1 /* v3_ncons.c */
2 /*
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
4 * project.
5 */
6 /* ====================================================================
7 * Copyright (c) 2003 The OpenSSL Project. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
19 * distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 * acknowledgment:
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59
60 #include <stdio.h>
61 #include "cryptlib.h"
62 #include <openssl/asn1t.h>
63 #include <openssl/conf.h>
64 #include <openssl/x509v3.h>
65
66 static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
67 X509V3_CTX *ctx,
68 STACK_OF(CONF_VALUE) *nval);
69 static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a,
70 BIO *bp, int ind);
71 static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
72 STACK_OF(GENERAL_SUBTREE) *trees, BIO *bp,
73 int ind, char *name);
74 static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip);
75
76 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc);
77 static int nc_match_single(GENERAL_NAME *sub, GENERAL_NAME *gen);
78 static int nc_dn(X509_NAME *sub, X509_NAME *nm);
79 static int nc_dns(ASN1_IA5STRING *sub, ASN1_IA5STRING *dns);
80 static int nc_email(ASN1_IA5STRING *sub, ASN1_IA5STRING *eml);
81 static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base);
82
83 const X509V3_EXT_METHOD v3_name_constraints = {
84 NID_name_constraints, 0,
85 ASN1_ITEM_ref(NAME_CONSTRAINTS),
86 0, 0, 0, 0,
87 0, 0,
88 0, v2i_NAME_CONSTRAINTS,
89 i2r_NAME_CONSTRAINTS, 0,
90 NULL
91 };
92
93 ASN1_SEQUENCE(GENERAL_SUBTREE) = {
94 ASN1_SIMPLE(GENERAL_SUBTREE, base, GENERAL_NAME),
95 ASN1_IMP_OPT(GENERAL_SUBTREE, minimum, ASN1_INTEGER, 0),
96 ASN1_IMP_OPT(GENERAL_SUBTREE, maximum, ASN1_INTEGER, 1)
97 } ASN1_SEQUENCE_END(GENERAL_SUBTREE)
98
99 ASN1_SEQUENCE(NAME_CONSTRAINTS) = {
100 ASN1_IMP_SEQUENCE_OF_OPT(NAME_CONSTRAINTS, permittedSubtrees,
101 GENERAL_SUBTREE, 0),
102 ASN1_IMP_SEQUENCE_OF_OPT(NAME_CONSTRAINTS, excludedSubtrees,
103 GENERAL_SUBTREE, 1),
104 } ASN1_SEQUENCE_END(NAME_CONSTRAINTS)
105
106
107 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(GENERAL_SUBTREE)
108 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(NAME_CONSTRAINTS)
109
110 /*
111 * We cannot use strncasecmp here because that applies locale specific rules.
112 * For example in Turkish 'I' is not the uppercase character for 'i'. We need to
113 * do a simple ASCII case comparison ignoring the locale (that is why we use
114 * numeric constants below).
115 */
116 static int ia5ncasecmp(const char *s1, const char *s2, size_t n)
117 {
118 for (; n > 0; n--, s1++, s2++) {
119 if (*s1 != *s2) {
120 unsigned char c1 = (unsigned char)*s1, c2 = (unsigned char)*s2;
121
122 /* Convert to lower case */
123 if (c1 >= 0x41 /* A */ && c1 <= 0x5A /* Z */)
124 c1 += 0x20;
125 if (c2 >= 0x41 /* A */ && c2 <= 0x5A /* Z */)
126 c2 += 0x20;
127
128 if (c1 == c2)
129 continue;
130
131 if (c1 < c2)
132 return -1;
133
134 /* c1 > c2 */
135 return 1;
136 } else if (*s1 == 0) {
137 /* If we get here we know that *s2 == 0 too */
138 return 0;
139 }
140 }
141
142 return 0;
143 }
144
ia5casecmp(const char * s1,const char * s2)145 static int ia5casecmp(const char *s1, const char *s2)
146 {
147 /* No portable definition of SIZE_MAX, so we use (size_t)(-1) instead */
148 return ia5ncasecmp(s1, s2, (size_t)(-1));
149 }
150
