1 /*
2 * Copyright 2003-2023 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include "internal/cryptlib.h"
11 #include "internal/numbers.h"
12 #include "internal/safe_math.h"
13 #include <stdio.h>
14 #include "crypto/asn1.h"
15 #include <openssl/asn1t.h>
16 #include <openssl/conf.h>
17 #include <openssl/x509v3.h>
18 #include <openssl/bn.h>
19
20 #include "crypto/x509.h"
21 #include "crypto/punycode.h"
22 #include "ext_dat.h"
23
24 OSSL_SAFE_MATH_SIGNED(int, int)
25
26 static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
27 X509V3_CTX *ctx,
28 STACK_OF(CONF_VALUE) *nval);
29 static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a,
30 BIO *bp, int ind);
31 static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
32 STACK_OF(GENERAL_SUBTREE) *trees, BIO *bp,
33 int ind, const char *name);
34 static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip);
35
36 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc);
37 static int nc_match_single(int effective_type, GENERAL_NAME *sub,
38 GENERAL_NAME *gen);
39 static int nc_dn(const X509_NAME *sub, const X509_NAME *nm);
40 static int nc_dns(ASN1_IA5STRING *sub, ASN1_IA5STRING *dns);
41 static int nc_email(ASN1_IA5STRING *sub, ASN1_IA5STRING *eml);
42 static int nc_email_eai(ASN1_TYPE *emltype, ASN1_IA5STRING *base);
43 static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base);
44 static int nc_ip(ASN1_OCTET_STRING *ip, ASN1_OCTET_STRING *base);
45
46 const X509V3_EXT_METHOD ossl_v3_name_constraints = {
47 NID_name_constraints, 0,
48 ASN1_ITEM_ref(NAME_CONSTRAINTS),
49 0, 0, 0, 0,
50 0, 0,
51 0, v2i_NAME_CONSTRAINTS,
52 i2r_NAME_CONSTRAINTS, 0,
53 NULL
54 };
55
56 const X509V3_EXT_METHOD ossl_v3_holder_name_constraints = {
57 NID_holder_name_constraints, 0,
58 ASN1_ITEM_ref(NAME_CONSTRAINTS),
59 0, 0, 0, 0,
60 0, 0,
61 0, v2i_NAME_CONSTRAINTS,
62 i2r_NAME_CONSTRAINTS, 0,
63 NULL
64 };
65
66 const X509V3_EXT_METHOD ossl_v3_delegated_name_constraints = {
67 NID_delegated_name_constraints, 0,
68 ASN1_ITEM_ref(NAME_CONSTRAINTS),
69 0, 0, 0, 0,
70 0, 0,
71 0, v2i_NAME_CONSTRAINTS,
72 i2r_NAME_CONSTRAINTS, 0,
73 NULL
74 };
75
76 ASN1_SEQUENCE(GENERAL_SUBTREE) = {
77 ASN1_SIMPLE(GENERAL_SUBTREE, base, GENERAL_NAME),
78 ASN1_IMP_OPT(GENERAL_SUBTREE, minimum, ASN1_INTEGER, 0),
79 ASN1_IMP_OPT(GENERAL_SUBTREE, maximum, ASN1_INTEGER, 1)
80 } ASN1_SEQUENCE_END(GENERAL_SUBTREE)
81
82 ASN1_SEQUENCE(NAME_CONSTRAINTS) = {
83 ASN1_IMP_SEQUENCE_OF_OPT(NAME_CONSTRAINTS, permittedSubtrees,
84 GENERAL_SUBTREE, 0),
85 ASN1_IMP_SEQUENCE_OF_OPT(NAME_CONSTRAINTS, excludedSubtrees,
86 GENERAL_SUBTREE, 1),
87 } ASN1_SEQUENCE_END(NAME_CONSTRAINTS)
88
89
90 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(GENERAL_SUBTREE)
91 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(NAME_CONSTRAINTS)
92
93
94 #define IA5_OFFSET_LEN(ia5base, offset) \
95 ((ia5base)->length - ((unsigned char *)(offset) - (ia5base)->data))
96
97 /* Like memchr but for ASN1_IA5STRING. Additionally you can specify the
98 * starting point to search from
99 */
100 # define ia5memchr(str, start, c) memchr(start, c, IA5_OFFSET_LEN(str, start))
101
102 /* Like memrrchr but for ASN1_IA5STRING */
103 static char *ia5memrchr(ASN1_IA5STRING *str, int c)
104 {
105 int i;
106
107 for (i = str->length; i > 0 && str->data[i - 1] != c; i--);
108
109 if (i == 0)
110 return NULL;
111
112 return (char *)&str->data[i - 1];
113 }
114
115 /*
116 * We cannot use strncasecmp here because that applies locale specific rules. It
117 * also doesn't work with ASN1_STRINGs that may have embedded NUL characters.
