crypto/x509/v3_asid.c - third_party/openssl - Git at Google

 /*
  * Copyright 2006-2021 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
  */

 /*
  * Implementation of RFC 3779 section 3.2.
  */

 #include <assert.h>
 #include <stdio.h>
 #include <string.h>
 #include "internal/cryptlib.h"
 #include <openssl/conf.h>
 #include <openssl/asn1.h>
 #include <openssl/asn1t.h>
 #include <openssl/x509v3.h>
 #include <openssl/x509.h>
 #include "crypto/x509.h"
 #include <openssl/bn.h>
 #include "ext_dat.h"
 #include "x509_local.h"

 #ifndef OPENSSL_NO_RFC3779

 /*
  * OpenSSL ASN.1 template translation of RFC 3779 3.2.3.
  */

 ASN1_SEQUENCE(ASRange) = {
   ASN1_SIMPLE(ASRange, min, ASN1_INTEGER),
   ASN1_SIMPLE(ASRange, max, ASN1_INTEGER)
 } ASN1_SEQUENCE_END(ASRange)

 ASN1_CHOICE(ASIdOrRange) = {
   ASN1_SIMPLE(ASIdOrRange, u.id,    ASN1_INTEGER),
   ASN1_SIMPLE(ASIdOrRange, u.range, ASRange)
 } ASN1_CHOICE_END(ASIdOrRange)

 ASN1_CHOICE(ASIdentifierChoice) = {
   ASN1_SIMPLE(ASIdentifierChoice,      u.inherit,       ASN1_NULL),
   ASN1_SEQUENCE_OF(ASIdentifierChoice, u.asIdsOrRanges, ASIdOrRange)
 } ASN1_CHOICE_END(ASIdentifierChoice)

 ASN1_SEQUENCE(ASIdentifiers) = {
   ASN1_EXP_OPT(ASIdentifiers, asnum, ASIdentifierChoice, 0),
   ASN1_EXP_OPT(ASIdentifiers, rdi,   ASIdentifierChoice, 1)
 } ASN1_SEQUENCE_END(ASIdentifiers)

 IMPLEMENT_ASN1_FUNCTIONS(ASRange)
 IMPLEMENT_ASN1_FUNCTIONS(ASIdOrRange)
 IMPLEMENT_ASN1_FUNCTIONS(ASIdentifierChoice)
 IMPLEMENT_ASN1_FUNCTIONS(ASIdentifiers)

 /*
  * i2r method for an ASIdentifierChoice.
  */
 static int i2r_ASIdentifierChoice(BIO *out,
                                   ASIdentifierChoice *choice,
                                   int indent, const char *msg)
 {
     int i;
     char *s;
     if (choice == NULL)
         return 1;
     BIO_printf(out, "%*s%s:\n", indent, "", msg);
     switch (choice->type) {
     case ASIdentifierChoice_inherit:
         BIO_printf(out, "%*sinherit\n", indent + 2, "");
         break;
     case ASIdentifierChoice_asIdsOrRanges:
         for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges); i++) {
             ASIdOrRange *aor =
                 sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
             switch (aor->type) {
             case ASIdOrRange_id:
                 if ((s = i2s_ASN1_INTEGER(NULL, aor->u.id)) == NULL)
                     return 0;
                 BIO_printf(out, "%*s%s\n", indent + 2, "", s);
                 OPENSSL_free(s);
                 break;
             case ASIdOrRange_range:
                 if ((s = i2s_ASN1_INTEGER(NULL, aor->u.range->min)) == NULL)
                     return 0;
                 BIO_printf(out, "%*s%s-", indent + 2, "", s);
                 OPENSSL_free(s);
                 if ((s = i2s_ASN1_INTEGER(NULL, aor->u.range->max)) == NULL)
                     return 0;
                 BIO_printf(out, "%s\n", s);
                 OPENSSL_free(s);
                 break;
             default:
                 return 0;
             }
         }
         break;
     default:
         return 0;
     }
     return 1;
 }

 /*
  * i2r method for an ASIdentifier extension.
  */
 static int i2r_ASIdentifiers(const X509V3_EXT_METHOD *method,
                              void *ext, BIO *out, int indent)
 {
     ASIdentifiers *asid = ext;
     return (i2r_ASIdentifierChoice(out, asid->asnum, indent,
                                    "Autonomous System Numbers") &&
             i2r_ASIdentifierChoice(out, asid->rdi, indent,
                                    "Routing Domain Identifiers"));
 }

 /*
  * Sort comparison function for a sequence of ASIdOrRange elements.
  */
 static int ASIdOrRange_cmp(const ASIdOrRange *const *a_,
                            const ASIdOrRange *const *b_)
 {
     const ASIdOrRange *a = *a_, *b = *b_;

     assert((a->type == ASIdOrRange_id && a->u.id != NULL) ||
            (a->type == ASIdOrRange_range && a->u.range != NULL &&
             a->u.range->min != NULL && a->u.range->max != NULL));

     assert((b->type == ASIdOrRange_id && b->u.id != NULL) ||
            (b->type == ASIdOrRange_range && b->u.range != NULL &&
             b->u.range->min != NULL && b->u.range->max != NULL));

     if (a->type == ASIdOrRange_id && b->type == ASIdOrRange_id)
         return ASN1_INTEGER_cmp(a->u.id, b->u.id);

     if (a->type == ASIdOrRange_range && b->type == ASIdOrRange_range) {
         int r = ASN1_INTEGER_cmp(a->u.range->min, b->u.range->min);
         return r != 0 ? r : ASN1_INTEGER_cmp(a->u.range->max,
                                              b->u.range->max);
     }

     if (a->type == ASIdOrRange_id)
         return ASN1_INTEGER_cmp(a->u.id, b->u.range->min);
     else
         return ASN1_INTEGER_cmp(a->u.range->min, b->u.id);
 }

 /*
  * Add an inherit element.
  */
 int X509v3_asid_add_inherit(ASIdentifiers *asid, int which)
 {
     ASIdentifierChoice **choice;
     if (asid == NULL)
         return 0;
     switch (which) {
     case V3_ASID_ASNUM:
         choice = &asid->asnum;
         break;
     case V3_ASID_RDI:
         choice = &asid->rdi;
         break;
     default:
         return 0;
     }
     if (*choice == NULL) {
         if ((*choice = ASIdentifierChoice_new()) == NULL)
             return 0;
         if (((*choice)->u.inherit = ASN1_NULL_new()) == NULL)
             return 0;
         (*choice)->type = ASIdentifierChoice_inherit;
     }
     return (*choice)->type == ASIdentifierChoice_inherit;
 }

