text: /*
   * 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 "internal/cryptlib.h"
  #include <openssl/conf.h>
  #include <openssl/x509v3.h>
  
  #include "ext_dat.h"
  
  static STACK_OF(X509V3_EXT_METHOD) *ext_list = NULL;
  
  static int ext_cmp(const X509V3_EXT_METHOD *const *a,
                     const X509V3_EXT_METHOD *const *b);
  static void ext_list_free(X509V3_EXT_METHOD *ext);
  
  int X509V3_EXT_add(X509V3_EXT_METHOD *ext)
  {
      if (ext_list == NULL
          && (ext_list = sk_X509V3_EXT_METHOD_new(ext_cmp)) == NULL) {
          X509V3err(X509V3_F_X509V3_EXT_ADD, ERR_R_MALLOC_FAILURE);
          return 0;
      }
      if (!sk_X509V3_EXT_METHOD_push(ext_list, ext)) {
          X509V3err(X509V3_F_X509V3_EXT_ADD, ERR_R_MALLOC_FAILURE);
          return 0;
      }
      return 1;
  }
  
  static int ext_cmp(const X509V3_EXT_METHOD *const *a,
                     const X509V3_EXT_METHOD *const *b)
  {
      return ((*a)->ext_nid - (*b)->ext_nid);
  }
  
  DECLARE_OBJ_BSEARCH_CMP_FN(const X509V3_EXT_METHOD *,
                             const X509V3_EXT_METHOD *, ext);
  IMPLEMENT_OBJ_BSEARCH_CMP_FN(const X509V3_EXT_METHOD *,
                               const X509V3_EXT_METHOD *, ext);
  
  /*
   * This table will be searched using OBJ_bsearch so it *must* kept in order
   * of the ext_nid values.
   */
  
  static const X509V3_EXT_METHOD *standard_exts[] = {
      &v3_nscert,
      &v3_ns_ia5_list[0],
      &v3_ns_ia5_list[1],
      &v3_ns_ia5_list[2],
      &v3_ns_ia5_list[3],
      &v3_ns_ia5_list[4],
      &v3_ns_ia5_list[5],
      &v3_ns_ia5_list[6],
      &v3_skey_id,
      &v3_key_usage,
      &v3_pkey_usage_period,
      &v3_alt[0],
      &v3_alt[1],
      &v3_bcons,
      &v3_crl_num,
      &v3_cpols,
      &v3_akey_id,
      &v3_crld,
      &v3_ext_ku,
      &v3_delta_crl,
      &v3_crl_reason,
  #ifndef OPENSSL_NO_OCSP
      &v3_crl_invdate,
  #endif
      &v3_sxnet,
      &v3_info,
  #ifndef OPENSSL_NO_RFC3779
      &v3_addr,
      &v3_asid,
  #endif
  #ifndef OPENSSL_NO_OCSP
      &v3_ocsp_nonce,
      &v3_ocsp_crlid,
      &v3_ocsp_accresp,
      &v3_ocsp_nocheck,
      &v3_ocsp_acutoff,
      &v3_ocsp_serviceloc,
  #endif
      &v3_sinfo,
      &v3_policy_constraints,
  #ifndef OPENSSL_NO_OCSP
      &v3_crl_hold,
  #endif
      &v3_pci,
      &v3_name_constraints,
      &v3_policy_mappings,
      &v3_inhibit_anyp,
      &v3_idp,
      &v3_alt[2],
      &v3_freshest_crl,
  #ifndef OPENSSL_NO_CT
      &v3_ct_scts[0],
      &v3_ct_scts[1],
      &v3_ct_scts[2],
  #endif
      &v3_tls_feature,
  };
  
