v3_ncons.c revision 280304
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