 /*
  * Add an ID or range to an ASIdentifierChoice.
  */
 int X509v3_asid_add_id_or_range(ASIdentifiers *asid,
                                 int which, ASN1_INTEGER *min, ASN1_INTEGER *max)
 {
     ASIdentifierChoice **choice;
     ASIdOrRange *aor;
     if (asid == NULL)
         return 0;
     switch (which) {
     case V3_ASID_ASNUM:
         choice = &asid->asnum;
         break;
     case V3_ASID_RDI:
         choice = &asid->rdi;
         break;
     default:
         return 0;
     }
     if (*choice != NULL && (*choice)->type == ASIdentifierChoice_inherit)
         return 0;
     if (*choice == NULL) {
         if ((*choice = ASIdentifierChoice_new()) == NULL)
             return 0;
         (*choice)->u.asIdsOrRanges = sk_ASIdOrRange_new(ASIdOrRange_cmp);
         if ((*choice)->u.asIdsOrRanges == NULL)
             return 0;
         (*choice)->type = ASIdentifierChoice_asIdsOrRanges;
     }
     if ((aor = ASIdOrRange_new()) == NULL)
         return 0;
     if (max == NULL) {
         aor->type = ASIdOrRange_id;
         aor->u.id = min;
     } else {
         aor->type = ASIdOrRange_range;
         if ((aor->u.range = ASRange_new()) == NULL)
             goto err;
         ASN1_INTEGER_free(aor->u.range->min);
         aor->u.range->min = min;
         ASN1_INTEGER_free(aor->u.range->max);
         aor->u.range->max = max;
     }
     if (!(sk_ASIdOrRange_push((*choice)->u.asIdsOrRanges, aor)))
         goto err;
     return 1;

  err:
     ASIdOrRange_free(aor);
     return 0;
 }

 /*
  * Extract min and max values from an ASIdOrRange.
  */
 static int extract_min_max(ASIdOrRange *aor,
                            ASN1_INTEGER **min, ASN1_INTEGER **max)
 {
     if (!ossl_assert(aor != NULL))
         return 0;
     switch (aor->type) {
     case ASIdOrRange_id:
         *min = aor->u.id;
         *max = aor->u.id;
         return 1;
     case ASIdOrRange_range:
         *min = aor->u.range->min;
         *max = aor->u.range->max;
         return 1;
     }

     return 0;
 }

 /*
  * Check whether an ASIdentifierChoice is in canonical form.
  */
 static int ASIdentifierChoice_is_canonical(ASIdentifierChoice *choice)
 {
     ASN1_INTEGER *a_max_plus_one = NULL;
     ASN1_INTEGER *orig;
     BIGNUM *bn = NULL;
     int i, ret = 0;

     /*
      * Empty element or inheritance is canonical.
      */
     if (choice == NULL || choice->type == ASIdentifierChoice_inherit)
         return 1;

     /*
      * If not a list, or if empty list, it's broken.
      */
     if (choice->type != ASIdentifierChoice_asIdsOrRanges ||
         sk_ASIdOrRange_num(choice->u.asIdsOrRanges) == 0)
         return 0;

     /*
      * It's a list, check it.
      */
     for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1; i++) {
         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
         ASIdOrRange *b = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i + 1);
         ASN1_INTEGER *a_min = NULL, *a_max = NULL, *b_min = NULL, *b_max =
             NULL;

         if (!extract_min_max(a, &a_min, &a_max)
                 || !extract_min_max(b, &b_min, &b_max))
             goto done;

         /*
          * Punt misordered list, overlapping start, or inverted range.
          */
         if (ASN1_INTEGER_cmp(a_min, b_min) >= 0 ||
             ASN1_INTEGER_cmp(a_min, a_max) > 0 ||
             ASN1_INTEGER_cmp(b_min, b_max) > 0)
             goto done;

         /*
          * Calculate a_max + 1 to check for adjacency.
          */
         if ((bn == NULL && (bn = BN_new()) == NULL) ||
             ASN1_INTEGER_to_BN(a_max, bn) == NULL ||
             !BN_add_word(bn, 1)) {
             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
             goto done;
         }

         if ((a_max_plus_one =
                 BN_to_ASN1_INTEGER(bn, orig = a_max_plus_one)) == NULL) {
             a_max_plus_one = orig;
             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
             goto done;
         }

         /*
          * Punt if adjacent or overlapping.
          */
         if (ASN1_INTEGER_cmp(a_max_plus_one, b_min) >= 0)
             goto done;
     }

     /*
      * Check for inverted range.
      */
     i = sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1;
     {
         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
         ASN1_INTEGER *a_min, *a_max;
         if (a != NULL && a->type == ASIdOrRange_range) {
             if (!extract_min_max(a, &a_min, &a_max)
                     || ASN1_INTEGER_cmp(a_min, a_max) > 0)
                 goto done;
         }
     }

     ret = 1;

  done:
     ASN1_INTEGER_free(a_max_plus_one);
     BN_free(bn);
     return ret;
 }

 /*
  * Check whether an ASIdentifier extension is in canonical form.
  */
 int X509v3_asid_is_canonical(ASIdentifiers *asid)
 {
     return (asid == NULL ||
             (ASIdentifierChoice_is_canonical(asid->asnum) &&
              ASIdentifierChoice_is_canonical(asid->rdi)));
 }

 /*
  * Whack an ASIdentifierChoice into canonical form.
  */
 static int ASIdentifierChoice_canonize(ASIdentifierChoice *choice)
 {
     ASN1_INTEGER *a_max_plus_one = NULL;
     ASN1_INTEGER *orig;
     BIGNUM *bn = NULL;
     int i, ret = 0;

     /*
      * Nothing to do for empty element or inheritance.
      */
     if (choice == NULL || choice->type == ASIdentifierChoice_inherit)
         return 1;

     /*
      * If not a list, or if empty list, it's broken.
      */
     if (choice->type != ASIdentifierChoice_asIdsOrRanges ||
         sk_ASIdOrRange_num(choice->u.asIdsOrRanges) == 0) {
         ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
         return 0;
     }

     /*
      * We have a non-empty list.  Sort it.
      */
     sk_ASIdOrRange_sort(choice->u.asIdsOrRanges);

     /*
      * Now check for errors and suboptimal encoding, rejecting the
      * former and fixing the latter.
      */
     for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1; i++) {
         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
         ASIdOrRange *b = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i + 1);
         ASN1_INTEGER *a_min = NULL, *a_max = NULL, *b_min = NULL, *b_max =
             NULL;

         if (!extract_min_max(a, &a_min, &a_max)
                 || !extract_min_max(b, &b_min, &b_max))
             goto done;

         /*
          * Make sure we're properly sorted (paranoia).
          */
         if (!ossl_assert(ASN1_INTEGER_cmp(a_min, b_min) <= 0))
             goto done;

         /*
          * Punt inverted ranges.
          */
         if (ASN1_INTEGER_cmp(a_min, a_max) > 0 ||
             ASN1_INTEGER_cmp(b_min, b_max) > 0)
             goto done;

         /*
          * Check for overlaps.
          */
         if (ASN1_INTEGER_cmp(a_max, b_min) >= 0) {
             ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
             goto done;
         }

         /*
          * Calculate a_max + 1 to check for adjacency.
          */
         if ((bn == NULL && (bn = BN_new()) == NULL) ||
             ASN1_INTEGER_to_BN(a_max, bn) == NULL ||
             !BN_add_word(bn, 1)) {
             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
             goto done;
         }

         if ((a_max_plus_one =
                  BN_to_ASN1_INTEGER(bn, orig = a_max_plus_one)) == NULL) {
             a_max_plus_one = orig;
             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
             goto done;
         }

