1 /*
   2  * Contributed to the OpenSSL Project by the American Registry for
   3  * Internet Numbers ("ARIN").
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2006 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  * Implementation of RFC 3779 section 2.2.
  60  */
  61 
  62 #include <stdio.h>
  63 #include <stdlib.h>
  64 
  65 #include "cryptlib.h"
  66 #include <openssl/conf.h>
  67 #include <openssl/asn1.h>
  68 #include <openssl/asn1t.h>
  69 #include <openssl/buffer.h>
  70 #include <openssl/x509v3.h>
  71 
  72 #ifndef OPENSSL_NO_RFC3779
  73 
  74 /*
  75  * OpenSSL ASN.1 template translation of RFC 3779 2.2.3.
  76  */
  77 
  78 ASN1_SEQUENCE(IPAddressRange) = {
  79   ASN1_SIMPLE(IPAddressRange, min, ASN1_BIT_STRING),
  80   ASN1_SIMPLE(IPAddressRange, max, ASN1_BIT_STRING)
  81 } ASN1_SEQUENCE_END(IPAddressRange)
  82 
  83 ASN1_CHOICE(IPAddressOrRange) = {
  84   ASN1_SIMPLE(IPAddressOrRange, u.addressPrefix, ASN1_BIT_STRING),
  85   ASN1_SIMPLE(IPAddressOrRange, u.addressRange,  IPAddressRange)
  86 } ASN1_CHOICE_END(IPAddressOrRange)
  87 
  88 ASN1_CHOICE(IPAddressChoice) = {
  89   ASN1_SIMPLE(IPAddressChoice,      u.inherit,           ASN1_NULL),
  90   ASN1_SEQUENCE_OF(IPAddressChoice, u.addressesOrRanges, IPAddressOrRange)
  91 } ASN1_CHOICE_END(IPAddressChoice)
  92 
  93 ASN1_SEQUENCE(IPAddressFamily) = {
  94   ASN1_SIMPLE(IPAddressFamily, addressFamily,   ASN1_OCTET_STRING),
  95   ASN1_SIMPLE(IPAddressFamily, ipAddressChoice, IPAddressChoice)
  96 } ASN1_SEQUENCE_END(IPAddressFamily)
  97 
  98 ASN1_ITEM_TEMPLATE(IPAddrBlocks) =
  99   ASN1_EX_TEMPLATE_TYPE(ASN1_TFLG_SEQUENCE_OF, 0,
 100                         IPAddrBlocks, IPAddressFamily)
 101 ASN1_ITEM_TEMPLATE_END(IPAddrBlocks)
 102 
 103 IMPLEMENT_ASN1_FUNCTIONS(IPAddressRange)
 104 IMPLEMENT_ASN1_FUNCTIONS(IPAddressOrRange)
 105 IMPLEMENT_ASN1_FUNCTIONS(IPAddressChoice)
 106 IMPLEMENT_ASN1_FUNCTIONS(IPAddressFamily)
 107 
 108 /*
 109  * How much buffer space do we need for a raw address?
 110  */
 111 #define ADDR_RAW_BUF_LEN        16
 112 
 113 /*
 114  * What's the address length associated with this AFI?
 115  */
 116 static int length_from_afi(const unsigned afi)
 117 {
 118   switch (afi) {
 119   case IANA_AFI_IPV4:
 120     return 4;
 121   case IANA_AFI_IPV6:
 122     return 16;
 123   default:
 124     return 0;
 125   }
 126 }
 127 
 128 /*
 129  * Extract the AFI from an IPAddressFamily.
 130  */
 131 unsigned int v3_addr_get_afi(const IPAddressFamily *f)
 132 {
 133   return ((f != NULL &&
 134            f->addressFamily != NULL &&
 135            f->addressFamily->data != NULL)
 136           ? ((f->addressFamily->data[0] << 8) |
 137              (f->addressFamily->data[1]))
 138           : 0);
 139 }
 140 
 141 /*
 142  * Expand the bitstring form of an address into a raw byte array.
 143  * At the moment this is coded for simplicity, not speed.
 144  */
 145 static int addr_expand(unsigned char *addr,
 146                         const ASN1_BIT_STRING *bs,
 147                         const int length,
 148                         const unsigned char fill)
 149 {
 150   if (bs->length < 0 || bs->length > length)
 151     return 0;
 152   if (bs->length > 0) {
 153     memcpy(addr, bs->data, bs->length);
 154     if ((bs->flags & 7) != 0) {
 155       unsigned char mask = 0xFF >> (8 - (bs->flags & 7));
 156       if (fill == 0)
 157         addr[bs->length - 1] &= ~mask;
 158       else
 159         addr[bs->length - 1] |= mask;
 160     }
 161   }
 162   memset(addr + bs->length, fill, length - bs->length);
 163   return 1;
 164 }
 165 
 166 /*
 167  * Extract the prefix length from a bitstring.
 168  */
 169 #define addr_prefixlen(bs) ((int) ((bs)->length * 8 - ((bs)->flags & 7)))
 170 
 171 /*
 172  * i2r handler for one address bitstring.
 173  */
 174 static int i2r_address(BIO *out,
 175                        const unsigned afi,
 176                        const unsigned char fill,
 177                        const ASN1_BIT_STRING *bs)
 178 {
 179   unsigned char addr[ADDR_RAW_BUF_LEN];
 180   int i, n;
 181 
 182   if (bs->length < 0)
 183     return 0;
 184   switch (afi) {
 185   case IANA_AFI_IPV4:
 186     if (!addr_expand(addr, bs, 4, fill))
 187       return 0;
 188     BIO_printf(out, "%d.%d.%d.%d", addr[0], addr[1], addr[2], addr[3]);
 189     break;
 190   case IANA_AFI_IPV6:
 191     if (!addr_expand(addr, bs, 16, fill))
 192       return 0;
 193     for (n = 16; n > 1 && addr[n-1] == 0x00 && addr[n-2] == 0x00; n -= 2)
 194       ;
 195     for (i = 0; i < n; i += 2)
 196       BIO_printf(out, "%x%s", (addr[i] << 8) | addr[i+1], (i < 14 ? ":" : ""));
 197     if (i < 16)
 198       BIO_puts(out, ":");
 199     if (i == 0)
 200       BIO_puts(out, ":");
 201     break;
 202   default:
 203     for (i = 0; i < bs->length; i++)
 204       BIO_printf(out, "%s%02x", (i > 0 ? ":" : ""), bs->data[i]);
 205     BIO_printf(out, "[%d]", (int) (bs->flags & 7));
 206     break;
 207   }
 208   return 1;
 209 }
 210 
 211 /*
 212  * i2r handler for a sequence of addresses and ranges.