118 * For example in Turkish 'I' is not the uppercase character for 'i'. We need to
119 * do a simple ASCII case comparison ignoring the locale (that is why we use
120 * numeric constants below).
121 */
ia5ncasecmp(const char * s1,const char * s2,size_t n)122 static int ia5ncasecmp(const char *s1, const char *s2, size_t n)
123 {
124 for (; n > 0; n--, s1++, s2++) {
125 if (*s1 != *s2) {
126 unsigned char c1 = (unsigned char)*s1, c2 = (unsigned char)*s2;
127
128 /* Convert to lower case */
129 if (c1 >= 0x41 /* A */ && c1 <= 0x5A /* Z */)
130 c1 += 0x20;
131 if (c2 >= 0x41 /* A */ && c2 <= 0x5A /* Z */)
132 c2 += 0x20;
133
134 if (c1 == c2)
135 continue;
136
137 if (c1 < c2)
138 return -1;
139
140 /* c1 > c2 */
141 return 1;
142 }
143 }
144
145 return 0;
146 }
147
v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD * method,X509V3_CTX * ctx,STACK_OF (CONF_VALUE)* nval)148 static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
149 X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval)
150 {
151 int i;
152 CONF_VALUE tval, *val;
153 STACK_OF(GENERAL_SUBTREE) **ptree = NULL;
154 NAME_CONSTRAINTS *ncons = NULL;
155 GENERAL_SUBTREE *sub = NULL;
156
157 ncons = NAME_CONSTRAINTS_new();
158 if (ncons == NULL) {
159 ERR_raise(ERR_LIB_X509V3, ERR_R_ASN1_LIB);
160 goto err;
161 }
162 for (i = 0; i < sk_CONF_VALUE_num(nval); i++) {
163 val = sk_CONF_VALUE_value(nval, i);
164 if (HAS_PREFIX(val->name, "permitted") && val->name[9]) {
165 ptree = &ncons->permittedSubtrees;
166 tval.name = val->name + 10;
167 } else if (HAS_PREFIX(val->name, "excluded") && val->name[8]) {
168 ptree = &ncons->excludedSubtrees;
169 tval.name = val->name + 9;
170 } else {
171 ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_SYNTAX);
172 goto err;
173 }
174 tval.value = val->value;
175 sub = GENERAL_SUBTREE_new();
176 if (sub == NULL) {
177 ERR_raise(ERR_LIB_X509V3, ERR_R_ASN1_LIB);
178 goto err;
179 }
180 if (!v2i_GENERAL_NAME_ex(sub->base, method, ctx, &tval, 1)) {
181 ERR_raise(ERR_LIB_X509V3, ERR_R_X509V3_LIB);
182 goto err;
183 }
184 if (*ptree == NULL)
185 *ptree = sk_GENERAL_SUBTREE_new_null();
186 if (*ptree == NULL || !sk_GENERAL_SUBTREE_push(*ptree, sub)) {
187 ERR_raise(ERR_LIB_X509V3, ERR_R_CRYPTO_LIB);
188 goto err;
189 }
190 sub = NULL;
191 }
192
193 return ncons;
194
195 err:
196 NAME_CONSTRAINTS_free(ncons);
197 GENERAL_SUBTREE_free(sub);
198
199 return NULL;
200 }
201
i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD * method,void * a,BIO * bp,int ind)202 static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a,
203 BIO *bp, int ind)
204 {
205 NAME_CONSTRAINTS *ncons = a;
206 do_i2r_name_constraints(method, ncons->permittedSubtrees,
207 bp, ind, "Permitted");
208 if (ncons->permittedSubtrees && ncons->excludedSubtrees)
209 BIO_puts(bp, "\n");
