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 #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
69 static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
70 X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval);
71 static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
72 void *a, BIO *bp, int ind);
73 static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
74 STACK_OF(GENERAL_SUBTREE) *trees,
75 BIO *bp, int ind, const char *name);
76 static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip);
77
78 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc);
79 static int nc_match_single(GENERAL_NAME *sub, GENERAL_NAME *gen);
80 static int nc_dn(X509_NAME *sub, X509_NAME *nm);
81 static int nc_dns(ASN1_IA5STRING *sub, ASN1_IA5STRING *dns);
82 static int nc_email(ASN1_IA5STRING *sub, ASN1_IA5STRING *eml);
83 static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base);
84
85 const X509V3_EXT_METHOD v3_name_constraints = {
86 NID_name_constraints, 0,
87 ASN1_ITEM_ref(NAME_CONSTRAINTS),
88 0,0,0,0,
89 0,0,
90 0, v2i_NAME_CONSTRAINTS,
91 i2r_NAME_CONSTRAINTS,0,
92 NULL
93 };
94
95 ASN1_SEQUENCE(GENERAL_SUBTREE) = {
96 ASN1_SIMPLE(GENERAL_SUBTREE, base, GENERAL_NAME),
97 ASN1_IMP_OPT(GENERAL_SUBTREE, minimum, ASN1_INTEGER, 0),
98 ASN1_IMP_OPT(GENERAL_SUBTREE, maximum, ASN1_INTEGER, 1)
99 } ASN1_SEQUENCE_END(GENERAL_SUBTREE)
100
101 ASN1_SEQUENCE(NAME_CONSTRAINTS) = {
102 ASN1_IMP_SEQUENCE_OF_OPT(NAME_CONSTRAINTS, permittedSubtrees,
103 GENERAL_SUBTREE, 0),
104 ASN1_IMP_SEQUENCE_OF_OPT(NAME_CONSTRAINTS, excludedSubtrees,
105 GENERAL_SUBTREE, 1),
106 } ASN1_SEQUENCE_END(NAME_CONSTRAINTS)
107
108
109 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(GENERAL_SUBTREE)
110 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(NAME_CONSTRAINTS)
111
112 static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
113 X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval)
114 {
115 size_t i;
116 CONF_VALUE tval, *val;
117 STACK_OF(GENERAL_SUBTREE) **ptree = NULL;
118 NAME_CONSTRAINTS *ncons = NULL;
119 GENERAL_SUBTREE *sub = NULL;
120 ncons = NAME_CONSTRAINTS_new();
121 if (!ncons)
122 goto memerr;
123 for(i = 0; i < sk_CONF_VALUE_num(nval); i++)
124 {
125 val = sk_CONF_VALUE_value(nval, i);
126 if (!strncmp(val->name, "permitted", 9) && val->name[9])
127 {
128 ptree = &ncons->permittedSubtrees;
129 tval.name = val->name + 10;
130 }
131 else if (!strncmp(val->name, "excluded", 8) && val->name[8])
132 {
133 ptree = &ncons->excludedSubtrees;
134 tval.name = val->name + 9;
135 }
136 else
137 {
138 OPENSSL_PUT_ERROR(X509V3, v2i_NAME_CONSTRAINTS, X509V3_R_INVALID_SYNTAX);
139 goto err;
140 }
141 tval.value = val->value;
142 sub = GENERAL_SUBTREE_new();
143 if (!v2i_GENERAL_NAME_ex(sub->base, method, ctx, &tval, 1))
144 goto err;
145 if (!*ptree)
146 *ptree = sk_GENERAL_SUBTREE_new_null();
147 if (!*ptree || !sk_GENERAL_SUBTREE_push(*ptree, sub))
148 goto memerr;
149 sub = NULL;
150 }
151
152 return ncons;
153
154 memerr:
155 OPENSSL_PUT_ERROR(X509V3, v2i_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE);
156 err:
157 if (ncons)
158 NAME_CONSTRAINTS_free(ncons);
159 if (sub)
160 GENERAL_SUBTREE_free(sub);
161
162 return NULL;
163 }
164
165
166
167
i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD * method,void * a,BIO * bp,int ind)168 static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a,
169 BIO *bp, int ind)
170 {
171 NAME_CONSTRAINTS *ncons = a;
172 do_i2r_name_constraints(method, ncons->permittedSubtrees,
173 bp, ind, "Permitted");
174 do_i2r_name_constraints(method, ncons->excludedSubtrees,
175 bp, ind, "Excluded");
176 return 1;
177 }
178
do_i2r_name_constraints(const X509V3_EXT_METHOD * method,STACK_OF (GENERAL_SUBTREE)* trees,BIO * bp,int ind,const char * name)179 static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
180 STACK_OF(GENERAL_SUBTREE) *trees,
181 BIO *bp, int ind, const char *name)
182 {
183 GENERAL_SUBTREE *tree;
184 size_t i;
185 if (sk_GENERAL_SUBTREE_num(trees) > 0)
186 BIO_printf(bp, "%*s%s:\n", ind, "", name);
187 for(i = 0; i < sk_GENERAL_SUBTREE_num(trees); i++)
188 {
189 tree = sk_GENERAL_SUBTREE_value(trees, i);
190 BIO_printf(bp, "%*s", ind + 2, "");
191 if (tree->base->type == GEN_IPADD)
192 print_nc_ipadd(bp, tree->base->d.ip);
193 else
194 GENERAL_NAME_print(bp, tree->base);
195 BIO_puts(bp, "\n");
196 }
197 return 1;
198 }
199
print_nc_ipadd(BIO * bp,ASN1_OCTET_STRING * ip)200 static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip)
201 {
202 int i, len;
203 unsigned char *p;
204 p = ip->data;
205 len = ip->length;
206 BIO_puts(bp, "IP:");
207 if(len == 8)
208 {
209 BIO_printf(bp, "%d.%d.%d.%d/%d.%d.%d.%d",
210 p[0], p[1], p[2], p[3],
211 p[4], p[5], p[6], p[7]);
212 }
213 else if(len == 32)
214 {
215 for (i = 0; i < 16; i++)
216 {
217 BIO_printf(bp, "%X", p[0] << 8 | p[1]);
218 p += 2;
219 if (i == 7)
220 BIO_puts(bp, "/");
221 else if (i != 15)
222 BIO_puts(bp, ":");
223 }
224 }
225 else
226 BIO_printf(bp, "IP Address:<invalid>");
227 return 1;
228 }
229
230 /* Check a certificate conforms to a specified set of constraints.