 213  */
 214 static int i2r_IPAddressOrRanges(BIO *out,
 215                                  const int indent,
 216                                  const IPAddressOrRanges *aors,
 217                                  const unsigned afi)
 218 {
 219   int i;
 220   for (i = 0; i < sk_IPAddressOrRange_num(aors); i++) {
 221     const IPAddressOrRange *aor = sk_IPAddressOrRange_value(aors, i);
 222     BIO_printf(out, "%*s", indent, "");
 223     switch (aor->type) {
 224     case IPAddressOrRange_addressPrefix:
 225       if (!i2r_address(out, afi, 0x00, aor->u.addressPrefix))
 226         return 0;
 227       BIO_printf(out, "/%d\n", addr_prefixlen(aor->u.addressPrefix));
 228       continue;
 229     case IPAddressOrRange_addressRange:
 230       if (!i2r_address(out, afi, 0x00, aor->u.addressRange->min))
 231         return 0;
 232       BIO_puts(out, "-");
 233       if (!i2r_address(out, afi, 0xFF, aor->u.addressRange->max))
 234         return 0;
 235       BIO_puts(out, "\n");
 236       continue;
 237     }
 238   }
 239   return 1;
 240 }
 241 
 242 /*
 243  * i2r handler for an IPAddrBlocks extension.
 244  */
 245 static int i2r_IPAddrBlocks(const X509V3_EXT_METHOD *method,
 246                             void *ext,
 247                             BIO *out,
 248                             int indent)
 249 {
 250   const IPAddrBlocks *addr = ext;
 251   int i;
 252   for (i = 0; i < sk_IPAddressFamily_num(addr); i++) {
 253     IPAddressFamily *f = sk_IPAddressFamily_value(addr, i);
 254     const unsigned int afi = v3_addr_get_afi(f);
 255     switch (afi) {
 256     case IANA_AFI_IPV4:
 257       BIO_printf(out, "%*sIPv4", indent, "");
 258       break;
 259     case IANA_AFI_IPV6:
 260       BIO_printf(out, "%*sIPv6", indent, "");
 261       break;
 262     default:
 263       BIO_printf(out, "%*sUnknown AFI %u", indent, "", afi);
 264       break;
 265     }
 266     if (f->addressFamily->length > 2) {
 267       switch (f->addressFamily->data[2]) {
 268       case   1:
 269         BIO_puts(out, " (Unicast)");
 270         break;
 271       case   2:
 272         BIO_puts(out, " (Multicast)");
 273         break;
 274       case   3:
 275         BIO_puts(out, " (Unicast/Multicast)");
 276         break;
 277       case   4:
 278         BIO_puts(out, " (MPLS)");
 279         break;
 280       case  64:
 281         BIO_puts(out, " (Tunnel)");
 282         break;
 283       case  65:
 284         BIO_puts(out, " (VPLS)");
 285         break;
 286       case  66:
 287         BIO_puts(out, " (BGP MDT)");
 288         break;
 289       case 128:
 290         BIO_puts(out, " (MPLS-labeled VPN)");
 291         break;
 292       default:
 293         BIO_printf(out, " (Unknown SAFI %u)",
 294                    (unsigned) f->addressFamily->data[2]);
 295         break;
 296       }
 297     }
 298     switch (f->ipAddressChoice->type) {
 299     case IPAddressChoice_inherit:
 300       BIO_puts(out, ": inherit\n");
 301       break;
 302     case IPAddressChoice_addressesOrRanges:
 303       BIO_puts(out, ":\n");
 304       if (!i2r_IPAddressOrRanges(out,
 305                                  indent + 2,
 306                                  f->ipAddressChoice->u.addressesOrRanges,
 307                                  afi))
 308         return 0;
 309       break;
 310     }
 311   }
 312   return 1;
 313 }
 314 
 315 /*
 316  * Sort comparison function for a sequence of IPAddressOrRange
 317  * elements.
 318  *
 319  * There's no sane answer we can give if addr_expand() fails, and an
 320  * assertion failure on externally supplied data is seriously uncool,
 321  * so we just arbitrarily declare that if given invalid inputs this
 322  * function returns -1.  If this messes up your preferred sort order
 323  * for garbage input, tough noogies.
 324  */
 325 static int IPAddressOrRange_cmp(const IPAddressOrRange *a,
 326                                 const IPAddressOrRange *b,
 327                                 const int length)
 328 {
 329   unsigned char addr_a[ADDR_RAW_BUF_LEN], addr_b[ADDR_RAW_BUF_LEN];
 330   int prefixlen_a = 0, prefixlen_b = 0;
 331   int r;
 332 
 333   switch (a->type) {
 334   case IPAddressOrRange_addressPrefix:
 335     if (!addr_expand(addr_a, a->u.addressPrefix, length, 0x00))
 336       return -1;
 337     prefixlen_a = addr_prefixlen(a->u.addressPrefix);
 338     break;
 339   case IPAddressOrRange_addressRange:
 340     if (!addr_expand(addr_a, a->u.addressRange->min, length, 0x00))
 341       return -1;
 342     prefixlen_a = length * 8;
 343     break;
 344   }
 345 
 346   switch (b->type) {
 347   case IPAddressOrRange_addressPrefix:
 348     if (!addr_expand(addr_b, b->u.addressPrefix, length, 0x00))
 349       return -1;
 350     prefixlen_b = addr_prefixlen(b->u.addressPrefix);
 351     break;
 352   case IPAddressOrRange_addressRange:
 353     if (!addr_expand(addr_b, b->u.addressRange->min, length, 0x00))
 354       return -1;
 355     prefixlen_b = length * 8;
 356     break;
 357   }
 358 
 359   if ((r = memcmp(addr_a, addr_b, length)) != 0)
 360     return r;
 361   else
 362     return prefixlen_a - prefixlen_b;
 363 }
 364 
 365 /*
 366  * IPv4-specific closure over IPAddressOrRange_cmp, since sk_sort()
 367  * comparision routines are only allowed two arguments.
 368  */
 369 static int v4IPAddressOrRange_cmp(const IPAddressOrRange * const *a,
 370                                   const IPAddressOrRange * const *b)
 371 {
 372   return IPAddressOrRange_cmp(*a, *b, 4);
 373 }
 374 
 375 /*
 376  * IPv6-specific closure over IPAddressOrRange_cmp, since sk_sort()
 377  * comparision routines are only allowed two arguments.
