_compare(a->email, b->email);
174 	if (res)
175 		return res;
176 
177 	return 0;
178 }
179 
180 
181 int x509_parse_algorithm_identifier(const u8 *buf, size_t len,
182 				    struct x509_algorithm_identifier *id,
183 				    const u8 **next)
184 {
185 	struct asn1_hdr hdr;
186 	const u8 *pos, *end;
187 
188 	/*
189 	 * AlgorithmIdentifier ::= SEQUENCE {
190 	 *     algorithm            OBJECT IDENTIFIER,
191 	 *     parameters           ANY DEFINED BY algorithm OPTIONAL
192 	 * }
193 	 */
194 
195 	if (asn1_get_next(buf, len, &hdr) < 0 ||
196 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
197 	    hdr.tag != ASN1_TAG_SEQUENCE) {
198 		wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
199 			   "(AlgorithmIdentifier) - found class %d tag 0x%x",
200 			   hdr.class, hdr.tag);
201 		return -1;
202 	}
203 	if (hdr.length > buf + len - hdr.payload)
204 		return -1;
205 	pos = hdr.payload;
206 	end = pos + hdr.length;
207 
208 	*next = end;
209 
210 	if (asn1_get_oid(pos, end - pos, &id->oid, &pos))
211 		return -1;
212 
213 	/* TODO: optional parameters */
214 
215 	return 0;
216 }
217 
218 
219 static int x509_parse_public_key(const u8 *buf, size_t len,
220 				 struct x509_certificate *cert,
221 				 const u8 **next)
222 {
223 	struct asn1_hdr hdr;
224 	const u8 *pos, *end;
225 
226 	/*
227 	 * SubjectPublicKeyInfo ::= SEQUENCE {
228 	 *     algorithm            AlgorithmIdentifier,
229 	 *     subjectPublicKey     BIT STRING
230 	 * }
231 	 */
232 
233 	pos = buf;
234 	end = buf + len;
235 
236 	if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
237 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
238 	    hdr.tag != ASN1_TAG_SEQUENCE) {
239 		wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
240 			   "(SubjectPublicKeyInfo) - found class %d tag 0x%x",
241 			   hdr.class, hdr.tag);
242 		return -1;
243 	}
244 	pos = hdr.payload;
245 
246 	if (hdr.length > end - pos)
247 		return -1;
248 	end = pos + hdr.length;
249 	*next = end;
250 
251 	if (x509_parse_algorithm_identifier(pos, end - pos,
252 					    &cert->public_key_alg, &pos))
253 		return -1;
254 
255 	if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
256 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
257 	    hdr.tag != ASN1_TAG_BITSTRING) {
258 		wpa_printf(MSG_DEBUG, "X509: Expected BITSTRING "
259 			   "(subjectPublicKey) - found class %d tag 0x%x",
260 			   hdr.class, hdr.tag);
261 		return -1;
262 	}
263 	if (hdr.length < 1)
264 		return -1;
265 	pos = hdr.payload;
266 	if (*pos) {
267 		wpa_printf(MSG_DEBUG, "X509: BITSTRING - %d unused bits",
268 			   *pos);
269 		/*
270 		 * TODO: should this be rejected? X.509 certificates are
271 		 * unlikely to use such a construction. Now we would end up
272 		 * including the extra bits in the buffer which may also be
273 		 * ok.
274 		 */
275 	}
276 	os_free(cert->public_key);
277 	cert->public_key = os_memdup(pos + 1, hdr.length - 1);
278 	if (cert->public_key == NULL) {
279 		wpa_printf(MSG_DEBUG, "X509: Failed to allocate memory for "
280 			   "public key");
281 		return -1;
282 	}
283 	cert->public_key_len = hdr.length - 1;
284 	wpa_hexdump(MSG_MSGDUMP, "X509: subjectPublicKey",
285 		    cert->public_key, cert->public_key_len);
286 
287 	return 0;
288 }
289 
290 
291 int x509_parse_name(const u8 *buf, size_t len, struct x509_name *name,
292 		    const u8 **next)
293 {
294 	struct asn1_hdr hdr;
295 	const u8 *pos, *end, *set_pos, *set_end, *seq_pos, *seq_end;
296 	struct asn1_oid oid;
297 	char *val;
298 
299 	/*
300 	 * Name ::= CHOICE { RDNSequence }
301 	 * RDNSequence ::= SEQUENCE OF RelativeDistinguishedName
302 	 * RelativeDistinguishedName ::= SET OF AttributeTypeAndValue
303 	 * AttributeTypeAndValue ::= SEQUENCE {
304 	 *     type     AttributeType,
305 	 *     value    AttributeValue
306 	 * }
307 	 * AttributeType ::= OBJECT IDENTIFIER
308 	 * AttributeValue ::= ANY DEFINED BY AttributeType
309 	 */
310 
311 	if (asn1_get_next(buf, len, &hdr) < 0 ||
312 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
313 	    hdr.tag != ASN1_TAG_SEQUENCE) {
314 		wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
315 			   "(Name / RDNSequencer) - found class %d tag 0x%x",
316 			   hdr.class, hdr.tag);
317 		return -1;
318 	}
319 	pos = hdr.payload;
320 
321 	if (hdr.length > buf + len - pos)
322 		return -1;
323 
324 	end = *next = pos + hdr.length;
325 
326 	while (pos < end) {
327 		enum x509_name_attr_type type;
328 
329 		if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
330 		    hdr.class != ASN1_CLASS_UNIVERSAL ||
331 		    hdr.tag != ASN1_TAG_SET) {
332 			wpa_printf(MSG_DEBUG, "X509: Expected SET "
333 				   "(RelativeDistinguishedName) - found class "
334 				   "%d tag 0x%x", hdr.class, hdr.tag);
335 			x509_free_name(name);
336 			return -1;
337 		}
338 
339 		set_pos = hdr.payload;
340 		pos = set_end = hdr.payload + hdr.length;
341 
342 		if (asn1_get_next(set_pos, set_end - set_pos, &hdr) < 0 ||
343 		    hdr.class != ASN1_CLASS_UNIVERSAL ||
344 		    hdr.tag != ASN1_TAG_SEQUENCE) {
345 			wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
346 				   "(AttributeTypeAndValue) - found class %d "
347 				   "tag 0x%x", hdr.class, hdr.tag);
348 			x509_free_name(name);
349 			return -1;
350 		}
351 
352 		seq_pos = hdr.payload;
353 		seq_end = hdr.payload + hdr.length;
354 
355 		if (asn1_get_oid(seq_pos, seq_end - seq_pos, &oid, &seq_pos)) {
356 			x509_free_name(name);
357 			return -1;
358 		}
359 
360 		if (asn1_get_next(seq_pos, seq_end - seq_pos, &hdr) < 0 ||
361 		    hdr.class != ASN1_CLASS_UNIVERSAL) {
362 			wpa_printf(MSG_DEBUG, "X509: Failed to parse "
363 				   "AttributeValue");
364 			x509_free_name(name);
365 			return -1;
366 		}
367 
368 		/* RFC 3280:
369 		 * MUST: country, organization, organizational-unit,
370 		 * distinguished name qualifier, state or province name,
371 		 * common name, serial number.
372 		 * SHOULD: locality, title, surname, given name, initials,
373 		 * pseudonym, generation qualifier.
374 		 * MUST: domainComponent (RFC 2247).