210 do_i2r_name_constraints(method, ncons->excludedSubtrees,
211 bp, ind, "Excluded");
212 return 1;
213 }
214
do_i2r_name_constraints(const X509V3_EXT_METHOD * method,STACK_OF (GENERAL_SUBTREE)* trees,BIO * bp,int ind,const char * name)215 static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
216 STACK_OF(GENERAL_SUBTREE) *trees,
217 BIO *bp, int ind, const char *name)
218 {
219 GENERAL_SUBTREE *tree;
220 int i;
221 if (sk_GENERAL_SUBTREE_num(trees) > 0)
222 BIO_printf(bp, "%*s%s:\n", ind, "", name);
223 for (i = 0; i < sk_GENERAL_SUBTREE_num(trees); i++) {
224 if (i > 0)
225 BIO_puts(bp, "\n");
226 tree = sk_GENERAL_SUBTREE_value(trees, i);
227 BIO_printf(bp, "%*s", ind + 2, "");
228 if (tree->base->type == GEN_IPADD)
229 print_nc_ipadd(bp, tree->base->d.ip);
230 else
231 GENERAL_NAME_print(bp, tree->base);
232 }
233 return 1;
234 }
235
print_nc_ipadd(BIO * bp,ASN1_OCTET_STRING * ip)236 static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip)
237 {
238 /* ip->length should be 8 or 32 and len1 == len2 == 4 or len1 == len2 == 16 */
239 int len1 = ip->length >= 16 ? 16 : ip->length >= 4 ? 4 : ip->length;
240 int len2 = ip->length - len1;
241 char *ip1 = ossl_ipaddr_to_asc(ip->data, len1);
242 char *ip2 = ossl_ipaddr_to_asc(ip->data + len1, len2);
243 int ret = ip1 != NULL && ip2 != NULL
244 && BIO_printf(bp, "IP:%s/%s", ip1, ip2) > 0;
245
246 OPENSSL_free(ip1);
247 OPENSSL_free(ip2);
248 return ret;
249 }
250
251 #define NAME_CHECK_MAX (1 << 20)
252
add_lengths(int * out,int a,int b)253 static int add_lengths(int *out, int a, int b)
254 {
255 int err = 0;
256
257 /* sk_FOO_num(NULL) returns -1 but is effectively 0 when iterating. */
258 if (a < 0)
259 a = 0;
260 if (b < 0)
261 b = 0;
262
263 *out = safe_add_int(a, b, &err);
264 return !err;
265 }
266
267 /*-
268 * Check a certificate conforms to a specified set of constraints.
269 * Return values:
270 * X509_V_OK: All constraints obeyed.
271 * X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation.
272 * X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation.
273 * X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type.
274 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: Unsupported constraint type.
275 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: bad unsupported constraint syntax.
276 * X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: bad or unsupported syntax of name
277 */
278
NAME_CONSTRAINTS_check(X509 * x,NAME_CONSTRAINTS * nc)279 int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc)
280 {
281 int r, i, name_count, constraint_count;
282 X509_NAME *nm;
283
284 nm = X509_get_subject_name(x);
285
286 /*
287 * Guard against certificates with an excessive number of names or
288 * constraints causing a computationally expensive name constraints check.
