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#include <stdio.h>
59#include <string.h>
60
61#include <openssl/asn1t.h>
62#include <openssl/conf.h>
63#include <openssl/err.h>
64#include <openssl/mem.h>
65#include <openssl/obj.h>
66#include <openssl/x509v3.h>
67
68#include "../internal.h"
69
70
71static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
72 X509V3_CTX *ctx,
73 STACK_OF(CONF_VALUE) *nval);
74static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a,
75 BIO *bp, int ind);
76static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
77 STACK_OF(GENERAL_SUBTREE) *trees, BIO *bp,
78 int ind, const char *name);
79static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip);
80
81static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc);
82static int nc_match_single(GENERAL_NAME *sub, GENERAL_NAME *gen);
83static int nc_dn(X509_NAME *sub, X509_NAME *nm);
84static int nc_dns(ASN1_IA5STRING *sub, ASN1_IA5STRING *dns);
85static int nc_email(ASN1_IA5STRING *sub, ASN1_IA5STRING *eml);
86static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base);
87
88const X509V3_EXT_METHOD v3_name_constraints = {
89 NID_name_constraints, 0,
90 ASN1_ITEM_ref(NAME_CONSTRAINTS),
91 0, 0, 0, 0,
92 0, 0,
93 0, v2i_NAME_CONSTRAINTS,
94 i2r_NAME_CONSTRAINTS, 0,
95 NULL
96};
97
98ASN1_SEQUENCE(GENERAL_SUBTREE) = {
99 ASN1_SIMPLE(GENERAL_SUBTREE, base, GENERAL_NAME),
100 ASN1_IMP_OPT(GENERAL_SUBTREE, minimum, ASN1_INTEGER, 0),
101 ASN1_IMP_OPT(GENERAL_SUBTREE, maximum, ASN1_INTEGER, 1)
102} ASN1_SEQUENCE_END(GENERAL_SUBTREE)
103
104ASN1_SEQUENCE(NAME_CONSTRAINTS) = {
105 ASN1_IMP_SEQUENCE_OF_OPT(NAME_CONSTRAINTS, permittedSubtrees,
106 GENERAL_SUBTREE, 0),
107 ASN1_IMP_SEQUENCE_OF_OPT(NAME_CONSTRAINTS, excludedSubtrees,
108 GENERAL_SUBTREE, 1),
109} ASN1_SEQUENCE_END(NAME_CONSTRAINTS)
110
111
112IMPLEMENT_ASN1_ALLOC_FUNCTIONS(GENERAL_SUBTREE)
113IMPLEMENT_ASN1_ALLOC_FUNCTIONS(NAME_CONSTRAINTS)
114
115static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
116 X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval)
117{
118 size_t i;
119 CONF_VALUE tval, *val;
120 STACK_OF(GENERAL_SUBTREE) **ptree = NULL;
121 NAME_CONSTRAINTS *ncons = NULL;
122 GENERAL_SUBTREE *sub = NULL;
123 ncons = NAME_CONSTRAINTS_new();
124 if (!ncons)
125 goto memerr;
126 for (i = 0; i < sk_CONF_VALUE_num(nval); i++) {
127 val = sk_CONF_VALUE_value(nval, i);
128 if (!strncmp(val->name, "permitted", 9) && val->name[9]) {
129 ptree = &ncons->permittedSubtrees;
130 tval.name = val->name + 10;
131 } else if (!strncmp(val->name, "excluded", 8) && val->name[8]) {
132 ptree = &ncons->excludedSubtrees;
133 tval.name = val->name + 9;
134 } else {
135 OPENSSL_PUT_ERROR(X509V3, X509V3_R_INVALID_SYNTAX);
136 goto err;
137 }
138 tval.value = val->value;
139 sub = GENERAL_SUBTREE_new();
140 if (!v2i_GENERAL_NAME_ex(sub->base, method, ctx, &tval, 1))
141 goto err;
142 if (!*ptree)
143 *ptree = sk_GENERAL_SUBTREE_new_null();
144 if (!*ptree || !sk_GENERAL_SUBTREE_push(*ptree, sub))
145 goto memerr;
146 sub = NULL;
147 }
148
149 return ncons;
150
151 memerr:
152 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
153 err:
154 if (ncons)
155 NAME_CONSTRAINTS_free(ncons);
156 if (sub)
157 GENERAL_SUBTREE_free(sub);
158
159 return NULL;
160}
161
162static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a,
163 BIO *bp, int ind)
164{
165 NAME_CONSTRAINTS *ncons = a;
166 do_i2r_name_constraints(method, ncons->permittedSubtrees,
167 bp, ind, "Permitted");
168 do_i2r_name_constraints(method, ncons->excludedSubtrees,
169 bp, ind, "Excluded");
170 return 1;
171}
172
173static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
174 STACK_OF(GENERAL_SUBTREE) *trees,
175 BIO *bp, int ind, const char *name)
176{
177 GENERAL_SUBTREE *tree;
178 size_t i;
179 if (sk_GENERAL_SUBTREE_num(trees) > 0)
180 BIO_printf(bp, "%*s%s:\n", ind, "", name);
181 for (i = 0; i < sk_GENERAL_SUBTREE_num(trees); i++) {
182 tree = sk_GENERAL_SUBTREE_value(trees, i);
183 BIO_printf(bp, "%*s", ind + 2, "");
184 if (tree->base->type == GEN_IPADD)
185 print_nc_ipadd(bp, tree->base->d.ip);
186 else
187 GENERAL_NAME_print(bp, tree->base);
188 BIO_puts(bp, "\n");
189 }
190 return 1;
191}
192
193static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip)
194{
195 int i, len;
196 unsigned char *p;
197 p = ip->data;
198 len = ip->length;
199 BIO_puts(bp, "IP:");
200 if (len == 8) {
201 BIO_printf(bp, "%d.%d.%d.%d/%d.%d.%d.%d",
202 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
203 } else if (len == 32) {
204 for (i = 0; i < 16; i++) {
205 BIO_printf(bp, "%X", p[0] << 8 | p[1]);
206 p += 2;
207 if (i == 7)
208 BIO_puts(bp, "/");
209 else if (i != 15)
210 BIO_puts(bp, ":");
211 }
212 } else
213 BIO_printf(bp, "IP Address:<invalid>");
214 return 1;
215}
216
217/*-
218 * Check a certificate conforms to a specified set of constraints.