 378  */
 379 static int v6IPAddressOrRange_cmp(const IPAddressOrRange * const *a,
 380                                   const IPAddressOrRange * const *b)
 381 {
 382   return IPAddressOrRange_cmp(*a, *b, 16);
 383 }
 384 
 385 /*
 386  * Calculate whether a range collapses to a prefix.
 387  * See last paragraph of RFC 3779 2.2.3.7.
 388  */
 389 static int range_should_be_prefix(const unsigned char *min,
 390                                   const unsigned char *max,
 391                                   const int length)
 392 {
 393   unsigned char mask;
 394   int i, j;
 395 
 396   OPENSSL_assert(memcmp(min, max, length) <= 0);
 397   for (i = 0; i < length && min[i] == max[i]; i++)
 398     ;
 399   for (j = length - 1; j >= 0 && min[j] == 0x00 && max[j] == 0xFF; j--)
 400     ;
 401   if (i < j)
 402     return -1;
 403   if (i > j)
 404     return i * 8;
 405   mask = min[i] ^ max[i];
 406   switch (mask) {
 407   case 0x01: j = 7; break;
 408   case 0x03: j = 6; break;
 409   case 0x07: j = 5; break;
 410   case 0x0F: j = 4; break;
 411   case 0x1F: j = 3; break;
 412   case 0x3F: j = 2; break;
 413   case 0x7F: j = 1; break;
 414   default:   return -1;
 415   }
 416   if ((min[i] & mask) != 0 || (max[i] & mask) != mask)
 417     return -1;
 418   else
 419     return i * 8 + j;
 420 }
 421 
 422 /*
 423  * Construct a prefix.
 424  */
 425 static int make_addressPrefix(IPAddressOrRange **result,
 426                               unsigned char *addr,
 427                               const int prefixlen)
 428 {
 429   int bytelen = (prefixlen + 7) / 8, bitlen = prefixlen % 8;
 430   IPAddressOrRange *aor = IPAddressOrRange_new();
 431 
 432   if (aor == NULL)
 433     return 0;
 434   aor->type = IPAddressOrRange_addressPrefix;
 435   if (aor->u.addressPrefix == NULL &&
 436       (aor->u.addressPrefix = ASN1_BIT_STRING_new()) == NULL)
 437     goto err;
 438   if (!ASN1_BIT_STRING_set(aor->u.addressPrefix, addr, bytelen))
 439     goto err;
 440   aor->u.addressPrefix->flags &= ~7;
 441   aor->u.addressPrefix->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 442   if (bitlen > 0) {
 443     aor->u.addressPrefix->data[bytelen - 1] &= ~(0xFF >> bitlen);
 444     aor->u.addressPrefix->flags |= 8 - bitlen;
 445   }
 446 
 447   *result = aor;
 448   return 1;
 449 
 450  err:
 451   IPAddressOrRange_free(aor);
 452   return 0;
 453 }
 454 
 455 /*
 456  * Construct a range.  If it can be expressed as a prefix,
 457  * return a prefix instead.  Doing this here simplifies
 458  * the rest of the code considerably.
 459  */
 460 static int make_addressRange(IPAddressOrRange **result,
 461                              unsigned char *min,
 462                              unsigned char *max,
 463                              const int length)
 464 {
 465   IPAddressOrRange *aor;
 466   int i, prefixlen;
 467 
 468   if ((prefixlen = range_should_be_prefix(min, max, length)) >= 0)
 469     return make_addressPrefix(result, min, prefixlen);
 470 
 471   if ((aor = IPAddressOrRange_new()) == NULL)
 472     return 0;
 473   aor->type = IPAddressOrRange_addressRange;
 474   OPENSSL_assert(aor->u.addressRange == NULL);
 475   if ((aor->u.addressRange = IPAddressRange_new()) == NULL)
 476     goto err;
 477   if (aor->u.addressRange->min == NULL &&
 478       (aor->u.addressRange->min = ASN1_BIT_STRING_new()) == NULL)
 479     goto err;
 480   if (aor->u.addressRange->max == NULL &&
 481       (aor->u.addressRange->max = ASN1_BIT_STRING_new()) == NULL)
 482     goto err;
 483 
 484   for (i = length; i > 0 && min[i - 1] == 0x00; --i)
 485     ;
 486   if (!ASN1_BIT_STRING_set(aor->u.addressRange->min, min, i))
 487     goto err;
 488   aor->u.addressRange->min->flags &= ~7;
 489   aor->u.addressRange->min->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 490   if (i > 0) {
 491     unsigned char b = min[i - 1];
 492     int j = 1;
 493     while ((b & (0xFFU >> j)) != 0)
 494       ++j;
 495     aor->u.addressRange->min->flags |= 8 - j;
 496   }
 497 
 498   for (i = length; i > 0 && max[i - 1] == 0xFF; --i)
 499     ;
 500   if (!ASN1_BIT_STRING_set(aor->u.addressRange->max, max, i))
 501     goto err;
 502   aor->u.addressRange->max->flags &= ~7;
 503   aor->u.addressRange->max->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 504   if (i > 0) {
 505     unsigned char b = max[i - 1];
 506     int j = 1;
 507     while ((b & (0xFFU >> j)) != (0xFFU >> j))
 508       ++j;
 509     aor->u.addressRange->max->flags |= 8 - j;
 510   }
 511 
 512   *result = aor;
 513   return 1;
 514 
 515  err:
 516   IPAddressOrRange_free(aor);
 517   return 0;
 518 }
 519 
 520 /*
 521  * Construct a new address family or find an existing one.