289 */
290 if (!add_lengths(&name_count, X509_NAME_entry_count(nm),
291 sk_GENERAL_NAME_num(x->altname))
292 || !add_lengths(&constraint_count,
293 sk_GENERAL_SUBTREE_num(nc->permittedSubtrees),
294 sk_GENERAL_SUBTREE_num(nc->excludedSubtrees))
295 || (name_count > 0 && constraint_count > NAME_CHECK_MAX / name_count))
296 return X509_V_ERR_UNSPECIFIED;
297
298 if (X509_NAME_entry_count(nm) > 0) {
299 GENERAL_NAME gntmp;
300 gntmp.type = GEN_DIRNAME;
301 gntmp.d.directoryName = nm;
302
303 r = nc_match(&gntmp, nc);
304
305 if (r != X509_V_OK)
306 return r;
307
308 gntmp.type = GEN_EMAIL;
309
310 /* Process any email address attributes in subject name */
311
312 for (i = -1;;) {
313 const X509_NAME_ENTRY *ne;
314
315 i = X509_NAME_get_index_by_NID(nm, NID_pkcs9_emailAddress, i);
316 if (i == -1)
317 break;
318 ne = X509_NAME_get_entry(nm, i);
319 gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne);
320 if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING)
321 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
322
323 r = nc_match(&gntmp, nc);
324
325 if (r != X509_V_OK)
326 return r;
327 }
328
329 }
330
331 for (i = 0; i < sk_GENERAL_NAME_num(x->altname); i++) {
332 GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, i);
333 r = nc_match(gen, nc);
334 if (r != X509_V_OK)
335 return r;
336 }
337
338 return X509_V_OK;
339
340 }
341
cn2dnsid(ASN1_STRING * cn,unsigned char ** dnsid,size_t * idlen)342 static int cn2dnsid(ASN1_STRING *cn, unsigned char **dnsid, size_t *idlen)
343 {
344 int utf8_length;
345 unsigned char *utf8_value;
346 int i;
347 int isdnsname = 0;
348
349 /* Don't leave outputs uninitialized */
350 *dnsid = NULL;
351 *idlen = 0;
352
353 /*-
354 * Per RFC 6125, DNS-IDs representing internationalized domain names appear
355 * in certificates in A-label encoded form:
356 *
357 * https://tools.ietf.org/html/rfc6125#section-6.4.2
358 *
359 * The same applies to CNs which are intended to represent DNS names.
360 * However, while in the SAN DNS-IDs are IA5Strings, as CNs they may be
361 * needlessly encoded in 16-bit Unicode. We perform a conversion to UTF-8
362 * to ensure that we get an ASCII representation of any CNs that are
363 * representable as ASCII, but just not encoded as ASCII. The UTF-8 form
364 * may contain some non-ASCII octets, and that's fine, such CNs are not
365 * valid legacy DNS names.
366 *
367 * Note, 'int' is the return type of ASN1_STRING_to_UTF8() so that's what
368 * we must use for 'utf8_length'.
369 */
370 if ((utf8_length = ASN1_STRING_to_UTF8(&utf8_value, cn)) < 0)
371 return X509_V_ERR_OUT_OF_MEM;
372
373 /*
374 * Some certificates have had names that include a *trailing* NUL byte.
375 * Remove these harmless NUL characters. They would otherwise yield false
376 * alarms with the following embedded NUL check.
377 */
378 while (utf8_length > 0 && utf8_value[utf8_length - 1] == '\0')
379 --utf8_length;
380
381 /* Reject *embedded* NULs */
382 if (memchr(utf8_value, 0, utf8_length) != NULL) {
383 OPENSSL_free(utf8_value);
384 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
385 }
386
387 /*
388 * XXX: Deviation from strict DNS name syntax, also check names with '_'
389 * Check DNS name syntax, any '-' or '.' must be internal,
390 * and on either side of each '.' we can't have a '-' or '.'.
391 *
392 * If the name has just one label, we don't consider it a DNS name. This
393 * means that "CN=sometld" cannot be precluded by DNS name constraints, but
394 * that is not a problem.
395 */
396 for (i = 0; i < utf8_length; ++i) {
397 unsigned char c = utf8_value[i];
398
399 if ((c >= 'a' && c <= 'z')
400 || (c >= 'A' && c <= 'Z')
401 || (c >= '0' && c <= '9')
402 || c == '_')
403 continue;
404
405 /* Dot and hyphen cannot be first or last. */
406 if (i > 0 && i < utf8_length - 1) {
407 if (c == '-')
408 continue;
409 /*
410 * Next to a dot the preceding and following characters must not be
411 * another dot or a hyphen. Otherwise, record that the name is
412 * plausible, since it has two or more labels.
