v3_ncons.c revision 325337
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) 109 110/* 111 * We cannot use strncasecmp here because that applies locale specific rules. 112 * For example in Turkish 'I' is not the uppercase character for 'i'. We need to 113 * do a simple ASCII case comparison ignoring the locale (that is why we use 114 * numeric constants below). 115 */ 116static int ia5ncasecmp(const char *s1, const char *s2, size_t n) 117{ 118 for (; n > 0; n--, s1++, s2++) { 119 if (*s1 != *s2) { 120 unsigned char c1 = (unsigned char)*s1, c2 = (unsigned char)*s2; 121 122 /* Convert to lower case */ 123 if (c1 >= 0x41 /* A */ && c1 <= 0x5A /* Z */) 124 c1 += 0x20; 125 if (c2 >= 0x41 /* A */ && c2 <= 0x5A /* Z */) 126 c2 += 0x20; 127 128 if (c1 == c2) 129 continue; 130 131 if (c1 < c2) 132 return -1; 133 134 /* c1 > c2 */ 135 return 1; 136 } else if (*s1 == 0) { 137 /* If we get here we know that *s2 == 0 too */ 138 return 0; 139 } 140 } 141 142 return 0; 143} 144 145static int ia5casecmp(const char *s1, const char *s2) 146{ 147 /* No portable definition of SIZE_MAX, so we use (size_t)(-1) instead */ 148 return ia5ncasecmp(s1, s2, (size_t)(-1)); 149} 150 151static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, 152 X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval) 153{ 154 int i; 155 CONF_VALUE tval, *val; 156 STACK_OF(GENERAL_SUBTREE) **ptree = NULL; 157 NAME_CONSTRAINTS *ncons = NULL; 158 GENERAL_SUBTREE *sub = NULL; 159 ncons = NAME_CONSTRAINTS_new(); 160 if (!ncons) 161 goto memerr; 162 for (i = 0; i < sk_CONF_VALUE_num(nval); i++) { 163 val = sk_CONF_VALUE_value(nval, i); 164 if (!strncmp(val->name, "permitted", 9) && val->name[9]) { 165 ptree = &ncons->permittedSubtrees; 166 tval.name = val->name + 10; 167 } else if (!strncmp(val->name, "excluded", 8) && val->name[8]) { 168 ptree = &ncons->excludedSubtrees; 169 tval.name = val->name + 9; 170 } else { 171 X509V3err(X509V3_F_V2I_NAME_CONSTRAINTS, X509V3_R_INVALID_SYNTAX); 172 goto err; 173 } 174 tval.value = val->value; 175 sub = GENERAL_SUBTREE_new(); 176 if (sub == NULL) 177 goto memerr; 178 if (!v2i_GENERAL_NAME_ex(sub->base, method, ctx, &tval, 1)) 179 goto err; 180 if (!*ptree) 181 *ptree = sk_GENERAL_SUBTREE_new_null(); 182 if (!*ptree || !sk_GENERAL_SUBTREE_push(*ptree, sub)) 183 goto memerr; 184 sub = NULL; 185 } 186 187 return ncons; 188 189 memerr: 190 X509V3err(X509V3_F_V2I_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE); 191 err: 192 if (ncons) 193 NAME_CONSTRAINTS_free(ncons); 194 if (sub) 195 GENERAL_SUBTREE_free(sub); 196 197 return NULL; 198} 199 200static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a, 201 BIO *bp, int ind) 202{ 203 NAME_CONSTRAINTS *ncons = a; 204 do_i2r_name_constraints(method, ncons->permittedSubtrees, 205 bp, ind, "Permitted"); 206 do_i2r_name_constraints(method, ncons->excludedSubtrees, 207 bp, ind, "Excluded"); 208 return 1; 209} 210 211static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method, 212 STACK_OF(GENERAL_SUBTREE) *trees, 213 BIO *bp, int ind, char *name) 214{ 215 GENERAL_SUBTREE *tree; 216 int i; 217 if (sk_GENERAL_SUBTREE_num(trees) > 0) 218 BIO_printf(bp, "%*s%s:\n", ind, "", name); 219 for (i = 0; i < sk_GENERAL_SUBTREE_num(trees); i++) { 220 tree = sk_GENERAL_SUBTREE_value(trees, i); 221 BIO_printf(bp, "%*s", ind + 2, ""); 222 if (tree->base->type == GEN_IPADD) 223 print_nc_ipadd(bp, tree->base->d.ip); 224 else 225 GENERAL_NAME_print(bp, tree->base); 226 BIO_puts(bp, "\n"); 227 } 228 return 1; 229} 230 231static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip) 232{ 233 int i, len; 234 unsigned char *p; 235 p = ip->data; 236 len = ip->length; 237 BIO_puts(bp, "IP:"); 238 if (len == 8) { 239 BIO_printf(bp, "%d.%d.%d.%d/%d.%d.%d.