         /*
          * If a and b are adjacent, merge them.
          */
         if (ASN1_INTEGER_cmp(a_max_plus_one, b_min) == 0) {
             ASRange *r;
             switch (a->type) {
             case ASIdOrRange_id:
                 if ((r = OPENSSL_malloc(sizeof(*r))) == NULL) {
                     ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
                     goto done;
                 }
                 r->min = a_min;
                 r->max = b_max;
                 a->type = ASIdOrRange_range;
                 a->u.range = r;
                 break;
             case ASIdOrRange_range:
                 ASN1_INTEGER_free(a->u.range->max);
                 a->u.range->max = b_max;
                 break;
             }
             switch (b->type) {
             case ASIdOrRange_id:
                 b->u.id = NULL;
                 break;
             case ASIdOrRange_range:
                 b->u.range->max = NULL;
                 break;
             }
             ASIdOrRange_free(b);
             (void)sk_ASIdOrRange_delete(choice->u.asIdsOrRanges, i + 1);
             i--;
             continue;
         }
     }

     /*
      * Check for final inverted range.
      */
     i = sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1;
     {
         ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
         ASN1_INTEGER *a_min, *a_max;
         if (a != NULL && a->type == ASIdOrRange_range) {
             if (!extract_min_max(a, &a_min, &a_max)
                     || ASN1_INTEGER_cmp(a_min, a_max) > 0)
                 goto done;
         }
     }

     /* Paranoia */
     if (!ossl_assert(ASIdentifierChoice_is_canonical(choice)))
         goto done;

     ret = 1;

  done:
     ASN1_INTEGER_free(a_max_plus_one);
     BN_free(bn);
     return ret;
 }

 /*
  * Whack an ASIdentifier extension into canonical form.
  */
 int X509v3_asid_canonize(ASIdentifiers *asid)
 {
     return (asid == NULL ||
             (ASIdentifierChoice_canonize(asid->asnum) &&
              ASIdentifierChoice_canonize(asid->rdi)));
 }

 /*
  * v2i method for an ASIdentifier extension.
  */
 static void *v2i_ASIdentifiers(const struct v3_ext_method *method,
                                struct v3_ext_ctx *ctx,
                                STACK_OF(CONF_VALUE) *values)
 {
     ASN1_INTEGER *min = NULL, *max = NULL;
     ASIdentifiers *asid = NULL;
     int i;

     if ((asid = ASIdentifiers_new()) == NULL) {
         ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
         return NULL;
     }

     for (i = 0; i < sk_CONF_VALUE_num(values); i++) {
         CONF_VALUE *val = sk_CONF_VALUE_value(values, i);
         int i1 = 0, i2 = 0, i3 = 0, is_range = 0, which = 0;

         /*
          * Figure out whether this is an AS or an RDI.
          */
         if (!ossl_v3_name_cmp(val->name, "AS")) {
             which = V3_ASID_ASNUM;
         } else if (!ossl_v3_name_cmp(val->name, "RDI")) {
             which = V3_ASID_RDI;
         } else {
             ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_NAME_ERROR);
             X509V3_conf_add_error_name_value(val);
             goto err;
         }

         /*
          * Handle inheritance.
          */
         if (strcmp(val->value, "inherit") == 0) {
             if (X509v3_asid_add_inherit(asid, which))
                 continue;
             ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_INHERITANCE);
             X509V3_conf_add_error_name_value(val);
             goto err;
         }

         /*
          * Number, range, or mistake, pick it apart and figure out which.
          */
         i1 = strspn(val->value, "0123456789");
         if (val->value[i1] == '\0') {
             is_range = 0;
         } else {
             is_range = 1;
             i2 = i1 + strspn(val->value + i1, " \t");
             if (val->value[i2] != '-') {
                 ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_ASNUMBER);
                 X509V3_conf_add_error_name_value(val);
                 goto err;
             }
             i2++;
             i2 = i2 + strspn(val->value + i2, " \t");
             i3 = i2 + strspn(val->value + i2, "0123456789");
             if (val->value[i3] != '\0') {
                 ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_ASRANGE);
                 X509V3_conf_add_error_name_value(val);
                 goto err;
             }
         }

         /*
          * Syntax is ok, read and add it.
          */
         if (!is_range) {
             if (!X509V3_get_value_int(val, &min)) {
                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
                 goto err;
             }
         } else {
             char *s = OPENSSL_strdup(val->value);
             if (s == NULL) {
                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
                 goto err;
             }
             s[i1] = '\0';
             min = s2i_ASN1_INTEGER(NULL, s);
             max = s2i_ASN1_INTEGER(NULL, s + i2);
             OPENSSL_free(s);
             if (min == NULL || max == NULL) {
                 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
                 goto err;
             }
             if (ASN1_INTEGER_cmp(min, max) > 0) {
                 ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
                 goto err;
             }
         }
         if (!X509v3_asid_add_id_or_range(asid, which, min, max)) {
             ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
             goto err;
         }
         min = max = NULL;
     }

     /*
      * Canonize the result, then we're done.
      */
     if (!X509v3_asid_canonize(asid))
         goto err;
     return asid;

  err:
     ASIdentifiers_free(asid);
     ASN1_INTEGER_free(min);
     ASN1_INTEGER_free(max);
     return NULL;
 }

 /*
  * OpenSSL dispatch.
  */
 const X509V3_EXT_METHOD ossl_v3_asid = {
     NID_sbgp_autonomousSysNum,  /* nid */
     0,                          /* flags */
     ASN1_ITEM_ref(ASIdentifiers), /* template */
     0, 0, 0, 0,                 /* old functions, ignored */
     0,                          /* i2s */
     0,                          /* s2i */
     0,                          /* i2v */
     v2i_ASIdentifiers,          /* v2i */
     i2r_ASIdentifiers,          /* i2r */
     0,                          /* r2i */
     NULL                        /* extension-specific data */
 };

 /*
  * Figure out whether extension uses inheritance.
  */
 int X509v3_asid_inherits(ASIdentifiers *asid)
 {
     return (asid != NULL &&
             ((asid->asnum != NULL &&
               asid->asnum->type == ASIdentifierChoice_inherit) ||
              (asid->rdi != NULL &&
               asid->rdi->type == ASIdentifierChoice_inherit)));
 }

 /*
  * Figure out whether parent contains child.
  */
 static int asid_contains(ASIdOrRanges *parent, ASIdOrRanges *child)
 {
     ASN1_INTEGER *p_min = NULL, *p_max = NULL, *c_min = NULL, *c_max = NULL;
     int p, c;

     if (child == NULL || parent == child)
         return 1;
     if (parent == NULL)
         return 0;

     p = 0;
     for (c = 0; c < sk_ASIdOrRange_num(child); c++) {
         if (!extract_min_max(sk_ASIdOrRange_value(child, c), &c_min, &c_max))
             return 0;
         for (;; p++) {
             if (p >= sk_ASIdOrRange_num(parent))
                 return 0;
             if (!extract_min_max(sk_ASIdOrRange_value(parent, p), &p_min,
                                  &p_max))
                 return 0;
             if (ASN1_INTEGER_cmp(p_max, c_max) < 0)
                 continue;
             if (ASN1_INTEGER_cmp(p_min, c_min) > 0)
                 return 0;
             break;
         }
     }

     return 1;
 }

 /*
  * Test whether a is a subset of b.
  */
 int X509v3_asid_subset(ASIdentifiers *a, ASIdentifiers *b)
 {
     return (a == NULL ||
             a == b ||
             (b != NULL &&
              !X509v3_asid_inherits(a) &&
              !X509v3_asid_inherits(b) &&
              asid_contains(b->asnum->u.asIdsOrRanges,
                            a->asnum->u.asIdsOrRanges) &&
              asid_contains(b->rdi->u.asIdsOrRanges,
                            a->rdi->u.asIdsOrRanges)));
 }

