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 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 66 static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, 67 X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval); 68 static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, 69 void *a, BIO *bp, int ind); 70 static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method, 71 STACK_OF(GENERAL_SUBTREE) *trees, 72 BIO *bp, int ind, char *name); 73 static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip); 74 75 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc); 76 static int nc_match_single(GENERAL_NAME *sub, GENERAL_NAME *gen); 77 static int nc_dn(X509_NAME *sub, X509_NAME *nm); 78 static int nc_dns(ASN1_IA5STRING *sub, ASN1_IA5STRING *dns); 79 static int nc_email(ASN1_IA5STRING *sub, ASN1_IA5STRING *eml); 80 static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base); 81 82 const 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 92 ASN1_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 98 ASN1_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) 104 105 106 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(GENERAL_SUBTREE) 107 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(NAME_CONSTRAINTS) 108 109 static 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 } 161 162 163 164 165 static 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 } 175 176 static 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 tree = sk_GENERAL_SUBTREE_value(trees, i); 193 BIO_puts(bp, "\n"); 194 } 195 return 1; 196 } 197 198 static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip) 199 { 200 int i, len; 201 unsigned char *p; 202 p = ip->data; 203 len = ip->length; 204 BIO_puts(bp, "IP:"); 205 if(len == 8) 206 { 207 BIO_printf(bp, "%d.%d.%d.%d/%d.%d.%d.%d", 208 p[0], p[1], p[2], p[3], 209 p[4], p[5], p[6], p[7]); 210 } 211 else if(len == 32) 212 { 213 for (i = 0; i < 16; i++) 214 { 215 BIO_printf(bp, "%X", p[0] << 8 | p[1]); 216 p += 2; 217 if (i == 7) 218 BIO_puts(bp, "/"); 219 else if (i != 15) 220 BIO_puts(bp, ":"); 221 } 222 } 223 else 224 BIO_printf(bp, "IP Address:<invalid>"); 225 return 1; 226 } 227 228 /* Check a certificate conforms to a specified set of constraints. 229 * Return values: 230 * X509_V_OK: All constraints obeyed. 231 * X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation. 232 * X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation. 233 * X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type. 234 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: Unsupported constraint type. 235 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: bad unsupported constraint syntax. 236 * X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: bad or unsupported syntax of name 237 238 */ 239 240 int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc) 241 { 242 int r, i; 243 X509_NAME *nm; 244 245 nm = X509_get_subject_name(x); 246 247 if (X509_NAME_entry_count(nm) > 0) 248 { 249 GENERAL_NAME gntmp; 250 gntmp.type = GEN_DIRNAME; 251 gntmp.d.directoryName = nm; 252 253 r = nc_match(&gntmp, nc); 254 255 if (r != X509_V_OK) 256 return r; 257 258 gntmp.type = GEN_EMAIL; 259 260 261 /* Process any email address attributes in subject name */ 262 263 for (i = -1;;) 264 { 265 X509_NAME_ENTRY *ne; 266 i = X509_NAME_get_index_by_NID(nm, 267 NID_pkcs9_emailAddress, 268 i); 269 if (i == -1) 270 break; 271 ne = X509_NAME_get_entry(nm, i); 272 gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne); 273 if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING) 274 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; 275 276 r = nc_match(&gntmp, nc); 277 278 if (r != X509_V_OK) 279 return r; 280 } 281 282 } 283 284 for (i = 0; i < sk_GENERAL_NAME_num(x->altname); i++) 285 { 286 GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, i); 287 r = nc_match(gen, nc); 288 if (r != X509_V_OK) 289 return r; 290 } 291 292 return X509_V_OK; 293 294 } 295 296 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc) 297 { 298 GENERAL_SUBTREE *sub; 299 int i, r, match = 0; 300 301 /* Permitted subtrees: if any subtrees exist of matching the type 302 * at least one subtree must match. 