text: /* crypto/engine/eng_lib.c */
  /*
   * Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL project
   * 2000.
   */
  /* ====================================================================
   * Copyright (c) 1999-2001 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).
   *
   */
  
  #include "eng_int.h"
  #include <openssl/rand.h>
  
  /* The "new"/"free" stuff first */
  
  ENGINE *ENGINE_new(void)
  {
      ENGINE *ret;
  
      ret = (ENGINE *)OPENSSL_malloc(sizeof(ENGINE));
      if (ret == NULL) {
          ENGINEerr(ENGINE_F_ENGINE_NEW, ERR_R_MALLOC_FAILURE);
          return NULL;
      }
      memset(ret, 0, sizeof(ENGINE));
      ret->struct_ref = 1;
      engine_ref_debug(ret, 0, 1)
          CRYPTO_new_ex_data(CRYPTO_EX_INDEX_ENGINE, ret, &ret->ex_data);
      return ret;
  }
  
  /*
   * Placed here (close proximity to ENGINE_new) so that modifications to the
   * elements of the ENGINE structure are more likely to be caught and changed
   * here.
   */
  void engine_set_all_null(ENGINE *e)
  {
      e->id = NULL;
      e->name = NULL;
      e->rsa_meth = NULL;
      e->dsa_meth = NULL;
      e->dh_meth = NULL;
      e->rand_meth = NULL;
      e->store_meth = NULL;
      e->ciphers = NULL;
      e->digests = NULL;
      e->destroy = NULL;
      e->init = NULL;
      e->finish = NULL;
      e->ctrl = NULL;
      e->load_privkey = NULL;
      e->load_pubkey = NULL;
      e->cmd_defns = NULL;
      e->flags = 0;
  }
  
  int engine_free_util(ENGINE *e, int locked)
  {
      int i;
  
      if (e == NULL) {
          ENGINEerr(ENGINE_F_ENGINE_FREE_UTIL, ERR_R_PASSED_NULL_PARAMETER);
          return 0;
      }
      if (locked)
          i = CRYPTO_add(&e->struct_ref, -1, CRYPTO_LOCK_ENGINE);
      else
          i = --e->struct_ref;
      engine_ref_debug(e, 0, -1)
          if (i > 0)
          return 1;
  #ifdef REF_CHECK
      if (i < 0) {
          fprintf(stderr, "ENGINE_free, bad structural reference count\n");
          abort();
      }
  #endif
      /* Free up any dynamically allocated public key methods */
      engine_pkey_meths_free(e);
      engine_pkey_asn1_meths_free(e);
      /*
       * Give the ENGINE a chance to do any structural cleanup corresponding to
       * allocation it did in its constructor (eg. unload error strings)
       */
      if (e->destroy)
          e->destroy(e);
      CRYPTO_free_ex_data(CRYPTO_EX_INDEX_ENGINE, e, &e->ex_data);
      OPENSSL_free(e);
      return 1;
  }
  
  int ENGINE_free(ENGINE *e)
  {
      return engine_free_util(e, 1);
  }
  
  /* Cleanup stuff */
  
  /*
   * ENGINE_cleanup() is coded such that anything that does work that will need
   * cleanup can register a "cleanup" callback here. That way we don't get
   * linker bloat by referring to all *possible* cleanups, but any linker bloat
   * into code "X" will cause X's cleanup function to end up here.
   */
  static STACK_OF(ENGINE_CLEANUP_ITEM) *cleanup_stack = NULL;
  static int int_cleanup_check(int create)
  {
      if (cleanup_stack)
          return 1;
      if (!create)
          return 0;
      cleanup_stack = sk_ENGINE_CLEANUP_ITEM_new_null();
      return (cleanup_stack ? 1 : 0);
  }
  
  static ENGINE_CLEANUP_ITEM *int_cleanup_item(ENGINE_CLEANUP_CB *cb)
  {
      ENGINE_CLEANUP_ITEM *item = OPENSSL_malloc(sizeof(ENGINE_CLEANUP_ITEM));
      if (!item)
          return NULL;
      item->cb = cb;
      return item;
  }
  
  void engine_cleanup_add_first(ENGINE_CLEANUP_CB *cb)
  {
      ENGINE_CLEANUP_ITEM *item;
      if (!int_cleanup_check(1))
          return;
      item = int_cleanup_item(cb);
      if (item)
          sk_ENGINE_CLEANUP_ITEM_insert(cleanup_stack, item, 0);
  }
  
  void engine_cleanup_add_last(ENGINE_CLEANUP_CB *cb)
  {
      ENGINE_CLEANUP_ITEM *item;
      if (!int_cleanup_check(1))
          return;
      item = int_cleanup_item(cb);
      if (item != NULL) {
          if (sk_ENGINE_CLEANUP_ITEM_push(cleanup_stack, item) <= 0)
              OPENSSL_free(item);
      }
  }
  