413 */
414 if (c == '.'
415 && utf8_value[i + 1] != '.'
416 && utf8_value[i - 1] != '-'
417 && utf8_value[i + 1] != '-') {
418 isdnsname = 1;
419 continue;
420 }
421 }
422 isdnsname = 0;
423 break;
424 }
425
426 if (isdnsname) {
427 *dnsid = utf8_value;
428 *idlen = (size_t)utf8_length;
429 return X509_V_OK;
430 }
431 OPENSSL_free(utf8_value);
432 return X509_V_OK;
433 }
434
435 /*
436 * Check CN against DNS-ID name constraints.
437 */
NAME_CONSTRAINTS_check_CN(X509 * x,NAME_CONSTRAINTS * nc)438 int NAME_CONSTRAINTS_check_CN(X509 *x, NAME_CONSTRAINTS *nc)
439 {
440 int r, i;
441 const X509_NAME *nm = X509_get_subject_name(x);
442 ASN1_STRING stmp;
443 GENERAL_NAME gntmp;
444
445 stmp.flags = 0;
446 stmp.type = V_ASN1_IA5STRING;
447 gntmp.type = GEN_DNS;
448 gntmp.d.dNSName = &stmp;
449
450 /* Process any commonName attributes in subject name */
451
452 for (i = -1;;) {
453 X509_NAME_ENTRY *ne;
454 ASN1_STRING *cn;
455 unsigned char *idval;
456 size_t idlen;
457
458 i = X509_NAME_get_index_by_NID(nm, NID_commonName, i);
459 if (i == -1)
460 break;
461 ne = X509_NAME_get_entry(nm, i);
462 cn = X509_NAME_ENTRY_get_data(ne);
463
464 /* Only process attributes that look like hostnames */
465 if ((r = cn2dnsid(cn, &idval, &idlen)) != X509_V_OK)
466 return r;
467 if (idlen == 0)
468 continue;
469
470 stmp.length = idlen;
471 stmp.data = idval;
472 r = nc_match(&gntmp, nc);
473 OPENSSL_free(idval);
474 if (r != X509_V_OK)
475 return r;
476 }
477 return X509_V_OK;
478 }
479
480 /*
481 * Return nonzero if the GeneralSubtree has valid 'minimum' field
482 * (must be absent or 0) and valid 'maximum' field (must be absent).
483 */
nc_minmax_valid(GENERAL_SUBTREE * sub)484 static int nc_minmax_valid(GENERAL_SUBTREE *sub) {
485 BIGNUM *bn = NULL;
486 int ok = 1;
487
488 if (sub->maximum)
489 ok = 0;
490
491 if (sub->minimum) {
492 bn = ASN1_INTEGER_to_BN(sub->minimum, NULL);
493 if (bn == NULL || !BN_is_zero(bn))
494 ok = 0;
495 BN_free(bn);
496 }
497
498 return ok;
499 }
500
nc_match(GENERAL_NAME * gen,NAME_CONSTRAINTS * nc)501 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)
502 {
503 GENERAL_SUBTREE *sub;
504 int i, r, match = 0;
505 int effective_type = gen->type;
506
507 /*
508 * We need to compare not gen->type field but an "effective" type because
509 * the otherName field may contain EAI email address treated specially
510 * according to RFC 8398, section 6
511 */
512 if (effective_type == GEN_OTHERNAME &&
513 (OBJ_obj2nid(gen->d.otherName->type_id) == NID_id_on_SmtpUTF8Mailbox)) {
514 effective_type = GEN_EMAIL;
515 }
516
517 /*
518 * Permitted subtrees: if any subtrees exist of matching the type at
519 * least one subtree must match.