 /*
  * Validation error handling via callback.
  */
 #define validation_err(_err_)           \
   do {                                  \
     if (ctx != NULL) {                  \
       ctx->error = _err_;               \
       ctx->error_depth = i;             \
       ctx->current_cert = x;            \
       ret = ctx->verify_cb(0, ctx);     \
     } else {                            \
       ret = 0;                          \
     }                                   \
     if (!ret)                           \
       goto done;                        \
   } while (0)

 /*
  * Core code for RFC 3779 3.3 path validation.
  */
 static int asid_validate_path_internal(X509_STORE_CTX *ctx,
                                        STACK_OF(X509) *chain,
                                        ASIdentifiers *ext)
 {
     ASIdOrRanges *child_as = NULL, *child_rdi = NULL;
     int i, ret = 1, inherit_as = 0, inherit_rdi = 0;
     X509 *x;

     if (!ossl_assert(chain != NULL && sk_X509_num(chain) > 0)
             || !ossl_assert(ctx != NULL || ext != NULL)
             || !ossl_assert(ctx == NULL || ctx->verify_cb != NULL)) {
         if (ctx != NULL)
             ctx->error = X509_V_ERR_UNSPECIFIED;
         return 0;
     }


     /*
      * Figure out where to start.  If we don't have an extension to
      * check, we're done.  Otherwise, check canonical form and
      * set up for walking up the chain.
      */
     if (ext != NULL) {
         i = -1;
         x = NULL;
     } else {
         i = 0;
         x = sk_X509_value(chain, i);
         if ((ext = x->rfc3779_asid) == NULL)
             goto done;
     }
     if (!X509v3_asid_is_canonical(ext))
         validation_err(X509_V_ERR_INVALID_EXTENSION);
     if (ext->asnum != NULL) {
         switch (ext->asnum->type) {
         case ASIdentifierChoice_inherit:
             inherit_as = 1;
             break;
         case ASIdentifierChoice_asIdsOrRanges:
             child_as = ext->asnum->u.asIdsOrRanges;
             break;
         }
     }
     if (ext->rdi != NULL) {
         switch (ext->rdi->type) {
         case ASIdentifierChoice_inherit:
             inherit_rdi = 1;
             break;
         case ASIdentifierChoice_asIdsOrRanges:
             child_rdi = ext->rdi->u.asIdsOrRanges;
             break;
         }
     }

     /*
      * Now walk up the chain.  Extensions must be in canonical form, no
      * cert may list resources that its parent doesn't list.
      */
     for (i++; i < sk_X509_num(chain); i++) {
         x = sk_X509_value(chain, i);
         if (!ossl_assert(x != NULL)) {
             if (ctx != NULL)
                 ctx->error = X509_V_ERR_UNSPECIFIED;
             return 0;
         }
         if (x->rfc3779_asid == NULL) {
             if (child_as != NULL || child_rdi != NULL)
                 validation_err(X509_V_ERR_UNNESTED_RESOURCE);
             continue;
         }
         if (!X509v3_asid_is_canonical(x->rfc3779_asid))
             validation_err(X509_V_ERR_INVALID_EXTENSION);
         if (x->rfc3779_asid->asnum == NULL && child_as != NULL) {
             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
             child_as = NULL;
             inherit_as = 0;
         }
         if (x->rfc3779_asid->asnum != NULL &&
             x->rfc3779_asid->asnum->type ==
             ASIdentifierChoice_asIdsOrRanges) {
             if (inherit_as
                 || asid_contains(x->rfc3779_asid->asnum->u.asIdsOrRanges,
                                  child_as)) {
                 child_as = x->rfc3779_asid->asnum->u.asIdsOrRanges;
                 inherit_as = 0;
             } else {
                 validation_err(X509_V_ERR_UNNESTED_RESOURCE);
             }
         }
         if (x->rfc3779_asid->rdi == NULL && child_rdi != NULL) {
             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
             child_rdi = NULL;
             inherit_rdi = 0;
         }
         if (x->rfc3779_asid->rdi != NULL &&
             x->rfc3779_asid->rdi->type == ASIdentifierChoice_asIdsOrRanges) {
             if (inherit_rdi ||
                 asid_contains(x->rfc3779_asid->rdi->u.asIdsOrRanges,
                               child_rdi)) {
                 child_rdi = x->rfc3779_asid->rdi->u.asIdsOrRanges;
                 inherit_rdi = 0;
             } else {
                 validation_err(X509_V_ERR_UNNESTED_RESOURCE);
             }
         }
     }

     /*
      * Trust anchor can't inherit.
      */
     if (!ossl_assert(x != NULL)) {
         if (ctx != NULL)
             ctx->error = X509_V_ERR_UNSPECIFIED;
         return 0;
     }
     if (x->rfc3779_asid != NULL) {
         if (x->rfc3779_asid->asnum != NULL &&
             x->rfc3779_asid->asnum->type == ASIdentifierChoice_inherit)
             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
         if (x->rfc3779_asid->rdi != NULL &&
             x->rfc3779_asid->rdi->type == ASIdentifierChoice_inherit)
             validation_err(X509_V_ERR_UNNESTED_RESOURCE);
     }

  done:
     return ret;
 }

 #undef validation_err

 /*
  * RFC 3779 3.3 path validation -- called from X509_verify_cert().
  */
 int X509v3_asid_validate_path(X509_STORE_CTX *ctx)
 {
     if (ctx->chain == NULL
             || sk_X509_num(ctx->chain) == 0
             || ctx->verify_cb == NULL) {
         ctx->error = X509_V_ERR_UNSPECIFIED;
         return 0;
     }
     return asid_validate_path_internal(ctx, ctx->chain, NULL);
 }

 /*
  * RFC 3779 3.3 path validation of an extension.
  * Test whether chain covers extension.
  */
 int X509v3_asid_validate_resource_set(STACK_OF(X509) *chain,
                                       ASIdentifiers *ext, int allow_inheritance)
 {
     if (ext == NULL)
         return 1;
     if (chain == NULL || sk_X509_num(chain) == 0)
         return 0;
     if (!allow_inheritance && X509v3_asid_inherits(ext))
         return 0;
     return asid_validate_path_internal(NULL, chain, ext);
 }

 #endif                          /* OPENSSL_NO_RFC3779 */
	/*
	* Copyright 2006-2021 The OpenSSL Project Authors. All Rights Reserved.
	*
	* Licensed under the Apache License 2.0 (the "License"). You may not use
	* this file except in compliance with the License. You can obtain a copy
	* in the file LICENSE in the source distribution or at
	* https://www.openssl.org/source/license.html
	*/