375 		 */
376 		type = X509_NAME_ATTR_NOT_USED;
377 		if (oid.len == 4 &&
378 		    oid.oid[0] == 2 && oid.oid[1] == 5 && oid.oid[2] == 4) {
379 			/* id-at ::= 2.5.4 */
380 			switch (oid.oid[3]) {
381 			case 3:
382 				/* commonName */
383 				type = X509_NAME_ATTR_CN;
384 				break;
385 			case 6:
386 				/*  countryName */
387 				type = X509_NAME_ATTR_C;
388 				break;
389 			case 7:
390 				/* localityName */
391 				type = X509_NAME_ATTR_L;
392 				break;
393 			case 8:
394 				/* stateOrProvinceName */
395 				type = X509_NAME_ATTR_ST;
396 				break;
397 			case 10:
398 				/* organizationName */
399 				type = X509_NAME_ATTR_O;
400 				break;
401 			case 11:
402 				/* organizationalUnitName */
403 				type = X509_NAME_ATTR_OU;
404 				break;
405 			}
406 		} else if (oid.len == 7 &&
407 			   oid.oid[0] == 1 && oid.oid[1] == 2 &&
408 			   oid.oid[2] == 840 && oid.oid[3] == 113549 &&
409 			   oid.oid[4] == 1 && oid.oid[5] == 9 &&
410 			   oid.oid[6] == 1) {
411 			/* 1.2.840.113549.1.9.1 - e-mailAddress */
412 			os_free(name->email);
413 			name->email = os_malloc(hdr.length + 1);
414 			if (name->email == NULL) {
415 				x509_free_name(name);
416 				return -1;
417 			}
418 			os_memcpy(name->email, hdr.payload, hdr.length);
419 			name->email[hdr.length] = '\0';
420 			continue;
421 		} else if (oid.len == 7 &&
422 			   oid.oid[0] == 0 && oid.oid[1] == 9 &&
423 			   oid.oid[2] == 2342 && oid.oid[3] == 19200300 &&
424 			   oid.oid[4] == 100 && oid.oid[5] == 1 &&
425 			   oid.oid[6] == 25) {
426 			/* 0.9.2342.19200300.100.1.25 - domainComponent */
427 			type = X509_NAME_ATTR_DC;
428 		}
429 
430 		if (type == X509_NAME_ATTR_NOT_USED) {
431 			wpa_hexdump(MSG_DEBUG, "X509: Unrecognized OID",
432 				    (u8 *) oid.oid,
433 				    oid.len * sizeof(oid.oid[0]));
434 			wpa_hexdump_ascii(MSG_MSGDUMP, "X509: Attribute Data",
435 					  hdr.payload, hdr.length);
436 			continue;
437 		}
438 
439 		if (name->num_attr == X509_MAX_NAME_ATTRIBUTES) {
440 			wpa_printf(MSG_INFO, "X509: Too many Name attributes");
441 			x509_free_name(name);
442 			return -1;
443 		}
444 
445 		val = dup_binstr(hdr.payload, hdr.length);
446 		if (val == NULL) {
447 			x509_free_name(name);
448 			return -1;
449 		}
450 		if (os_strlen(val) != hdr.length) {
451 			wpa_printf(MSG_INFO, "X509: Reject certificate with "
452 				   "embedded NUL byte in a string (%s[NUL])",
453 				   val);
454 			os_free(val);
455 			x509_free_name(name);
456 			return -1;
457 		}
458 
459 		name->attr[name->num_attr].type = type;
460 		name->attr[name->num_attr].value = val;
461 		name->num_attr++;
462 	}
463 
464 	return 0;
465 }
466 
467 
468 static char * x509_name_attr_str(enum x509_name_attr_type type)
469 {
470 	switch (type) {
471 	case X509_NAME_ATTR_NOT_USED:
472 		return "[N/A]";
473 	case X509_NAME_ATTR_DC:
474 		return "DC";
475 	case X509_NAME_ATTR_CN:
476 		return "CN";
477 	case X509_NAME_ATTR_C:
478 		return "C";
479 	case X509_NAME_ATTR_L:
480 		return "L";
481 	case X509_NAME_ATTR_ST:
482 		return "ST";
483 	case X509_NAME_ATTR_O:
484 		return "O";
485 	case X509_NAME_ATTR_OU:
486 		return "OU";
487 	}
488 	return "?";
489 }
490 
491 
492 /**
493  * x509_name_string - Convert an X.509 certificate name into a string
494  * @name: Name to convert
495  * @buf: Buffer for the string
496  * @len: Maximum buffer length
497  */
498 void x509_name_string(struct x509_name *name, char *buf, size_t len)
499 {
500 	char *pos, *end;
501 	int ret;
502 	size_t i;
503 
504 	if (len == 0)
505 		return;
506 
507 	pos = buf;
508 	end = buf + len;
509 
510 	for (i = 0; i < name->num_attr; i++) {
511 		ret = os_snprintf(pos, end - pos, "%s=%s, ",
512 				  x509_name_attr_str(name->attr[i].type),
513 				  name->attr[i].value);
514 		if (os_snprintf_error(end - pos, ret))
515 			goto done;
516 		pos += ret;
517 	}
518 
519 	if (pos > buf + 1 && pos[-1] == ' ' && pos[-2] == ',') {
520 		pos--;
521 		*pos = '\0';
522 		pos--;
523 		*pos = '\0';
524 	}
525 
526 	if (name->email) {
527 		ret = os_snprintf(pos, end - pos, "/emailAddress=%s",
528 				  name->email);
529 		if (os_snprintf_error(end - pos, ret))
530 			goto done;
531 		pos += ret;
532 	}
533 
534 done:
535 	end[-1] = '\0';
536 }
537 
538 
539 int x509_parse_time(const u8 *buf, size_t len, u8 asn1_tag, os_time_t *val)
540 {
541 	const char *pos;
542 	int year, month, day, hour, min, sec;
543 
544 	/*
545 	 * Time ::= CHOICE {
546 	 *     utcTime        UTCTime,
547 	 *     generalTime    GeneralizedTime
548 	 * }
549 	 *
550 	 * UTCTime: YYMMDDHHMMSSZ
551 	 * GeneralizedTime: YYYYMMDDHHMMSSZ
552 	 */
553 
554 	pos = (const char *) buf;
555 
556 	switch (asn1_tag) {
557 	case ASN1_TAG_UTCTIME:
558 		if (len != 13 || buf[12] != 'Z') {
559 			wpa_hexdump_ascii(MSG_DEBUG, "X509: Unrecognized "
560 					  "UTCTime format", buf, len);
561 			return -1;
562 		}
563 		if (sscanf(pos, "%02d", &year) != 1) {
564 			wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse "
565 					  "UTCTime year", buf, len);
566 			return -1;
567 		}
568 		if (year < 50)
569 			year += 2000;
570 		else
571 			year += 1900;
572 		pos += 2;
573 		break;
574 	case ASN1_TAG_GENERALIZEDTIME:
575 		if (len != 15 || buf[14] != 'Z') {
576 			wpa_hexdump_ascii(MSG_DEBUG, "X509: Unrecognized "
577 					  "GeneralizedTime format", buf, len);
578 			return -1;
579 		}
580 		if (sscanf(pos, "%04d", &year) != 1) {
581 			wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse "
582 					  "GeneralizedTime year", buf, len);
583 			return -1;
584 		}
585 		pos += 4;
586 		break;
587 	default:
588 		wpa_printf(MSG_DEBUG, "X509: Expected UTCTime or "
589 			   "GeneralizedTime - found tag 0x%x", asn1_tag);
590 		return -1;
591 	}
592 
593 	if (sscanf(pos, "%02d", &month) != 1) {
594 		wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time "
595 				  "(month)", buf, len);
596 		return -1;
597 	}
598 	pos += 2;
599 
600 	if (sscanf(pos, "%02d", &day) != 1) {
601 		wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time "
602 				  "(day)", buf, len);
603 		return -1;
604 	}
605 	pos += 2;
606 
607 	if (sscanf(pos, "%02d", &hour) != 1) {
608 		wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time "
609 				  "(hour)", buf, len);
610 		return -1;
611 	}
612 	pos += 2;
613 
614 	if (sscanf(pos, "%02d", &min) != 1) {
615 		wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time "
616 				  "(min)", buf, len);
617 		return -1;
618 	}
619 	pos += 2;
620 
621 	if (sscanf(pos, "%02d", &sec) != 1) {
622 		wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time "
623 				  "(sec)", buf, len);
624 		return -1;
625 	}
626 
627 	if (os_mktime(year, month, day, hour, min, sec, val) < 0) {
628 		wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to convert Time",
629 				  buf, len);
630 		if (year < 1970) {
631 			/*
632 			 * At least some test certificates have been configured
633 			 * to use dates prior to 1970. Set the date to
634 			 * beginning of 1970 to handle these case.
635 			 */
636 			wpa_printf(MSG_DEBUG, "X509: Year=%d before epoch - "
637 				   "assume epoch as the time", year);
638 			*val = 0;
639 			return 0;
640 		}
641 		return -1;
642 	}
643 
644 	return 0;
645 }
646 
647 
648 static int x509_parse_validity(const u8 *buf, size_t len,
649 			       struct x509_certificate *cert, const u8 **next)
650 {
651 	struct asn1_hdr hdr;
652 	const u8 *pos;
653 	size_t plen;
654 
655 	/*
656 	 * Validity ::= SEQUENCE {
657 	 *     notBefore      Time,
658 	 *     notAfter       Time
659 	 * }
660 	 *
661 	 * RFC 3280, 4.1.2.5:
662 	 * CAs conforming to this profile MUST always encode certificate
663 	 * validity dates through the year 2049 as UTCTime; certificate
664 	 * validity dates in 2050 or later MUST be encoded as GeneralizedTime.