520 */
521
522 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++) {
523 sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i);
524 if (effective_type != sub->base->type
525 || (effective_type == GEN_OTHERNAME &&
526 OBJ_cmp(gen->d.otherName->type_id,
527 sub->base->d.otherName->type_id) != 0))
528 continue;
529 if (!nc_minmax_valid(sub))
530 return X509_V_ERR_SUBTREE_MINMAX;
531 /* If we already have a match don't bother trying any more */
532 if (match == 2)
533 continue;
534 if (match == 0)
535 match = 1;
536 r = nc_match_single(effective_type, gen, sub->base);
537 if (r == X509_V_OK)
538 match = 2;
539 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
540 return r;
541 }
542
543 if (match == 1)
544 return X509_V_ERR_PERMITTED_VIOLATION;
545
546 /* Excluded subtrees: must not match any of these */
547
548 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++) {
549 sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i);
550 if (effective_type != sub->base->type
551 || (effective_type == GEN_OTHERNAME &&
552 OBJ_cmp(gen->d.otherName->type_id,
553 sub->base->d.otherName->type_id) != 0))
554 continue;
555 if (!nc_minmax_valid(sub))
556 return X509_V_ERR_SUBTREE_MINMAX;
557
558 r = nc_match_single(effective_type, gen, sub->base);
559 if (r == X509_V_OK)
560 return X509_V_ERR_EXCLUDED_VIOLATION;
561 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
562 return r;
563
564 }
565
566 return X509_V_OK;
567
568 }
569
nc_match_single(int effective_type,GENERAL_NAME * gen,GENERAL_NAME * base)570 static int nc_match_single(int effective_type, GENERAL_NAME *gen,
571 GENERAL_NAME *base)
572 {
573 switch (gen->type) {
574 case GEN_OTHERNAME:
575 switch (effective_type) {
576 case GEN_EMAIL:
577 /*
578 * We are here only when we have SmtpUTF8 name,
579 * so we match the value of othername with base->d.rfc822Name
580 */
581 return nc_email_eai(gen->d.otherName->value, base->d.rfc822Name);
582
583 default:
584 return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE;
585 }
586
587 case GEN_DIRNAME:
588 return nc_dn(gen->d.directoryName, base->d.directoryName);
589
590 case GEN_DNS:
591 return nc_dns(gen->d.dNSName, base->d.dNSName);
592
593 case GEN_EMAIL:
594 return nc_email(gen->d.rfc822Name, base->d.rfc822Name);
595
596 case GEN_URI:
597 return nc_uri(gen->d.uniformResourceIdentifier,
598 base->d.uniformResourceIdentifier);
599
600 case GEN_IPADD:
601 return nc_ip(gen->d.iPAddress, base->d.iPAddress);
602
603 default:
604 return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE;
605 }
606
607 }
608
609 /*
610 * directoryName name constraint matching. The canonical encoding of
611 * X509_NAME makes this comparison easy. It is matched if the subtree is a
612 * subset of the name.
613 */
614
nc_dn(const X509_NAME * nm,const X509_NAME * base)615 static int nc_dn(const X509_NAME *nm, const X509_NAME *base)
616 {
617 /* Ensure canonical encodings are up to date. */
618 if (nm->modified && i2d_X509_NAME(nm, NULL) < 0)
619 return X509_V_ERR_OUT_OF_MEM;
620 if (base->modified && i2d_X509_NAME(base, NULL) < 0)
621 return X509_V_ERR_OUT_OF_MEM;
622 if (base->canon_enclen > nm->canon_enclen)
623 return X509_V_ERR_PERMITTED_VIOLATION;
624 if (memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen))
625 return X509_V_ERR_PERMITTED_VIOLATION;
626 return X509_V_OK;
627 }
628
nc_dns(ASN1_IA5STRING * dns,ASN1_IA5STRING * base)629 static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base)
630 {
631 char *baseptr = (char *)base->data;
632 char *dnsptr = (char *)dns->data;
633
634 /* Empty matches everything */
635 if (base->length == 0)
636 return X509_V_OK;
637
638 if (dns->length < base->length)
639 return X509_V_ERR_PERMITTED_VIOLATION;
640
641 /*
642 * Otherwise can add zero or more components on the left so compare RHS
643 * and if dns is longer and expect '.' as preceding character.
644 */
645 if (dns->length > base->length) {
646 dnsptr += dns->length - base->length;
647 if (*baseptr != '.' && dnsptr[-1] != '.')
