v3_ncons.c revision 296341 
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 */
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,
68                                  STACK_OF(CONF_VALUE) *nval);
69static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a,
70                                BIO *bp, int ind);
71static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
72                                   STACK_OF(GENERAL_SUBTREE) *trees, BIO *bp,
73                                   int ind, char *name);
74static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip);
75
76static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc);
77static int nc_match_single(GENERAL_NAME *sub, GENERAL_NAME *gen);
78static int nc_dn(X509_NAME *sub, X509_NAME *nm);
79static int nc_dns(ASN1_IA5STRING *sub, ASN1_IA5STRING *dns);
80static int nc_email(ASN1_IA5STRING *sub, ASN1_IA5STRING *eml);
81static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base);
82
83const X509V3_EXT_METHOD v3_name_constraints = {
84    NID_name_constraints, 0,
85    ASN1_ITEM_ref(NAME_CONSTRAINTS),
86    0, 0, 0, 0,
87    0, 0,
88    0, v2i_NAME_CONSTRAINTS,
89    i2r_NAME_CONSTRAINTS, 0,
90    NULL
91};
92
93ASN1_SEQUENCE(GENERAL_SUBTREE) = {
94        ASN1_SIMPLE(GENERAL_SUBTREE, base, GENERAL_NAME),
95        ASN1_IMP_OPT(GENERAL_SUBTREE, minimum, ASN1_INTEGER, 0),
96        ASN1_IMP_OPT(GENERAL_SUBTREE, maximum, ASN1_INTEGER, 1)
97} ASN1_SEQUENCE_END(GENERAL_SUBTREE)
98
99ASN1_SEQUENCE(NAME_CONSTRAINTS) = {
100        ASN1_IMP_SEQUENCE_OF_OPT(NAME_CONSTRAINTS, permittedSubtrees,
101                                                        GENERAL_SUBTREE, 0),
102        ASN1_IMP_SEQUENCE_OF_OPT(NAME_CONSTRAINTS, excludedSubtrees,
103                                                        GENERAL_SUBTREE, 1),
104} ASN1_SEQUENCE_END(NAME_CONSTRAINTS)
105
106
107IMPLEMENT_ASN1_ALLOC_FUNCTIONS(GENERAL_SUBTREE)
108IMPLEMENT_ASN1_ALLOC_FUNCTIONS(NAME_CONSTRAINTS)
109
110static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
111                                  X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval)
112{
113    int i;
114    CONF_VALUE tval, *val;
115    STACK_OF(GENERAL_SUBTREE) **ptree = NULL;
116    NAME_CONSTRAINTS *ncons = NULL;
117    GENERAL_SUBTREE *sub = NULL;
118    ncons = NAME_CONSTRAINTS_new();
119    if (!ncons)
120        goto memerr;
121    for (i = 0; i < sk_CONF_VALUE_num(nval); i++) {
122        val = sk_CONF_VALUE_value(nval, i);
123        if (!strncmp(val->name, "permitted", 9) && val->name[9]) {
124            ptree = &ncons->permittedSubtrees;
125            tval.name = val->name + 10;
126        } else if (!strncmp(val->name, "excluded", 8) && val->name[8]) {
127            ptree = &ncons->excludedSubtrees;
128            tval.name = val->name + 9;
129        } else {
130            X509V3err(X509V3_F_V2I_NAME_CONSTRAINTS, X509V3_R_INVALID_SYNTAX);
131            goto err;
132        }
133        tval.value = val->value;
134        sub = GENERAL_SUBTREE_new();
135        if (!v2i_GENERAL_NAME_ex(sub->base, method, ctx, &tval, 1))
136            goto err;
137        if (!*ptree)
138            *ptree = sk_GENERAL_SUBTREE_new_null();
139        if (!*ptree || !sk_GENERAL_SUBTREE_push(*ptree, sub))
140            goto memerr;
141        sub = NULL;
142    }
143
144    return ncons;
145
146 memerr:
147    X509V3err(X509V3_F_V2I_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE);
148 err:
149    if (ncons)
150        NAME_CONSTRAINTS_free(ncons);
151    if (sub)
152        GENERAL_SUBTREE_free(sub);
153
154    return NULL;
155}
156
157static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a,
158                                BIO *bp, int ind)
159{
160    NAME_CONSTRAINTS *ncons = a;
161    do_i2r_name_constraints(method, ncons->permittedSubtrees,
162                            bp, ind, "Permitted");
163    do_i2r_name_constraints(method, ncons->excludedSubtrees,
164                            bp, ind, "Excluded");
165    return 1;
166}
167
168static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
169                                   STACK_OF(GENERAL_SUBTREE) *trees,
170                                   BIO *bp, int ind, char *name)
171{
172    GENERAL_SUBTREE *tree;
173    int i;
174    if (sk_GENERAL_SUBTREE_num(trees) > 0)
175        BIO_printf(bp, "%*s%s:\n", ind, "", name);
176    for (i = 0; i < sk_GENERAL_SUBTREE_num(trees); i++) {
177        tree = sk_GENERAL_SUBTREE_value(trees, i);
178        BIO_printf(bp, "%*s", ind + 2, "");
179        if (tree->base->type == GEN_IPADD)
180            print_nc_ipadd(bp, tree->base->d.ip);
181        else
182            GENERAL_NAME_print(bp, tree->base);
183        BIO_puts(bp, "\n");
184    }
185    return 1;
186}
187
188static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip)
189{
190    int i, len;
191    unsigned char *p;
192    p = ip->data;
193    len = ip->length;
194    BIO_puts(bp, "IP:");
195    if (len == 8) {
196        BIO_printf(bp, "%d.%d.%d.%d/%d.%d.%d.%d",