 522  */
 523 static IPAddressFamily *make_IPAddressFamily(IPAddrBlocks *addr,
 524                                              const unsigned afi,
 525                                              const unsigned *safi)
 526 {
 527   IPAddressFamily *f;
 528   unsigned char key[3];
 529   unsigned keylen;
 530   int i;
 531 
 532   key[0] = (afi >> 8) & 0xFF;
 533   key[1] = afi & 0xFF;
 534   if (safi != NULL) {
 535     key[2] = *safi & 0xFF;
 536     keylen = 3;
 537   } else {
 538     keylen = 2;
 539   }
 540 
 541   for (i = 0; i < sk_IPAddressFamily_num(addr); i++) {
 542     f = sk_IPAddressFamily_value(addr, i);
 543     OPENSSL_assert(f->addressFamily->data != NULL);
 544     if (f->addressFamily->length == keylen &&
 545         !memcmp(f->addressFamily->data, key, keylen))
 546       return f;
 547   }
 548 
 549   if ((f = IPAddressFamily_new()) == NULL)
 550     goto err;
 551   if (f->ipAddressChoice == NULL &&
 552       (f->ipAddressChoice = IPAddressChoice_new()) == NULL)
 553     goto err;
 554   if (f->addressFamily == NULL &&
 555       (f->addressFamily = ASN1_OCTET_STRING_new()) == NULL)
 556     goto err;
 557   if (!ASN1_OCTET_STRING_set(f->addressFamily, key, keylen))
 558     goto err;
 559   if (!sk_IPAddressFamily_push(addr, f))
 560     goto err;
 561 
 562   return f;
 563 
 564  err:
 565   IPAddressFamily_free(f);
 566   return NULL;
 567 }
 568 
 569 /*
 570  * Add an inheritance element.
 571  */
 572 int v3_addr_add_inherit(IPAddrBlocks *addr,
 573                         const unsigned afi,
 574                         const unsigned *safi)
 575 {
 576   IPAddressFamily *f = make_IPAddressFamily(addr, afi, safi);
 577   if (f == NULL ||
 578       f->ipAddressChoice == NULL ||
 579       (f->ipAddressChoice->type == IPAddressChoice_addressesOrRanges &&
 580        f->ipAddressChoice->u.addressesOrRanges != NULL))
 581     return 0;
 582   if (f->ipAddressChoice->type == IPAddressChoice_inherit &&
 583       f->ipAddressChoice->u.inherit != NULL)
 584     return 1;
 585   if (f->ipAddressChoice->u.inherit == NULL &&
 586       (f->ipAddressChoice->u.inherit = ASN1_NULL_new()) == NULL)
 587     return 0;
 588   f->ipAddressChoice->type = IPAddressChoice_inherit;
 589   return 1;
 590 }
 591 
 592 /*
 593  * Construct an IPAddressOrRange sequence, or return an existing one.
 594  */
 595 static IPAddressOrRanges *make_prefix_or_range(IPAddrBlocks *addr,
 596                                                const unsigned afi,
 597                                                const unsigned *safi)
 598 {
 599   IPAddressFamily *f = make_IPAddressFamily(addr, afi, safi);
 600   IPAddressOrRanges *aors = NULL;
 601 
 602   if (f == NULL ||
 603       f->ipAddressChoice == NULL ||
 604       (f->ipAddressChoice->type == IPAddressChoice_inherit &&
 605        f->ipAddressChoice->u.inherit != NULL))
 606     return NULL;
 607   if (f->ipAddressChoice->type == IPAddressChoice_addressesOrRanges)
 608     aors = f->ipAddressChoice->u.addressesOrRanges;
 609   if (aors != NULL)
 610     return aors;
 611   if ((aors = sk_IPAddressOrRange_new_null()) == NULL)
 612     return NULL;
 613   switch (afi) {
 614   case IANA_AFI_IPV4:
 615     (void) sk_IPAddressOrRange_set_cmp_func(aors, v4IPAddressOrRange_cmp);
 616     break;
 617   case IANA_AFI_IPV6:
 618     (void) sk_IPAddressOrRange_set_cmp_func(aors, v6IPAddressOrRange_cmp);
 619     break;
 620   }
 621   f->ipAddressChoice->type = IPAddressChoice_addressesOrRanges;
 622   f->ipAddressChoice->u.addressesOrRanges = aors;
 623   return aors;
 624 }
 625 
 626 /*
 627  * Add a prefix.
 628  */
 629 int v3_addr_add_prefix(IPAddrBlocks *addr,
 630                        const unsigned afi,
 631                        const unsigned *safi,
 632                        unsigned char *a,
 633                        const int prefixlen)
 634 {
 635   IPAddressOrRanges *aors = make_prefix_or_range(addr, afi, safi);
 636   IPAddressOrRange *aor;
 637   if (aors == NULL || !make_addressPrefix(&aor, a, prefixlen))
 638     return 0;
 639   if (sk_IPAddressOrRange_push(aors, aor))
 640     return 1;
 641   IPAddressOrRange_free(aor);
 642   return 0;
 643 }
 644 
 645 /*
 646  * Add a range.
 647  */
 648 int v3_addr_add_range(IPAddrBlocks *addr,
 649                       const unsigned afi,
 650                       const unsigned *safi,
 651                       unsigned char *min,
 652                       unsigned char *max)
 653 {
 654   IPAddressOrRanges *aors = make_prefix_or_range(addr, afi, safi);
 655   IPAddressOrRange *aor;
 656   int length = length_from_afi(afi);
 657   if (aors == NULL)
 658     return 0;
 659   if (!make_addressRange(&aor, min, max, length))
 660     return 0;
 661   if (sk_IPAddressOrRange_push(aors, aor))
 662     return 1;
 663   IPAddressOrRange_free(aor);
 664   return 0;
 665 }
 666 
 667 /*
 668  * Extract min and max values from an IPAddressOrRange.
 669  */
 670 static int extract_min_max(IPAddressOrRange *aor,
 671                             unsigned char *min,
 672                             unsigned char *max,
 673                             int length)
 674 {
 675   if (aor == NULL || min == NULL || max == NULL)
 676     return 0;
 677   switch (aor->type) {
 678   case IPAddressOrRange_addressPrefix:
 679     return (addr_expand(min, aor->u.addressPrefix, length, 0x00) &&
 680             addr_expand(max, aor->u.addressPrefix, length, 0xFF));
 681   case IPAddressOrRange_addressRange:
 682     return (addr_expand(min, aor->u.addressRange->min, length, 0x00) &&
 683             addr_expand(max, aor->u.addressRange->max, length, 0xFF));
 684   }
 685   return 0;
 686 }
 687 
 688 /*
 689  * Public wrapper for extract_min_max().
 690  */
 691 int v3_addr_get_range(IPAddressOrRange *aor,
 692                       const unsigned afi,
 693                       unsigned char *min,
 694                       unsigned char *max,
 695                       const int length)
 696 {
 697   int afi_length = length_from_afi(afi);
 698   if (aor == NULL || min == NULL || max == NULL ||
 699       afi_length == 0 || length < afi_length ||
 700       (aor->type != IPAddressOrRange_addressPrefix &&
 701        aor->type != IPAddressOrRange_addressRange) ||
 702       !extract_min_max(aor, min, max, afi_length))
 703     return 0;
 704 
 705   return afi_length;
 706 }
 707 
 708 /*
 709  * Sort comparision function for a sequence of IPAddressFamily.