648 return X509_V_ERR_PERMITTED_VIOLATION;
649 }
650
651 if (ia5ncasecmp(baseptr, dnsptr, base->length))
652 return X509_V_ERR_PERMITTED_VIOLATION;
653
654 return X509_V_OK;
655
656 }
657
658 /*
659 * This function implements comparison between ASCII/U-label in emltype
660 * and A-label in base according to RFC 8398, section 6.
661 * Convert base to U-label and ASCII-parts of domain names, for base
662 * Octet-to-octet comparison of `emltype` and `base` hostname parts
663 * (ASCII-parts should be compared in case-insensitive manner)
664 */
nc_email_eai(ASN1_TYPE * emltype,ASN1_IA5STRING * base)665 static int nc_email_eai(ASN1_TYPE *emltype, ASN1_IA5STRING *base)
666 {
667 ASN1_UTF8STRING *eml;
668 char *baseptr = NULL;
669 const char *emlptr;
670 const char *emlat;
671 char ulabel[256];
672 size_t size = sizeof(ulabel);
673 int ret = X509_V_OK;
674 size_t emlhostlen;
675
676 /* We do not accept embedded NUL characters */
677 if (base->length > 0 && memchr(base->data, 0, base->length) != NULL)
678 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
679
680 /* 'base' may not be NUL terminated. Create a copy that is */
681 baseptr = OPENSSL_strndup((char *)base->data, base->length);
682 if (baseptr == NULL)
683 return X509_V_ERR_OUT_OF_MEM;
684
685 if (emltype->type != V_ASN1_UTF8STRING) {
686 ret = X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
687 goto end;
688 }
689
690 eml = emltype->value.utf8string;
691 emlptr = (char *)eml->data;
692 emlat = ia5memrchr(eml, '@');
693
694 if (emlat == NULL) {
695 ret = X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
696 goto end;
697 }
698
699 /* Special case: initial '.' is RHS match */
700 if (*baseptr == '.') {
701 ulabel[0] = '.';
702 if (ossl_a2ulabel(baseptr, ulabel + 1, size - 1) <= 0) {
703 ret = X509_V_ERR_UNSPECIFIED;
704 goto end;
705 }
706
707 if ((size_t)eml->length > strlen(ulabel)) {
708 emlptr += eml->length - strlen(ulabel);
709 /* X509_V_OK */
710 if (ia5ncasecmp(ulabel, emlptr, strlen(ulabel)) == 0)
711 goto end;
712 }
713 ret = X509_V_ERR_PERMITTED_VIOLATION;
714 goto end;
715 }
716
717 if (ossl_a2ulabel(baseptr, ulabel, size) <= 0) {
718 ret = X509_V_ERR_UNSPECIFIED;
719 goto end;
720 }
721 /* Just have hostname left to match: case insensitive */
722 emlptr = emlat + 1;
723 emlhostlen = IA5_OFFSET_LEN(eml, emlptr);
724 if (emlhostlen != strlen(ulabel)
725 || ia5ncasecmp(ulabel, emlptr, emlhostlen) != 0) {
726 ret = X509_V_ERR_PERMITTED_VIOLATION;
727 goto end;
728 }
729
730 end:
731 OPENSSL_free(baseptr);
732 return ret;
733 }
734
nc_email(ASN1_IA5STRING * eml,ASN1_IA5STRING * base)735 static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base)
736 {
737 const char *baseptr = (char *)base->data;
738 const char *emlptr = (char *)eml->data;
739 const char *baseat = ia5memrchr(base, '@');
740 const char *emlat = ia5memrchr(eml, '@');
741 size_t basehostlen, emlhostlen;
742
743 if (!emlat)
744 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
745 /* Special case: initial '.' is RHS match */
746 if (!baseat && base->length > 0 && (*baseptr == '.')) {
747 if (eml->length > base->length) {
748 emlptr += eml->length - base->length;
749 if (ia5ncasecmp(baseptr, emlptr, base->length) == 0)
750 return X509_V_OK;
751 }
752 return X509_V_ERR_PERMITTED_VIOLATION;
753 }
754