	/*
	* Implementation of RFC 3779 section 3.2.
	*/

	#include <assert.h>
	#include <stdio.h>
	#include <string.h>
	#include "internal/cryptlib.h"
	#include <openssl/conf.h>
	#include <openssl/asn1.h>
	#include <openssl/asn1t.h>
	#include <openssl/x509v3.h>
	#include <openssl/x509.h>
	#include "crypto/x509.h"
	#include <openssl/bn.h>
	#include "ext_dat.h"
	#include "x509_local.h"

	#ifndef OPENSSL_NO_RFC3779

	/*
	* OpenSSL ASN.1 template translation of RFC 3779 3.2.3.
	*/

	ASN1_SEQUENCE(ASRange) = {
	ASN1_SIMPLE(ASRange, min, ASN1_INTEGER),
	ASN1_SIMPLE(ASRange, max, ASN1_INTEGER)
	} ASN1_SEQUENCE_END(ASRange)

	ASN1_CHOICE(ASIdOrRange) = {
	ASN1_SIMPLE(ASIdOrRange, u.id, ASN1_INTEGER),
	ASN1_SIMPLE(ASIdOrRange, u.range, ASRange)
	} ASN1_CHOICE_END(ASIdOrRange)

	ASN1_CHOICE(ASIdentifierChoice) = {
	ASN1_SIMPLE(ASIdentifierChoice, u.inherit, ASN1_NULL),
	ASN1_SEQUENCE_OF(ASIdentifierChoice, u.asIdsOrRanges, ASIdOrRange)
	} ASN1_CHOICE_END(ASIdentifierChoice)

	ASN1_SEQUENCE(ASIdentifiers) = {
	ASN1_EXP_OPT(ASIdentifiers, asnum, ASIdentifierChoice, 0),
	ASN1_EXP_OPT(ASIdentifiers, rdi, ASIdentifierChoice, 1)
	} ASN1_SEQUENCE_END(ASIdentifiers)

	IMPLEMENT_ASN1_FUNCTIONS(ASRange)
	IMPLEMENT_ASN1_FUNCTIONS(ASIdOrRange)
	IMPLEMENT_ASN1_FUNCTIONS(ASIdentifierChoice)
	IMPLEMENT_ASN1_FUNCTIONS(ASIdentifiers)

	/*
	* i2r method for an ASIdentifierChoice.
	*/
	static int i2r_ASIdentifierChoice(BIO *out,
	ASIdentifierChoice *choice,
	int indent, const char *msg)
	{
	int i;
	char *s;
	if (choice == NULL)
	return 1;
	BIO_printf(out, "%*s%s:\n", indent, "", msg);
	switch (choice->type) {
	case ASIdentifierChoice_inherit:
	BIO_printf(out, "%*sinherit\n", indent + 2, "");
	break;
	case ASIdentifierChoice_asIdsOrRanges:
	for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges); i++) {
	ASIdOrRange *aor =
	sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
	switch (aor->type) {
	case ASIdOrRange_id:
	if ((s = i2s_ASN1_INTEGER(NULL, aor->u.id)) == NULL)
	return 0;
	BIO_printf(out, "%*s%s\n", indent + 2, "", s);
	OPENSSL_free(s);
	break;
	case ASIdOrRange_range:
	if ((s = i2s_ASN1_INTEGER(NULL, aor->u.range->min)) == NULL)
	return 0;
	BIO_printf(out, "%*s%s-", indent + 2, "", s);
	OPENSSL_free(s);
	if ((s = i2s_ASN1_INTEGER(NULL, aor->u.range->max)) == NULL)
	return 0;
	BIO_printf(out, "%s\n", s);
	OPENSSL_free(s);
	break;
	default:
	return 0;
	}
	}
	break;
	default:
	return 0;
	}
	return 1;
	}

	/*
	* i2r method for an ASIdentifier extension.
	*/
	static int i2r_ASIdentifiers(const X509V3_EXT_METHOD *method,
	void ext, BIO out, int indent)
	{
	ASIdentifiers *asid = ext;
	return (i2r_ASIdentifierChoice(out, asid->asnum, indent,
	"Autonomous System Numbers") &&
	i2r_ASIdentifierChoice(out, asid->rdi, indent,
	"Routing Domain Identifiers"));
	}

	/*
	* Sort comparison function for a sequence of ASIdOrRange elements.
	*/
	static int ASIdOrRange_cmp(const ASIdOrRange const a_,
	const ASIdOrRange const b_)
	{
	const ASIdOrRange a = a_, b = b_;

	assert((a->type == ASIdOrRange_id && a->u.id != NULL) \|\|
	(a->type == ASIdOrRange_range && a->u.range != NULL &&
	a->u.range->min != NULL && a->u.range->max != NULL));

	assert((b->type == ASIdOrRange_id && b->u.id != NULL) \|\|
	(b->type == ASIdOrRange_range && b->u.range != NULL &&
	b->u.range->min != NULL && b->u.range->max != NULL));

	if (a->type == ASIdOrRange_id && b->type == ASIdOrRange_id)
	return ASN1_INTEGER_cmp(a->u.id, b->u.id);

	if (a->type == ASIdOrRange_range && b->type == ASIdOrRange_range) {
	int r = ASN1_INTEGER_cmp(a->u.range->min, b->u.range->min);
	return r != 0 ? r : ASN1_INTEGER_cmp(a->u.range->max,
	b->u.range->max);
	}

	if (a->type == ASIdOrRange_id)
	return ASN1_INTEGER_cmp(a->u.id, b->u.range->min);
	else
	return ASN1_INTEGER_cmp(a->u.range->min, b->u.id);
	}

	/*
	* Add an inherit element.
	*/
	int X509v3_asid_add_inherit(ASIdentifiers *asid, int which)
	{
	ASIdentifierChoice **choice;
	if (asid == NULL)
	return 0;
	switch (which) {
	case V3_ASID_ASNUM:
	choice = &asid->asnum;
	break;
	case V3_ASID_RDI:
	choice = &asid->rdi;
	break;
	default:
	return 0;
	}
	if (*choice == NULL) {
	if ((*choice = ASIdentifierChoice_new()) == NULL)
	return 0;
	if (((*choice)->u.inherit = ASN1_NULL_new()) == NULL)
	return 0;
	(*choice)->type = ASIdentifierChoice_inherit;
	}
	return (*choice)->type == ASIdentifierChoice_inherit;
	}

