1 /* v3_ncons.c */
   2 /* Written by Dr Stephen N Henson (steve@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@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@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@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                 BIO_puts(bp, "\n");
 193                 }
 194         return 1;
 195         }
 196 
 197 static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip)
 198         {
 199         int i, len;
 200         unsigned char *p;
 201         p = ip->data;
 202         len = ip->length;
 203         BIO_puts(bp, "IP:");
 204         if(len == 8)
 205                 {
 206                 BIO_printf(bp, "%d.%d.%d.%d/%d.%d.%d.%d",
 207                                 p[0], p[1], p[2], p[3],
 208                                 p[4], p[5], p[6], p[7]);
 209                 }
 210         else if(len == 32)
 211                 {
 212                 for (i = 0; i < 16; i++)
 213                         {
 214                         BIO_printf(bp, "%X", p[0] << 8 | p[1]);
 215                         p += 2;
 216                         if (i == 7)
 217                                 BIO_puts(bp, "/");
 218                         else if (i != 15)
 219                                 BIO_puts(bp, ":");
 220                         }
 221                 }
 222         else
 223                 BIO_printf(bp, "IP Address:<invalid>");
 224         return 1;
 225         }
 226 
 227 /* Check a certificate conforms to a specified set of constraints.
 228  * Return values:
 229  *  X509_V_OK: All constraints obeyed.
 230  *  X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation.
 231  *  X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation.
 232  *  X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type.
 233  *  X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE:  Unsupported constraint type.
 234  *  X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: bad unsupported constraint syntax.
 235  *  X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: bad or unsupported syntax of name
 236 
 237  */
 238 
 239 int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc)
 240         {
 241         int r, i;
 242         X509_NAME *nm;
 243 
 244         nm = X509_get_subject_name(x);
 245 
 246         if (X509_NAME_entry_count(nm) > 0)
 247                 {
 248                 GENERAL_NAME gntmp;
 249                 gntmp.type = GEN_DIRNAME;
 250                 gntmp.d.directoryName = nm;
 251 
 252                 r = nc_match(&gntmp, nc);
 253 
 254                 if (r != X509_V_OK)
 255                         return r;
 256 
 257                 gntmp.type = GEN_EMAIL;
 258 
 259 
 260                 /* Process any email address attributes in subject name */
 261 
 262                 for (i = -1;;)
 263                         {
 264                         X509_NAME_ENTRY *ne;
 265                         i = X509_NAME_get_index_by_NID(nm,
 266                                                        NID_pkcs9_emailAddress,
 267                                                        i);
 268                         if (i == -1)
 269                                 break;
 270                         ne = X509_NAME_get_entry(nm, i);
 271                         gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne);
 272                         if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING)
 273                                 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
 274 
 275                         r = nc_match(&gntmp, nc);
 276 
 277                         if (r != X509_V_OK)
 278                                 return r;
 279                         }
 280 
 281                 }
 282 
 283         for (i = 0; i < sk_GENERAL_NAME_num(x->altname); i++)
 284                 {
 285                 GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, i);
 286                 r = nc_match(gen, nc);
 287                 if (r != X509_V_OK)
 288                         return r;
 289                 }
 290 
 291         return X509_V_OK;
 292 
 293         }
 294 
 295 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)
 296         {
 297         GENERAL_SUBTREE *sub;
 298         int i, r, match = 0;
 299 
 300         /* Permitted subtrees: if any subtrees exist of matching the type
 301          * at least one subtree must match.
 302          */
 303 
 304         for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++)
 305                 {
 306                 sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i);
 307                 if (gen->type != sub->base->type)
 308                         continue;
 309                 if (sub->minimum || sub->maximum)
 310                         return X509_V_ERR_SUBTREE_MINMAX;
 311                 /* If we already have a match don't bother trying any more */
 312                 if (match == 2)
 313                         continue;
 314                 if (match == 0)
 315                         match = 1;
 316                 r = nc_match_single(gen, sub->base);
 317                 if (r == X509_V_OK)
 318                         match = 2;
 319                 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
 320                         return r;
 321                 }
 322 
 323         if (match == 1)
 324                 return X509_V_ERR_PERMITTED_VIOLATION;
 325 
 326         /* Excluded subtrees: must not match any of these */
 327 
 328         for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++)
 329                 {
 330                 sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i);
 331                 if (gen->type != sub->base->type)
 332                         continue;
 333                 if (sub->minimum || sub->maximum)
 334                         return X509_V_ERR_SUBTREE_MINMAX;
 335 
 336                 r = nc_match_single(gen, sub->base);
 337                 if (r == X509_V_OK)
 338                         return X509_V_ERR_EXCLUDED_VIOLATION;
 339                 else if (r != X509_V_ERR_PERMITTED_VIOLATION)
 340                         return r;
 341 
 342                 }
 343 
 344         return X509_V_OK;
 345 
 346         }
 347 
 348 static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base)
 349         {
 350         switch(base->type)
 351                 {
 352                 case GEN_DIRNAME:
 353                 return nc_dn(gen->d.directoryName, base->d.directoryName);
 354 
 355                 case GEN_DNS:
 356                 return nc_dns(gen->d.dNSName, base->d.dNSName);
 357 
 358                 case GEN_EMAIL:
 359                 return nc_email(gen->d.rfc822Name, base->d.rfc822Name);
 360 
 361                 case GEN_URI:
 362                 return nc_uri(gen->d.uniformResourceIdentifier,
 363                                         base->d.uniformResourceIdentifier);
 364 
 365                 default:
 366                 return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE;
 367                 }
 368 
 369         }
 370 
 371 /* directoryName name constraint matching.