665 	 */
666 
667 	if (asn1_get_next(buf, len, &hdr) < 0 ||
668 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
669 	    hdr.tag != ASN1_TAG_SEQUENCE) {
670 		wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
671 			   "(Validity) - found class %d tag 0x%x",
672 			   hdr.class, hdr.tag);
673 		return -1;
674 	}
675 	pos = hdr.payload;
676 	plen = hdr.length;
677 
678 	if (plen > (size_t) (buf + len - pos))
679 		return -1;
680 
681 	*next = pos + plen;
682 
683 	if (asn1_get_next(pos, plen, &hdr) < 0 ||
684 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
685 	    x509_parse_time(hdr.payload, hdr.length, hdr.tag,
686 			    &cert->not_before) < 0) {
687 		wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse notBefore "
688 				  "Time", hdr.payload, hdr.length);
689 		return -1;
690 	}
691 
692 	pos = hdr.payload + hdr.length;
693 	plen = *next - pos;
694 
695 	if (asn1_get_next(pos, plen, &hdr) < 0 ||
696 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
697 	    x509_parse_time(hdr.payload, hdr.length, hdr.tag,
698 			    &cert->not_after) < 0) {
699 		wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse notAfter "
700 				  "Time", hdr.payload, hdr.length);
701 		return -1;
702 	}
703 
704 	wpa_printf(MSG_MSGDUMP, "X509: Validity: notBefore: %lu notAfter: %lu",
705 		   (unsigned long) cert->not_before,
706 		   (unsigned long) cert->not_after);
707 
708 	return 0;
709 }
710 
711 
712 static int x509_id_ce_oid(struct asn1_oid *oid)
713 {
714 	/* id-ce arc from X.509 for standard X.509v3 extensions */
715 	return oid->len >= 4 &&
716 		oid->oid[0] == 2 /* joint-iso-ccitt */ &&
717 		oid->oid[1] == 5 /* ds */ &&
718 		oid->oid[2] == 29 /* id-ce */;
719 }
720 
721 
722 static int x509_any_ext_key_usage_oid(struct asn1_oid *oid)
723 {
724 	return oid->len == 6 &&
725 		x509_id_ce_oid(oid) &&
726 		oid->oid[3] == 37 /* extKeyUsage */ &&
727 		oid->oid[4] == 0 /* anyExtendedKeyUsage */;
728 }
729 
730 
731 static int x509_parse_ext_key_usage(struct x509_certificate *cert,
732 				    const u8 *pos, size_t len)
733 {
734 	struct asn1_hdr hdr;
735 
736 	/*
737 	 * KeyUsage ::= BIT STRING {
738 	 *     digitalSignature        (0),
739 	 *     nonRepudiation          (1),
740 	 *     keyEncipherment         (2),
741 	 *     dataEncipherment        (3),
742 	 *     keyAgreement            (4),
743 	 *     keyCertSign             (5),
744 	 *     cRLSign                 (6),
745 	 *     encipherOnly            (7),
746 	 *     decipherOnly            (8) }
747 	 */
748 
749 	if (asn1_get_next(pos, len, &hdr) < 0 ||
750 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
751 	    hdr.tag != ASN1_TAG_BITSTRING ||
752 	    hdr.length < 1) {
753 		wpa_printf(MSG_DEBUG, "X509: Expected BIT STRING in "
754 			   "KeyUsage; found %d tag 0x%x len %d",
755 			   hdr.class, hdr.tag, hdr.length);
756 		return -1;
757 	}
758 
759 	cert->extensions_present |= X509_EXT_KEY_USAGE;
760 	cert->key_usage = asn1_bit_string_to_long(hdr.payload, hdr.length);
761 
762 	wpa_printf(MSG_DEBUG, "X509: KeyUsage 0x%lx", cert->key_usage);
763 
764 	return 0;
765 }
766 
767 
768 static int x509_parse_ext_basic_constraints(struct x509_certificate *cert,
769 					    const u8 *pos, size_t len)
770 {
771 	struct asn1_hdr hdr;
772 	unsigned long value;
773 	size_t left;
774 
775 	/*
776 	 * BasicConstraints ::= SEQUENCE {
777 	 * cA                      BOOLEAN DEFAULT FALSE,
778 	 * pathLenConstraint       INTEGER (0..MAX) OPTIONAL }
779 	 */
780 
781 	if (asn1_get_next(pos, len, &hdr) < 0 ||
782 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
783 	    hdr.tag != ASN1_TAG_SEQUENCE) {
784 		wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE in "
785 			   "BasicConstraints; found %d tag 0x%x",
786 			   hdr.class, hdr.tag);
787 		return -1;
788 	}
789 
790 	cert->extensions_present |= X509_EXT_BASIC_CONSTRAINTS;
791 
792 	if (hdr.length == 0)
793 		return 0;
794 
795 	if (asn1_get_next(hdr.payload, hdr.length, &hdr) < 0 ||
796 	    hdr.class != ASN1_CLASS_UNIVERSAL) {
797 		wpa_printf(MSG_DEBUG, "X509: Failed to parse "
798 			   "BasicConstraints");
799 		return -1;
800 	}
801 
802 	if (hdr.tag == ASN1_TAG_BOOLEAN) {
803 		if (hdr.length != 1) {
804 			wpa_printf(MSG_DEBUG, "X509: Unexpected "
805 				   "Boolean length (%u) in BasicConstraints",
806 				   hdr.length);
807 			return -1;
808 		}
809 		cert->ca = hdr.payload[0];
810 
811 		if (hdr.length == pos + len - hdr.payload) {
812 			wpa_printf(MSG_DEBUG, "X509: BasicConstraints - cA=%d",
813 				   cert->ca);
814 			return 0;
815 		}
816 
817 		if (asn1_get_next(hdr.payload + hdr.length, len - hdr.length,
818 				  &hdr) < 0 ||
819 		    hdr.class != ASN1_CLASS_UNIVERSAL) {
820 			wpa_printf(MSG_DEBUG, "X509: Failed to parse "
821 				   "BasicConstraints");
822 			return -1;
823 		}
824 	}
825 
826 	if (hdr.tag != ASN1_TAG_INTEGER) {
827 		wpa_printf(MSG_DEBUG, "X509: Expected INTEGER in "
828 			   "BasicConstraints; found class %d tag 0x%x",
829 			   hdr.class, hdr.tag);
830 		return -1;
831 	}
832 
833 	pos = hdr.payload;
834 	left = hdr.length;
835 	value = 0;
836 	while (left) {
837 		value <<= 8;
838 		value |= *pos++;
839 		left--;
840 	}
841 
842 	cert->path_len_constraint = value;
843 	cert->extensions_present |= X509_EXT_PATH_LEN_CONSTRAINT;
844 
845 	wpa_printf(MSG_DEBUG, "X509: BasicConstraints - cA=%d "
846 		   "pathLenConstraint=%lu",
847 		   cert->ca, cert->path_len_constraint);
848 
849 	return 0;
850 }
851 
852 
853 static int x509_parse_alt_name_rfc8222(struct x509_name *name,
854 				       const u8 *pos, size_t len)
855 {
856 	/* rfc822Name IA5String */
857 	wpa_hexdump_ascii(MSG_MSGDUMP, "X509: altName - rfc822Name", pos, len);
858 	os_free(name->alt_email);
859 	name->alt_email = os_zalloc(len + 1);
860 	if (name->alt_email == NULL)
861 		return -1;
862 	os_memcpy(name->alt_email, pos, len);
863 	if (os_strlen(name->alt_email) != len) {
864 		wpa_printf(MSG_INFO, "X509: Reject certificate with "
865 			   "embedded NUL byte in rfc822Name (%s[NUL])",
866 			   name->alt_email);
867 		os_free(name->alt_email);
868 		name->alt_email = NULL;
869 		return -1;
870 	}
871 	return 0;
872 }
873 
874 
875 static int x509_parse_alt_name_dns(struct x509_name *name,
876 				   const u8 *pos, size_t len)
877 {
878 	/* dNSName IA5String */
879 	wpa_hexdump_ascii(MSG_MSGDUMP, "X509: altName - dNSName", pos, len);
880 	os_free(name->dns);
881 	name->dns = os_zalloc(len + 1);
882 	if (name->dns == NULL)
883 		return -1;
884 	os_memcpy(name->dns, pos, len);
885 	if (os_strlen(name->dns) != len) {
886 		wpa_printf(MSG_INFO, "X509: Reject certificate with "
887 			   "embedded NUL byte in dNSName (%s[NUL])",
888 			   name->dns);
889 		os_free(name->dns);
890 		name->dns = NULL;
891 		return -1;
892 	}
893 	return 0;
894 }
895 
896 
897 static int x509_parse_alt_name_uri(struct x509_name *name,
898 				   const u8 *pos, size_t len)
899 {
900 	/* uniformResourceIdentifier IA5String */
901 	wpa_hexdump_ascii(MSG_MSGDUMP,
902 			  "X509: altName - uniformResourceIdentifier",
903 			  pos, len);
904 	os_free(name->uri);
905 	name->uri = os_zalloc(len + 1);
906 	if (name->uri == NULL)
907 		return -1;
908 	os_memcpy(name->uri, pos, len);
909 	if (os_strlen(name->uri) != len) {
910 		wpa_printf(MSG_INFO, "X509: Reject certificate with "
911 			   "embedded NUL byte in uniformResourceIdentifier "
912 			   "(%s[NUL])", name->uri);
913 		os_free(name->uri);
914 		name->uri = NULL;
915 		return -1;
916 	}
917 	return 0;
918 }
919 
920 
921 static int x509_parse_alt_name_ip(struct x509_name *name,
922 				       const u8 *pos, size_t len)
923 {
924 	/* iPAddress OCTET STRING */
925 	wpa_hexdump(MSG_MSGDUMP, "X509: altName - iPAddress", pos, len);
926 	os_free(name->ip);
927 	name->ip = os_memdup(pos, len);
928 	if (name->ip == NULL)
929 		return -1;
930 	name->ip_len = len;
931 	return 0;
932 }
933 
934 