 710  *
 711  * The last paragraph of RFC 3779 2.2.3.3 is slightly ambiguous about
 712  * the ordering: I can read it as meaning that IPv6 without a SAFI
 713  * comes before IPv4 with a SAFI, which seems pretty weird.  The
 714  * examples in appendix B suggest that the author intended the
 715  * null-SAFI rule to apply only within a single AFI, which is what I
 716  * would have expected and is what the following code implements.
 717  */
 718 static int IPAddressFamily_cmp(const IPAddressFamily * const *a_,
 719                                const IPAddressFamily * const *b_)
 720 {
 721   const ASN1_OCTET_STRING *a = (*a_)->addressFamily;
 722   const ASN1_OCTET_STRING *b = (*b_)->addressFamily;
 723   int len = ((a->length <= b->length) ? a->length : b->length);
 724   int cmp = memcmp(a->data, b->data, len);
 725   return cmp ? cmp : a->length - b->length;
 726 }
 727 
 728 /*
 729  * Check whether an IPAddrBLocks is in canonical form.
 730  */
 731 int v3_addr_is_canonical(IPAddrBlocks *addr)
 732 {
 733   unsigned char a_min[ADDR_RAW_BUF_LEN], a_max[ADDR_RAW_BUF_LEN];
 734   unsigned char b_min[ADDR_RAW_BUF_LEN], b_max[ADDR_RAW_BUF_LEN];
 735   IPAddressOrRanges *aors;
 736   int i, j, k;
 737 
 738   /*
 739    * Empty extension is cannonical.
 740    */
 741   if (addr == NULL)
 742     return 1;
 743 
 744   /*
 745    * Check whether the top-level list is in order.
 746    */
 747   for (i = 0; i < sk_IPAddressFamily_num(addr) - 1; i++) {
 748     const IPAddressFamily *a = sk_IPAddressFamily_value(addr, i);
 749     const IPAddressFamily *b = sk_IPAddressFamily_value(addr, i + 1);
 750     if (IPAddressFamily_cmp(&a, &b) >= 0)
 751       return 0;
 752   }
 753 
 754   /*
 755    * Top level's ok, now check each address family.
 756    */
 757   for (i = 0; i < sk_IPAddressFamily_num(addr); i++) {
 758     IPAddressFamily *f = sk_IPAddressFamily_value(addr, i);
 759     int length = length_from_afi(v3_addr_get_afi(f));
 760 
 761     /*
 762      * Inheritance is canonical.  Anything other than inheritance or
 763      * a SEQUENCE OF IPAddressOrRange is an ASN.1 error or something.
 764      */
 765     if (f == NULL || f->ipAddressChoice == NULL)
 766       return 0;
 767     switch (f->ipAddressChoice->type) {
 768     case IPAddressChoice_inherit:
 769       continue;
 770     case IPAddressChoice_addressesOrRanges:
 771       break;
 772     default:
 773       return 0;
 774     }
 775 
 776     /*
 777      * It's an IPAddressOrRanges sequence, check it.
 778      */
 779     aors = f->ipAddressChoice->u.addressesOrRanges;
 780     if (sk_IPAddressOrRange_num(aors) == 0)
 781       return 0;
 782     for (j = 0; j < sk_IPAddressOrRange_num(aors) - 1; j++) {
 783       IPAddressOrRange *a = sk_IPAddressOrRange_value(aors, j);
 784       IPAddressOrRange *b = sk_IPAddressOrRange_value(aors, j + 1);
 785 
 786       if (!extract_min_max(a, a_min, a_max, length) ||
 787           !extract_min_max(b, b_min, b_max, length))
 788         return 0;
 789 
 790       /*
 791        * Punt misordered list, overlapping start, or inverted range.
 792        */
 793       if (memcmp(a_min, b_min, length) >= 0 ||
 794           memcmp(a_min, a_max, length) > 0 ||
 795           memcmp(b_min, b_max, length) > 0)
 796         return 0;
 797 
 798       /*
 799        * Punt if adjacent or overlapping.  Check for adjacency by
 800        * subtracting one from b_min first.
 801        */
 802       for (k = length - 1; k >= 0 && b_min[k]-- == 0x00; k--)
 803         ;
 804       if (memcmp(a_max, b_min, length) >= 0)
 805         return 0;
 806 
 807       /*
 808        * Check for range that should be expressed as a prefix.
 809        */
 810       if (a->type == IPAddressOrRange_addressRange &&
 811           range_should_be_prefix(a_min, a_max, length) >= 0)
 812         return 0;
 813     }
 814 
 815     /*
 816      * Check range to see if it's inverted or should be a
 817      * prefix.
 818      */
 819     j = sk_IPAddressOrRange_num(aors) - 1;
 820     {
 821       IPAddressOrRange *a = sk_IPAddressOrRange_value(aors, j);
 822       if (a != NULL && a->type == IPAddressOrRange_addressRange) {
 823         if (!extract_min_max(a, a_min, a_max, length))
 824           return 0;
 825         if (memcmp(a_min, a_max, length) > 0 ||
 826             range_should_be_prefix(a_min, a_max, length) >= 0)
 827           return 0;
 828       }
 829     }
 830   }
 831 
 832   /*
 833    * If we made it through all that, we're happy.
 834    */
 835   return 1;
 836 }
 837 
 838 /*
 839  * Whack an IPAddressOrRanges into canonical form.
 840  */
 841 static int IPAddressOrRanges_canonize(IPAddressOrRanges *aors,
 842                                       const unsigned afi)
 843 {
 844   int i, j, length = length_from_afi(afi);
 845 
 846   /*
 847    * Sort the IPAddressOrRanges sequence.
 848    */
 849   sk_IPAddressOrRange_sort(aors);
 850 
 851   /*
 852    * Clean up representation issues, punt on duplicates or overlaps.
 853    */
 854   for (i = 0; i < sk_IPAddressOrRange_num(aors) - 1; i++) {
 855     IPAddressOrRange *a = sk_IPAddressOrRange_value(aors, i);
 856     IPAddressOrRange *b = sk_IPAddressOrRange_value(aors, i + 1);
 857     unsigned char a_min[ADDR_RAW_BUF_LEN], a_max[ADDR_RAW_BUF_LEN];
 858     unsigned char b_min[ADDR_RAW_BUF_LEN], b_max[ADDR_RAW_BUF_LEN];
 859 
 860     if (!extract_min_max(a, a_min, a_max, length) ||
 861         !extract_min_max(b, b_min, b_max, length))
 862       return 0;
 863 
 864     /*
 865      * Punt inverted ranges.