 372  * The canonical encoding of X509_NAME makes this comparison easy. It is
 373  * matched if the subtree is a subset of the name.
 374  */
 375 
 376 static int nc_dn(X509_NAME *nm, X509_NAME *base)
 377         {
 378         /* Ensure canonical encodings are up to date.  */
 379         if (nm->modified && i2d_X509_NAME(nm, NULL) < 0)
 380                 return X509_V_ERR_OUT_OF_MEM;
 381         if (base->modified && i2d_X509_NAME(base, NULL) < 0)
 382                 return X509_V_ERR_OUT_OF_MEM;
 383         if (base->canon_enclen > nm->canon_enclen)
 384                 return X509_V_ERR_PERMITTED_VIOLATION;
 385         if (memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen))
 386                 return X509_V_ERR_PERMITTED_VIOLATION;
 387         return X509_V_OK;
 388         }
 389 
 390 static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base)
 391         {
 392         char *baseptr = (char *)base->data;
 393         char *dnsptr = (char *)dns->data;
 394         /* Empty matches everything */
 395         if (!*baseptr)
 396                 return X509_V_OK;
 397         /* Otherwise can add zero or more components on the left so
 398          * compare RHS and if dns is longer and expect '.' as preceding
 399          * character.
 400          */
 401         if (dns->length > base->length)
 402                 {
 403                 dnsptr += dns->length - base->length;
 404                 if (dnsptr[-1] != '.')
 405                         return X509_V_ERR_PERMITTED_VIOLATION;
 406                 }
 407 
 408         if (strcasecmp(baseptr, dnsptr))
 409                         return X509_V_ERR_PERMITTED_VIOLATION;
 410 
 411         return X509_V_OK;
 412 
 413         }
 414 
 415 static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base)
 416         {
 417         const char *baseptr = (char *)base->data;
 418         const char *emlptr = (char *)eml->data;
 419 
 420         const char *baseat = strchr(baseptr, '@');
 421         const char *emlat = strchr(emlptr, '@');
 422         if (!emlat)
 423                 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
 424         /* Special case: inital '.' is RHS match */
 425         if (!baseat && (*baseptr == '.'))
 426                 {
 427                 if (eml->length > base->length)
 428                         {
 429                         emlptr += eml->length - base->length;
 430                         if (!strcasecmp(baseptr, emlptr))
 431                                 return X509_V_OK;
 432                         }
 433                 return X509_V_ERR_PERMITTED_VIOLATION;
 434                 }
 435 
 436         /* If we have anything before '@' match local part */
 437 
 438         if (baseat)
 439                 {
 440                 if (baseat != baseptr)
 441                         {
 442                         if ((baseat - baseptr) != (emlat - emlptr))
 443                                 return X509_V_ERR_PERMITTED_VIOLATION;
 444                         /* Case sensitive match of local part */
 445                         if (strncmp(baseptr, emlptr, emlat - emlptr))
 446                                 return X509_V_ERR_PERMITTED_VIOLATION;
 447                         }
 448                 /* Position base after '@' */
 449                 baseptr = baseat + 1;
 450                 }
 451         emlptr = emlat + 1;
 452         /* Just have hostname left to match: case insensitive */
 453         if (strcasecmp(baseptr, emlptr))
 454                 return X509_V_ERR_PERMITTED_VIOLATION;
 455 
 456         return X509_V_OK;
 457 
 458         }
 459 
 460 static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
 461         {
 462         const char *baseptr = (char *)base->data;
 463         const char *hostptr = (char *)uri->data;
 464         const char *p = strchr(hostptr, ':');
 465         int hostlen;
 466         /* Check for foo:// and skip past it */
 467         if (!p || (p[1] != '/') || (p[2] != '/'))
 468                 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
 469         hostptr = p + 3;
 470 
 471         /* Determine length of hostname part of URI */
 472 
 473         /* Look for a port indicator as end of hostname first */
 474 
 475         p = strchr(hostptr, ':');
 476         /* Otherwise look for trailing slash */
 477         if (!p)
 478                 p = strchr(hostptr, '/');
 479 
 480         if (!p)
 481                 hostlen = strlen(hostptr);
 482         else
 483                 hostlen = p - hostptr;
 484 
 485         if (hostlen == 0)
 486                 return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
 487 
 488         /* Special case: inital '.' is RHS match */
 489         if (*baseptr == '.')
 490                 {
 491                 if (hostlen > base->length)
 492                         {
 493                         p = hostptr + hostlen - base->length;
 494                         if (!strncasecmp(p, baseptr, base->length))
 495                                 return X509_V_OK;
 496                         }
 497                 return X509_V_ERR_PERMITTED_VIOLATION;
 498                 }
 499 
 500         if ((base->length != (int)hostlen) || strncasecmp(hostptr, baseptr, hostlen))
 501                 return X509_V_ERR_PERMITTED_VIOLATION;
 502 
 503         return X509_V_OK;
 504 
 505         }