1 /* v3_ncons.c */ 2 /* Written by Dr Stephen N Henson (steve (at) 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 (at) 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 (at) cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh (at) 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, 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, 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 } 164 165 166 167 168 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 } 178 179 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 } 199 200 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 */ 241 242 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 } 298 299 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 } 352 353 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 */ 380 381 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 } 394 395 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 } 419 420 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 } 464 465 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
