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