 866      */
 867     if (memcmp(a_min, a_max, length) > 0 ||
 868         memcmp(b_min, b_max, length) > 0)
 869       return 0;
 870 
 871     /*
 872      * Punt overlaps.
 873      */
 874     if (memcmp(a_max, b_min, length) >= 0)
 875       return 0;
 876 
 877     /*
 878      * Merge if a and b are adjacent.  We check for
 879      * adjacency by subtracting one from b_min first.
 880      */
 881     for (j = length - 1; j >= 0 && b_min[j]-- == 0x00; j--)
 882       ;
 883     if (memcmp(a_max, b_min, length) == 0) {
 884       IPAddressOrRange *merged;
 885       if (!make_addressRange(&merged, a_min, b_max, length))
 886         return 0;
 887       (void) sk_IPAddressOrRange_set(aors, i, merged);
 888       (void) sk_IPAddressOrRange_delete(aors, i + 1);
 889       IPAddressOrRange_free(a);
 890       IPAddressOrRange_free(b);
 891       --i;
 892       continue;
 893     }
 894   }
 895 
 896   /*
 897    * Check for inverted final range.
 898    */
 899   j = sk_IPAddressOrRange_num(aors) - 1;
 900   {
 901     IPAddressOrRange *a = sk_IPAddressOrRange_value(aors, j);
 902     if (a != NULL && a->type == IPAddressOrRange_addressRange) {
 903       unsigned char a_min[ADDR_RAW_BUF_LEN], a_max[ADDR_RAW_BUF_LEN];
 904       extract_min_max(a, a_min, a_max, length);
 905       if (memcmp(a_min, a_max, length) > 0)
 906         return 0;
 907     }
 908   }
 909 
 910   return 1;
 911 }
 912 
 913 /*
 914  * Whack an IPAddrBlocks extension into canonical form.
 915  */
 916 int v3_addr_canonize(IPAddrBlocks *addr)
 917 {
 918   int i;
 919   for (i = 0; i < sk_IPAddressFamily_num(addr); i++) {
 920     IPAddressFamily *f = sk_IPAddressFamily_value(addr, i);
 921     if (f->ipAddressChoice->type == IPAddressChoice_addressesOrRanges &&
 922         !IPAddressOrRanges_canonize(f->ipAddressChoice->u.addressesOrRanges,
 923                                     v3_addr_get_afi(f)))
 924       return 0;
 925   }
 926   (void) sk_IPAddressFamily_set_cmp_func(addr, IPAddressFamily_cmp);
 927   sk_IPAddressFamily_sort(addr);
 928   OPENSSL_assert(v3_addr_is_canonical(addr));
 929   return 1;
 930 }
 931 
 932 /*
 933  * v2i handler for the IPAddrBlocks extension.
 934  */
 935 static void *v2i_IPAddrBlocks(const struct v3_ext_method *method,
 936                               struct v3_ext_ctx *ctx,
 937                               STACK_OF(CONF_VALUE) *values)
 938 {
 939   static const char v4addr_chars[] = "0123456789.";
 940   static const char v6addr_chars[] = "0123456789.:abcdefABCDEF";
 941   IPAddrBlocks *addr = NULL;
 942   char *s = NULL, *t;
 943   int i;
 944 
 945   if ((addr = sk_IPAddressFamily_new(IPAddressFamily_cmp)) == NULL) {
 946     X509V3err(X509V3_F_V2I_IPADDRBLOCKS, ERR_R_MALLOC_FAILURE);
 947     return NULL;
 948   }
 949 
 950   for (i = 0; i < sk_CONF_VALUE_num(values); i++) {
 951     CONF_VALUE *val = sk_CONF_VALUE_value(values, i);
 952     unsigned char min[ADDR_RAW_BUF_LEN], max[ADDR_RAW_BUF_LEN];
 953     unsigned afi, *safi = NULL, safi_;
 954     const char *addr_chars;
 955     int prefixlen, i1, i2, delim, length;
 956 
 957     if (       !name_cmp(val->name, "IPv4")) {
 958       afi = IANA_AFI_IPV4;
 959     } else if (!name_cmp(val->name, "IPv6")) {
 960       afi = IANA_AFI_IPV6;
 961     } else if (!name_cmp(val->name, "IPv4-SAFI")) {
 962       afi = IANA_AFI_IPV4;
 963       safi = &safi_;
 964     } else if (!name_cmp(val->name, "IPv6-SAFI")) {
 965       afi = IANA_AFI_IPV6;
 966       safi = &safi_;
 967     } else {
 968       X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_EXTENSION_NAME_ERROR);
 969       X509V3_conf_err(val);
 970       goto err;
 971     }
 972 
 973     switch (afi) {
 974     case IANA_AFI_IPV4:
 975       addr_chars = v4addr_chars;
 976       break;
 977     case IANA_AFI_IPV6:
 978       addr_chars = v6addr_chars;
 979       break;
 980     }
 981 
 982     length = length_from_afi(afi);
 983 
 984     /*
 985      * Handle SAFI, if any, and BUF_strdup() so we can null-terminate
 986      * the other input values.
 987      */
 988     if (safi != NULL) {
 989       *safi = strtoul(val->value, &t, 0);
 990       t += strspn(t, " \t");
 991       if (*safi > 0xFF || *t++ != ':') {
 992         X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_INVALID_SAFI);
 993         X509V3_conf_err(val);
 994         goto err;
 995       }
 996       t += strspn(t, " \t");
 997       s = BUF_strdup(t);
 998     } else {
 999       s = BUF_strdup(val->value);
1000     }
1001     if (s == NULL) {
1002       X509V3err(X509V3_F_V2I_IPADDRBLOCKS, ERR_R_MALLOC_FAILURE);
1003       goto err;
1004     }
1005 
1006     /*
1007      * Check for inheritance.  Not worth additional complexity to
1008      * optimize this (seldom-used) case.