%d", 240 p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]); 241 } else if (len == 32) { 242 for (i = 0; i < 16; i++) { 243 BIO_printf(bp, "%X", p[0] << 8 | p[1]); 244 p += 2; 245 if (i == 7) 246 BIO_puts(bp, "/"); 247 else if (i != 15) 248 BIO_puts(bp, ":"); 249 } 250 } else 251 BIO_printf(bp, "IP Address:<invalid>"); 252 return 1; 253} 254 255/*- 256 * Check a certificate conforms to a specified set of constraints. 257 * Return values: 258 * X509_V_OK: All constraints obeyed. 259 * X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation. 260 * X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation. 261 * X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type. 262 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: Unsupported constraint type. 263 * X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: bad unsupported constraint syntax. 264 * X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: bad or unsupported syntax of name 265 */ 266 267int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc) 268{ 269 int r, i; 270 X509_NAME *nm; 271 272 nm = X509_get_subject_name(x); 273 274 if (X509_NAME_entry_count(nm) > 0) { 275 GENERAL_NAME gntmp; 276 gntmp.type = GEN_DIRNAME; 277 gntmp.d.directoryName = nm; 278 279 r = nc_match(&gntmp, nc); 280 281 if (r != X509_V_OK) 282 return r; 283 284 gntmp.type = GEN_EMAIL; 285 286 /* Process any email address attributes in subject name */ 287 288 for (i = -1;;) { 289 X509_NAME_ENTRY *ne; 290 i = X509_NAME_get_index_by_NID(nm, NID_pkcs9_emailAddress, i); 291 if (i == -1) 292 break; 293 ne = X509_NAME_get_entry(nm, i); 294 gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne); 295 if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING) 296 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; 297 298 r = nc_match(&gntmp, nc); 299 300 if (r != X509_V_OK) 301 return r; 302 } 303 304 } 305 306 for (i = 0; i < sk_GENERAL_NAME_num(x->altname); i++) { 307 GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, i); 308 r = nc_match(gen, nc); 309 if (r != X509_V_OK) 310 return r; 311 } 312 313 return X509_V_OK; 314 315} 316 317static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc) 318{ 319 GENERAL_SUBTREE *sub; 320 int i, r, match = 0; 321 322 /* 323 * Permitted subtrees: if any subtrees exist of matching the type at 324 * least one subtree must match. 325 */ 326 327 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++) { 328 sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i); 329 if (gen->type != sub->base->type) 330 continue; 331 if (sub->minimum || sub->maximum) 332 return X509_V_ERR_SUBTREE_MINMAX; 333 /* If we already have a match don't bother trying any more */ 334 if (match == 2) 335 continue; 336 if (match == 0) 337 match = 1; 338 r = nc_match_single(gen, sub->base); 339 if (r == X509_V_OK) 340 match = 2; 341 else if (r != X509_V_ERR_PERMITTED_VIOLATION) 342 return r; 343 } 344 345 if (match == 1) 346 return X509_V_ERR_PERMITTED_VIOLATION; 347 348 /* Excluded subtrees: must not match any of these */ 349 350 for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++) { 351 sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i); 352 if (gen->type != sub->base->type) 353 continue; 354 if (sub->minimum || sub->maximum) 355 return X509_V_ERR_SUBTREE_MINMAX; 356 357 r = nc_match_single(gen, sub->base); 358 if (r == X509_V_OK) 359 return X509_V_ERR_EXCLUDED_VIOLATION; 360 else if (r != X509_V_ERR_PERMITTED_VIOLATION) 361 return r; 362 363 } 364 365 return X509_V_OK; 366 367} 368 369static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base) 370{ 371 switch (base->type) { 372 case GEN_DIRNAME: 373 return nc_dn(gen->d.directoryName, base->d.directoryName); 374 375 case GEN_DNS: 376 return nc_dns(gen->d.dNSName, base->d.dNSName); 377 378 case GEN_EMAIL: 379 return nc_email(gen->d.rfc822Name, base->d.rfc822Name); 380 381 case GEN_URI: 382 return nc_uri(gen->d.uniformResourceIdentifier, 383 base->d.uniformResourceIdentifier); 384 385 default: 386 return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE; 