935 static int x509_parse_alt_name_rid(struct x509_name *name,
936 				   const u8 *pos, size_t len)
937 {
938 	char buf[80];
939 
940 	/* registeredID OBJECT IDENTIFIER */
941 	if (asn1_parse_oid(pos, len, &name->rid) < 0)
942 		return -1;
943 
944 	asn1_oid_to_str(&name->rid, buf, sizeof(buf));
945 	wpa_printf(MSG_MSGDUMP, "X509: altName - registeredID: %s", buf);
946 
947 	return 0;
948 }
949 
950 
951 static int x509_parse_ext_alt_name(struct x509_name *name,
952 				   const u8 *pos, size_t len)
953 {
954 	struct asn1_hdr hdr;
955 	const u8 *p, *end;
956 
957 	/*
958 	 * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
959 	 *
960 	 * GeneralName ::= CHOICE {
961 	 *     otherName                       [0]     OtherName,
962 	 *     rfc822Name                      [1]     IA5String,
963 	 *     dNSName                         [2]     IA5String,
964 	 *     x400Address                     [3]     ORAddress,
965 	 *     directoryName                   [4]     Name,
966 	 *     ediPartyName                    [5]     EDIPartyName,
967 	 *     uniformResourceIdentifier       [6]     IA5String,
968 	 *     iPAddress                       [7]     OCTET STRING,
969 	 *     registeredID                    [8]     OBJECT IDENTIFIER }
970 	 *
971 	 * OtherName ::= SEQUENCE {
972 	 *     type-id    OBJECT IDENTIFIER,
973 	 *     value      [0] EXPLICIT ANY DEFINED BY type-id }
974 	 *
975 	 * EDIPartyName ::= SEQUENCE {
976 	 *     nameAssigner            [0]     DirectoryString OPTIONAL,
977 	 *     partyName               [1]     DirectoryString }
978 	 */
979 
980 	for (p = pos, end = pos + len; p < end; p = hdr.payload + hdr.length) {
981 		int res;
982 
983 		if (asn1_get_next(p, end - p, &hdr) < 0) {
984 			wpa_printf(MSG_DEBUG, "X509: Failed to parse "
985 				   "SubjectAltName item");
986 			return -1;
987 		}
988 
989 		if (hdr.class != ASN1_CLASS_CONTEXT_SPECIFIC)
990 			continue;
991 
992 		switch (hdr.tag) {
993 		case 1:
994 			res = x509_parse_alt_name_rfc8222(name, hdr.payload,
995 							  hdr.length);
996 			break;
997 		case 2:
998 			res = x509_parse_alt_name_dns(name, hdr.payload,
999 						      hdr.length);
1000 			break;
1001 		case 6:
1002 			res = x509_parse_alt_name_uri(name, hdr.payload,
1003 						      hdr.length);
1004 			break;
1005 		case 7:
1006 			res = x509_parse_alt_name_ip(name, hdr.payload,
1007 						     hdr.length);
1008 			break;
1009 		case 8:
1010 			res = x509_parse_alt_name_rid(name, hdr.payload,
1011 						      hdr.length);
1012 			break;
1013 		case 0: /* TODO: otherName */
1014 		case 3: /* TODO: x500Address */
1015 		case 4: /* TODO: directoryName */
1016 		case 5: /* TODO: ediPartyName */
1017 		default:
1018 			res = 0;
1019 			break;
1020 		}
1021 		if (res < 0)
1022 			return res;
1023 	}
1024 
1025 	return 0;
1026 }
1027 
1028 
1029 static int x509_parse_ext_subject_alt_name(struct x509_certificate *cert,
1030 					   const u8 *pos, size_t len)
1031 {
1032 	struct asn1_hdr hdr;
1033 
1034 	/* SubjectAltName ::= GeneralNames */
1035 
1036 	if (asn1_get_next(pos, len, &hdr) < 0 ||
1037 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
1038 	    hdr.tag != ASN1_TAG_SEQUENCE) {
1039 		wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE in "
1040 			   "SubjectAltName; found %d tag 0x%x",
1041 			   hdr.class, hdr.tag);
1042 		return -1;
1043 	}
1044 
1045 	wpa_printf(MSG_DEBUG, "X509: SubjectAltName");
1046 	cert->extensions_present |= X509_EXT_SUBJECT_ALT_NAME;
1047 
1048 	if (hdr.length == 0)
1049 		return 0;
1050 
1051 	return x509_parse_ext_alt_name(&cert->subject, hdr.payload,
1052 				       hdr.length);
1053 }
1054 
1055 
1056 static int x509_parse_ext_issuer_alt_name(struct x509_certificate *cert,
1057 					  const u8 *pos, size_t len)
1058 {
1059 	struct asn1_hdr hdr;
1060 
1061 	/* IssuerAltName ::= GeneralNames */
1062 
1063 	if (asn1_get_next(pos, len, &hdr) < 0 ||
1064 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
1065 	    hdr.tag != ASN1_TAG_SEQUENCE) {
1066 		wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE in "
1067 			   "IssuerAltName; found %d tag 0x%x",
1068 			   hdr.class, hdr.tag);
1069 		return -1;
1070 	}
1071 
1072 	wpa_printf(MSG_DEBUG, "X509: IssuerAltName");
1073 	cert->extensions_present |= X509_EXT_ISSUER_ALT_NAME;
1074 
1075 	if (hdr.length == 0)
1076 		return 0;
1077 
1078 	return x509_parse_ext_alt_name(&cert->issuer, hdr.payload,
1079 				       hdr.length);
1080 }
1081 
1082 
1083 static int x509_id_pkix_oid(struct asn1_oid *oid)
1084 {
1085 	return oid->len >= 7 &&
1086 		oid->oid[0] == 1 /* iso */ &&
1087 		oid->oid[1] == 3 /* identified-organization */ &&
1088 		oid->oid[2] == 6 /* dod */ &&
1089 		oid->oid[3] == 1 /* internet */ &&
1090 		oid->oid[4] == 5 /* security */ &&
1091 		oid->oid[5] == 5 /* mechanisms */ &&
1092 		oid->oid[6] == 7 /* id-pkix */;
1093 }
1094 
1095 
1096 static int x509_id_kp_oid(struct asn1_oid *oid)
1097 {
1098 	/* id-kp */
1099 	return oid->len >= 8 &&
1100 		x509_id_pkix_oid(oid) &&
1101 		oid->oid[7] == 3 /* id-kp */;
1102 }
1103 
1104 
1105 static int x509_id_kp_server_auth_oid(struct asn1_oid *oid)
1106 {
1107 	/* id-kp */
1108 	return oid->len == 9 &&
1109 		x509_id_kp_oid(oid) &&
1110 		oid->oid[8] == 1 /* id-kp-serverAuth */;
1111 }
1112 
1113 
1114 static int x509_id_kp_client_auth_oid(struct asn1_oid *oid)
1115 {
1116 	/* id-kp */
1117 	return oid->len == 9 &&
1118 		x509_id_kp_oid(oid) &&
1119 		oid->oid[8] == 2 /* id-kp-clientAuth */;
1120 }
1121 
1122 
1123 static int x509_id_kp_ocsp_oid(struct asn1_oid *oid)
1124 {
1125 	/* id-kp */
1126 	return oid->len == 9 &&
1127 		x509_id_kp_oid(oid) &&
1128 		oid->oid[8] == 9 /* id-kp-OCSPSigning */;
1129 }
1130 
1131 
1132 static int x509_parse_ext_ext_key_usage(struct x509_certificate *cert,
1133 					const u8 *pos, size_t len)
1134 {
1135 	struct asn1_hdr hdr;
1136 	const u8 *end;
1137 	struct asn1_oid oid;
1138 
1139 	/*
1140 	 * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
1141 	 *
1142 	 * KeyPurposeId ::= OBJECT IDENTIFIER
1143 	 */
1144 
1145 	if (asn1_get_next(pos, len, &hdr) < 0 ||
1146 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
1147 	    hdr.tag != ASN1_TAG_SEQUENCE) {
1148 		wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
1149 			   "(ExtKeyUsageSyntax) - found class %d tag 0x%x",
1150 			   hdr.class, hdr.tag);
1151 		return -1;
1152 	}
1153 	if (hdr.length > pos + len - hdr.payload)
1154 		return -1;
1155 	pos = hdr.payload;
1156 	end = pos + hdr.length;
1157 
1158 	wpa_hexdump(MSG_MSGDUMP, "X509: ExtKeyUsageSyntax", pos, end - pos);
1159 
1160 	while (pos < end) {
1161 		char buf[80];
1162 
1163 		if (asn1_get_oid(pos, end - pos, &oid, &pos))
1164 			return -1;
1165 		if (x509_any_ext_key_usage_oid(&oid)) {
1166 			os_strlcpy(buf, "anyExtendedKeyUsage", sizeof(buf));
1167 			cert->ext_key_usage |= X509_EXT_KEY_USAGE_ANY;
1168 		} else if (x509_id_kp_server_auth_oid(&oid)) {
1169 			os_strlcpy(buf, "id-kp-serverAuth", sizeof(buf));
1170 			cert->ext_key_usage |= X509_EXT_KEY_USAGE_SERVER_AUTH;
1171 		} else if (x509_id_kp_client_auth_oid(&oid)) {
1172 			os_strlcpy(buf, "id-kp-clientAuth", sizeof(buf));
1173 			cert->ext_key_usage |= X509_EXT_KEY_USAGE_CLIENT_AUTH;
1174 		} else if (x509_id_kp_ocsp_oid(&oid)) {
1175 			os_strlcpy(buf, "id-kp-OCSPSigning", sizeof(buf));
1176 			cert->ext_key_usage |= X509_EXT_KEY_USAGE_OCSP;
1177 		} else {
1178 			asn1_oid_to_str(&oid, buf, sizeof(buf));
1179 		}
1180 		wpa_printf(MSG_DEBUG, "ExtKeyUsage KeyPurposeId: %s", buf);
1181 	}
1182 
1183 	cert->extensions_present |= X509_EXT_EXT_KEY_USAGE;
1184 
1185 	return 0;
1186 }
1187 
1188 
1189 static int x509_parse_extension_data(struct x509_certificate *cert,
1190 				     struct asn1_oid *oid,
1191 				     const u8 *pos, size_t len)
1192 {
1193 	if (!x509_id_ce_oid(oid))
1194 		return 1;
1195 
1196 	/* TODO: add other extensions required by RFC 3280, Ch 4.2:
1197 	 * certificate policies (section 4.2.1.5)