v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD * method,X509V3_CTX * ctx,STACK_OF (CONF_VALUE)* nval)151 static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
152 X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval)
153 {
154 int i;
155 CONF_VALUE tval, *val;
156 STACK_OF(GENERAL_SUBTREE) **ptree = NULL;
157 NAME_CONSTRAINTS *ncons = NULL;
158 GENERAL_SUBTREE *sub = NULL;
159 ncons = NAME_CONSTRAINTS_new();
160 if (!ncons)
161 goto memerr;
162 for (i = 0; i < sk_CONF_VALUE_num(nval); i++) {
163 val = sk_CONF_VALUE_value(nval, i);
164 if (!strncmp(val->name, "permitted", 9) && val->name[9]) {
165 ptree = &ncons->permittedSubtrees;
166 tval.name = val->name + 10;
167 } else if (!strncmp(val->name, "excluded", 8) && val->name[8]) {
168 ptree = &ncons->excludedSubtrees;
169 tval.name = val->name + 9;
170 } else {
171 X509V3err(X509V3_F_V2I_NAME_CONSTRAINTS, X509V3_R_INVALID_SYNTAX);
172 goto err;
173 }
174 tval.value = val->value;
175 sub = GENERAL_SUBTREE_new();
176 if (sub == NULL)
177 goto memerr;
178 if (!v2i_GENERAL_NAME_ex(sub->base, method, ctx, &tval, 1))
179 goto err;
180 if (!*ptree)
181 *ptree = sk_GENERAL_SUBTREE_new_null();
182 if (!*ptree || !sk_GENERAL_SUBTREE_push(*ptree, sub))
183 goto memerr;
184 sub = NULL;
185 }
186
187 return ncons;
188
189 memerr:
190 X509V3err(X509V3_F_V2I_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE);
191 err:
192 if (ncons)
193 NAME_CONSTRAINTS_free(ncons);
194 if (sub)
195 GENERAL_SUBTREE_free(sub);
196
197 return NULL;
198 }
199
i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD * method,void * a,BIO * bp,int ind)200 static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a,
201 BIO *bp, int ind)
202 {
203 NAME_CONSTRAINTS *ncons = a;
204 do_i2r_name_constraints(method, ncons->permittedSubtrees,
205 bp, ind, "Permitted");
206 do_i2r_name_constraints(method, ncons->excludedSubtrees,
207 bp, ind, "Excluded");
208 return 1;
209 }
210
do_i2r_name_constraints(const X509V3_EXT_METHOD * method,STACK_OF (GENERAL_SUBTREE)* trees,BIO * bp,int ind,char * name)211 static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
212 STACK_OF(GENERAL_SUBTREE) *trees,
213 BIO *bp, int ind, char *name)
214 {
215 GENERAL_SUBTREE *tree;
216 int i;
217 if (sk_GENERAL_SUBTREE_num(trees) > 0)
218 BIO_printf(bp, "%*s%s:\n", ind, "", name);
219 for (i = 0; i < sk_GENERAL_SUBTREE_num(trees); i++) {
220 tree = sk_GENERAL_SUBTREE_value(trees, i);
221 BIO_printf(bp, "%*s", ind + 2, "");
222 if (tree->base->type == GEN_IPADD)
223 print_nc_ipadd(bp, tree->base->d.ip);
224 else
225 GENERAL_NAME_print(bp, tree->base);
226 BIO_puts(bp, "\n");
227 }
228 return 1;
229 }
230
print_nc_ipadd(BIO * bp,ASN1_OCTET_STRING * ip)231 static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip)
232 {
233 int i, len;
234 unsigned char *p;
235 p = ip->data;
236 len = ip->length;
237 BIO_puts(bp, "IP:");
238 if (len == 8) {
239 BIO_printf(bp, "%d.%d.%d.%d/%d.%d.%d.%d",
240 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
241 } else if (len == 32) {
242 for (i = 0; i < 16; i++) {
243 BIO_printf(bp, "%X", p[0] << 8 | p[1]);
244 p += 2;
245 if (i == 7)
246 BIO_puts(bp, "/");
247 else if (i != 15)
248 BIO_puts(bp, ":");
249 }
250 } else
251 BIO_printf(bp, "IP Address:<invalid>");
252 return 1;
253 }
254
255 /*-
256 * Check a certificate conforms to a specified set of constraints.
257 * Return values:
258 * X509_V_OK: All constraints obeyed.