	/*
	* Add an ID or range to an ASIdentifierChoice.
	*/
	int X509v3_asid_add_id_or_range(ASIdentifiers *asid,
	int which, ASN1_INTEGER min, ASN1_INTEGER max)
	{
	ASIdentifierChoice **choice;
	ASIdOrRange *aor;
	if (asid == NULL)
	return 0;
	switch (which) {
	case V3_ASID_ASNUM:
	choice = &asid->asnum;
	break;
	case V3_ASID_RDI:
	choice = &asid->rdi;
	break;
	default:
	return 0;
	}
	if (choice != NULL && (choice)->type == ASIdentifierChoice_inherit)
	return 0;
	if (*choice == NULL) {
	if ((*choice = ASIdentifierChoice_new()) == NULL)
	return 0;
	(*choice)->u.asIdsOrRanges = sk_ASIdOrRange_new(ASIdOrRange_cmp);
	if ((*choice)->u.asIdsOrRanges == NULL)
	return 0;
	(*choice)->type = ASIdentifierChoice_asIdsOrRanges;
	}
	if ((aor = ASIdOrRange_new()) == NULL)
	return 0;
	if (max == NULL) {
	aor->type = ASIdOrRange_id;
	aor->u.id = min;
	} else {
	aor->type = ASIdOrRange_range;
	if ((aor->u.range = ASRange_new()) == NULL)
	goto err;
	ASN1_INTEGER_free(aor->u.range->min);
	aor->u.range->min = min;
	ASN1_INTEGER_free(aor->u.range->max);
	aor->u.range->max = max;
	}
	if (!(sk_ASIdOrRange_push((*choice)->u.asIdsOrRanges, aor)))
	goto err;
	return 1;

	err:
	ASIdOrRange_free(aor);
	return 0;
	}

	/*
	* Extract min and max values from an ASIdOrRange.
	*/
	static int extract_min_max(ASIdOrRange *aor,
	ASN1_INTEGER min, ASN1_INTEGER max)
	{
	if (!ossl_assert(aor != NULL))
	return 0;
	switch (aor->type) {
	case ASIdOrRange_id:
	*min = aor->u.id;
	*max = aor->u.id;
	return 1;
	case ASIdOrRange_range:
	*min = aor->u.range->min;
	*max = aor->u.range->max;
	return 1;
	}

	return 0;
	}

	/*
	* Check whether an ASIdentifierChoice is in canonical form.
	*/
	static int ASIdentifierChoice_is_canonical(ASIdentifierChoice *choice)
	{
	ASN1_INTEGER *a_max_plus_one = NULL;
	ASN1_INTEGER *orig;
	BIGNUM *bn = NULL;
	int i, ret = 0;

	/*
	* Empty element or inheritance is canonical.
	*/
	if (choice == NULL \|\| choice->type == ASIdentifierChoice_inherit)
	return 1;

	/*
	* If not a list, or if empty list, it's broken.
	*/
	if (choice->type != ASIdentifierChoice_asIdsOrRanges \|\|
	sk_ASIdOrRange_num(choice->u.asIdsOrRanges) == 0)
	return 0;

	/*
	* It's a list, check it.
	*/
	for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1; i++) {
	ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
	ASIdOrRange *b = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i + 1);
	ASN1_INTEGER a_min = NULL, a_max = NULL, b_min = NULL, b_max =
	NULL;

	if (!extract_min_max(a, &a_min, &a_max)
	\|\| !extract_min_max(b, &b_min, &b_max))
	goto done;

	/*
	* Punt misordered list, overlapping start, or inverted range.
	*/
	if (ASN1_INTEGER_cmp(a_min, b_min) >= 0 \|\|
	ASN1_INTEGER_cmp(a_min, a_max) > 0 \|\|
	ASN1_INTEGER_cmp(b_min, b_max) > 0)
	goto done;

	/*
	* Calculate a_max + 1 to check for adjacency.
	*/
	if ((bn == NULL && (bn = BN_new()) == NULL) \|\|
	ASN1_INTEGER_to_BN(a_max, bn) == NULL \|\|
	!BN_add_word(bn, 1)) {
	ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
	goto done;
	}

	if ((a_max_plus_one =
	BN_to_ASN1_INTEGER(bn, orig = a_max_plus_one)) == NULL) {
	a_max_plus_one = orig;
	ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
	goto done;
	}

	/*
	* Punt if adjacent or overlapping.
	*/
	if (ASN1_INTEGER_cmp(a_max_plus_one, b_min) >= 0)
	goto done;
	}

	/*
	* Check for inverted range.
	*/
	i = sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1;
	{
	ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
	ASN1_INTEGER a_min, a_max;
	if (a != NULL && a->type == ASIdOrRange_range) {
	if (!extract_min_max(a, &a_min, &a_max)
	\|\| ASN1_INTEGER_cmp(a_min, a_max) > 0)
	goto done;
	}
	}

	ret = 1;

	done:
	ASN1_INTEGER_free(a_max_plus_one);
	BN_free(bn);
	return ret;
	}

	/*
	* Check whether an ASIdentifier extension is in canonical form.
	*/
	int X509v3_asid_is_canonical(ASIdentifiers *asid)
	{
	return (asid == NULL \|\|
	(ASIdentifierChoice_is_canonical(asid->asnum) &&
	ASIdentifierChoice_is_canonical(asid->rdi)));
	}

	/*
	* Whack an ASIdentifierChoice into canonical form.
	*/
	static int ASIdentifierChoice_canonize(ASIdentifierChoice *choice)
	{
	ASN1_INTEGER *a_max_plus_one = NULL;
	ASN1_INTEGER *orig;
	BIGNUM *bn = NULL;
	int i, ret = 0;

	/*
	* Nothing to do for empty element or inheritance.
	*/
	if (choice == NULL \|\| choice->type == ASIdentifierChoice_inherit)
	return 1;

	/*
	* If not a list, or if empty list, it's broken.
	*/
	if (choice->type != ASIdentifierChoice_asIdsOrRanges \|\|
	sk_ASIdOrRange_num(choice->u.asIdsOrRanges) == 0) {
	ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
	return 0;
	}

	/*
	* We have a non-empty list. Sort it.
	*/
	sk_ASIdOrRange_sort(choice->u.asIdsOrRanges);

	/*
	* Now check for errors and suboptimal encoding, rejecting the
	* former and fixing the latter.
	*/
	for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1; i++) {
	ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
	ASIdOrRange *b = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i + 1);
	ASN1_INTEGER a_min = NULL, a_max = NULL, b_min = NULL, b_max =
	NULL;

	if (!extract_min_max(a, &a_min, &a_max)
	\|\| !extract_min_max(b, &b_min, &b_max))
	goto done;

	/*
	* Make sure we're properly sorted (paranoia).
	*/
	if (!ossl_assert(ASN1_INTEGER_cmp(a_min, b_min) <= 0))
	goto done;

	/*
	* Punt inverted ranges.
	*/
	if (ASN1_INTEGER_cmp(a_min, a_max) > 0 \|\|
	ASN1_INTEGER_cmp(b_min, b_max) > 0)
	goto done;

	/*
	* Check for overlaps.
	*/
	if (ASN1_INTEGER_cmp(a_max, b_min) >= 0) {
	ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
	goto done;
	}

	/*
	* Calculate a_max + 1 to check for adjacency.
	*/
	if ((bn == NULL && (bn = BN_new()) == NULL) \|\|
	ASN1_INTEGER_to_BN(a_max, bn) == NULL \|\|
	!BN_add_word(bn, 1)) {
	ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
	goto done;
	}

	if ((a_max_plus_one =
	BN_to_ASN1_INTEGER(bn, orig = a_max_plus_one)) == NULL) {
	a_max_plus_one = orig;
	ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
	goto done;
	}