1198 	 * name constraints (section 4.2.1.11)
1199 	 * policy constraints (section 4.2.1.12)
1200 	 * inhibit any-policy (section 4.2.1.15)
1201 	 */
1202 	switch (oid->oid[3]) {
1203 	case 15: /* id-ce-keyUsage */
1204 		return x509_parse_ext_key_usage(cert, pos, len);
1205 	case 17: /* id-ce-subjectAltName */
1206 		return x509_parse_ext_subject_alt_name(cert, pos, len);
1207 	case 18: /* id-ce-issuerAltName */
1208 		return x509_parse_ext_issuer_alt_name(cert, pos, len);
1209 	case 19: /* id-ce-basicConstraints */
1210 		return x509_parse_ext_basic_constraints(cert, pos, len);
1211 	case 37: /* id-ce-extKeyUsage */
1212 		return x509_parse_ext_ext_key_usage(cert, pos, len);
1213 	default:
1214 		return 1;
1215 	}
1216 }
1217 
1218 
1219 static int x509_parse_extension(struct x509_certificate *cert,
1220 				const u8 *pos, size_t len, const u8 **next)
1221 {
1222 	const u8 *end;
1223 	struct asn1_hdr hdr;
1224 	struct asn1_oid oid;
1225 	int critical_ext = 0, res;
1226 	char buf[80];
1227 
1228 	/*
1229 	 * Extension  ::=  SEQUENCE  {
1230 	 *     extnID      OBJECT IDENTIFIER,
1231 	 *     critical    BOOLEAN DEFAULT FALSE,
1232 	 *     extnValue   OCTET STRING
1233 	 * }
1234 	 */
1235 
1236 	if (asn1_get_next(pos, len, &hdr) < 0 ||
1237 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
1238 	    hdr.tag != ASN1_TAG_SEQUENCE) {
1239 		wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 header in "
1240 			   "Extensions: class %d tag 0x%x; expected SEQUENCE",
1241 			   hdr.class, hdr.tag);
1242 		return -1;
1243 	}
1244 	pos = hdr.payload;
1245 	*next = end = pos + hdr.length;
1246 
1247 	if (asn1_get_oid(pos, end - pos, &oid, &pos) < 0) {
1248 		wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 data for "
1249 			   "Extension (expected OID)");
1250 		return -1;
1251 	}
1252 
1253 	if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
1254 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
1255 	    (hdr.tag != ASN1_TAG_BOOLEAN &&
1256 	     hdr.tag != ASN1_TAG_OCTETSTRING)) {
1257 		wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 header in "
1258 			   "Extensions: class %d tag 0x%x; expected BOOLEAN "
1259 			   "or OCTET STRING", hdr.class, hdr.tag);
1260 		return -1;
1261 	}
1262 
1263 	if (hdr.tag == ASN1_TAG_BOOLEAN) {
1264 		if (hdr.length != 1) {
1265 			wpa_printf(MSG_DEBUG, "X509: Unexpected "
1266 				   "Boolean length (%u)", hdr.length);
1267 			return -1;
1268 		}
1269 		critical_ext = hdr.payload[0];
1270 		pos = hdr.payload;
1271 		if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
1272 		    (hdr.class != ASN1_CLASS_UNIVERSAL &&
1273 		     hdr.class != ASN1_CLASS_PRIVATE) ||
1274 		    hdr.tag != ASN1_TAG_OCTETSTRING) {
1275 			wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 header "
1276 				   "in Extensions: class %d tag 0x%x; "
1277 				   "expected OCTET STRING",
1278 				   hdr.class, hdr.tag);
1279 			return -1;
1280 		}
1281 	}
1282 
1283 	asn1_oid_to_str(&oid, buf, sizeof(buf));
1284 	wpa_printf(MSG_DEBUG, "X509: Extension: extnID=%s critical=%d",
1285 		   buf, critical_ext);
1286 	wpa_hexdump(MSG_MSGDUMP, "X509: extnValue", hdr.payload, hdr.length);
1287 
1288 	res = x509_parse_extension_data(cert, &oid, hdr.payload, hdr.length);
1289 	if (res < 0)
1290 		return res;
1291 	if (res == 1 && critical_ext) {
1292 		wpa_printf(MSG_INFO, "X509: Unknown critical extension %s",
1293 			   buf);
1294 		return -1;
1295 	}
1296 
1297 	return 0;
1298 }
1299 
1300 
1301 static int x509_parse_extensions(struct x509_certificate *cert,
1302 				 const u8 *pos, size_t len)
1303 {
1304 	const u8 *end;
1305 	struct asn1_hdr hdr;
1306 
1307 	/* Extensions  ::=  SEQUENCE SIZE (1..MAX) OF Extension */
1308 
1309 	if (asn1_get_next(pos, len, &hdr) < 0 ||
1310 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
1311 	    hdr.tag != ASN1_TAG_SEQUENCE) {
1312 		wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 data "
1313 			   "for Extensions: class %d tag 0x%x; "
1314 			   "expected SEQUENCE", hdr.class, hdr.tag);
1315 		return -1;
1316 	}
1317 
1318 	pos = hdr.payload;
1319 	end = pos + hdr.length;
1320 
1321 	while (pos < end) {
1322 		if (x509_parse_extension(cert, pos, end - pos, &pos)
1323 		    < 0)
1324 			return -1;
1325 	}
1326 
1327 	return 0;
1328 }
1329 
1330 
1331 static int x509_parse_tbs_certificate(const u8 *buf, size_t len,
1332 				      struct x509_certificate *cert,
1333 				      const u8 **next)
1334 {
1335 	struct asn1_hdr hdr;
1336 	const u8 *pos, *end;
1337 	size_t left;
1338 	char sbuf[128];
1339 	unsigned long value;
1340 	const u8 *subject_dn;
1341 
1342 	/* tbsCertificate TBSCertificate ::= SEQUENCE */
1343 	if (asn1_get_next(buf, len, &hdr) < 0 ||
1344 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
1345 	    hdr.tag != ASN1_TAG_SEQUENCE) {
1346 		wpa_printf(MSG_DEBUG, "X509: tbsCertificate did not start "
1347 			   "with a valid SEQUENCE - found class %d tag 0x%x",
1348 			   hdr.class, hdr.tag);
1349 		return -1;
1350 	}
1351 	pos = hdr.payload;
1352 	end = *next = pos + hdr.length;
1353 
1354 	/*
1355 	 * version [0]  EXPLICIT Version DEFAULT v1
1356 	 * Version  ::=  INTEGER  {  v1(0), v2(1), v3(2)  }
1357 	 */
1358 	if (asn1_get_next(pos, end - pos, &hdr) < 0)
1359 		return -1;
1360 	pos = hdr.payload;
1361 
1362 	if (hdr.class == ASN1_CLASS_CONTEXT_SPECIFIC) {
1363 		if (asn1_get_next(pos, end - pos, &hdr) < 0)
1364 			return -1;
1365 
1366 		if (hdr.class != ASN1_CLASS_UNIVERSAL ||
1367 		    hdr.tag != ASN1_TAG_INTEGER) {
1368 			wpa_printf(MSG_DEBUG, "X509: No INTEGER tag found for "
1369 				   "version field - found class %d tag 0x%x",
1370 				   hdr.class, hdr.tag);
1371 			return -1;
1372 		}
1373 		if (hdr.length != 1) {
1374 			wpa_printf(MSG_DEBUG, "X509: Unexpected version field "
1375 				   "length %u (expected 1)", hdr.length);
1376 			return -1;
1377 		}
1378 		pos = hdr.payload;
1379 		left = hdr.length;
1380 		value = 0;
1381 		while (left) {
1382 			value <<= 8;
1383 			value |= *pos++;
1384 			left--;
1385 		}
1386 
1387 		cert->version = value;
1388 		if (cert->version != X509_CERT_V1 &&
1389 		    cert->version != X509_CERT_V2 &&
1390 		    cert->version != X509_CERT_V3) {
1391 			wpa_printf(MSG_DEBUG, "X509: Unsupported version %d",
1392 				   cert->version + 1);
1393 			return -1;
1394 		}
1395 
1396 		if (asn1_get_next(pos, end - pos, &hdr) < 0)
1397 			return -1;
1398 	} else
1399 		cert->version = X509_CERT_V1;
1400 	wpa_printf(MSG_MSGDUMP, "X509: Version X.509v%d", cert->version + 1);
1401 
1402 	/* serialNumber CertificateSerialNumber ::= INTEGER */
1403 	if (hdr.class != ASN1_CLASS_UNIVERSAL ||
1404 	    hdr.tag != ASN1_TAG_INTEGER ||
1405 	    hdr.length < 1 || hdr.length > X509_MAX_SERIAL_NUM_LEN) {
1406 		wpa_printf(MSG_DEBUG, "X509: No INTEGER tag found for "
1407 			   "serialNumber; class=%d tag=0x%x length=%u",
1408 			   hdr.class, hdr.tag, hdr.length);
1409 		return -1;
1410 	}
1411 
1412 	pos = hdr.payload + hdr.length;
1413 	while (hdr.length > 0 && hdr.payload[0] == 0) {
1414 		hdr.payload++;
1415 		hdr.length--;
1416 	}
1417 	os_memcpy(cert->serial_number, hdr.payload, hdr.length);
1418 	cert->serial_number_len = hdr.length;
1419 	wpa_hexdump(MSG_MSGDUMP, "X509: serialNumber", cert->serial_number,
1420 		    cert->serial_number_len);
1421 
1422 	/* signature AlgorithmIdentifier */
1423 	if (x509_parse_algorithm_identifier(pos, end - pos, &cert->signature,
1424 					    &pos))
1425 		return -1;
1426 
1427 	/* issuer Name */
1428 	if (x509_parse_name(pos, end - pos, &cert->issuer, &pos))
1429 		return -1;
1430 	x509_name_string(&cert->issuer, sbuf, sizeof(sbuf));
1431 	wpa_printf(MSG_MSGDUMP, "X509: issuer %s", sbuf);
1432 
1433 	/* validity Validity */
1434 	if (x509_parse_validity(pos, end - pos, cert, &pos))
1435 		return -1;
1436 
1437 	/* subject Name */
1438 	subject_dn = pos;
1439 	if (x509_parse_name(pos, end - pos, &cert->subject, &pos))
