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
66static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
67				  X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval);
68static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
69				void *a, BIO *bp, int ind);
70static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
71				   STACK_OF(GENERAL_SUBTREE) *trees,
72				   BIO *bp, int ind, char *name);
73static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip);
74
75static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc);
76static int nc_match_single(GENERAL_NAME *sub, GENERAL_NAME *gen);
77static int nc_dn(X509_NAME *sub, X509_NAME *nm);
78static int nc_dns(ASN1_IA5STRING *sub, ASN1_IA5STRING *dns);
79static int nc_email(ASN1_IA5STRING *sub, ASN1_IA5STRING *eml);
80static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base);
81
82const 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
92ASN1_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
98ASN1_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
106IMPLEMENT_ASN1_ALLOC_FUNCTIONS(GENERAL_SUBTREE)
107IMPLEMENT_ASN1_ALLOC_FUNCTIONS(NAME_CONSTRAINTS)
108
109static 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
165static 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
176static 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
197static 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
239int 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
295static 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
348static 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
376static 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
390static 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
415static 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
460static 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	}
506