text: /* v3_lib.c */
  /*
   * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
   * 1999.
   */
  /* ====================================================================
   * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. All advertising materials mentioning features or use of this
   *    software must display the following acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
   *
   * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
   *    endorse or promote products derived from this software without
   *    prior written permission. For written permission, please contact
   *    licensing@OpenSSL.org.
   *
   * 5. Products derived from this software may not be called "OpenSSL"
   *    nor may "OpenSSL" appear in their names without prior written
   *    permission of the OpenSSL Project.
   *
   * 6. Redistributions of any form whatsoever must retain the following
   *    acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
   *
   * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
   * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
   * OF THE POSSIBILITY OF SUCH DAMAGE.
   * ====================================================================
   *
   * This product includes cryptographic software written by Eric Young
   * (eay@cryptsoft.com).  This product includes software written by Tim
   * Hudson (tjh@cryptsoft.com).
   *
   */
  /* X509 v3 extension utilities */
  
  #include <stdio.h>
  
  #include <CNIOBoringSSL_conf.h>
  #include <CNIOBoringSSL_err.h>
  #include <CNIOBoringSSL_mem.h>
  #include <CNIOBoringSSL_obj.h>
  #include <CNIOBoringSSL_x509v3.h>
  
  #include "../x509/internal.h"
  
  #include "ext_dat.h"
  static STACK_OF(X509V3_EXT_METHOD) *ext_list = NULL;
  
  static void ext_list_free(X509V3_EXT_METHOD *ext);
  
  static int ext_stack_cmp(const X509V3_EXT_METHOD **a,
                           const X509V3_EXT_METHOD **b)
  {
      return ((*a)->ext_nid - (*b)->ext_nid);
  }
  
  int X509V3_EXT_add(X509V3_EXT_METHOD *ext)
  {
      if (!ext_list && !(ext_list = sk_X509V3_EXT_METHOD_new(ext_stack_cmp))) {
          OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
          ext_list_free(ext);
          return 0;
      }
      if (!sk_X509V3_EXT_METHOD_push(ext_list, ext)) {
          OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
          ext_list_free(ext);
          return 0;
      }
      return 1;
  }
  
  static int ext_cmp(const void *void_a, const void *void_b)
  {
      const X509V3_EXT_METHOD **a = (const X509V3_EXT_METHOD **)void_a;
      const X509V3_EXT_METHOD **b = (const X509V3_EXT_METHOD **)void_b;
      return ext_stack_cmp(a, b);
  }
  
  const X509V3_EXT_METHOD *X509V3_EXT_get_nid(int nid)
  {
      X509V3_EXT_METHOD tmp;
      const X509V3_EXT_METHOD *t = &tmp, *const *ret;
      size_t idx;
  
      if (nid < 0)
          return NULL;
      tmp.ext_nid = nid;
      ret =
          bsearch(&t, standard_exts, STANDARD_EXTENSION_COUNT,
                  sizeof(X509V3_EXT_METHOD *), ext_cmp);
      if (ret)
          return *ret;
      if (!ext_list)
          return NULL;
  
      sk_X509V3_EXT_METHOD_sort(ext_list);
      if (!sk_X509V3_EXT_METHOD_find(ext_list, &idx, &tmp))
          return NULL;
      return sk_X509V3_EXT_METHOD_value(ext_list, idx);
  }
  
  const X509V3_EXT_METHOD *X509V3_EXT_get(const X509_EXTENSION *ext)
  {
      int nid;
      if ((nid = OBJ_obj2nid(ext->object)) == NID_undef)
          return NULL;
      return X509V3_EXT_get_nid(nid);
  }
  
  int X509V3_EXT_free(int nid, void *ext_data)
  {
      const X509V3_EXT_METHOD *ext_method = X509V3_EXT_get_nid(nid);
      if (ext_method == NULL) {
          OPENSSL_PUT_ERROR(X509V3, X509V3_R_CANNOT_FIND_FREE_FUNCTION);
          return 0;
      }
  
      if (ext_method->it != NULL)
          ASN1_item_free(ext_data, ASN1_ITEM_ptr(ext_method->it));
      else if (ext_method->ext_free != NULL)
          ext_method->ext_free(ext_data);
      else {
          OPENSSL_PUT_ERROR(X509V3, X509V3_R_CANNOT_FIND_FREE_FUNCTION);
          return 0;
      }
  
      return 1;
  }
  
  int X509V3_EXT_add_list(X509V3_EXT_METHOD *extlist)
  {
      for (; extlist->ext_nid != -1; extlist++)
          if (!X509V3_EXT_add(extlist))
              return 0;
      return 1;
  }
  
  int X509V3_EXT_add_alias(int nid_to, int nid_from)
  {
      const X509V3_EXT_METHOD *ext;
      X509V3_EXT_METHOD *tmpext;
  
      if (!(ext = X509V3_EXT_get_nid(nid_from))) {
          OPENSSL_PUT_ERROR(X509V3, X509V3_R_EXTENSION_NOT_FOUND);
          return 0;
      }
      if (!
          (tmpext =
           (X509V3_EXT_METHOD *)OPENSSL_malloc(sizeof(X509V3_EXT_METHOD)))) {
          OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
          return 0;
      }
      *tmpext = *ext;
      tmpext->ext_nid = nid_to;
      tmpext->ext_flags |= X509V3_EXT_DYNAMIC;
      return X509V3_EXT_add(tmpext);
  }
  
  void X509V3_EXT_cleanup(void)
  {
      sk_X509V3_EXT_METHOD_pop_free(ext_list, ext_list_free);
      ext_list = NULL;
  }
  
  static void ext_list_free(X509V3_EXT_METHOD *ext)
  {
      if (ext->ext_flags & X509V3_EXT_DYNAMIC)
          OPENSSL_free(ext);
  }
  