1009      */
1010     if (!strcmp(s, "inherit")) {
1011       if (!v3_addr_add_inherit(addr, afi, safi)) {
1012         X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_INVALID_INHERITANCE);
1013         X509V3_conf_err(val);
1014         goto err;
1015       }
1016       OPENSSL_free(s);
1017       s = NULL;
1018       continue;
1019     }
1020 
1021     i1 = strspn(s, addr_chars);
1022     i2 = i1 + strspn(s + i1, " \t");
1023     delim = s[i2++];
1024     s[i1] = '\0';
1025 
1026     if (a2i_ipadd(min, s) != length) {
1027       X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_INVALID_IPADDRESS);
1028       X509V3_conf_err(val);
1029       goto err;
1030     }
1031 
1032     switch (delim) {
1033     case '/':
1034       prefixlen = (int) strtoul(s + i2, &t, 10);
1035       if (t == s + i2 || *t != '\0') {
1036         X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_EXTENSION_VALUE_ERROR);
1037         X509V3_conf_err(val);
1038         goto err;
1039       }
1040       if (!v3_addr_add_prefix(addr, afi, safi, min, prefixlen)) {
1041         X509V3err(X509V3_F_V2I_IPADDRBLOCKS, ERR_R_MALLOC_FAILURE);
1042         goto err;
1043       }
1044       break;
1045     case '-':
1046       i1 = i2 + strspn(s + i2, " \t");
1047       i2 = i1 + strspn(s + i1, addr_chars);
1048       if (i1 == i2 || s[i2] != '\0') {
1049         X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_EXTENSION_VALUE_ERROR);
1050         X509V3_conf_err(val);
1051         goto err;
1052       }
1053       if (a2i_ipadd(max, s + i1) != length) {
1054         X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_INVALID_IPADDRESS);
1055         X509V3_conf_err(val);
1056         goto err;
1057       }
1058       if (memcmp(min, max, length_from_afi(afi)) > 0) {
1059         X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_EXTENSION_VALUE_ERROR);
1060         X509V3_conf_err(val);
1061         goto err;
1062       }
1063       if (!v3_addr_add_range(addr, afi, safi, min, max)) {
1064         X509V3err(X509V3_F_V2I_IPADDRBLOCKS, ERR_R_MALLOC_FAILURE);
1065         goto err;
1066       }
1067       break;
1068     case '\0':
1069       if (!v3_addr_add_prefix(addr, afi, safi, min, length * 8)) {
1070         X509V3err(X509V3_F_V2I_IPADDRBLOCKS, ERR_R_MALLOC_FAILURE);
1071         goto err;
1072       }
1073       break;
1074     default:
1075       X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_EXTENSION_VALUE_ERROR);
1076       X509V3_conf_err(val);
1077       goto err;
1078     }
1079 
1080     OPENSSL_free(s);
1081     s = NULL;
1082   }
1083 
1084   /*
1085    * Canonize the result, then we're done.
1086    */
1087   if (!v3_addr_canonize(addr))
1088     goto err;
1089   return addr;
1090 
1091  err:
1092   OPENSSL_free(s);
1093   sk_IPAddressFamily_pop_free(addr, IPAddressFamily_free);
1094   return NULL;
1095 }
1096 
1097 /*
1098  * OpenSSL dispatch
1099  */
1100 const X509V3_EXT_METHOD v3_addr = {
1101   NID_sbgp_ipAddrBlock,         /* nid */
1102   0,                            /* flags */
1103   ASN1_ITEM_ref(IPAddrBlocks),  /* template */
1104   0, 0, 0, 0,                   /* old functions, ignored */
1105   0,                            /* i2s */
1106   0,                            /* s2i */
1107   0,                            /* i2v */
1108   v2i_IPAddrBlocks,             /* v2i */
1109   i2r_IPAddrBlocks,             /* i2r */
1110   0,                            /* r2i */
1111   NULL                          /* extension-specific data */
1112 };
1113 
1114 /*
1115  * Figure out whether extension sues inheritance.
1116  */
1117 int v3_addr_inherits(IPAddrBlocks *addr)
1118 {
1119   int i;
1120   if (addr == NULL)
1121     return 0;
1122   for (i = 0; i < sk_IPAddressFamily_num(addr); i++) {
1123     IPAddressFamily *f = sk_IPAddressFamily_value(addr, i);
1124     if (f->ipAddressChoice->type == IPAddressChoice_inherit)
1125       return 1;
1126   }
1127   return 0;
1128 }
1129 
1130 /*
1131  * Figure out whether parent contains child.
1132  */
1133 static int addr_contains(IPAddressOrRanges *parent,
1134                          IPAddressOrRanges *child,
1135                          int length)
1136 {
1137   unsigned char p_min[ADDR_RAW_BUF_LEN], p_max[ADDR_RAW_BUF_LEN];
1138   unsigned char c_min[ADDR_RAW_BUF_LEN], c_max[ADDR_RAW_BUF_LEN];
1139   int p, c;
1140 
1141   if (child == NULL || parent == child)
1142     return 1;
1143   if (parent == NULL)
1144     return 0;
1145 
1146   p = 0;
1147   for (c = 0; c < sk_IPAddressOrRange_num(child); c++) {
1148     if (!extract_min_max(sk_IPAddressOrRange_value(child, c),
1149                          c_min, c_max, length))
1150       return -1;
1151     for (;; p++) {
1152       if (p >= sk_IPAddressOrRange_num(parent))
1153         return 0;
1154       if (!extract_min_max(sk_IPAddressOrRange_value(parent, p),
1155                            p_min, p_max, length))
1156         return 0;
1157       if (memcmp(p_max, c_max, length) < 0)
1158         continue;
1159       if (memcmp(p_min, c_min, length) > 0)
1160         return 0;
1161       break;
1162     }
1163   }
1164 
1165   return 1;
1166 }
1167 
1168 /*
1169  * Test whether a is a subset of b.
1170  */
1171 int v3_addr_subset(IPAddrBlocks *a, IPAddrBlocks *b)
1172 {
1173   int i;
1174   if (a == NULL || a == b)
1175     return 1;
1176   if (b == NULL || v3_addr_inherits(a) || v3_addr_inherits(b))
1177     return 0;
1178   (void) sk_IPAddressFamily_set_cmp_func(b, IPAddressFamily_cmp);
1179   for (i = 0; i < sk_IPAddressFamily_num(a); i++) {
1180     IPAddressFamily *fa = sk_IPAddressFamily_value(a, i);
1181     int j = sk_IPAddressFamily_find(b, fa);
1182     IPAddressFamily *fb;
1183     fb = sk_IPAddressFamily_value(b, j);
1184     if (fb == NULL)
1185        return 0;
1186     if (!addr_contains(fb->ipAddressChoice->u.addressesOrRanges,
1187                        fa->ipAddressChoice->u.addressesOrRanges,
1188                        length_from_afi(v3_addr_get_afi(fb))))
1189       return 0;
1190   }
1191   return 1;
1192 }
1193 
1194 /*
1195  * Validation error handling via callback.
