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
71 static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
72 X509V3_CTX *ctx,
73 STACK_OF(CONF_VALUE) *nval);
74 static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a,
75 BIO *bp, int ind);
76 static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
77 STACK_OF(GENERAL_SUBTREE) *trees, BIO *bp,
78 int ind, const char *name);
79 static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip);
80
81 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc);
82 static int nc_match_single(GENERAL_NAME *sub, GENERAL_NAME *gen);
83 static int nc_dn(X509_NAME *sub, X509_NAME *nm);
84 static int nc_dns(ASN1_IA5STRING *sub, ASN1_IA5STRING *dns);
85 static int nc_email(ASN1_IA5STRING *sub, ASN1_IA5STRING *eml);
86 static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base);
87
88 const 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
98 ASN1_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
104 ASN1_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
112 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(GENERAL_SUBTREE)
113 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(NAME_CONSTRAINTS)
114
115 static 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
i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD * method,void * a,BIO * bp,int ind)162 static 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
do_i2r_name_constraints(const X509V3_EXT_METHOD * method,STACK_OF (GENERAL_SUBTREE)* trees,BIO * bp,int ind,const char * name)173 static 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
print_nc_ipadd(BIO * bp,ASN1_OCTET_STRING * ip)193 static 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. Return
219 * values: X509_V_OK: All constraints obeyed.
220 * X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation.
221 * X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation.
222 * X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type.
223 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: Unsupported constraint type.
224 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: bad unsupported constraint
225 * syntax. X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: bad or unsupported syntax of
226 * name
227 *
228 */
229
NAME_CONSTRAINTS_check(X509 * x,NAME_CONSTRAINTS * nc)230 int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc)
231 {
232 int r, i;
233 size_t j;
234 X509_NAME *nm;
235
236 nm = X509_get_subject_name(x);
237
238 if (X509_NAME_entry_count(nm) > 0) {
239 GENERAL_NAME gntmp;
240 gntmp.type = GEN_DIRNAME;
241 gntmp.d.directoryName = nm;
242
243 r = nc_match(&gntmp, nc);
244
245 if (r != X509_V_OK)
246 return r;
247
248 gntmp.type = GEN_EMAIL;
249
250 /* Process any email address attributes in subject name */
251
252 for (i = -1;;) {
253 X509_NAME_ENTRY *ne;
254 i = X509_NAME_get_index_by_NID(nm, NID_pkcs9_emailAddress, i);
255 if (i == -1)
256 break;
257 ne = X509_NAME_get_entry(nm, i);
258 gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne);
259 if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING)
260 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
261
262 r = nc_match(&gntmp, nc);
263
264 if (r != X509_V_OK)
265 return r;
266 }
267
268 }
269
270 for (j = 0; j < sk_GENERAL_NAME_num(x->altname); j++) {
271 GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, j);
272 r = nc_match(gen, nc);
273 if (r != X509_V_OK)
274 return r;
275 }
276
277 return X509_V_OK;
278
279 }
280
nc_match(GENERAL_NAME * gen,NAME_CONSTRAINTS * nc)281 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)
282 {
283 GENERAL_SUBTREE *sub;
284 int r, match = 0;
285 size_t i;
286
287 /*
288 * Permitted subtrees: if any subtrees exist of matching the type at
289 * least one subtree must match.
290 */
291
292 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++) {
293 sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i);
294 if (gen->type != sub->base->type)
295 continue;
296 if (sub->minimum || sub->maximum)
297 return X509_V_ERR_SUBTREE_MINMAX;
298 /* If we already have a match don't bother trying any more */
299 if (match == 2)
300 continue;
301 if (match == 0)
302 match = 1;
303 r = nc_match_single(gen, sub->base);
304 if (r == X509_V_OK)
305 match = 2;
306 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
307 return r;
308 }
309
310 if (match == 1)
311 return X509_V_ERR_PERMITTED_VIOLATION;
312
313 /* Excluded subtrees: must not match any of these */
314
315 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++) {
316 sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i);
317 if (gen->type != sub->base->type)
318 continue;
319 if (sub->minimum || sub->maximum)
320 return X509_V_ERR_SUBTREE_MINMAX;
321
322 r = nc_match_single(gen, sub->base);
323 if (r == X509_V_OK)
324 return X509_V_ERR_EXCLUDED_VIOLATION;
325 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
326 return r;
327
328 }
329
330 return X509_V_OK;
331
332 }
333
nc_match_single(GENERAL_NAME * gen,GENERAL_NAME * base)334 static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base)
335 {
336 switch (base->type) {
337 case GEN_DIRNAME:
338 return nc_dn(gen->d.directoryName, base->d.directoryName);
339
340 case GEN_DNS:
341 return nc_dns(gen->d.dNSName, base->d.dNSName);
342
343 case GEN_EMAIL:
344 return nc_email(gen->d.rfc822Name, base->d.rfc822Name);
345
346 case GEN_URI:
347 return nc_uri(gen->d.uniformResourceIdentifier,
348 base->d.uniformResourceIdentifier);
349
350 default:
351 return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE;
352 }
353
354 }
355
356 /*
357 * directoryName name constraint matching. The canonical encoding of
358 * X509_NAME makes this comparison easy. It is matched if the subtree is a
359 * subset of the name.