197                   p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
198    } else if (len == 32) {
199        for (i = 0; i < 16; i++) {
200            BIO_printf(bp, "%X", p[0] << 8 | p[1]);
201            p += 2;
202            if (i == 7)
203                BIO_puts(bp, "/");
204            else if (i != 15)
205                BIO_puts(bp, ":");
206        }
207    } else
208        BIO_printf(bp, "IP Address:<invalid>");
209    return 1;
210}
211
212/*-
213 * Check a certificate conforms to a specified set of constraints.
214 * Return values:
215 *  X509_V_OK: All constraints obeyed.
216 *  X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation.
217 *  X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation.
218 *  X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type.
219 *  X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE:  Unsupported constraint type.
220 *  X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: bad unsupported constraint syntax.
221 *  X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: bad or unsupported syntax of name
222 */
223
224int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc)
225{
226    int r, i;
227    X509_NAME *nm;
228
229    nm = X509_get_subject_name(x);
230
231    if (X509_NAME_entry_count(nm) > 0) {
232        GENERAL_NAME gntmp;
233        gntmp.type = GEN_DIRNAME;
234        gntmp.d.directoryName = nm;
235
236        r = nc_match(&gntmp, nc);
237
238        if (r != X509_V_OK)
239            return r;
240
241        gntmp.type = GEN_EMAIL;
242
243        /* Process any email address attributes in subject name */
244
245        for (i = -1;;) {
246            X509_NAME_ENTRY *ne;
247            i = X509_NAME_get_index_by_NID(nm, NID_pkcs9_emailAddress, i);
248            if (i == -1)
249                break;
250            ne = X509_NAME_get_entry(nm, i);
251            gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne);
252            if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING)
253                return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
254
255            r = nc_match(&gntmp, nc);
256
257            if (r != X509_V_OK)
258                return r;
259        }
260
261    }
262
263    for (i = 0; i < sk_GENERAL_NAME_num(x->altname); i++) {
264        GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, i);
265        r = nc_match(gen, nc);
266        if (r != X509_V_OK)
267            return r;
268    }
269
270    return X509_V_OK;
271
272}
273
274static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)
275{
276    GENERAL_SUBTREE *sub;
277    int i, r, match = 0;
278
279    /*
280     * Permitted subtrees: if any subtrees exist of matching the type at
281     * least one subtree must match.
282     */
283
284    for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++) {
285        sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i);
286        if (gen->type != sub->base->type)
287            continue;
288        if (sub->minimum || sub->maximum)
289            return X509_V_ERR_SUBTREE_MINMAX;
290        /* If we already have a match don't bother trying any more */
291        if (match == 2)
292            continue;
293        if (match == 0)
294            match = 1;
295        r = nc_match_single(gen, sub->base);
296        if (r == X509_V_OK)
297            match = 2;
298        else if (r != X509_V_ERR_PERMITTED_VIOLATION)
299            return r;
300    }
301
302    if (match == 1)
303        return X509_V_ERR_PERMITTED_VIOLATION;
304
305    /* Excluded subtrees: must not match any of these */
306
307    for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++) {
308        sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i);
309        if (gen->type != sub->base->type)
310            continue;
311        if (sub->minimum || sub->maximum)
312            return X509_V_ERR_SUBTREE_MINMAX;
313
314        r = nc_match_single(gen, sub->base);
315        if (r == X509_V_OK)
316            return X509_V_ERR_EXCLUDED_VIOLATION;
317        else if (r != X509_V_ERR_PERMITTED_VIOLATION)
318            return r;
319
320    }
321
322    return X509_V_OK;
323
324}
325
326static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base)
327{
328    switch (base->type) {
329    case GEN_DIRNAME:
330        return nc_dn(gen->d.directoryName, base->d.directoryName);
331
332    case GEN_DNS:
333        return nc_dns(gen->d.dNSName, base->d.dNSName);
334
335    case GEN_EMAIL:
336        return nc_email(gen->d.rfc822Name, base->d.rfc822Name);
337
338    case GEN_URI:
339        return nc_uri(gen->d.uniformResourceIdentifier,
340                      base->d.uniformResourceIdentifier);
341
342    default:
343        return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE;
344    }
345
346}
347
348/*
349 * directoryName name constraint matching. The canonical encoding of
350 * X509_NAME makes this comparison easy. It is matched if the subtree is a
351 * subset of the name.