1196  */
1197 #define validation_err(_err_)           \
1198   do {                                  \
1199     if (ctx != NULL) {                  \
1200       ctx->error = _err_;            \
1201       ctx->error_depth = i;          \
1202       ctx->current_cert = x;         \
1203       ret = ctx->verify_cb(0, ctx);  \
1204     } else {                            \
1205       ret = 0;                          \
1206     }                                   \
1207     if (!ret)                           \
1208       goto done;                        \
1209   } while (0)
1210 
1211 /*
1212  * Core code for RFC 3779 2.3 path validation.
1213  */
1214 static int v3_addr_validate_path_internal(X509_STORE_CTX *ctx,
1215                                           STACK_OF(X509) *chain,
1216                                           IPAddrBlocks *ext)
1217 {
1218   IPAddrBlocks *child = NULL;
1219   int i, j, ret = 1;
1220   X509 *x;
1221 
1222   OPENSSL_assert(chain != NULL && sk_X509_num(chain) > 0);
1223   OPENSSL_assert(ctx != NULL || ext != NULL);
1224   OPENSSL_assert(ctx == NULL || ctx->verify_cb != NULL);
1225 
1226   /*
1227    * Figure out where to start.  If we don't have an extension to
1228    * check, we're done.  Otherwise, check canonical form and
1229    * set up for walking up the chain.
1230    */
1231   if (ext != NULL) {
1232     i = -1;
1233     x = NULL;
1234   } else {
1235     i = 0;
1236     x = sk_X509_value(chain, i);
1237     OPENSSL_assert(x != NULL);
1238     if ((ext = x->rfc3779_addr) == NULL)
1239       goto done;
1240   }
1241   if (!v3_addr_is_canonical(ext))
1242     validation_err(X509_V_ERR_INVALID_EXTENSION);
1243   (void) sk_IPAddressFamily_set_cmp_func(ext, IPAddressFamily_cmp);
1244   if ((child = sk_IPAddressFamily_dup(ext)) == NULL) {
1245     X509V3err(X509V3_F_V3_ADDR_VALIDATE_PATH_INTERNAL, ERR_R_MALLOC_FAILURE);
1246     ret = 0;
1247     goto done;
1248   }
1249 
1250   /*
1251    * Now walk up the chain.  No cert may list resources that its
1252    * parent doesn't list.
1253    */
1254   for (i++; i < sk_X509_num(chain); i++) {
1255     x = sk_X509_value(chain, i);
1256     OPENSSL_assert(x != NULL);
1257     if (!v3_addr_is_canonical(x->rfc3779_addr))
1258       validation_err(X509_V_ERR_INVALID_EXTENSION);
1259     if (x->rfc3779_addr == NULL) {
1260       for (j = 0; j < sk_IPAddressFamily_num(child); j++) {
1261         IPAddressFamily *fc = sk_IPAddressFamily_value(child, j);
1262         if (fc->ipAddressChoice->type != IPAddressChoice_inherit) {
1263           validation_err(X509_V_ERR_UNNESTED_RESOURCE);
1264           break;
1265         }
1266       }
1267       continue;
1268     }
1269     (void) sk_IPAddressFamily_set_cmp_func(x->rfc3779_addr, IPAddressFamily_cmp);
1270     for (j = 0; j < sk_IPAddressFamily_num(child); j++) {
1271       IPAddressFamily *fc = sk_IPAddressFamily_value(child, j);
1272       int k = sk_IPAddressFamily_find(x->rfc3779_addr, fc);
1273       IPAddressFamily *fp = sk_IPAddressFamily_value(x->rfc3779_addr, k);
1274       if (fp == NULL) {
1275         if (fc->ipAddressChoice->type == IPAddressChoice_addressesOrRanges) {
1276           validation_err(X509_V_ERR_UNNESTED_RESOURCE);
1277           break;
1278         }
1279         continue;
1280       }
1281       if (fp->ipAddressChoice->type == IPAddressChoice_addressesOrRanges) {
1282         if (fc->ipAddressChoice->type == IPAddressChoice_inherit ||
1283             addr_contains(fp->ipAddressChoice->u.addressesOrRanges,
1284                           fc->ipAddressChoice->u.addressesOrRanges,
1285                           length_from_afi(v3_addr_get_afi(fc))))
1286           sk_IPAddressFamily_set(child, j, fp);
1287         else
1288           validation_err(X509_V_ERR_UNNESTED_RESOURCE);
1289       }
1290     }
1291   }
1292 
1293   /*
1294    * Trust anchor can't inherit.
1295    */
1296   OPENSSL_assert(x != NULL);
1297   if (x->rfc3779_addr != NULL) {
1298     for (j = 0; j < sk_IPAddressFamily_num(x->rfc3779_addr); j++) {
1299       IPAddressFamily *fp = sk_IPAddressFamily_value(x->rfc3779_addr, j);
1300       if (fp->ipAddressChoice->type == IPAddressChoice_inherit &&
1301           sk_IPAddressFamily_find(child, fp) >= 0)
1302         validation_err(X509_V_ERR_UNNESTED_RESOURCE);
1303     }
1304   }
1305 
1306  done:
1307   sk_IPAddressFamily_free(child);
1308   return ret;
1309 }
1310 
1311 #undef validation_err
1312 
1313 /*
1314  * RFC 3779 2.3 path validation -- called from X509_verify_cert().
1315  */
1316 int v3_addr_validate_path(X509_STORE_CTX *ctx)
1317 {
1318   return v3_addr_validate_path_internal(ctx, ctx->chain, NULL);
1319 }
1320 
1321 /*
1322  * RFC 3779 2.3 path validation of an extension.
1323  * Test whether chain covers extension.
1324  */
1325 int v3_addr_validate_resource_set(STACK_OF(X509) *chain,
1326                                   IPAddrBlocks *ext,
1327                                   int allow_inheritance)
1328 {
1329   if (ext == NULL)
1330     return 1;
1331   if (chain == NULL || sk_X509_num(chain) == 0)
1332     return 0;
1333   if (!allow_inheritance && v3_addr_inherits(ext))
1334     return 0;
1335   return v3_addr_validate_path_internal(NULL, chain, ext);
1336 }
1337 
1338 #endif /* OPENSSL_NO_RFC3779 */