259 * X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation.
260 * X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation.
261 * X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type.
262 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: Unsupported constraint type.
263 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: bad unsupported constraint syntax.
264 * X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: bad or unsupported syntax of name
265 */
266
NAME_CONSTRAINTS_check(X509 * x,NAME_CONSTRAINTS * nc)267 int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc)
268 {
269 int r, i;
270 X509_NAME *nm;
271
272 nm = X509_get_subject_name(x);
273
274 if (X509_NAME_entry_count(nm) > 0) {
275 GENERAL_NAME gntmp;
276 gntmp.type = GEN_DIRNAME;
277 gntmp.d.directoryName = nm;
278
279 r = nc_match(&gntmp, nc);
280
281 if (r != X509_V_OK)
282 return r;
283
284 gntmp.type = GEN_EMAIL;
285
286 /* Process any email address attributes in subject name */
287
288 for (i = -1;;) {
289 X509_NAME_ENTRY *ne;
290 i = X509_NAME_get_index_by_NID(nm, NID_pkcs9_emailAddress, i);
291 if (i == -1)
292 break;
293 ne = X509_NAME_get_entry(nm, i);
294 gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne);
295 if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING)
296 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
297
298 r = nc_match(&gntmp, nc);
299
300 if (r != X509_V_OK)
301 return r;
302 }
303
304 }
305
306 for (i = 0; i < sk_GENERAL_NAME_num(x->altname); i++) {
307 GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, i);
308 r = nc_match(gen, nc);
309 if (r != X509_V_OK)
310 return r;
311 }
312
313 return X509_V_OK;
314
315 }
316
nc_match(GENERAL_NAME * gen,NAME_CONSTRAINTS * nc)317 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)
318 {
319 GENERAL_SUBTREE *sub;
320 int i, r, match = 0;
321
322 /*
323 * Permitted subtrees: if any subtrees exist of matching the type at
324 * least one subtree must match.
325 */
326
327 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++) {
328 sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i);
329 if (gen->type != sub->base->type)
330 continue;
331 if (sub->minimum || sub->maximum)
332 return X509_V_ERR_SUBTREE_MINMAX;
333 /* If we already have a match don't bother trying any more */
334 if (match == 2)
335 continue;
336 if (match == 0)
337 match = 1;
338 r = nc_match_single(gen, sub->base);
339 if (r == X509_V_OK)
340 match = 2;
341 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
342 return r;
343 }
344
345 if (match == 1)
346 return X509_V_ERR_PERMITTED_VIOLATION;
347
348 /* Excluded subtrees: must not match any of these */
349
350 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++) {
351 sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i);
352 if (gen->type != sub->base->type)
353 continue;
354 if (sub->minimum || sub->maximum)
355 return X509_V_ERR_SUBTREE_MINMAX;
356
357 r = nc_match_single(gen, sub->base);
358 if (r == X509_V_OK)
359 return X509_V_ERR_EXCLUDED_VIOLATION;
360 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
361 return r;
362
363 }
364
365 return X509_V_OK;
366
367 }
368
nc_match_single(GENERAL_NAME * gen,GENERAL_NAME * base)369 static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base)
370 {
371 switch (base->type) {
372 case GEN_DIRNAME:
373 return nc_dn(gen->d.directoryName, base->d.directoryName);
374
375 case GEN_DNS:
376 return nc_dns(gen->d.dNSName, base->d.dNSName);
377
378 case GEN_EMAIL:
379 return nc_email(gen->d.rfc822Name, base->d.rfc822Name);
380
381 case GEN_URI:
382 return nc_uri(gen->d.uniformResourceIdentifier,
383 base->d.uniformResourceIdentifier);
384
385 default:
386 return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE;
387 }
388
389 }
390
391 /*
392 * directoryName name constraint matching. The canonical encoding of
393 * X509_NAME makes this comparison easy. It is matched if the subtree is a
394 * subset of the name.