219 * Return values:
220 * X509_V_OK: All constraints obeyed.
221 * X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation.
222 * X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation.
223 * X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type.
224 * X509_V_ERR_UNSPECIFIED: Unspecified error.
225 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: Unsupported constraint type.
226 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: Bad or unsupported constraint
227 * syntax.
228 * X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: Bad or unsupported syntax of name.
229 */
230
231int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc)
232{
233 int r, i;
234 size_t j;
235 X509_NAME *nm;
236
237 nm = X509_get_subject_name(x);
238
239 /* Guard against certificates with an excessive number of names or
240 * constraints causing a computationally expensive name constraints
241 * check. */
242 size_t name_count =
243 X509_NAME_entry_count(nm) + sk_GENERAL_NAME_num(x->altname);
244 size_t constraint_count = sk_GENERAL_SUBTREE_num(nc->permittedSubtrees) +
245 sk_GENERAL_SUBTREE_num(nc->excludedSubtrees);
246 size_t check_count = constraint_count * name_count;
247 if (name_count < (size_t)X509_NAME_entry_count(nm) ||
248 constraint_count < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees) ||
249 (constraint_count && check_count / constraint_count != name_count) ||
250 check_count > 1 << 20) {
251 return X509_V_ERR_UNSPECIFIED;
252 }
253
254 if (X509_NAME_entry_count(nm) > 0) {
255 GENERAL_NAME gntmp;
256 gntmp.type = GEN_DIRNAME;
257 gntmp.d.directoryName = nm;
258
259 r = nc_match(&gntmp, nc);
260
261 if (r != X509_V_OK)
262 return r;
263
264 gntmp.type = GEN_EMAIL;
265
266 /* Process any email address attributes in subject name */
267
268 for (i = -1;;) {
269 X509_NAME_ENTRY *ne;
270 i = X509_NAME_get_index_by_NID(nm, NID_pkcs9_emailAddress, i);
271 if (i == -1)
272 break;
273 ne = X509_NAME_get_entry(nm, i);
274 gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne);
275 if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING)
276 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
277
278 r = nc_match(&gntmp, nc);
279
280 if (r != X509_V_OK)
281 return r;
282 }
283
284 }
285
286 for (j = 0; j < sk_GENERAL_NAME_num(x->altname); j++) {
287 GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, j);
288 r = nc_match(gen, nc);
289 if (r != X509_V_OK)
290 return r;
291 }
292
293 return X509_V_OK;
294
295}
296
297static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)
298{
299 GENERAL_SUBTREE *sub;
300 int r, match = 0;
301 size_t i;
302
303 /*
304 * Permitted subtrees: if any subtrees exist of matching the type at
305 * least one subtree must match.
306 */
307
308 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++) {
309 sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i);
310 if (gen->type != sub->base->type)
311 continue;
312 if (sub->minimum || sub->maximum)
313 return X509_V_ERR_SUBTREE_MINMAX;
314 /* If we already have a match don't bother trying any more */
315 if (match == 2)
316 continue;
317 if (match == 0)
318 match = 1;
319 r = nc_match_single(gen, sub->base);
320 if (r == X509_V_OK)
321 match = 2;
322 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
323 return r;
324 }
325
326 if (match == 1)
327 return X509_V_ERR_PERMITTED_VIOLATION;
328
329 /* Excluded subtrees: must not match any of these */
330
331 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++) {
332 sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i);
333 if (gen->type != sub->base->type)
334 continue;
335 if (sub->minimum || sub->maximum)
336 return X509_V_ERR_SUBTREE_MINMAX;
337
338 r = nc_match_single(gen, sub->base);
339 if (r == X509_V_OK)
340 return X509_V_ERR_EXCLUDED_VIOLATION;
341 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
342 return r;
343
344 }
345
346 return X509_V_OK;
347
348}
349
350static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base)
351{
352 switch (base->type) {
353 case GEN_DIRNAME:
354 return nc_dn(gen->d.directoryName, base->d.directoryName);
355
356 case GEN_DNS:
357 return nc_dns(gen->d.dNSName, base->d.dNSName);
358
359 case GEN_EMAIL:
360 return nc_email(gen->d.rfc822Name, base->d.rfc822Name);
361
362 case GEN_URI:
363 return nc_uri(gen->d.uniformResourceIdentifier,
364 base->d.uniformResourceIdentifier);
365
366 default:
367 return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE;
368 }
369
370}
371
372/*
373 * directoryName name constraint matching. The canonical encoding of
374 * X509_NAME makes this comparison easy. It is matched if the subtree is a
375 * subset of the name.