231 * Return values:
232 * X509_V_OK: All constraints obeyed.
233 * X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation.
234 * X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation.
235 * X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type.
236 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: Unsupported constraint type.
237 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: bad unsupported constraint syntax.
238 * X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: bad or unsupported syntax of name
239
240 */
241
NAME_CONSTRAINTS_check(X509 * x,NAME_CONSTRAINTS * nc)242 int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc)
243 {
244 int r, i;
245 size_t j;
246 X509_NAME *nm;
247
248 nm = X509_get_subject_name(x);
249
250 if (X509_NAME_entry_count(nm) > 0)
251 {
252 GENERAL_NAME gntmp;
253 gntmp.type = GEN_DIRNAME;
254 gntmp.d.directoryName = nm;
255
256 r = nc_match(&gntmp, nc);
257
258 if (r != X509_V_OK)
259 return r;
260
261 gntmp.type = GEN_EMAIL;
262
263
264 /* Process any email address attributes in subject name */
265
266 for (i = -1;;)
267 {
268 X509_NAME_ENTRY *ne;
269 i = X509_NAME_get_index_by_NID(nm,
270 NID_pkcs9_emailAddress,
271 i);
272 if (i == -1)
273 break;
274 ne = X509_NAME_get_entry(nm, i);
275 gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne);
276 if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING)
277 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
278
279 r = nc_match(&gntmp, nc);
280
281 if (r != X509_V_OK)
282 return r;
283 }
284
285 }
286
287 for (j = 0; j < sk_GENERAL_NAME_num(x->altname); j++)
288 {
289 GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, j);
290 r = nc_match(gen, nc);
291 if (r != X509_V_OK)
292 return r;
293 }
294
295 return X509_V_OK;
296
297 }
298
nc_match(GENERAL_NAME * gen,NAME_CONSTRAINTS * nc)299 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)
300 {
301 GENERAL_SUBTREE *sub;
302 int r, match = 0;
303 size_t i;
304
305 /* Permitted subtrees: if any subtrees exist of matching the type
306 * at least one subtree must match.
307 */
308
309 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++)
310 {
311 sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i);
312 if (gen->type != sub->base->type)
313 continue;
314 if (sub->minimum || sub->maximum)
315 return X509_V_ERR_SUBTREE_MINMAX;
316 /* If we already have a match don't bother trying any more */
317 if (match == 2)
318 continue;
319 if (match == 0)
320 match = 1;
321 r = nc_match_single(gen, sub->base);
322 if (r == X509_V_OK)
323 match = 2;
324 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
325 return r;
326 }
327
328 if (match == 1)
329 return X509_V_ERR_PERMITTED_VIOLATION;
330
331 /* Excluded subtrees: must not match any of these */
332
333 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++)
334 {
335 sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i);
336 if (gen->type != sub->base->type)
337 continue;
338 if (sub->minimum || sub->maximum)
339 return X509_V_ERR_SUBTREE_MINMAX;
340
341 r = nc_match_single(gen, sub->base);
342 if (r == X509_V_OK)
343 return X509_V_ERR_EXCLUDED_VIOLATION;
344 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
345 return r;
346
347 }
348
349 return X509_V_OK;
350
351 }
352
nc_match_single(GENERAL_NAME * gen,GENERAL_NAME * base)353 static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base)
354 {
355 switch(base->type)
356 {
357 case GEN_DIRNAME:
358 return nc_dn(gen->d.directoryName, base->d.directoryName);
359
360 case GEN_DNS:
361 return nc_dns(gen->d.dNSName, base->d.dNSName);
362
363 case GEN_EMAIL:
364 return nc_email(gen->d.rfc822Name, base->d.rfc822Name);
365
366 case GEN_URI:
367 return nc_uri(gen->d.uniformResourceIdentifier,
368 base->d.uniformResourceIdentifier);
369
370 default:
371 return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE;
372 }
373
374 }
375
376 /* directoryName name constraint matching.