360 */
361
nc_dn(X509_NAME * nm,X509_NAME * base)362 static int nc_dn(X509_NAME *nm, X509_NAME *base)
363 {
364 /* Ensure canonical encodings are up to date. */
365 if (nm->modified && i2d_X509_NAME(nm, NULL) < 0)
366 return X509_V_ERR_OUT_OF_MEM;
367 if (base->modified && i2d_X509_NAME(base, NULL) < 0)
368 return X509_V_ERR_OUT_OF_MEM;
369 if (base->canon_enclen > nm->canon_enclen)
370 return X509_V_ERR_PERMITTED_VIOLATION;
371 if (OPENSSL_memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen))
372 return X509_V_ERR_PERMITTED_VIOLATION;
373 return X509_V_OK;
374 }
375
nc_dns(ASN1_IA5STRING * dns,ASN1_IA5STRING * base)376 static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base)
377 {
378 char *baseptr = (char *)base->data;
379 char *dnsptr = (char *)dns->data;
380 /* Empty matches everything */
381 if (!*baseptr)
382 return X509_V_OK;
383 /*
384 * Otherwise can add zero or more components on the left so compare RHS
385 * and if dns is longer and expect '.' as preceding character.
386 */
387 if (dns->length > base->length) {
388 dnsptr += dns->length - base->length;
389 if (*baseptr != '.' && dnsptr[-1] != '.')
390 return X509_V_ERR_PERMITTED_VIOLATION;
391 }
392
393 if (OPENSSL_strcasecmp(baseptr, dnsptr))
394 return X509_V_ERR_PERMITTED_VIOLATION;
395
396 return X509_V_OK;
397
398 }
399
nc_email(ASN1_IA5STRING * eml,ASN1_IA5STRING * base)400 static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base)
401 {
402 const char *baseptr = (char *)base->data;
403 const char *emlptr = (char *)eml->data;
404
405 const char *baseat = strchr(baseptr, '@');
406 const char *emlat = strchr(emlptr, '@');
407 if (!emlat)
408 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
409 /* Special case: inital '.' is RHS match */
410 if (!baseat && (*baseptr == '.')) {
411 if (eml->length > base->length) {
412 emlptr += eml->length - base->length;
413 if (!OPENSSL_strcasecmp(baseptr, emlptr))
414 return X509_V_OK;
415 }
416 return X509_V_ERR_PERMITTED_VIOLATION;
417 }
418
419 /* If we have anything before '@' match local part */
420
421 if (baseat) {
422 if (baseat != baseptr) {
423 if ((baseat - baseptr) != (emlat - emlptr))
424 return X509_V_ERR_PERMITTED_VIOLATION;
425 /* Case sensitive match of local part */
426 if (strncmp(baseptr, emlptr, emlat - emlptr))
427 return X509_V_ERR_PERMITTED_VIOLATION;
428 }
429 /* Position base after '@' */
430 baseptr = baseat + 1;
431 }
432 emlptr = emlat + 1;
433 /* Just have hostname left to match: case insensitive */
434 if (OPENSSL_strcasecmp(baseptr, emlptr))
435 return X509_V_ERR_PERMITTED_VIOLATION;
436
437 return X509_V_OK;
438
439 }
440
nc_uri(ASN1_IA5STRING * uri,ASN1_IA5STRING * base)441 static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
442 {
443 const char *baseptr = (char *)base->data;
444 const char *hostptr = (char *)uri->data;
445 const char *p = strchr(hostptr, ':');
446 int hostlen;
447 /* Check for foo:// and skip past it */
448 if (!p || (p[1] != '/') || (p[2] != '/'))
449 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
450 hostptr = p + 3;
451
452 /* Determine length of hostname part of URI */
453
454 /* Look for a port indicator as end of hostname first */
455
456 p = strchr(hostptr, ':');
457 /* Otherwise look for trailing slash */
458 if (!p)
459 p = strchr(hostptr, '/');
460
461 if (!p)
462 hostlen = strlen(hostptr);
463 else
464 hostlen = p - hostptr;
465
466 if (hostlen == 0)
467 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
468
469 /* Special case: inital '.' is RHS match */
470 if (*baseptr == '.') {
471 if (hostlen > base->length) {
472 p = hostptr + hostlen - base->length;
473 if (!OPENSSL_strncasecmp(p, baseptr, base->length))
474 return X509_V_OK;
475 }
476 return X509_V_ERR_PERMITTED_VIOLATION;
477 }
478
479 if ((base->length != (int)hostlen)
480 || OPENSSL_strncasecmp(hostptr, baseptr, hostlen))
481 return X509_V_ERR_PERMITTED_VIOLATION;
482
483 return X509_V_OK;
484
485 }
486