	/*
	* If a and b are adjacent, merge them.
	*/
	if (ASN1_INTEGER_cmp(a_max_plus_one, b_min) == 0) {
	ASRange *r;
	switch (a->type) {
	case ASIdOrRange_id:
	if ((r = OPENSSL_malloc(sizeof(*r))) == NULL) {
	ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
	goto done;
	}
	r->min = a_min;
	r->max = b_max;
	a->type = ASIdOrRange_range;
	a->u.range = r;
	break;
	case ASIdOrRange_range:
	ASN1_INTEGER_free(a->u.range->max);
	a->u.range->max = b_max;
	break;
	}
	switch (b->type) {
	case ASIdOrRange_id:
	b->u.id = NULL;
	break;
	case ASIdOrRange_range:
	b->u.range->max = NULL;
	break;
	}
	ASIdOrRange_free(b);
	(void)sk_ASIdOrRange_delete(choice->u.asIdsOrRanges, i + 1);
	i--;
	continue;
	}
	}

	/*
	* Check for final inverted range.
	*/
	i = sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1;
	{
	ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);
	ASN1_INTEGER a_min, a_max;
	if (a != NULL && a->type == ASIdOrRange_range) {
	if (!extract_min_max(a, &a_min, &a_max)
	\|\| ASN1_INTEGER_cmp(a_min, a_max) > 0)
	goto done;
	}
	}

	/* Paranoia */
	if (!ossl_assert(ASIdentifierChoice_is_canonical(choice)))
	goto done;

	ret = 1;

	done:
	ASN1_INTEGER_free(a_max_plus_one);
	BN_free(bn);
	return ret;
	}

	/*
	* Whack an ASIdentifier extension into canonical form.
	*/
	int X509v3_asid_canonize(ASIdentifiers *asid)
	{
	return (asid == NULL \|\|
	(ASIdentifierChoice_canonize(asid->asnum) &&
	ASIdentifierChoice_canonize(asid->rdi)));
	}

	/*
	* v2i method for an ASIdentifier extension.
	*/
	static void v2i_ASIdentifiers(const struct v3_ext_method method,
	struct v3_ext_ctx *ctx,
	STACK_OF(CONF_VALUE) *values)
	{
	ASN1_INTEGER min = NULL, max = NULL;
	ASIdentifiers *asid = NULL;
	int i;

	if ((asid = ASIdentifiers_new()) == NULL) {
	ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
	return NULL;
	}

	for (i = 0; i < sk_CONF_VALUE_num(values); i++) {
	CONF_VALUE *val = sk_CONF_VALUE_value(values, i);
	int i1 = 0, i2 = 0, i3 = 0, is_range = 0, which = 0;

	/*
	* Figure out whether this is an AS or an RDI.
	*/
	if (!ossl_v3_name_cmp(val->name, "AS")) {
	which = V3_ASID_ASNUM;
	} else if (!ossl_v3_name_cmp(val->name, "RDI")) {
	which = V3_ASID_RDI;
	} else {
	ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_NAME_ERROR);
	X509V3_conf_add_error_name_value(val);
	goto err;
	}

	/*
	* Handle inheritance.
	*/
	if (strcmp(val->value, "inherit") == 0) {
	if (X509v3_asid_add_inherit(asid, which))
	continue;
	ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_INHERITANCE);
	X509V3_conf_add_error_name_value(val);
	goto err;
	}

	/*
	* Number, range, or mistake, pick it apart and figure out which.
	*/
	i1 = strspn(val->value, "0123456789");
	if (val->value[i1] == '\0') {
	is_range = 0;
	} else {
	is_range = 1;
	i2 = i1 + strspn(val->value + i1, " \t");
	if (val->value[i2] != '-') {
	ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_ASNUMBER);
	X509V3_conf_add_error_name_value(val);
	goto err;
	}
	i2++;
	i2 = i2 + strspn(val->value + i2, " \t");
	i3 = i2 + strspn(val->value + i2, "0123456789");
	if (val->value[i3] != '\0') {
	ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_ASRANGE);
	X509V3_conf_add_error_name_value(val);
	goto err;
	}
	}

	/*
	* Syntax is ok, read and add it.
	*/
	if (!is_range) {
	if (!X509V3_get_value_int(val, &min)) {
	ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
	goto err;
	}
	} else {
	char *s = OPENSSL_strdup(val->value);
	if (s == NULL) {
	ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
	goto err;
	}
	s[i1] = '\0';
	min = s2i_ASN1_INTEGER(NULL, s);
	max = s2i_ASN1_INTEGER(NULL, s + i2);
	OPENSSL_free(s);
	if (min == NULL \|\| max == NULL) {
	ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
	goto err;
	}
	if (ASN1_INTEGER_cmp(min, max) > 0) {
	ERR_raise(ERR_LIB_X509V3, X509V3_R_EXTENSION_VALUE_ERROR);
	goto err;
	}
	}
	if (!X509v3_asid_add_id_or_range(asid, which, min, max)) {
	ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
	goto err;
	}
	min = max = NULL;
	}

	/*
	* Canonize the result, then we're done.
	*/
	if (!X509v3_asid_canonize(asid))
	goto err;
	return asid;

	err:
	ASIdentifiers_free(asid);
	ASN1_INTEGER_free(min);
	ASN1_INTEGER_free(max);
	return NULL;
	}

	/*
	* OpenSSL dispatch.
	*/
	const X509V3_EXT_METHOD ossl_v3_asid = {
	NID_sbgp_autonomousSysNum, /* nid */
	0, /* flags */
	ASN1_ITEM_ref(ASIdentifiers), /* template */
	0, 0, 0, 0, /* old functions, ignored */
	0, /* i2s */
	0, /* s2i */
	0, /* i2v */
	v2i_ASIdentifiers, /* v2i */
	i2r_ASIdentifiers, /* i2r */
	0, /* r2i */
	NULL /* extension-specific data */
	};

	/*
	* Figure out whether extension uses inheritance.
	*/
	int X509v3_asid_inherits(ASIdentifiers *asid)
	{
	return (asid != NULL &&
	((asid->asnum != NULL &&
	asid->asnum->type == ASIdentifierChoice_inherit) \|\|
	(asid->rdi != NULL &&
	asid->rdi->type == ASIdentifierChoice_inherit)));
	}

	/*
	* Figure out whether parent contains child.
	*/
	static int asid_contains(ASIdOrRanges parent, ASIdOrRanges child)
	{
	ASN1_INTEGER p_min = NULL, p_max = NULL, c_min = NULL, c_max = NULL;
	int p, c;

	if (child == NULL \|\| parent == child)
	return 1;
	if (parent == NULL)
	return 0;

	p = 0;
	for (c = 0; c < sk_ASIdOrRange_num(child); c++) {
	if (!extract_min_max(sk_ASIdOrRange_value(child, c), &c_min, &c_max))
	return 0;
	for (;; p++) {
	if (p >= sk_ASIdOrRange_num(parent))
	return 0;
	if (!extract_min_max(sk_ASIdOrRange_value(parent, p), &p_min,
	&p_max))
	return 0;
	if (ASN1_INTEGER_cmp(p_max, c_max) < 0)
	continue;
	if (ASN1_INTEGER_cmp(p_min, c_min) > 0)
	return 0;
	break;
	}
	}

	return 1;
	}

	/*
	* Test whether a is a subset of b.
	*/
	int X509v3_asid_subset(ASIdentifiers a, ASIdentifiers b)
	{
	return (a == NULL \|\|
	a == b \|\|
	(b != NULL &&
	!X509v3_asid_inherits(a) &&
	!X509v3_asid_inherits(b) &&
	asid_contains(b->asnum->u.asIdsOrRanges,
	a->asnum->u.asIdsOrRanges) &&
	asid_contains(b->rdi->u.asIdsOrRanges,
	a->rdi->u.asIdsOrRanges)));
	}