  /* Number of standard extensions */
  
  #define STANDARD_EXTENSION_COUNT OSSL_NELEM(standard_exts)
  
  const X509V3_EXT_METHOD *X509V3_EXT_get_nid(int nid)
  {
      X509V3_EXT_METHOD tmp;
      const X509V3_EXT_METHOD *t = &tmp, *const *ret;
      int idx;
      if (nid < 0)
          return NULL;
      tmp.ext_nid = nid;
      ret = OBJ_bsearch_ext(&t, standard_exts, STANDARD_EXTENSION_COUNT);
      if (ret)
          return *ret;
      if (!ext_list)
          return NULL;
      idx = sk_X509V3_EXT_METHOD_find(ext_list, &tmp);
      if (idx == -1)
          return NULL;
      return sk_X509V3_EXT_METHOD_value(ext_list, idx);
  }
  
  const X509V3_EXT_METHOD *X509V3_EXT_get(X509_EXTENSION *ext)
  {
      int nid;
      if ((nid = OBJ_obj2nid(X509_EXTENSION_get_object(ext))) == NID_undef)
          return NULL;
      return X509V3_EXT_get_nid(nid);
  }
  
  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)) == NULL) {
          X509V3err(X509V3_F_X509V3_EXT_ADD_ALIAS, X509V3_R_EXTENSION_NOT_FOUND);
          return 0;
      }
      if ((tmpext = OPENSSL_malloc(sizeof(*tmpext))) == NULL) {
          X509V3err(X509V3_F_X509V3_EXT_ADD_ALIAS, 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(X509_EXTENSION *ext)
  {
      const X509V3_EXT_METHOD *method;
      const unsigned char *p;
      ASN1_STRING *extvalue;
      int extlen;
  
      if ((method = X509V3_EXT_get(ext)) == NULL)
          return NULL;
      extvalue = X509_EXTENSION_get_data(ext);
      p = ASN1_STRING_data(extvalue);
      extlen = ASN1_STRING_length(extvalue);
      if (method->it)
          return ASN1_item_d2i(NULL, &p, extlen, ASN1_ITEM_ptr(method->it));
      return method->d2i(NULL, &p, extlen);
  }
  
  /*-
   * Get critical flag and decoded version of extension from a NID.
   * The "idx" variable returns the last found extension and can
   * be used to retrieve multiple extensions of the same NID.
   * However multiple extensions with the same NID is usually
   * due to a badly encoded certificate so if idx is NULL we
   * choke if multiple extensions exist.
   * The "crit" variable is set to the critical value.
   * The return value is the decoded extension or NULL on
   * error. The actual error can have several different causes,
   * the value of *crit reflects the cause:
   * >= 0, extension found but not decoded (reflects critical value).
   * -1 extension not found.
   * -2 extension occurs more than once.
   */
  
  void *X509V3_get_d2i(STACK_OF(X509_EXTENSION) *x, int nid, int *crit,
                       int *idx)
  {
      int lastpos, i;
      X509_EXTENSION *ex, *found_ex = NULL;
      if (!x) {
          if (idx)
              *idx = -1;
          if (crit)
              *crit = -1;
          return NULL;
      }
      if (idx)
          lastpos = *idx + 1;
      else
          lastpos = 0;
      if (lastpos < 0)
          lastpos = 0;
      for (i = lastpos; i < sk_X509_EXTENSION_num(x); i++) {
          ex = sk_X509_EXTENSION_value(x, i);
          if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) == nid) {
              if (idx) {
                  *idx = i;
                  found_ex = ex;
                  break;
              } else if (found_ex) {
                  /* Found more than one */
                  if (crit)
                      *crit = -2;
                  return NULL;
              }
              found_ex = ex;
          }
      }
      if (found_ex) {
          /* Found it */
          if (crit)
              *crit = X509_EXTENSION_get_critical(found_ex);
          return X509V3_EXT_d2i(found_ex);
      }
  
      /* Extension not found */
      if (idx)
          *idx = -1;
      if (crit)
          *crit = -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 extidx = -1;
      int errcode;
      X509_EXTENSION *ext, *extmp;
      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) {
          X509V3err(X509V3_F_X509V3_ADD1_I2D,
                    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 (*x == NULL
          && (*x = sk_X509_EXTENSION_new_null()) == NULL)
          return -1;
      if (!sk_X509_EXTENSION_push(*x, ext))
          return -1;
  
      return 1;
  
   err:
      if (!(flags & X509V3_ADD_SILENT))
          X509V3err(X509V3_F_X509V3_ADD1_I2D, errcode);
      return 0;
  }
  