  /*
   * Legacy function: we don't need to add standard extensions any more because
   * they are now kept in ext_dat.h.
   */
  
  int X509V3_add_standard_extensions(void)
  {
      return 1;
  }
  
  /* Return an extension internal structure */
  
  void *X509V3_EXT_d2i(const X509_EXTENSION *ext)
  {
      const X509V3_EXT_METHOD *method;
      const unsigned char *p;
  
      if (!(method = X509V3_EXT_get(ext)))
          return NULL;
      p = ext->value->data;
      void *ret;
      if (method->it) {
          ret = ASN1_item_d2i(NULL, &p, ext->value->length,
                              ASN1_ITEM_ptr(method->it));
      } else {
          ret = method->d2i(NULL, &p, ext->value->length);
      }
      if (ret == NULL) {
          return NULL;
      }
      /* Check for trailing data. */
      if (p != ext->value->data + ext->value->length) {
          if (method->it) {
              ASN1_item_free(ret, ASN1_ITEM_ptr(method->it));
          } else {
              method->ext_free(ret);
          }
          OPENSSL_PUT_ERROR(X509V3, X509V3_R_TRAILING_DATA_IN_EXTENSION);
          return NULL;
      }
      return ret;
  }
  
  void *X509V3_get_d2i(const STACK_OF(X509_EXTENSION) *extensions, int nid,
                       int *out_critical, int *out_idx)
  {
      int lastpos;
      size_t i;
      X509_EXTENSION *ex, *found_ex = NULL;
      if (!extensions) {
          if (out_idx)
              *out_idx = -1;
          if (out_critical)
              *out_critical = -1;
          return NULL;
      }
      if (out_idx)
          lastpos = *out_idx + 1;
      else
          lastpos = 0;
      if (lastpos < 0)
          lastpos = 0;
      for (i = lastpos; i < sk_X509_EXTENSION_num(extensions); i++) {
          ex = sk_X509_EXTENSION_value(extensions, i);
          if (OBJ_obj2nid(ex->object) == nid) {
              if (out_idx) {
                  /* TODO(https://crbug.com/boringssl/379): Consistently reject
                   * duplicate extensions. */
                  *out_idx = i;
                  found_ex = ex;
                  break;
              } else if (found_ex) {
                  /* Found more than one */
                  if (out_critical)
                      *out_critical = -2;
                  return NULL;
              }
              found_ex = ex;
          }
      }
      if (found_ex) {
          /* Found it */
          if (out_critical)
              *out_critical = X509_EXTENSION_get_critical(found_ex);
          return X509V3_EXT_d2i(found_ex);
      }
  
      /* Extension not found */
      if (out_idx)
          *out_idx = -1;
      if (out_critical)
          *out_critical = -1;
      return NULL;
  }
  
  /*
   * This function is a general extension append, replace and delete utility.
   * The precise operation is governed by the 'flags' value. The 'crit' and
   * 'value' arguments (if relevant) are the extensions internal structure.
   */
  
  int X509V3_add1_i2d(STACK_OF(X509_EXTENSION) **x, int nid, void *value,
                      int crit, unsigned long flags)
  {
      int errcode, extidx = -1;
      X509_EXTENSION *ext = NULL, *extmp;
      STACK_OF(X509_EXTENSION) *ret = NULL;
      unsigned long ext_op = flags & X509V3_ADD_OP_MASK;
  
      /*
       * If appending we don't care if it exists, otherwise look for existing
       * extension.
       */
      if (ext_op != X509V3_ADD_APPEND)
          extidx = X509v3_get_ext_by_NID(*x, nid, -1);
  
      /* See if extension exists */
      if (extidx >= 0) {
          /* If keep existing, nothing to do */
          if (ext_op == X509V3_ADD_KEEP_EXISTING)
              return 1;
          /* If default then its an error */
          if (ext_op == X509V3_ADD_DEFAULT) {
              errcode = X509V3_R_EXTENSION_EXISTS;
              goto err;
          }
          /* If delete, just delete it */
          if (ext_op == X509V3_ADD_DELETE) {
              if (!sk_X509_EXTENSION_delete(*x, extidx))
                  return -1;
              return 1;
          }
      } else {
          /*
           * If replace existing or delete, error since extension must exist
           */
          if ((ext_op == X509V3_ADD_REPLACE_EXISTING) ||
              (ext_op == X509V3_ADD_DELETE)) {
              errcode = X509V3_R_EXTENSION_NOT_FOUND;
              goto err;
          }
      }
  
      /*
       * If we get this far then we have to create an extension: could have
       * some flags for alternative encoding schemes...
       */
  
      ext = X509V3_EXT_i2d(nid, crit, value);
  
      if (!ext) {
          OPENSSL_PUT_ERROR(X509V3, X509V3_R_ERROR_CREATING_EXTENSION);
          return 0;
      }
  
      /* If extension exists replace it.. */
      if (extidx >= 0) {
          extmp = sk_X509_EXTENSION_value(*x, extidx);
          X509_EXTENSION_free(extmp);
          if (!sk_X509_EXTENSION_set(*x, extidx, ext))
              return -1;
          return 1;
      }
  
      if ((ret = *x) == NULL
           && (ret = sk_X509_EXTENSION_new_null()) == NULL)
          goto m_fail;
      if (!sk_X509_EXTENSION_push(ret, ext))
          goto m_fail;
  
      *x = ret;
      return 1;
  
   m_fail:
      if (ret != *x)
          sk_X509_EXTENSION_free(ret);
      X509_EXTENSION_free(ext);
      return -1;
  
   err:
      if (!(flags & X509V3_ADD_SILENT))
          OPENSSL_PUT_ERROR(X509V3, errcode);
      return 0;
  }
  