	/*
	* Validation error handling via callback.
	*/
	#define validation_err(_err_) \
	do { \
	if (ctx != NULL) { \
	ctx->error = _err_; \
	ctx->error_depth = i; \
	ctx->current_cert = x; \
	ret = ctx->verify_cb(0, ctx); \
	} else { \
	ret = 0; \
	} \
	if (!ret) \
	goto done; \
	} while (0)

	/*
	* Core code for RFC 3779 3.3 path validation.
	*/
	static int asid_validate_path_internal(X509_STORE_CTX *ctx,
	STACK_OF(X509) *chain,
	ASIdentifiers *ext)
	{
	ASIdOrRanges child_as = NULL, child_rdi = NULL;
	int i, ret = 1, inherit_as = 0, inherit_rdi = 0;
	X509 *x;

	if (!ossl_assert(chain != NULL && sk_X509_num(chain) > 0)
	\|\| !ossl_assert(ctx != NULL \|\| ext != NULL)
	\|\| !ossl_assert(ctx == NULL \|\| ctx->verify_cb != NULL)) {
	if (ctx != NULL)
	ctx->error = X509_V_ERR_UNSPECIFIED;
	return 0;
	}


	/*
	* Figure out where to start. If we don't have an extension to
	* check, we're done. Otherwise, check canonical form and
	* set up for walking up the chain.
	*/
	if (ext != NULL) {
	i = -1;
	x = NULL;
	} else {
	i = 0;
	x = sk_X509_value(chain, i);
	if ((ext = x->rfc3779_asid) == NULL)
	goto done;
	}
	if (!X509v3_asid_is_canonical(ext))
	validation_err(X509_V_ERR_INVALID_EXTENSION);
	if (ext->asnum != NULL) {
	switch (ext->asnum->type) {
	case ASIdentifierChoice_inherit:
	inherit_as = 1;
	break;
	case ASIdentifierChoice_asIdsOrRanges:
	child_as = ext->asnum->u.asIdsOrRanges;
	break;
	}
	}
	if (ext->rdi != NULL) {
	switch (ext->rdi->type) {
	case ASIdentifierChoice_inherit:
	inherit_rdi = 1;
	break;
	case ASIdentifierChoice_asIdsOrRanges:
	child_rdi = ext->rdi->u.asIdsOrRanges;
	break;
	}
	}

	/*
	* Now walk up the chain. Extensions must be in canonical form, no
	* cert may list resources that its parent doesn't list.
	*/
	for (i++; i < sk_X509_num(chain); i++) {
	x = sk_X509_value(chain, i);
	if (!ossl_assert(x != NULL)) {
	if (ctx != NULL)
	ctx->error = X509_V_ERR_UNSPECIFIED;
	return 0;
	}
	if (x->rfc3779_asid == NULL) {
	if (child_as != NULL \|\| child_rdi != NULL)
	validation_err(X509_V_ERR_UNNESTED_RESOURCE);
	continue;
	}
	if (!X509v3_asid_is_canonical(x->rfc3779_asid))
	validation_err(X509_V_ERR_INVALID_EXTENSION);
	if (x->rfc3779_asid->asnum == NULL && child_as != NULL) {
	validation_err(X509_V_ERR_UNNESTED_RESOURCE);
	child_as = NULL;
	inherit_as = 0;
	}
	if (x->rfc3779_asid->asnum != NULL &&
	x->rfc3779_asid->asnum->type ==
	ASIdentifierChoice_asIdsOrRanges) {
	if (inherit_as
	\|\| asid_contains(x->rfc3779_asid->asnum->u.asIdsOrRanges,
	child_as)) {
	child_as = x->rfc3779_asid->asnum->u.asIdsOrRanges;
	inherit_as = 0;
	} else {
	validation_err(X509_V_ERR_UNNESTED_RESOURCE);
	}
	}
	if (x->rfc3779_asid->rdi == NULL && child_rdi != NULL) {
	validation_err(X509_V_ERR_UNNESTED_RESOURCE);
	child_rdi = NULL;
	inherit_rdi = 0;
	}
	if (x->rfc3779_asid->rdi != NULL &&
	x->rfc3779_asid->rdi->type == ASIdentifierChoice_asIdsOrRanges) {
	if (inherit_rdi \|\|
	asid_contains(x->rfc3779_asid->rdi->u.asIdsOrRanges,
	child_rdi)) {
	child_rdi = x->rfc3779_asid->rdi->u.asIdsOrRanges;
	inherit_rdi = 0;
	} else {
	validation_err(X509_V_ERR_UNNESTED_RESOURCE);
	}
	}
	}

	/*
	* Trust anchor can't inherit.
	*/
	if (!ossl_assert(x != NULL)) {
	if (ctx != NULL)
	ctx->error = X509_V_ERR_UNSPECIFIED;
	return 0;
	}
	if (x->rfc3779_asid != NULL) {
	if (x->rfc3779_asid->asnum != NULL &&
	x->rfc3779_asid->asnum->type == ASIdentifierChoice_inherit)
	validation_err(X509_V_ERR_UNNESTED_RESOURCE);
	if (x->rfc3779_asid->rdi != NULL &&
	x->rfc3779_asid->rdi->type == ASIdentifierChoice_inherit)
	validation_err(X509_V_ERR_UNNESTED_RESOURCE);
	}

	done:
	return ret;
	}

	#undef validation_err

	/*
	* RFC 3779 3.3 path validation -- called from X509_verify_cert().
	*/
	int X509v3_asid_validate_path(X509_STORE_CTX *ctx)
	{
	if (ctx->chain == NULL
	\|\| sk_X509_num(ctx->chain) == 0
	\|\| ctx->verify_cb == NULL) {
	ctx->error = X509_V_ERR_UNSPECIFIED;
	return 0;
	}
	return asid_validate_path_internal(ctx, ctx->chain, NULL);
	}

	/*
	* RFC 3779 3.3 path validation of an extension.
	* Test whether chain covers extension.
	*/
	int X509v3_asid_validate_resource_set(STACK_OF(X509) *chain,
	ASIdentifiers *ext, int allow_inheritance)
	{
	if (ext == NULL)
	return 1;
	if (chain == NULL \|\| sk_X509_num(chain) == 0)
	return 0;
	if (!allow_inheritance && X509v3_asid_inherits(ext))
	return 0;
	return asid_validate_path_internal(NULL, chain, ext);
	}

	#endif /* OPENSSL_NO_RFC3779 */