395 */
396
nc_dn(X509_NAME * nm,X509_NAME * base)397 static int nc_dn(X509_NAME *nm, X509_NAME *base)
398 {
399 /* Ensure canonical encodings are up to date. */
400 if (nm->modified && i2d_X509_NAME(nm, NULL) < 0)
401 return X509_V_ERR_OUT_OF_MEM;
402 if (base->modified && i2d_X509_NAME(base, NULL) < 0)
403 return X509_V_ERR_OUT_OF_MEM;
404 if (base->canon_enclen > nm->canon_enclen)
405 return X509_V_ERR_PERMITTED_VIOLATION;
406 if (memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen))
407 return X509_V_ERR_PERMITTED_VIOLATION;
408 return X509_V_OK;
409 }
410
nc_dns(ASN1_IA5STRING * dns,ASN1_IA5STRING * base)411 static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base)
412 {
413 char *baseptr = (char *)base->data;
414 char *dnsptr = (char *)dns->data;
415 /* Empty matches everything */
416 if (!*baseptr)
417 return X509_V_OK;
418 /*
419 * Otherwise can add zero or more components on the left so compare RHS
420 * and if dns is longer and expect '.' as preceding character.
421 */
422 if (dns->length > base->length) {
423 dnsptr += dns->length - base->length;
424 if (*baseptr != '.' && dnsptr[-1] != '.')
425 return X509_V_ERR_PERMITTED_VIOLATION;
426 }
427
428 if (ia5casecmp(baseptr, dnsptr))
429 return X509_V_ERR_PERMITTED_VIOLATION;
430
431 return X509_V_OK;
432
433 }
434
nc_email(ASN1_IA5STRING * eml,ASN1_IA5STRING * base)435 static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base)
436 {
437 const char *baseptr = (char *)base->data;
438 const char *emlptr = (char *)eml->data;
439
440 const char *baseat = strchr(baseptr, '@');
441 const char *emlat = strchr(emlptr, '@');
442 if (!emlat)
443 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
444 /* Special case: inital '.' is RHS match */
445 if (!baseat && (*baseptr == '.')) {
446 if (eml->length > base->length) {
447 emlptr += eml->length - base->length;
448 if (ia5casecmp(baseptr, emlptr) == 0)
449 return X509_V_OK;
450 }
451 return X509_V_ERR_PERMITTED_VIOLATION;
452 }
453
454 /* If we have anything before '@' match local part */
455
456 if (baseat) {
457 if (baseat != baseptr) {
458 if ((baseat - baseptr) != (emlat - emlptr))
459 return X509_V_ERR_PERMITTED_VIOLATION;
460 /* Case sensitive match of local part */
461 if (strncmp(baseptr, emlptr, emlat - emlptr))
462 return X509_V_ERR_PERMITTED_VIOLATION;
463 }
464 /* Position base after '@' */
465 baseptr = baseat + 1;
466 }
467 emlptr = emlat + 1;
468 /* Just have hostname left to match: case insensitive */
469 if (ia5casecmp(baseptr, emlptr))
470 return X509_V_ERR_PERMITTED_VIOLATION;
471
472 return X509_V_OK;
473
474 }
475
nc_uri(ASN1_IA5STRING * uri,ASN1_IA5STRING * base)476 static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
477 {
478 const char *baseptr = (char *)base->data;
479 const char *hostptr = (char *)uri->data;
480 const char *p = strchr(hostptr, ':');
481 int hostlen;
482 /* Check for foo:// and skip past it */
483 if (!p || (p[1] != '/') || (p[2] != '/'))
484 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
485 hostptr = p + 3;
486
487 /* Determine length of hostname part of URI */
488
489 /* Look for a port indicator as end of hostname first */
490
491 p = strchr(hostptr, ':');
492 /* Otherwise look for trailing slash */
493 if (!p)
494 p = strchr(hostptr, '/');
495
496 if (!p)
497 hostlen = strlen(hostptr);
498 else
499 hostlen = p - hostptr;
500
501 if (hostlen == 0)
502 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
503
504 /* Special case: inital '.' is RHS match */
505 if (*baseptr == '.') {
506 if (hostlen > base->length) {
507 p = hostptr + hostlen - base->length;
508 if (ia5ncasecmp(p, baseptr, base->length) == 0)
509 return X509_V_OK;
510 }
511 return X509_V_ERR_PERMITTED_VIOLATION;
512 }
513
514 if ((base->length != (int)hostlen)
515 || ia5ncasecmp(hostptr, baseptr, hostlen))
516 return X509_V_ERR_PERMITTED_VIOLATION;
517
518 return X509_V_OK;
519
520 }
521