1440 		return -1;
1441 	cert->subject_dn = os_malloc(pos - subject_dn);
1442 	if (!cert->subject_dn)
1443 		return -1;
1444 	cert->subject_dn_len = pos - subject_dn;
1445 	os_memcpy(cert->subject_dn, subject_dn, cert->subject_dn_len);
1446 	x509_name_string(&cert->subject, sbuf, sizeof(sbuf));
1447 	wpa_printf(MSG_MSGDUMP, "X509: subject %s", sbuf);
1448 
1449 	/* subjectPublicKeyInfo SubjectPublicKeyInfo */
1450 	if (x509_parse_public_key(pos, end - pos, cert, &pos))
1451 		return -1;
1452 
1453 	if (pos == end)
1454 		return 0;
1455 
1456 	if (cert->version == X509_CERT_V1)
1457 		return 0;
1458 
1459 	if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
1460 	    hdr.class != ASN1_CLASS_CONTEXT_SPECIFIC) {
1461 		wpa_printf(MSG_DEBUG, "X509: Expected Context-Specific"
1462 			   " tag to parse optional tbsCertificate "
1463 			   "field(s); parsed class %d tag 0x%x",
1464 			   hdr.class, hdr.tag);
1465 		return -1;
1466 	}
1467 
1468 	if (hdr.tag == 1) {
1469 		/* issuerUniqueID  [1]  IMPLICIT UniqueIdentifier OPTIONAL */
1470 		wpa_printf(MSG_DEBUG, "X509: issuerUniqueID");
1471 		/* TODO: parse UniqueIdentifier ::= BIT STRING */
1472 
1473 		pos = hdr.payload + hdr.length;
1474 		if (pos == end)
1475 			return 0;
1476 
1477 		if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
1478 		    hdr.class != ASN1_CLASS_CONTEXT_SPECIFIC) {
1479 			wpa_printf(MSG_DEBUG, "X509: Expected Context-Specific"
1480 				   " tag to parse optional tbsCertificate "
1481 				   "field(s); parsed class %d tag 0x%x",
1482 				   hdr.class, hdr.tag);
1483 			return -1;
1484 		}
1485 	}
1486 
1487 	if (hdr.tag == 2) {
1488 		/* subjectUniqueID [2]  IMPLICIT UniqueIdentifier OPTIONAL */
1489 		wpa_printf(MSG_DEBUG, "X509: subjectUniqueID");
1490 		/* TODO: parse UniqueIdentifier ::= BIT STRING */
1491 
1492 		pos = hdr.payload + hdr.length;
1493 		if (pos == end)
1494 			return 0;
1495 
1496 		if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
1497 		    hdr.class != ASN1_CLASS_CONTEXT_SPECIFIC) {
1498 			wpa_printf(MSG_DEBUG, "X509: Expected Context-Specific"
1499 				   " tag to parse optional tbsCertificate "
1500 				   "field(s); parsed class %d tag 0x%x",
1501 				   hdr.class, hdr.tag);
1502 			return -1;
1503 		}
1504 	}
1505 
1506 	if (hdr.tag != 3) {
1507 		wpa_printf(MSG_DEBUG, "X509: Ignored unexpected "
1508 			   "Context-Specific tag %d in optional "
1509 			   "tbsCertificate fields", hdr.tag);
1510 		return 0;
1511 	}
1512 
1513 	/* extensions      [3]  EXPLICIT Extensions OPTIONAL */
1514 
1515 	if (cert->version != X509_CERT_V3) {
1516 		wpa_printf(MSG_DEBUG, "X509: X.509%d certificate and "
1517 			   "Extensions data which are only allowed for "
1518 			   "version 3", cert->version + 1);
1519 		return -1;
1520 	}
1521 
1522 	if (x509_parse_extensions(cert, hdr.payload, hdr.length) < 0)
1523 		return -1;
1524 
1525 	pos = hdr.payload + hdr.length;
1526 	if (pos < end) {
1527 		wpa_hexdump(MSG_DEBUG,
1528 			    "X509: Ignored extra tbsCertificate data",
1529 			    pos, end - pos);
1530 	}
1531 
1532 	return 0;
1533 }
1534 
1535 
1536 static int x509_rsadsi_oid(struct asn1_oid *oid)
1537 {
1538 	return oid->len >= 4 &&
1539 		oid->oid[0] == 1 /* iso */ &&
1540 		oid->oid[1] == 2 /* member-body */ &&
1541 		oid->oid[2] == 840 /* us */ &&
1542 		oid->oid[3] == 113549 /* rsadsi */;
1543 }
1544 
1545 
1546 static int x509_pkcs_oid(struct asn1_oid *oid)
1547 {
1548 	return oid->len >= 5 &&
1549 		x509_rsadsi_oid(oid) &&
1550 		oid->oid[4] == 1 /* pkcs */;
1551 }
1552 
1553 
1554 static int x509_digest_oid(struct asn1_oid *oid)
1555 {
1556 	return oid->len >= 5 &&
1557 		x509_rsadsi_oid(oid) &&
1558 		oid->oid[4] == 2 /* digestAlgorithm */;
1559 }
1560 
1561 
1562 int x509_sha1_oid(struct asn1_oid *oid)
1563 {
1564 	return oid->len == 6 &&
1565 		oid->oid[0] == 1 /* iso */ &&
1566 		oid->oid[1] == 3 /* identified-organization */ &&
1567 		oid->oid[2] == 14 /* oiw */ &&
1568 		oid->oid[3] == 3 /* secsig */ &&
1569 		oid->oid[4] == 2 /* algorithms */ &&
1570 		oid->oid[5] == 26 /* id-sha1 */;
1571 }
1572 
1573 
1574 static int x509_sha2_oid(struct asn1_oid *oid)
1575 {
1576 	return oid->len == 9 &&
1577 		oid->oid[0] == 2 /* joint-iso-itu-t */ &&
1578 		oid->oid[1] == 16 /* country */ &&
1579 		oid->oid[2] == 840 /* us */ &&
1580 		oid->oid[3] == 1 /* organization */ &&
1581 		oid->oid[4] == 101 /* gov */ &&
1582 		oid->oid[5] == 3 /* csor */ &&
1583 		oid->oid[6] == 4 /* nistAlgorithm */ &&
1584 		oid->oid[7] == 2 /* hashAlgs */;
1585 }
1586 
1587 
1588 int x509_sha256_oid(struct asn1_oid *oid)
1589 {
1590 	return x509_sha2_oid(oid) &&
1591 		oid->oid[8] == 1 /* sha256 */;
1592 }
1593 
1594 
1595 int x509_sha384_oid(struct asn1_oid *oid)
1596 {
1597 	return x509_sha2_oid(oid) &&
1598 		oid->oid[8] == 2 /* sha384 */;
1599 }
1600 
1601 
1602 int x509_sha512_oid(struct asn1_oid *oid)
1603 {
1604 	return x509_sha2_oid(oid) &&
1605 		oid->oid[8] == 3 /* sha512 */;
1606 }
1607 
1608 
1609 /**
1610  * x509_certificate_parse - Parse a X.509 certificate in DER format
1611  * @buf: Pointer to the X.509 certificate in DER format
1612  * @len: Buffer length
1613  * Returns: Pointer to the parsed certificate or %NULL on failure
1614  *
1615  * Caller is responsible for freeing the returned certificate by calling
1616  * x509_certificate_free().
1617  */
1618 struct x509_certificate * x509_certificate_parse(const u8 *buf, size_t len)
1619 {
1620 	struct asn1_hdr hdr;
1621 	const u8 *pos, *end, *hash_start;
1622 	struct x509_certificate *cert;
1623 
1624 	cert = os_zalloc(sizeof(*cert) + len);
1625 	if (cert == NULL)
1626 		return NULL;
1627 	os_memcpy(cert + 1, buf, len);
1628 	cert->cert_start = (u8 *) (cert + 1);
1629 	cert->cert_len = len;
1630 
1631 	pos = buf;
1632 	end = buf + len;
1633 
1634 	/* RFC 3280 - X.509 v3 certificate / ASN.1 DER */
1635 
1636 	/* Certificate ::= SEQUENCE */
1637 	if (asn1_get_next(pos, len, &hdr) < 0 ||
1638 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
1639 	    hdr.tag != ASN1_TAG_SEQUENCE) {
1640 		wpa_printf(MSG_DEBUG, "X509: Certificate did not start with "
1641 			   "a valid SEQUENCE - found class %d tag 0x%x",
1642 			   hdr.class, hdr.tag);
1643 		x509_certificate_free(cert);
1644 		return NULL;
1645 	}
1646 	pos = hdr.payload;
1647 
1648 	if (hdr.length > end - pos) {
1649 		x509_certificate_free(cert);
1650 		return NULL;
1651 	}
1652 
1653 	if (hdr.length < end - pos) {
1654 		wpa_hexdump(MSG_MSGDUMP, "X509: Ignoring extra data after DER "
1655 			    "encoded certificate",
1656 			    pos + hdr.length, end - (pos + hdr.length));
1657 		end = pos + hdr.length;
1658 	}
1659 
1660 	hash_start = pos;
1661 	cert->tbs_cert_start = cert->cert_start + (hash_start - buf);
1662 	if (x509_parse_tbs_certificate(pos, end - pos, cert, &pos)) {
1663 		x509_certificate_free(cert);
1664 		return NULL;
1665 	}
1666 	cert->tbs_cert_len = pos - hash_start;
1667 
1668 	/* signatureAlgorithm AlgorithmIdentifier */
1669 	if (x509_parse_algorithm_identifier(pos, end - pos,
1670 					    &cert->signature_alg, &pos)) {
1671 		x509_certificate_free(cert);
1672 		return NULL;
1673 	}
1674 
1675 	/* signatureValue BIT STRING */
1676 	if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
1677 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
1678 	    hdr.tag != ASN1_TAG_BITSTRING) {
1679 		wpa_printf(MSG_DEBUG, "X509: Expected BITSTRING "
1680 			   "(signatureValue) - found class %d tag 0x%x",
1681 			   hdr.class, hdr.tag);
1682 		x509_certificate_free(cert);
1683 		return NULL;
1684 	}
1685 	if (hdr.length < 1) {
1686 		x509_certificate_free(cert);
1687 		return NULL;
1688 	}
1689 	pos = hdr.payload;
1690 	if (*pos) {
1691 		wpa_printf(MSG_DEBUG, "X509: BITSTRING - %d unused bits",
1692 			   *pos);
1693 		/* PKCS #1 v1.5 10.2.1:
1694 		 * It is an error if the length in bits of the signature S is
1695 		 * not a multiple of eight.
