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 (sub == NULL) 136 goto memerr; 137 if (!v2i_GENERAL_NAME_ex(sub->base, method, ctx, &tval, 1)) 138 goto err; 139 if (!*ptree) 140 *ptree = sk_GENERAL_SUBTREE_new_null(); 141 if (!*ptree || !sk_GENERAL_SUBTREE_push(*ptree, sub)) 142 goto memerr; 143 sub = NULL; 144 } 145 146 return ncons; 147 148 memerr: 149 X509V3err(X509V3_F_V2I_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE); 150 err: 151 if (ncons) 152 NAME_CONSTRAINTS_free(ncons); 153 if (sub) 154 GENERAL_SUBTREE_free(sub); 155 156 return NULL; 157} 158 159static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a, 160 BIO *bp, int ind) 161{ 162 NAME_CONSTRAINTS *ncons = a; 163 do_i2r_name_constraints(method, ncons->permittedSubtrees, 164 bp, ind, "Permitted"); 165 do_i2r_name_constraints(method, ncons->excludedSubtrees, 166 bp, ind, "Excluded"); 167 return 1; 168} 169 170static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method, 171 STACK_OF(GENERAL_SUBTREE) *trees, 172 BIO *bp, int ind, char *name) 173{ 174 GENERAL_SUBTREE *tree; 175 int i; 176 if (sk_GENERAL_SUBTREE_num(trees) > 0) 177 BIO_printf(bp, "%*s%s:\n", ind, "", name); 178 for (i = 0; i < sk_GENERAL_SUBTREE_num(trees); i++) { 179 tree = sk_GENERAL_SUBTREE_value(trees, i); 180 BIO_printf(bp, "%*s", ind + 2, ""); 181 if (tree->base->type == GEN_IPADD) 182 print_nc_ipadd(bp, tree->base->d.ip); 183 else 184 GENERAL_NAME_print(bp, tree->base); 185 BIO_puts(bp, "\n"); 186 } 187 return 1; 188} 189 190static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip) 191{ 192 int i, len; 193 unsigned char *p; 194 p = ip->data; 195 len = ip->length; 196 BIO_puts(bp, "IP:"); 197 if (len == 8) { 198 BIO_printf(bp, "%d.%d.%d.%d/%d.%d.%d.%d", 199 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]); 200 } else if (len == 32) { 201 for (i = 0; i < 16; i++) { 202 BIO_printf(bp, "%X", p[0] << 8 | p[1]); 203 p += 2; 204 if (i == 7) 205 BIO_puts(bp, "/"); 206 else if (i != 15) 207 BIO_puts(bp, ":"); 208 } 209 } else 210 BIO_printf(bp, "IP Address:<invalid>"); 211 return 1; 212} 213 214/*- 215 * Check a certificate conforms to a specified set of constraints. 216 * Return values: 217 * X509_V_OK: All constraints obeyed. 218 * X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation. 219 * X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation. 220 * X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type. 221 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: Unsupported constraint type. 222 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: bad unsupported constraint syntax. 223 * X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: bad or unsupported syntax of name 224 */ 225 226int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc) 227{ 228 int r, i; 229 X509_NAME *nm; 230 231 nm = X509_get_subject_name(x); 232 233 if (X509_NAME_entry_count(nm) > 0) { 234 GENERAL_NAME gntmp; 235 gntmp.type = GEN_DIRNAME; 236 gntmp.d.directoryName = nm; 237 238 r = nc_match(&gntmp, nc); 239 240 if (r != X509_V_OK) 241 return r; 242 243 gntmp.type = GEN_EMAIL; 244 245 /* Process any email address attributes in subject name */ 246 247 for (i = -1;;) { 248 X509_NAME_ENTRY *ne; 249 i = X509_NAME_get_index_by_NID(nm, NID_pkcs9_emailAddress, i); 250 if (i == -1) 251 break; 252 ne = X509_NAME_get_entry(nm, i); 253 gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne); 254 if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING) 255 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; 256 257 r = nc_match(&gntmp, nc); 258 259 if (r != X509_V_OK) 260 return r; 261 } 262 263 } 264 265 for (i = 0; i < sk_GENERAL_NAME_num(x->altname); i++) { 266 GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, i); 267 r = nc_match(gen, nc); 268 if (r != X509_V_OK) 269 return r; 270 } 271 272 return X509_V_OK; 273 274} 275 276static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc) 277{ 278 GENERAL_SUBTREE *sub; 279 int i, r, match = 0; 280 281 /* 282 * Permitted subtrees: if any subtrees exist of matching the type at 283 * least one subtree must match. 284 */ 285 286 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++) { 287 sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i); 288 if (gen->type != sub->base->type) 289 continue; 290 if (sub->minimum || sub->maximum) 291 return X509_V_ERR_SUBTREE_MINMAX; 292 /* If we already have a match don't bother trying any more */ 293 if (match == 2) 294 continue; 295 if (match == 0) 296 match = 1; 297 r = nc_match_single(gen, sub->base); 298 if (r == X509_V_OK) 299 match = 2; 300 else if (r != X509_V_ERR_PERMITTED_VIOLATION) 301 return r; 302 } 303 304 if (match == 1) 305 return X509_V_ERR_PERMITTED_VIOLATION; 306 307 /* Excluded subtrees: must not match any of these */ 308 309 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++) { 310 sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i); 311 if (gen->type != sub->base->type) 312 continue; 313 if (sub->minimum || sub->maximum) 314 return X509_V_ERR_SUBTREE_MINMAX; 315 316 r = nc_match_single(gen, sub->base); 317 if (r == X509_V_OK) 318 return X509_V_ERR_EXCLUDED_VIOLATION; 319 else if (r != X509_V_ERR_PERMITTED_VIOLATION) 320 return r; 321 322 } 323 324 return X509_V_OK; 325 326} 327 328static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base) 329{ 330 switch (base->type) { 331 case GEN_DIRNAME: 332 return nc_dn(gen->d.directoryName, base->d.directoryName); 333 334 case GEN_DNS: 335 return nc_dns(gen->d.dNSName, base->d.dNSName); 336 337 case GEN_EMAIL: 338 return nc_email(gen->d.rfc822Name, base->d.rfc822Name); 339 340 case GEN_URI: 341 return nc_uri(gen->d.uniformResourceIdentifier, 342 base->d.uniformResourceIdentifier); 343 344 default: 345 return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE; 346 } 347 348} 349 350/* 351 * directoryName name constraint matching. The canonical encoding of 352 * X509_NAME makes this comparison easy. It is matched if the subtree is a 353 * subset of the name. 354 */ 355 356static int nc_dn(X509_NAME *nm, X509_NAME *base) 357{ 358 /* Ensure canonical encodings are up to date. */ 359 if (nm->modified && i2d_X509_NAME(nm, NULL) < 0) 360 return X509_V_ERR_OUT_OF_MEM; 361 if (base->modified && i2d_X509_NAME(base, NULL) < 0) 362 return X509_V_ERR_OUT_OF_MEM; 363 if (base->canon_enclen > nm->canon_enclen) 364 return X509_V_ERR_PERMITTED_VIOLATION; 365 if (memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen)) 366 return X509_V_ERR_PERMITTED_VIOLATION; 367 return X509_V_OK; 368} 369 370static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base) 371{ 372 char *baseptr = (char *)base->data; 373 char *dnsptr = (char *)dns->data; 374 /* Empty matches everything */ 375 if (!*baseptr) 376 return X509_V_OK; 377 /* 378 * Otherwise can add zero or more components on the left so compare RHS 379 * and if dns is longer and expect '.' as preceding character. 380 */ 381 if (dns->length > base->length) { 382 dnsptr += dns->length - base->length; 383 if (*baseptr != '.' && dnsptr[-1] != '.') 384 return X509_V_ERR_PERMITTED_VIOLATION; 385 } 386 387 if (strcasecmp(baseptr, dnsptr)) 388 return X509_V_ERR_PERMITTED_VIOLATION; 389 390 return X509_V_OK; 391 392} 393 394static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base) 395{ 396 const char *baseptr = (char *)base->data; 397 const char *emlptr = (char *)eml->data; 398 399 const char *baseat = strchr(baseptr, '@'); 400 const char *emlat = strchr(emlptr, '@'); 401 if (!emlat) 402 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; 403 /* Special case: inital '.' is RHS match */ 404 if (!baseat && (*baseptr == '.')) { 405 if (eml->length > base->length) { 406 emlptr += eml->length - base->length; 407 if (!strcasecmp(baseptr, emlptr)) 408 return X509_V_OK; 409 } 410 return X509_V_ERR_PERMITTED_VIOLATION; 411 } 412 413 /* If we have anything before '@' match local part */ 414 415 if (baseat) { 416 if (baseat != baseptr) { 417 if ((baseat - baseptr) != (emlat - emlptr)) 418 return X509_V_ERR_PERMITTED_VIOLATION; 419 /* Case sensitive match of local part */ 420 if (strncmp(baseptr, emlptr, emlat - emlptr)) 421 return X509_V_ERR_PERMITTED_VIOLATION; 422 } 423 /* Position base after '@' */ 424 baseptr = baseat + 1; 425 } 426 emlptr = emlat + 1; 427 /* Just have hostname left to match: case insensitive */ 428 if (strcasecmp(baseptr, emlptr)) 429 return X509_V_ERR_PERMITTED_VIOLATION; 430 431 return X509_V_OK; 432 433} 434 435static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base) 436{ 437 const char *baseptr = (char *)base->data; 438 const char *hostptr = (char *)uri->data; 439 const char *p = strchr(hostptr, ':'); 440 int hostlen; 441 /* Check for foo:// and skip past it */ 442 if (!p || (p[1] != '/') || (p[2] != '/')) 443 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; 444 hostptr = p + 3; 445 446 /* Determine length of hostname part of URI */ 447 448 /* Look for a port indicator as end of hostname first */ 449 450 p = strchr(hostptr, ':'); 451 /* Otherwise look for trailing slash */ 452 if (!p) 453 p = strchr(hostptr, '/'); 454 455 if (!p) 456 hostlen = strlen(hostptr); 457 else 458 hostlen = p - hostptr; 459 460 if (hostlen == 0) 461 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; 462 463 /* Special case: inital '.' is RHS match */ 464 if (*baseptr == '.') { 465 if (hostlen > base->length) { 466 p = hostptr + hostlen - base->length; 467 if (!strncasecmp(p, baseptr, base->length)) 468 return X509_V_OK; 469 } 470 return X509_V_ERR_PERMITTED_VIOLATION; 471 } 472 473 if ((base->length != (int)hostlen) 474 || strncasecmp(hostptr, baseptr, hostlen)) 475 return X509_V_ERR_PERMITTED_VIOLATION; 476 477 return X509_V_OK; 478 479} 480