303 */ 304 305 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++) 306 { 307 sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i); 308 if (gen->type != sub->base->type) 309 continue; 310 if (sub->minimum || sub->maximum) 311 return X509_V_ERR_SUBTREE_MINMAX; 312 /* If we already have a match don't bother trying any more */ 313 if (match == 2) 314 continue; 315 if (match == 0) 316 match = 1; 317 r = nc_match_single(gen, sub->base); 318 if (r == X509_V_OK) 319 match = 2; 320 else if (r != X509_V_ERR_PERMITTED_VIOLATION) 321 return r; 322 } 323 324 if (match == 1) 325 return X509_V_ERR_PERMITTED_VIOLATION; 326 327 /* Excluded subtrees: must not match any of these */ 328 329 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++) 330 { 331 sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i); 332 if (gen->type != sub->base->type) 333 continue; 334 if (sub->minimum || sub->maximum) 335 return X509_V_ERR_SUBTREE_MINMAX; 336 337 r = nc_match_single(gen, sub->base); 338 if (r == X509_V_OK) 339 return X509_V_ERR_EXCLUDED_VIOLATION; 340 else if (r != X509_V_ERR_PERMITTED_VIOLATION) 341 return r; 342 343 } 344 345 return X509_V_OK; 346 347 } 348 349 static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base) 350 { 351 switch(base->type) 352 { 353 case GEN_DIRNAME: 354 return nc_dn(gen->d.directoryName, base->d.directoryName); 355 356 case GEN_DNS: 357 return nc_dns(gen->d.dNSName, base->d.dNSName); 358 359 case GEN_EMAIL: 360 return nc_email(gen->d.rfc822Name, base->d.rfc822Name); 361 362 case GEN_URI: 363 return nc_uri(gen->d.uniformResourceIdentifier, 364 base->d.uniformResourceIdentifier); 365 366 default: 367 return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE; 368 } 369 370 } 371 372 /* directoryName name constraint matching. 373 * The canonical encoding of X509_NAME makes this comparison easy. It is 374 * matched if the subtree is a subset of the name. 375 */ 376 377 static int nc_dn(X509_NAME *nm, X509_NAME *base) 378 { 379 /* Ensure canonical encodings are up to date. */ 380 if (nm->modified && i2d_X509_NAME(nm, NULL) < 0) 381 return X509_V_ERR_OUT_OF_MEM; 382 if (base->modified && i2d_X509_NAME(base, NULL) < 0) 383 return X509_V_ERR_OUT_OF_MEM; 384 if (base->canon_enclen > nm->canon_enclen) 385 return X509_V_ERR_PERMITTED_VIOLATION; 386 if (memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen)) 387 return X509_V_ERR_PERMITTED_VIOLATION; 388 return X509_V_OK; 389 } 390 391 static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base) 392 { 393 char *baseptr = (char *)base->data; 394 char *dnsptr = (char *)dns->data; 395 /* Empty matches everything */ 396 if (!*baseptr) 397 return X509_V_OK; 398 /* Otherwise can add zero or more components on the left so 399 * compare RHS and if dns is longer and expect '.' as preceding 400 * character. 401 */ 402 if (dns->length > base->length) 403 { 404 dnsptr += dns->length - base->length; 405 if (dnsptr[-1] != '.') 406 return X509_V_ERR_PERMITTED_VIOLATION; 407 } 408 409 if (strcasecmp(baseptr, dnsptr)) 410 return X509_V_ERR_PERMITTED_VIOLATION; 411 412 return X509_V_OK; 413 414 } 415 416 static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base) 417 { 418 const char *baseptr = (char *)base->data; 419 const char *emlptr = (char *)eml->data; 420 421 const char *baseat = strchr(baseptr, '@'); 422 const char *emlat = strchr(emlptr, '@'); 423 if (!emlat) 424 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; 425 /* Special case: inital '.' is RHS match */ 426 if (!baseat && (*baseptr == '.')) 427 { 428 if (eml->length > base->length) 429 { 430 emlptr += eml->length - base->length; 431 if (!strcasecmp(baseptr, emlptr)) 432 return X509_V_OK; 433 } 434 return X509_V_ERR_PERMITTED_VIOLATION; 435 } 436 437 /* If we have anything before '@' match local part */ 438 439 if (baseat) 440 { 441 if (baseat != baseptr) 442 { 443 if ((baseat - baseptr) != (emlat - emlptr)) 444 return X509_V_ERR_PERMITTED_VIOLATION; 445 /* Case sensitive match of local part */ 446 if (strncmp(baseptr, emlptr, emlat - emlptr)) 447 return X509_V_ERR_PERMITTED_VIOLATION; 448 } 449 /* Position base after '@' */ 450 baseptr = baseat + 1; 451 } 452 emlptr = emlat + 1; 453 /* Just have hostname left to match: case insensitive */ 454 if (strcasecmp(baseptr, emlptr)) 455 return X509_V_ERR_PERMITTED_VIOLATION; 456 457 return X509_V_OK; 458 459 } 460 461 static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base) 462 { 463 const char *baseptr = (char *)base->data; 464 const char *hostptr = (char *)uri->data; 465 const char *p = strchr(hostptr, ':'); 466 int hostlen; 467 /* Check for foo:// and skip past it */ 468 if (!p || (p[1] != '/') || (p[2] != '/')) 469 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; 470 hostptr = p + 3; 471 472 /* Determine length of hostname part of URI */ 473 474 /* Look for a port indicator as end of hostname first */ 475 476 p = strchr(hostptr, ':'); 477 /* Otherwise look for trailing slash */ 478 if (!p) 479 p = strchr(hostptr, '/'); 480 481 if (!p) 482 hostlen = strlen(hostptr); 483 else 484 hostlen = p - hostptr; 485 486 if (hostlen == 0) 487 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; 488 489 /* Special case: inital '.' is RHS match */ 490 if (*baseptr == '.') 491 { 492 if (hostlen > base->length) 493 { 494 p = hostptr + hostlen - base->length; 495 if (!strncasecmp(p, baseptr, base->length)) 496 return X509_V_OK; 497 } 498 return X509_V_ERR_PERMITTED_VIOLATION; 499 } 500 501 if ((base->length != (int)hostlen) || strncasecmp(hostptr, baseptr, hostlen)) 502 return X509_V_ERR_PERMITTED_VIOLATION; 503 504 return X509_V_OK; 505 506 } 507