1696 		 */
1697 		x509_certificate_free(cert);
1698 		return NULL;
1699 	}
1700 	os_free(cert->sign_value);
1701 	cert->sign_value = os_memdup(pos + 1, hdr.length - 1);
1702 	if (cert->sign_value == NULL) {
1703 		wpa_printf(MSG_DEBUG, "X509: Failed to allocate memory for "
1704 			   "signatureValue");
1705 		x509_certificate_free(cert);
1706 		return NULL;
1707 	}
1708 	cert->sign_value_len = hdr.length - 1;
1709 	wpa_hexdump(MSG_MSGDUMP, "X509: signature",
1710 		    cert->sign_value, cert->sign_value_len);
1711 
1712 	return cert;
1713 }
1714 
1715 
1716 /**
1717  * x509_certificate_check_signature - Verify certificate signature
1718  * @issuer: Issuer certificate
1719  * @cert: Certificate to be verified
1720  * Returns: 0 if cert has a valid signature that was signed by the issuer,
1721  * -1 if not
1722  */
1723 int x509_certificate_check_signature(struct x509_certificate *issuer,
1724 				     struct x509_certificate *cert)
1725 {
1726 	return x509_check_signature(issuer, &cert->signature,
1727 				    cert->sign_value, cert->sign_value_len,
1728 				    cert->tbs_cert_start, cert->tbs_cert_len);
1729 }
1730 
1731 
1732 int x509_check_signature(struct x509_certificate *issuer,
1733 			 struct x509_algorithm_identifier *signature,
1734 			 const u8 *sign_value, size_t sign_value_len,
1735 			 const u8 *signed_data, size_t signed_data_len)
1736 {
1737 	struct crypto_public_key *pk;
1738 	u8 *data;
1739 	const u8 *pos, *end, *next, *da_end;
1740 	size_t data_len;
1741 	struct asn1_hdr hdr;
1742 	struct asn1_oid oid;
1743 	u8 hash[64];
1744 	size_t hash_len;
1745 	const u8 *addr[1] = { signed_data };
1746 	size_t len[1] = { signed_data_len };
1747 
1748 	if (!x509_pkcs_oid(&signature->oid) ||
1749 	    signature->oid.len != 7 ||
1750 	    signature->oid.oid[5] != 1 /* pkcs-1 */) {
1751 		wpa_printf(MSG_DEBUG, "X509: Unrecognized signature "
1752 			   "algorithm");
1753 		return -1;
1754 	}
1755 
1756 	pk = crypto_public_key_import(issuer->public_key,
1757 				      issuer->public_key_len);
1758 	if (pk == NULL)
1759 		return -1;
1760 
1761 	data_len = sign_value_len;
1762 	data = os_malloc(data_len);
1763 	if (data == NULL) {
1764 		crypto_public_key_free(pk);
1765 		return -1;
1766 	}
1767 
1768 	if (crypto_public_key_decrypt_pkcs1(pk, sign_value,
1769 					    sign_value_len, data,
1770 					    &data_len) < 0) {
1771 		wpa_printf(MSG_DEBUG, "X509: Failed to decrypt signature");
1772 		crypto_public_key_free(pk);
1773 		os_free(data);
1774 		return -1;
1775 	}
1776 	crypto_public_key_free(pk);
1777 
1778 	wpa_hexdump(MSG_MSGDUMP, "X509: Signature data D", data, data_len);
1779 
1780 	/*
1781 	 * PKCS #1 v1.5, 10.1.2:
1782 	 *
1783 	 * DigestInfo ::= SEQUENCE {
1784 	 *     digestAlgorithm DigestAlgorithmIdentifier,
1785 	 *     digest Digest
1786 	 * }
1787 	 *
1788 	 * DigestAlgorithmIdentifier ::= AlgorithmIdentifier
1789 	 *
1790 	 * Digest ::= OCTET STRING
1791 	 *
1792 	 */
1793 	if (asn1_get_next(data, data_len, &hdr) < 0 ||
1794 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
1795 	    hdr.tag != ASN1_TAG_SEQUENCE) {
1796 		wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
1797 			   "(DigestInfo) - found class %d tag 0x%x",
1798 			   hdr.class, hdr.tag);
1799 		os_free(data);
1800 		return -1;
1801 	}
1802 
1803 	pos = hdr.payload;
1804 	end = pos + hdr.length;
1805 
1806 	/*
1807 	 * X.509:
1808 	 * AlgorithmIdentifier ::= SEQUENCE {
1809 	 *     algorithm            OBJECT IDENTIFIER,
1810 	 *     parameters           ANY DEFINED BY algorithm OPTIONAL
1811 	 * }
1812 	 */
1813 
1814 	if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
1815 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
1816 	    hdr.tag != ASN1_TAG_SEQUENCE) {
1817 		wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
1818 			   "(AlgorithmIdentifier) - found class %d tag 0x%x",
1819 			   hdr.class, hdr.tag);
1820 		os_free(data);
1821 		return -1;
1822 	}
1823 	da_end = hdr.payload + hdr.length;
1824 
1825 	if (asn1_get_oid(hdr.payload, hdr.length, &oid, &next)) {
1826 		wpa_printf(MSG_DEBUG, "X509: Failed to parse digestAlgorithm");
1827 		os_free(data);
1828 		return -1;
1829 	}
1830 
1831 	if (x509_sha1_oid(&oid)) {
1832 		if (signature->oid.oid[6] != 5 /* sha-1WithRSAEncryption */) {
1833 			wpa_printf(MSG_DEBUG, "X509: digestAlgorithm SHA1 "
1834 				   "does not match with certificate "
1835 				   "signatureAlgorithm (%lu)",
1836 				   signature->oid.oid[6]);
1837 			os_free(data);
1838 			return -1;
1839 		}
1840 		goto skip_digest_oid;
1841 	}
1842 
1843 	if (x509_sha256_oid(&oid)) {
1844 		if (signature->oid.oid[6] !=
1845 		    11 /* sha2561WithRSAEncryption */) {
1846 			wpa_printf(MSG_DEBUG, "X509: digestAlgorithm SHA256 "
1847 				   "does not match with certificate "
1848 				   "signatureAlgorithm (%lu)",
1849 				   signature->oid.oid[6]);
1850 			os_free(data);
1851 			return -1;
1852 		}
1853 		goto skip_digest_oid;
1854 	}
1855 
1856 	if (x509_sha384_oid(&oid)) {
1857 		if (signature->oid.oid[6] != 12 /* sha384WithRSAEncryption */) {
1858 			wpa_printf(MSG_DEBUG, "X509: digestAlgorithm SHA384 "
1859 				   "does not match with certificate "
1860 				   "signatureAlgorithm (%lu)",
1861 				   signature->oid.oid[6]);
1862 			os_free(data);
1863 			return -1;
1864 		}
1865 		goto skip_digest_oid;
1866 	}
1867 
1868 	if (x509_sha512_oid(&oid)) {
1869 		if (signature->oid.oid[6] != 13 /* sha512WithRSAEncryption */) {
1870 			wpa_printf(MSG_DEBUG, "X509: digestAlgorithm SHA512 "
1871 				   "does not match with certificate "
1872 				   "signatureAlgorithm (%lu)",
1873 				   signature->oid.oid[6]);
1874 			os_free(data);
1875 			return -1;
1876 		}
1877 		goto skip_digest_oid;
1878 	}
1879 
1880 	if (!x509_digest_oid(&oid)) {
1881 		wpa_printf(MSG_DEBUG, "X509: Unrecognized digestAlgorithm");
1882 		os_free(data);
1883 		return -1;
1884 	}
1885 	switch (oid.oid[5]) {
1886 	case 5: /* md5 */
1887 		if (signature->oid.oid[6] != 4 /* md5WithRSAEncryption */) {
1888 			wpa_printf(MSG_DEBUG, "X509: digestAlgorithm MD5 does "
1889 				   "not match with certificate "
1890 				   "signatureAlgorithm (%lu)",
1891 				   signature->oid.oid[6]);
1892 			os_free(data);
1893 			return -1;
1894 		}
1895 		break;
1896 	case 2: /* md2 */
1897 	case 4: /* md4 */
1898 	default:
1899 		wpa_printf(MSG_DEBUG, "X509: Unsupported digestAlgorithm "
1900 			   "(%lu)", oid.oid[5]);
1901 		os_free(data);
1902 		return -1;
1903 	}
1904 
1905 skip_digest_oid:
1906 	/* Digest ::= OCTET STRING */
1907 	pos = da_end;
1908 	end = data + data_len;
1909 
1910 	if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
1911 	    hdr.class != ASN1_CLASS_UNIVERSAL ||
1912 	    hdr.tag != ASN1_TAG_OCTETSTRING) {
1913 		wpa_printf(MSG_DEBUG, "X509: Expected OCTETSTRING "
1914 			   "(Digest) - found class %d tag 0x%x",
1915 			   hdr.class, hdr.tag);
1916 		os_free(data);
1917 		return -1;
1918 	}
1919 	wpa_hexdump(MSG_MSGDUMP, "X509: Decrypted Digest",
1920 		    hdr.payload, hdr.length);
1921 
1922 	switch (signature->oid.oid[6]) {
1923 	case 4: /* md5WithRSAEncryption */
1924 		md5_vector(1, addr, len, hash);
1925 		hash_len = 16;
1926 		wpa_hexdump(MSG_MSGDUMP, "X509: Certificate hash (MD5)",
1927 			    hash, hash_len);
1928 		break;
1929 	case 5: /* sha-1WithRSAEncryption */
1930 		sha1_vector(1, addr, len, hash);
1931 		hash_len = 20;
1932 		wpa_hexdump(MSG_MSGDUMP, "X509: Certificate hash (SHA1)",
1933 			    hash, hash_len);
1934 		break;
1935 	case 11: /* sha256WithRSAEncryption */
1936 		sha256_vector(1, addr, len, hash);
1937 		hash_len = 32;
1938 		wpa_hexdump(MSG_MSGDUMP, "X509: Certificate hash (SHA256)",
1939 			    hash, hash_len);