387 } 388 389} 390 391/* 392 * directoryName name constraint matching. The canonical encoding of 393 * X509_NAME makes this comparison easy. It is matched if the subtree is a 394 * subset of the name. 395 */ 396 397static int nc_dn(X509_NAME *nm, X509_NAME *base) 398{ 399 /* Ensure canonical encodings are up to date. */ 400 if (nm->modified && i2d_X509_NAME(nm, NULL) < 0) 401 return X509_V_ERR_OUT_OF_MEM; 402 if (base->modified && i2d_X509_NAME(base, NULL) < 0) 403 return X509_V_ERR_OUT_OF_MEM; 404 if (base->canon_enclen > nm->canon_enclen) 405 return X509_V_ERR_PERMITTED_VIOLATION; 406 if (memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen)) 407 return X509_V_ERR_PERMITTED_VIOLATION; 408 return X509_V_OK; 409} 410 411static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base) 412{ 413 char *baseptr = (char *)base->data; 414 char *dnsptr = (char *)dns->data; 415 /* Empty matches everything */ 416 if (!*baseptr) 417 return X509_V_OK; 418 /* 419 * Otherwise can add zero or more components on the left so compare RHS 420 * and if dns is longer and expect '.' as preceding character. 421 */ 422 if (dns->length > base->length) { 423 dnsptr += dns->length - base->length; 424 if (*baseptr != '.' && dnsptr[-1] != '.') 425 return X509_V_ERR_PERMITTED_VIOLATION; 426 } 427 428 if (ia5casecmp(baseptr, dnsptr)) 429 return X509_V_ERR_PERMITTED_VIOLATION; 430 431 return X509_V_OK; 432 433} 434 435static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base) 436{ 437 const char *baseptr = (char *)base->data; 438 const char *emlptr = (char *)eml->data; 439 440 const char *baseat = strchr(baseptr, '@'); 441 const char *emlat = strchr(emlptr, '@'); 442 if (!emlat) 443 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; 444 /* Special case: inital '.' is RHS match */ 445 if (!baseat && (*baseptr == '.')) { 446 if (eml->length > base->length) { 447 emlptr += eml->length - base->length; 448 if (ia5casecmp(baseptr, emlptr) == 0) 449 return X509_V_OK; 450 } 451 return X509_V_ERR_PERMITTED_VIOLATION; 452 } 453 454 /* If we have anything before '@' match local part */ 455 456 if (baseat) { 457 if (baseat != baseptr) { 458 if ((baseat - baseptr) != (emlat - emlptr)) 459 return X509_V_ERR_PERMITTED_VIOLATION; 460 /* Case sensitive match of local part */ 461 if (strncmp(baseptr, emlptr, emlat - emlptr)) 462 return X509_V_ERR_PERMITTED_VIOLATION; 463 } 464 /* Position base after '@' */ 465 baseptr = baseat + 1; 466 } 467 emlptr = emlat + 1; 468 /* Just have hostname left to match: case insensitive */ 469 if (ia5casecmp(baseptr, emlptr)) 470 return X509_V_ERR_PERMITTED_VIOLATION; 471 472 return X509_V_OK; 473 474} 475 476static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base) 477{ 478 const char *baseptr = (char *)base->data; 479 const char *hostptr = (char *)uri->data; 480 const char *p = strchr(hostptr, ':'); 481 int hostlen; 482 /* Check for foo:// and skip past it */ 483 if (!p || (p[1] != '/') || (p[2] != '/')) 484 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; 485 hostptr = p + 3; 486 487 /* Determine length of hostname part of URI */ 488 489 /* Look for a port indicator as end of hostname first */ 490 491 p = strchr(hostptr, ':'); 492 /* Otherwise look for trailing slash */ 493 if (!p) 494 p = strchr(hostptr, '/'); 495 496 if (!p) 497 hostlen = strlen(hostptr); 498 else 499 hostlen = p - hostptr; 500 501 if (hostlen == 0) 502 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; 503 504 /* Special case: inital '.' is RHS match */ 505 if (*baseptr == '.') { 506 if (hostlen > base->length) { 507 p = hostptr + hostlen - base->length; 508 if (ia5ncasecmp(p, baseptr, base->length) == 0) 509 return X509_V_OK; 510 } 511 return X509_V_ERR_PERMITTED_VIOLATION; 512 } 513 514 if ((base->length != (int)hostlen) 515 || ia5ncasecmp(hostptr, baseptr, hostlen)) 516 return X509_V_ERR_PERMITTED_VIOLATION; 517 518 return X509_V_OK; 519 520} 521