376 */
377
378static int nc_dn(X509_NAME *nm, X509_NAME *base)
379{
380 /* Ensure canonical encodings are up to date. */
381 if (nm->modified && i2d_X509_NAME(nm, NULL) < 0)
382 return X509_V_ERR_OUT_OF_MEM;
383 if (base->modified && i2d_X509_NAME(base, NULL) < 0)
384 return X509_V_ERR_OUT_OF_MEM;
385 if (base->canon_enclen > nm->canon_enclen)
386 return X509_V_ERR_PERMITTED_VIOLATION;
387 if (OPENSSL_memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen))
388 return X509_V_ERR_PERMITTED_VIOLATION;
389 return X509_V_OK;
390}
391
392static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base)
393{
394 char *baseptr = (char *)base->data;
395 char *dnsptr = (char *)dns->data;
396 /* Empty matches everything */
397 if (!*baseptr)
398 return X509_V_OK;
399 /*
400 * Otherwise can add zero or more components on the left so compare RHS
401 * and if dns is longer and expect '.' as preceding character.
402 */
403 if (dns->length > base->length) {
404 dnsptr += dns->length - base->length;
405 if (*baseptr != '.' && dnsptr[-1] != '.')
406 return X509_V_ERR_PERMITTED_VIOLATION;
407 }
408
409 if (OPENSSL_strcasecmp(baseptr, dnsptr))
410 return X509_V_ERR_PERMITTED_VIOLATION;
411
412 return X509_V_OK;
413
414}
415
416static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base)
417{
418 const char *baseptr = (char *)base->data;
419 const char *emlptr = (char *)eml->data;
420
421 const char *baseat = strchr(baseptr, '@');
422 const char *emlat = strchr(emlptr, '@');
423 if (!emlat)
424 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
425 /* Special case: inital '.' is RHS match */
426 if (!baseat && (*baseptr == '.')) {
427 if (eml->length > base->length) {
428 emlptr += eml->length - base->length;
429 if (!OPENSSL_strcasecmp(baseptr, emlptr))
430 return X509_V_OK;
431 }
432 return X509_V_ERR_PERMITTED_VIOLATION;
433 }
434
435 /* If we have anything before '@' match local part */
436
437 if (baseat) {
438 if (baseat != baseptr) {
439 if ((baseat - baseptr) != (emlat - emlptr))
440 return X509_V_ERR_PERMITTED_VIOLATION;
441 /* Case sensitive match of local part */
442 if (strncmp(baseptr, emlptr, emlat - emlptr))
443 return X509_V_ERR_PERMITTED_VIOLATION;
444 }
445 /* Position base after '@' */
446 baseptr = baseat + 1;
447 }
448 emlptr = emlat + 1;
449 /* Just have hostname left to match: case insensitive */
450 if (OPENSSL_strcasecmp(baseptr, emlptr))
451 return X509_V_ERR_PERMITTED_VIOLATION;
452
453 return X509_V_OK;
454
455}
456
457static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
458{
459 const char *baseptr = (char *)base->data;
460 const char *hostptr = (char *)uri->data;
461 const char *p = strchr(hostptr, ':');
462 int hostlen;
463 /* Check for foo:// and skip past it */
464 if (!p || (p[1] != '/') || (p[2] != '/'))
465 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
466 hostptr = p + 3;
467
468 /* Determine length of hostname part of URI */
469
470 /* Look for a port indicator as end of hostname first */
471
472 p = strchr(hostptr, ':');
473 /* Otherwise look for trailing slash */
474 if (!p)
475 p = strchr(hostptr, '/');
476
477 if (!p)
478 hostlen = strlen(hostptr);
479 else
480 hostlen = p - hostptr;
481
482 if (hostlen == 0)
483 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
484
485 /* Special case: inital '.' is RHS match */
486 if (*baseptr == '.') {
487 if (hostlen > base->length) {
488 p = hostptr + hostlen - base->length;
489 if (!OPENSSL_strncasecmp(p, baseptr, base->length))
490 return X509_V_OK;
491 }
492 return X509_V_ERR_PERMITTED_VIOLATION;
493 }
494
495 if ((base->length != (int)hostlen)
496 || OPENSSL_strncasecmp(hostptr, baseptr, hostlen))
497 return X509_V_ERR_PERMITTED_VIOLATION;
498
499 return X509_V_OK;
500
501}
502