377 * The canonical encoding of X509_NAME makes this comparison easy. It is
378 * matched if the subtree is a subset of the name.
379 */
380
nc_dn(X509_NAME * nm,X509_NAME * base)381 static int nc_dn(X509_NAME *nm, X509_NAME *base)
382 {
383 /* Ensure canonical encodings are up to date. */
384 if (nm->modified && i2d_X509_NAME(nm, NULL) < 0)
385 return X509_V_ERR_OUT_OF_MEM;
386 if (base->modified && i2d_X509_NAME(base, NULL) < 0)
387 return X509_V_ERR_OUT_OF_MEM;
388 if (base->canon_enclen > nm->canon_enclen)
389 return X509_V_ERR_PERMITTED_VIOLATION;
390 if (memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen))
391 return X509_V_ERR_PERMITTED_VIOLATION;
392 return X509_V_OK;
393 }
394
nc_dns(ASN1_IA5STRING * dns,ASN1_IA5STRING * base)395 static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base)
396 {
397 char *baseptr = (char *)base->data;
398 char *dnsptr = (char *)dns->data;
399 /* Empty matches everything */
400 if (!*baseptr)
401 return X509_V_OK;
402 /* Otherwise can add zero or more components on the left so
403 * compare RHS and if dns is longer and expect '.' as preceding
404 * character.
405 */
406 if (dns->length > base->length)
407 {
408 dnsptr += dns->length - base->length;
409 if (*baseptr != '.' && dnsptr[-1] != '.')
410 return X509_V_ERR_PERMITTED_VIOLATION;
411 }
412
413 if (OPENSSL_strcasecmp(baseptr, dnsptr))
414 return X509_V_ERR_PERMITTED_VIOLATION;
415
416 return X509_V_OK;
417
418 }
419
nc_email(ASN1_IA5STRING * eml,ASN1_IA5STRING * base)420 static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base)
421 {
422 const char *baseptr = (char *)base->data;
423 const char *emlptr = (char *)eml->data;
424
425 const char *baseat = strchr(baseptr, '@');
426 const char *emlat = strchr(emlptr, '@');
427 if (!emlat)
428 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
429 /* Special case: inital '.' is RHS match */
430 if (!baseat && (*baseptr == '.'))
431 {
432 if (eml->length > base->length)
433 {
434 emlptr += eml->length - base->length;
435 if (!OPENSSL_strcasecmp(baseptr, emlptr))
436 return X509_V_OK;
437 }
438 return X509_V_ERR_PERMITTED_VIOLATION;
439 }
440
441 /* If we have anything before '@' match local part */
442
443 if (baseat)
444 {
445 if (baseat != baseptr)
446 {
447 if ((baseat - baseptr) != (emlat - emlptr))
448 return X509_V_ERR_PERMITTED_VIOLATION;
449 /* Case sensitive match of local part */
450 if (strncmp(baseptr, emlptr, emlat - emlptr))
451 return X509_V_ERR_PERMITTED_VIOLATION;
452 }
453 /* Position base after '@' */
454 baseptr = baseat + 1;
455 }
456 emlptr = emlat + 1;
457 /* Just have hostname left to match: case insensitive */
458 if (OPENSSL_strcasecmp(baseptr, emlptr))
459 return X509_V_ERR_PERMITTED_VIOLATION;
460
461 return X509_V_OK;
462
463 }
464
nc_uri(ASN1_IA5STRING * uri,ASN1_IA5STRING * base)465 static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
466 {
467 const char *baseptr = (char *)base->data;
468 const char *hostptr = (char *)uri->data;
469 const char *p = strchr(hostptr, ':');
470 int hostlen;
471 /* Check for foo:// and skip past it */
472 if (!p || (p[1] != '/') || (p[2] != '/'))
473 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
474 hostptr = p + 3;
475
476 /* Determine length of hostname part of URI */
477
478 /* Look for a port indicator as end of hostname first */
479
480 p = strchr(hostptr, ':');
481 /* Otherwise look for trailing slash */
482 if (!p)
483 p = strchr(hostptr, '/');
484
485 if (!p)
486 hostlen = strlen(hostptr);
487 else
488 hostlen = p - hostptr;
489
490 if (hostlen == 0)
491 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
492
493 /* Special case: inital '.' is RHS match */
494 if (*baseptr == '.')
495 {
496 if (hostlen > base->length)
497 {
498 p = hostptr + hostlen - base->length;
499 if (!OPENSSL_strncasecmp(p, baseptr, base->length))
500 return X509_V_OK;
501 }
502 return X509_V_ERR_PERMITTED_VIOLATION;
503 }
504
505 if ((base->length != (int)hostlen) || OPENSSL_strncasecmp(hostptr, baseptr, hostlen))
506 return X509_V_ERR_PERMITTED_VIOLATION;
507
508 return X509_V_OK;
509
510 }
511