352 */
353
354static int nc_dn(X509_NAME *nm, X509_NAME *base)
355{
356    /* Ensure canonical encodings are up to date.  */
357    if (nm->modified && i2d_X509_NAME(nm, NULL) < 0)
358        return X509_V_ERR_OUT_OF_MEM;
359    if (base->modified && i2d_X509_NAME(base, NULL) < 0)
360        return X509_V_ERR_OUT_OF_MEM;
361    if (base->canon_enclen > nm->canon_enclen)
362        return X509_V_ERR_PERMITTED_VIOLATION;
363    if (memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen))
364        return X509_V_ERR_PERMITTED_VIOLATION;
365    return X509_V_OK;
366}
367
368static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base)
369{
370    char *baseptr = (char *)base->data;
371    char *dnsptr = (char *)dns->data;
372    /* Empty matches everything */
373    if (!*baseptr)
374        return X509_V_OK;
375    /*
376     * Otherwise can add zero or more components on the left so compare RHS
377     * and if dns is longer and expect '.' as preceding character.
378     */
379    if (dns->length > base->length) {
380        dnsptr += dns->length - base->length;
381        if (*baseptr != '.' && dnsptr[-1] != '.')
382            return X509_V_ERR_PERMITTED_VIOLATION;
383    }
384
385    if (strcasecmp(baseptr, dnsptr))
386        return X509_V_ERR_PERMITTED_VIOLATION;
387
388    return X509_V_OK;
389
390}
391
392static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base)
393{
394    const char *baseptr = (char *)base->data;
395    const char *emlptr = (char *)eml->data;
396
397    const char *baseat = strchr(baseptr, '@');
398    const char *emlat = strchr(emlptr, '@');
399    if (!emlat)
400        return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
401    /* Special case: inital '.' is RHS match */
402    if (!baseat && (*baseptr == '.')) {
403        if (eml->length > base->length) {
404            emlptr += eml->length - base->length;
405            if (!strcasecmp(baseptr, emlptr))
406                return X509_V_OK;
407        }
408        return X509_V_ERR_PERMITTED_VIOLATION;
409    }
410
411    /* If we have anything before '@' match local part */
412
413    if (baseat) {
414        if (baseat != baseptr) {
415            if ((baseat - baseptr) != (emlat - emlptr))
416                return X509_V_ERR_PERMITTED_VIOLATION;
417            /* Case sensitive match of local part */
418            if (strncmp(baseptr, emlptr, emlat - emlptr))
419                return X509_V_ERR_PERMITTED_VIOLATION;
420        }
421        /* Position base after '@' */
422        baseptr = baseat + 1;
423    }
424    emlptr = emlat + 1;
425    /* Just have hostname left to match: case insensitive */
426    if (strcasecmp(baseptr, emlptr))
427        return X509_V_ERR_PERMITTED_VIOLATION;
428
429    return X509_V_OK;
430
431}
432
433static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
434{
435    const char *baseptr = (char *)base->data;
436    const char *hostptr = (char *)uri->data;
437    const char *p = strchr(hostptr, ':');
438    int hostlen;
439    /* Check for foo:// and skip past it */
440    if (!p || (p[1] != '/') || (p[2] != '/'))
441        return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
442    hostptr = p + 3;
443
444    /* Determine length of hostname part of URI */
445
446    /* Look for a port indicator as end of hostname first */
447
448    p = strchr(hostptr, ':');
449    /* Otherwise look for trailing slash */
450    if (!p)
451        p = strchr(hostptr, '/');
452
453    if (!p)
454        hostlen = strlen(hostptr);
455    else
456        hostlen = p - hostptr;
457
458    if (hostlen == 0)
459        return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
460
461    /* Special case: inital '.' is RHS match */
462    if (*baseptr == '.') {
463        if (hostlen > base->length) {
464            p = hostptr + hostlen - base->length;
465            if (!strncasecmp(p, baseptr, base->length))
466                return X509_V_OK;
467        }
468        return X509_V_ERR_PERMITTED_VIOLATION;
469    }
470
471    if ((base->length != (int)hostlen)
472        || strncasecmp(hostptr, baseptr, hostlen))
473        return X509_V_ERR_PERMITTED_VIOLATION;
474
475    return X509_V_OK;
476
477}
478