  /* The API function that performs all cleanup */
  static void engine_cleanup_cb_free(ENGINE_CLEANUP_ITEM *item)
  {
      (*(item->cb)) ();
      OPENSSL_free(item);
  }
  
  void ENGINE_cleanup(void)
  {
      if (int_cleanup_check(0)) {
          sk_ENGINE_CLEANUP_ITEM_pop_free(cleanup_stack,
                                          engine_cleanup_cb_free);
          cleanup_stack = NULL;
      }
      /*
       * FIXME: This should be handled (somehow) through RAND, eg. by it
       * registering a cleanup callback.
       */
      RAND_set_rand_method(NULL);
  }
  
  /* Now the "ex_data" support */
  
  int ENGINE_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
                              CRYPTO_EX_dup *dup_func,
                              CRYPTO_EX_free *free_func)
  {
      return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_ENGINE, argl, argp,
                                     new_func, dup_func, free_func);
  }
  
  int ENGINE_set_ex_data(ENGINE *e, int idx, void *arg)
  {
      return (CRYPTO_set_ex_data(&e->ex_data, idx, arg));
  }
  
  void *ENGINE_get_ex_data(const ENGINE *e, int idx)
  {
      return (CRYPTO_get_ex_data(&e->ex_data, idx));
  }
  
  /*
   * Functions to get/set an ENGINE's elements - mainly to avoid exposing the
   * ENGINE structure itself.
   */
  
  int ENGINE_set_id(ENGINE *e, const char *id)
  {
      if (id == NULL) {
          ENGINEerr(ENGINE_F_ENGINE_SET_ID, ERR_R_PASSED_NULL_PARAMETER);
          return 0;
      }
      e->id = id;
      return 1;
  }
  
  int ENGINE_set_name(ENGINE *e, const char *name)
  {
      if (name == NULL) {
          ENGINEerr(ENGINE_F_ENGINE_SET_NAME, ERR_R_PASSED_NULL_PARAMETER);
          return 0;
      }
      e->name = name;
      return 1;
  }
  
  int ENGINE_set_destroy_function(ENGINE *e, ENGINE_GEN_INT_FUNC_PTR destroy_f)
  {
      e->destroy = destroy_f;
      return 1;
  }
  
  int ENGINE_set_init_function(ENGINE *e, ENGINE_GEN_INT_FUNC_PTR init_f)
  {
      e->init = init_f;
      return 1;
  }
  
  int ENGINE_set_finish_function(ENGINE *e, ENGINE_GEN_INT_FUNC_PTR finish_f)
  {
      e->finish = finish_f;
      return 1;
  }
  
  int ENGINE_set_ctrl_function(ENGINE *e, ENGINE_CTRL_FUNC_PTR ctrl_f)
  {
      e->ctrl = ctrl_f;
      return 1;
  }
  
  int ENGINE_set_flags(ENGINE *e, int flags)
  {
      e->flags = flags;
      return 1;
  }
  
  int ENGINE_set_cmd_defns(ENGINE *e, const ENGINE_CMD_DEFN *defns)
  {
      e->cmd_defns = defns;
      return 1;
  }
  
  const char *ENGINE_get_id(const ENGINE *e)
  {
      return e->id;
  }
  
  const char *ENGINE_get_name(const ENGINE *e)
  {
      return e->name;
  }
  
  ENGINE_GEN_INT_FUNC_PTR ENGINE_get_destroy_function(const ENGINE *e)
  {
      return e->destroy;
  }
  
  ENGINE_GEN_INT_FUNC_PTR ENGINE_get_init_function(const ENGINE *e)
  {
      return e->init;
  }
  
  ENGINE_GEN_INT_FUNC_PTR ENGINE_get_finish_function(const ENGINE *e)
  {
      return e->finish;
  }
  
  ENGINE_CTRL_FUNC_PTR ENGINE_get_ctrl_function(const ENGINE *e)
  {
      return e->ctrl;
  }
  
  int ENGINE_get_flags(const ENGINE *e)
  {
      return e->flags;
  }
  
  const ENGINE_CMD_DEFN *ENGINE_get_cmd_defns(const ENGINE *e)
  {
      return e->cmd_defns;
  }
  
  /*
   * eng_lib.o is pretty much linked into anything that touches ENGINE already,
   * so put the "static_state" hack here.
   */
  
  static int internal_static_hack = 0;
  
  void *ENGINE_get_static_state(void)
  {
      return &internal_static_hack;
  }
  