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 static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
111 X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval)
112 {
113 int i;
114 CONF_VALUE tval, *val;
115 STACK_OF(GENERAL_SUBTREE) **ptree = NULL;
116 NAME_CONSTRAINTS *ncons = NULL;
117 GENERAL_SUBTREE *sub = NULL;
118 ncons = NAME_CONSTRAINTS_new();
119 if (!ncons)
120 goto memerr;
121 for (i = 0; i < sk_CONF_VALUE_num(nval); i++) {
122 val = sk_CONF_VALUE_value(nval, i);
123 if (!strncmp(val->name, "permitted", 9) && val->name[9]) {
124 ptree = &ncons->permittedSubtrees;
125 tval.name = val->name + 10;
126 } else if (!strncmp(val->name, "excluded", 8) && val->name[8]) {
127 ptree = &ncons->excludedSubtrees;
128 tval.name = val->name + 9;
129 } else {
130 X509V3err(X509V3_F_V2I_NAME_CONSTRAINTS, X509V3_R_INVALID_SYNTAX);
131 goto err;
132 }
133 tval.value = val->value;
134 sub = GENERAL_SUBTREE_new();
135 if (!v2i_GENERAL_NAME_ex(sub->base, method, ctx, &tval, 1))
136 goto err;
137 if (!*ptree)
138 *ptree = sk_GENERAL_SUBTREE_new_null();
139 if (!*ptree || !sk_GENERAL_SUBTREE_push(*ptree, sub))
140 goto memerr;
141 sub = NULL;
142 }
143
144 return ncons;
145
146 memerr:
147 X509V3err(X509V3_F_V2I_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE);
148 err:
149 if (ncons)
150 NAME_CONSTRAINTS_free(ncons);
151 if (sub)
152 GENERAL_SUBTREE_free(sub);
153
154 return NULL;
155 }
156
i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD * method,void * a,BIO * bp,int ind)157 static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a,
158 BIO *bp, int ind)
159 {
160 NAME_CONSTRAINTS *ncons = a;
161 do_i2r_name_constraints(method, ncons->permittedSubtrees,
162 bp, ind, "Permitted");
163 do_i2r_name_constraints(method, ncons->excludedSubtrees,
164 bp, ind, "Excluded");
165 return 1;
166 }
167
do_i2r_name_constraints(const X509V3_EXT_METHOD * method,STACK_OF (GENERAL_SUBTREE)* trees,BIO * bp,int ind,char * name)168 static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
169 STACK_OF(GENERAL_SUBTREE) *trees,
170 BIO *bp, int ind, char *name)
171 {
172 GENERAL_SUBTREE *tree;
173 int i;
174 if (sk_GENERAL_SUBTREE_num(trees) > 0)
175 BIO_printf(bp, "%*s%s:\n", ind, "", name);
176 for (i = 0; i < sk_GENERAL_SUBTREE_num(trees); i++) {
177 tree = sk_GENERAL_SUBTREE_value(trees, i);
178 BIO_printf(bp, "%*s", ind + 2, "");
179 if (tree->base->type == GEN_IPADD)
180 print_nc_ipadd(bp, tree->base->d.ip);
181 else
182 GENERAL_NAME_print(bp, tree->base);
183 BIO_puts(bp, "\n");
184 }
185 return 1;
186 }
187
print_nc_ipadd(BIO * bp,ASN1_OCTET_STRING * ip)188 static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip)
189 {
190 int i, len;
191 unsigned char *p;
192 p = ip->data;
193 len = ip->length;
194 BIO_puts(bp, "IP:");
195 if (len == 8) {
196 BIO_printf(bp, "%d.%d.%d.%d/%d.%d.%d.%d",
197 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
198 } else if (len == 32) {
199 for (i = 0; i < 16; i++) {
200 BIO_printf(bp, "%X", p[0] << 8 | p[1]);
201 p += 2;
202 if (i == 7)
203 BIO_puts(bp, "/");
204 else if (i != 15)
205 BIO_puts(bp, ":");
206 }
207 } else
208 BIO_printf(bp, "IP Address:<invalid>");
209 return 1;
210 }
211
212 /*-
213 * Check a certificate conforms to a specified set of constraints.
214 * Return values:
215 * X509_V_OK: All constraints obeyed.