755 /* If we have anything before '@' match local part */
756
757 if (baseat) {
758 if (baseat != baseptr) {
759 if ((baseat - baseptr) != (emlat - emlptr))
760 return X509_V_ERR_PERMITTED_VIOLATION;
761 if (memchr(baseptr, 0, baseat - baseptr) ||
762 memchr(emlptr, 0, emlat - emlptr))
763 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
764 /* Case sensitive match of local part */
765 if (strncmp(baseptr, emlptr, emlat - emlptr))
766 return X509_V_ERR_PERMITTED_VIOLATION;
767 }
768 /* Position base after '@' */
769 baseptr = baseat + 1;
770 }
771 emlptr = emlat + 1;
772 basehostlen = IA5_OFFSET_LEN(base, baseptr);
773 emlhostlen = IA5_OFFSET_LEN(eml, emlptr);
774 /* Just have hostname left to match: case insensitive */
775 if (basehostlen != emlhostlen || ia5ncasecmp(baseptr, emlptr, emlhostlen))
776 return X509_V_ERR_PERMITTED_VIOLATION;
777
778 return X509_V_OK;
779
780 }
781
nc_uri(ASN1_IA5STRING * uri,ASN1_IA5STRING * base)782 static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
783 {
784 const char *baseptr = (char *)base->data;
785 const char *hostptr = (char *)uri->data;
786 const char *p = ia5memchr(uri, (char *)uri->data, ':');
787 int hostlen;
788
789 /* Check for foo:// and skip past it */
790 if (p == NULL
791 || IA5_OFFSET_LEN(uri, p) < 3
792 || p[1] != '/'
793 || p[2] != '/')
794 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
795 hostptr = p + 3;
796
797 /* Determine length of hostname part of URI */
798
799 /* Look for a port indicator as end of hostname first */
800
801 p = ia5memchr(uri, hostptr, ':');
802 /* Otherwise look for trailing slash */
803 if (p == NULL)
804 p = ia5memchr(uri, hostptr, '/');
805
806 if (p == NULL)
807 hostlen = IA5_OFFSET_LEN(uri, hostptr);
808 else
809 hostlen = p - hostptr;
810
811 if (hostlen == 0)
812 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
813
814 /* Special case: initial '.' is RHS match */
815 if (base->length > 0 && *baseptr == '.') {
816 if (hostlen > base->length) {
817 p = hostptr + hostlen - base->length;
818 if (ia5ncasecmp(p, baseptr, base->length) == 0)
819 return X509_V_OK;
820 }
821 return X509_V_ERR_PERMITTED_VIOLATION;
822 }
823
824 if ((base->length != (int)hostlen)
825 || ia5ncasecmp(hostptr, baseptr, hostlen))
826 return X509_V_ERR_PERMITTED_VIOLATION;
827
828 return X509_V_OK;
829
830 }
831
nc_ip(ASN1_OCTET_STRING * ip,ASN1_OCTET_STRING * base)832 static int nc_ip(ASN1_OCTET_STRING *ip, ASN1_OCTET_STRING *base)
833 {
834 int hostlen, baselen, i;
835 unsigned char *hostptr, *baseptr, *maskptr;
836 hostptr = ip->data;
837 hostlen = ip->length;
838 baseptr = base->data;
839 baselen = base->length;
840
841 /* Invalid if not IPv4 or IPv6 */
842 if (!((hostlen == 4) || (hostlen == 16)))
843 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
844 if (!((baselen == 8) || (baselen == 32)))
845 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
846
847 /* Do not match IPv4 with IPv6 */
848 if (hostlen * 2 != baselen)
849 return X509_V_ERR_PERMITTED_VIOLATION;
850
851 maskptr = base->data + hostlen;
852
853 /* Considering possible not aligned base ipAddress */
854 /* Not checking for wrong mask definition: i.e.: 255.0.255.0 */
855 for (i = 0; i < hostlen; i++)
856 if ((hostptr[i] & maskptr[i]) != (baseptr[i] & maskptr[i]))
857 return X509_V_ERR_PERMITTED_VIOLATION;
858
859 return X509_V_OK;
860
861 }
862