1940 		break;
1941 	case 12: /* sha384WithRSAEncryption */
1942 		sha384_vector(1, addr, len, hash);
1943 		hash_len = 48;
1944 		wpa_hexdump(MSG_MSGDUMP, "X509: Certificate hash (SHA384)",
1945 			    hash, hash_len);
1946 		break;
1947 	case 13: /* sha512WithRSAEncryption */
1948 		sha512_vector(1, addr, len, hash);
1949 		hash_len = 64;
1950 		wpa_hexdump(MSG_MSGDUMP, "X509: Certificate hash (SHA512)",
1951 			    hash, hash_len);
1952 		break;
1953 	case 2: /* md2WithRSAEncryption */
1954 	default:
1955 		wpa_printf(MSG_INFO, "X509: Unsupported certificate signature "
1956 			   "algorithm (%lu)", signature->oid.oid[6]);
1957 		os_free(data);
1958 		return -1;
1959 	}
1960 
1961 	if (hdr.length != hash_len ||
1962 	    os_memcmp_const(hdr.payload, hash, hdr.length) != 0) {
1963 		wpa_printf(MSG_INFO, "X509: Certificate Digest does not match "
1964 			   "with calculated tbsCertificate hash");
1965 		os_free(data);
1966 		return -1;
1967 	}
1968 
1969 	if (hdr.payload + hdr.length < data + data_len) {
1970 		wpa_hexdump(MSG_INFO,
1971 			    "X509: Extra data after certificate signature hash",
1972 			    hdr.payload + hdr.length,
1973 			    data + data_len - hdr.payload - hdr.length);
1974 		os_free(data);
1975 		return -1;
1976 	}
1977 
1978 	os_free(data);
1979 
1980 	wpa_printf(MSG_DEBUG, "X509: Certificate Digest matches with "
1981 		   "calculated tbsCertificate hash");
1982 
1983 	return 0;
1984 }
1985 
1986 
1987 static int x509_valid_issuer(const struct x509_certificate *cert)
1988 {
1989 	if ((cert->extensions_present & X509_EXT_BASIC_CONSTRAINTS) &&
1990 	    !cert->ca) {
1991 		wpa_printf(MSG_DEBUG, "X509: Non-CA certificate used as an "
1992 			   "issuer");
1993 		return -1;
1994 	}
1995 
1996 	if (cert->version == X509_CERT_V3 &&
1997 	    !(cert->extensions_present & X509_EXT_BASIC_CONSTRAINTS)) {
1998 		wpa_printf(MSG_DEBUG, "X509: v3 CA certificate did not "
1999 			   "include BasicConstraints extension");
2000 		return -1;
2001 	}
2002 
2003 	if ((cert->extensions_present & X509_EXT_KEY_USAGE) &&
2004 	    !(cert->key_usage & X509_KEY_USAGE_KEY_CERT_SIGN)) {
2005 		wpa_printf(MSG_DEBUG, "X509: Issuer certificate did not have "
2006 			   "keyCertSign bit in Key Usage");
2007 		return -1;
2008 	}
2009 
2010 	return 0;
2011 }
2012 
2013 
2014 /**
2015  * x509_certificate_chain_validate - Validate X.509 certificate chain
2016  * @trusted: List of trusted certificates
2017  * @chain: Certificate chain to be validated (first chain must be issued by
2018  * signed by the second certificate in the chain and so on)
2019  * @reason: Buffer for returning failure reason (X509_VALIDATE_*)
2020  * Returns: 0 if chain is valid, -1 if not
2021  */
2022 int x509_certificate_chain_validate(struct x509_certificate *trusted,
2023 				    struct x509_certificate *chain,
2024 				    int *reason, int disable_time_checks)
2025 {
2026 	long unsigned idx;
2027 	int chain_trusted = 0;
2028 	struct x509_certificate *cert, *trust;
2029 	char buf[128];
2030 	struct os_time now;
2031 
2032 	*reason = X509_VALIDATE_OK;
2033 
2034 	wpa_printf(MSG_DEBUG, "X509: Validate certificate chain");
2035 	os_get_time(&now);
2036 
2037 	for (cert = chain, idx = 0; cert; cert = cert->next, idx++) {
2038 		cert->issuer_trusted = 0;
2039 		x509_name_string(&cert->subject, buf, sizeof(buf));
2040 		wpa_printf(MSG_DEBUG, "X509: %lu: %s", idx, buf);
2041 
2042 		if (chain_trusted)
2043 			continue;
2044 
2045 		if (!disable_time_checks &&
2046 		    ((unsigned long) now.sec <
2047 		     (unsigned long) cert->not_before ||
2048 		     (unsigned long) now.sec >
2049 		     (unsigned long) cert->not_after)) {
2050 			wpa_printf(MSG_INFO, "X509: Certificate not valid "
2051 				   "(now=%lu not_before=%lu not_after=%lu)",
2052 				   now.sec, cert->not_before, cert->not_after);
2053 			*reason = X509_VALIDATE_CERTIFICATE_EXPIRED;
2054 			return -1;
2055 		}
2056 
2057 		if (cert->next) {
2058 			if (x509_name_compare(&cert->issuer,
2059 					      &cert->next->subject) != 0) {
2060 				wpa_printf(MSG_DEBUG, "X509: Certificate "
2061 					   "chain issuer name mismatch");
2062 				x509_name_string(&cert->issuer, buf,
2063 						 sizeof(buf));
2064 				wpa_printf(MSG_DEBUG, "X509: cert issuer: %s",
2065 					   buf);
2066 				x509_name_string(&cert->next->subject, buf,
2067 						 sizeof(buf));
2068 				wpa_printf(MSG_DEBUG, "X509: next cert "
2069 					   "subject: %s", buf);
2070 				*reason = X509_VALIDATE_CERTIFICATE_UNKNOWN;
2071 				return -1;
2072 			}
2073 
2074 			if (x509_valid_issuer(cert->next) < 0) {
2075 				*reason = X509_VALIDATE_BAD_CERTIFICATE;
2076 				return -1;
2077 			}
2078 
2079 			if ((cert->next->extensions_present &
2080 			     X509_EXT_PATH_LEN_CONSTRAINT) &&
2081 			    idx > cert->next->path_len_constraint) {
2082 				wpa_printf(MSG_DEBUG, "X509: pathLenConstraint"
2083 					   " not met (idx=%lu issuer "
2084 					   "pathLenConstraint=%lu)", idx,
2085 					   cert->next->path_len_constraint);
2086 				*reason = X509_VALIDATE_BAD_CERTIFICATE;
2087 				return -1;
2088 			}
2089 
2090 			if (x509_certificate_check_signature(cert->next, cert)
2091 			    < 0) {
2092 				wpa_printf(MSG_DEBUG, "X509: Invalid "
2093 					   "certificate signature within "
2094 					   "chain");
2095 				*reason = X509_VALIDATE_BAD_CERTIFICATE;
2096 				return -1;
2097 			}
2098 		}
2099 
2100 		for (trust = trusted; trust; trust = trust->next) {
2101 			if (x509_name_compare(&cert->issuer, &trust->subject)
2102 			    == 0)
2103 				break;
2104 		}
2105 
2106 		if (trust) {
2107 			wpa_printf(MSG_DEBUG, "X509: Found issuer from the "
2108 				   "list of trusted certificates");
2109 			if (x509_valid_issuer(trust) < 0) {
2110 				*reason = X509_VALIDATE_BAD_CERTIFICATE;
2111 				return -1;
2112 			}
2113 
2114 			if (x509_certificate_check_signature(trust, cert) < 0)
2115 			{
2116 				wpa_printf(MSG_DEBUG, "X509: Invalid "
2117 					   "certificate signature");
2118 				*reason = X509_VALIDATE_BAD_CERTIFICATE;
2119 				return -1;
2120 			}
2121 
2122 			wpa_printf(MSG_DEBUG, "X509: Trusted certificate "
2123 				   "found to complete the chain");
2124 			cert->issuer_trusted = 1;
2125 			chain_trusted = 1;
2126 		}
2127 	}
2128 
2129 	if (!chain_trusted) {
2130 		wpa_printf(MSG_DEBUG, "X509: Did not find any of the issuers "
2131 			   "from the list of trusted certificates");
2132 		if (trusted) {
2133 			*reason = X509_VALIDATE_UNKNOWN_CA;
2134 			return -1;
2135 		}
2136 		wpa_printf(MSG_DEBUG, "X509: Certificate chain validation "
2137 			   "disabled - ignore unknown CA issue");
2138 	}
2139 
2140 	wpa_printf(MSG_DEBUG, "X509: Certificate chain valid");
2141 
2142 	return 0;
2143 }
2144 
2145 
2146 /**
2147  * x509_certificate_get_subject - Get a certificate based on Subject name
2148  * @chain: Certificate chain to search through
2149  * @name: Subject name to search for
2150  * Returns: Pointer to the certificate with the given Subject name or
2151  * %NULL on failure
2152  */
2153 struct x509_certificate *
2154 x509_certificate_get_subject(struct x509_certificate *chain,
2155 			     struct x509_name *name)
2156 {
2157 	struct x509_certificate *cert;
2158 
2159 	for (cert = chain; cert; cert = cert->next) {
2160 		if (x509_name_compare(&cert->subject, name) == 0)
2161 			return cert;
2162 	}
2163 	return NULL;
2164 }
2165 
2166 
2167 /**
2168  * x509_certificate_self_signed - Is the certificate self-signed?
2169  * @cert: Certificate
2170  * Returns: 1 if certificate is self-signed, 0 if not
2171  */
2172 int x509_certificate_self_signed(struct x509_certificate *cert)
2173 {
2174 	return x509_name_compare(&cert->issuer, &cert->subject) == 0;
2175 }
2176