216 * X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation.
217 * X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation.
218 * X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type.
219 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: Unsupported constraint type.
220 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: bad unsupported constraint syntax.
221 * X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: bad or unsupported syntax of name
222 */
223
NAME_CONSTRAINTS_check(X509 * x,NAME_CONSTRAINTS * nc)224 int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc)
225 {
226 int r, i;
227 X509_NAME *nm;
228
229 nm = X509_get_subject_name(x);
230
231 if (X509_NAME_entry_count(nm) > 0) {
232 GENERAL_NAME gntmp;
233 gntmp.type = GEN_DIRNAME;
234 gntmp.d.directoryName = nm;
235
236 r = nc_match(&gntmp, nc);
237
238 if (r != X509_V_OK)
239 return r;
240
241 gntmp.type = GEN_EMAIL;
242
243 /* Process any email address attributes in subject name */
244
245 for (i = -1;;) {
246 X509_NAME_ENTRY *ne;
247 i = X509_NAME_get_index_by_NID(nm, NID_pkcs9_emailAddress, i);
248 if (i == -1)
249 break;
250 ne = X509_NAME_get_entry(nm, i);
251 gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne);
252 if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING)
253 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
254
255 r = nc_match(&gntmp, nc);
256
257 if (r != X509_V_OK)
258 return r;
259 }
260
261 }
262
263 for (i = 0; i < sk_GENERAL_NAME_num(x->altname); i++) {
264 GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, i);
265 r = nc_match(gen, nc);
266 if (r != X509_V_OK)
267 return r;
268 }
269
270 return X509_V_OK;
271
272 }
273
nc_match(GENERAL_NAME * gen,NAME_CONSTRAINTS * nc)274 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)
275 {
276 GENERAL_SUBTREE *sub;
277 int i, r, match = 0;
278
279 /*
280 * Permitted subtrees: if any subtrees exist of matching the type at
281 * least one subtree must match.
282 */
283
284 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++) {
285 sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i);
286 if (gen->type != sub->base->type)
287 continue;
288 if (sub->minimum || sub->maximum)
289 return X509_V_ERR_SUBTREE_MINMAX;
290 /* If we already have a match don't bother trying any more */
291 if (match == 2)
292 continue;
293 if (match == 0)
294 match = 1;
295 r = nc_match_single(gen, sub->base);
296 if (r == X509_V_OK)
297 match = 2;
298 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
299 return r;
300 }
301
302 if (match == 1)
303 return X509_V_ERR_PERMITTED_VIOLATION;
304
305 /* Excluded subtrees: must not match any of these */
306
307 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++) {
308 sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i);
309 if (gen->type != sub->base->type)
310 continue;
311 if (sub->minimum || sub->maximum)
312 return X509_V_ERR_SUBTREE_MINMAX;
313
314 r = nc_match_single(gen, sub->base);
315 if (r == X509_V_OK)
316 return X509_V_ERR_EXCLUDED_VIOLATION;
317 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
318 return r;
319
320 }
321
322 return X509_V_OK;
323
324 }
325
nc_match_single(GENERAL_NAME * gen,GENERAL_NAME * base)326 static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base)
327 {
328 switch (base->type) {
329 case GEN_DIRNAME:
330 return nc_dn(gen->d.directoryName, base->d.directoryName);
331
332 case GEN_DNS:
333 return nc_dns(gen->d.dNSName, base->d.dNSName);
334
335 case GEN_EMAIL:
336 return nc_email(gen->d.rfc822Name, base->d.rfc822Name);
337
338 case GEN_URI:
339 return nc_uri(gen->d.uniformResourceIdentifier,
340 base->d.uniformResourceIdentifier);
341
342 default:
343 return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE;
344 }
345
346 }
347
348 /*
349 * directoryName name constraint matching. The canonical encoding of
350 * X509_NAME makes this comparison easy. It is matched if the subtree is a
351 * subset of the name.
352 */
353
nc_dn(X509_NAME * nm,X509_NAME * base)354 static int nc_dn(X509_NAME *nm, X509_NAME *base)
355 {
356 /* Ensure canonical encodings are up to date. */
357 if (nm->modified && i2d_X509_NAME(nm, NULL) < 0)
358 return X509_V_ERR_OUT_OF_MEM;
359 if (base->modified && i2d_X509_NAME(base, NULL) < 0)
360 return X509_V_ERR_OUT_OF_MEM;
361 if (base->canon_enclen > nm->canon_enclen)
362 return X509_V_ERR_PERMITTED_VIOLATION;
363 if (memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen))
364 return X509_V_ERR_PERMITTED_VIOLATION;
365 return X509_V_OK;
366 }
367
nc_dns(ASN1_IA5STRING * dns,ASN1_IA5STRING * base)368 static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base)
369 {
370 char *baseptr = (char *)base->data;
371 char *dnsptr = (char *)dns->data;
372 /* Empty matches everything */
373 if (!*baseptr)
374 return X509_V_OK;
375 /*
376 * Otherwise can add zero or more components on the left so compare RHS
377 * and if dns is longer and expect '.' as preceding character.
378 */
379 if (dns->length > base->length) {
380 dnsptr += dns->length - base->length;
381 if (*baseptr != '.' && dnsptr[-1] != '.')
382 return X509_V_ERR_PERMITTED_VIOLATION;
383 }
384
385 if (strcasecmp(baseptr, dnsptr))
386 return X509_V_ERR_PERMITTED_VIOLATION;
387
388 return X509_V_OK;
389
390 }
391
nc_email(ASN1_IA5STRING * eml,ASN1_IA5STRING * base)392 static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base)
393 {
394 const char *baseptr = (char *)base->data;
395 const char *emlptr = (char *)eml->data;
396
397 const char *baseat = strchr(baseptr, '@');
398 const char *emlat = strchr(emlptr, '@');
399 if (!emlat)
400 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
401 /* Special case: inital '.' is RHS match */
402 if (!baseat && (*baseptr == '.')) {
403 if (eml->length > base->length) {
404 emlptr += eml->length - base->length;
405 if (!strcasecmp(baseptr, emlptr))
406 return X509_V_OK;
407 }
408 return X509_V_ERR_PERMITTED_VIOLATION;
409 }
410
411 /* If we have anything before '@' match local part */
412
413 if (baseat) {
414 if (baseat != baseptr) {
415 if ((baseat - baseptr) != (emlat - emlptr))
416 return X509_V_ERR_PERMITTED_VIOLATION;
417 /* Case sensitive match of local part */
418 if (strncmp(baseptr, emlptr, emlat - emlptr))
419 return X509_V_ERR_PERMITTED_VIOLATION;
420 }
421 /* Position base after '@' */
422 baseptr = baseat + 1;
423 }
424 emlptr = emlat + 1;
425 /* Just have hostname left to match: case insensitive */
426 if (strcasecmp(baseptr, emlptr))
427 return X509_V_ERR_PERMITTED_VIOLATION;
428
429 return X509_V_OK;
430
431 }
432
nc_uri(ASN1_IA5STRING * uri,ASN1_IA5STRING * base)433 static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
434 {
435 const char *baseptr = (char *)base->data;
436 const char *hostptr = (char *)uri->data;
437 const char *p = strchr(hostptr, ':');
438 int hostlen;
439 /* Check for foo:// and skip past it */
440 if (!p || (p[1] != '/') || (p[2] != '/'))
441 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
442 hostptr = p + 3;
443
444 /* Determine length of hostname part of URI */
445
446 /* Look for a port indicator as end of hostname first */
447
448 p = strchr(hostptr, ':');
449 /* Otherwise look for trailing slash */
450 if (!p)
451 p = strchr(hostptr, '/');
452
453 if (!p)
454 hostlen = strlen(hostptr);
455 else
456 hostlen = p - hostptr;
457
458 if (hostlen == 0)
459 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
460
461 /* Special case: inital '.' is RHS match */
462 if (*baseptr == '.') {
463 if (hostlen > base->length) {
464 p = hostptr + hostlen - base->length;
465 if (!strncasecmp(p, baseptr, base->length))
466 return X509_V_OK;
467 }
468 return X509_V_ERR_PERMITTED_VIOLATION;
469 }
470
471 if ((base->length != (int)hostlen)
472 || strncasecmp(hostptr, baseptr, hostlen))
473 return X509_V_ERR_PERMITTED_VIOLATION;
474
475 return X509_V_OK;
476
477 }
478