crypto/engine/eng_init.c

   1 /*
   2  * Copyright 2001-2020 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /* We need to use some engine deprecated APIs */
  11 #define OPENSSL_SUPPRESS_DEPRECATED
  12
  13 #include "e_os.h"
  14 #include "eng_local.h"
  15
  16 /*
  17  * Initialise a engine type for use (or up its functional reference count if
  18  * it's already in use). This version is only used internally.
  19  */
  20 int engine_unlocked_init(ENGINE *e)
  21 {
  22     int to_return = 1;
  23
  24     if ((e->funct_ref == 0) && e->init)
  25         /*
  26          * This is the first functional reference and the engine requires
  27          * initialisation so we do it now.
  28          */
  29         to_return = e->init(e);
  30     if (to_return) {
  31         /*
  32          * OK, we return a functional reference which is also a structural
  33          * reference.
  34          */
  35         e->struct_ref++;
  36         e->funct_ref++;
  37         engine_ref_debug(e, 0, 1);
  38         engine_ref_debug(e, 1, 1);
  39     }
  40     return to_return;
  41 }
  42
  43 /*
  44  * Free a functional reference to a engine type. This version is only used
  45  * internally.
  46  */
  47 int engine_unlocked_finish(ENGINE *e, int unlock_for_handlers)
  48 {
  49     int to_return = 1;
  50
  51     /*
  52      * Reduce the functional reference count here so if it's the terminating
  53      * case, we can release the lock safely and call the finish() handler
  54      * without risk of a race. We get a race if we leave the count until
  55      * after and something else is calling "finish" at the same time -
  56      * there's a chance that both threads will together take the count from 2
  57      * to 0 without either calling finish().
  58      */
  59     e->funct_ref--;
  60     engine_ref_debug(e, 1, -1);
  61     if ((e->funct_ref == 0) && e->finish) {
  62         if (unlock_for_handlers)
  63             CRYPTO_THREAD_unlock(global_engine_lock);
  64         to_return = e->finish(e);
  65         if (unlock_for_handlers)
  66             CRYPTO_THREAD_write_lock(global_engine_lock);
  67         if (!to_return)
  68             return 0;
  69     }
  70     REF_ASSERT_ISNT(e->funct_ref < 0);
  71     /* Release the structural reference too */
  72     if (!engine_free_util(e, 0)) {
  73         ERR_raise(ERR_LIB_ENGINE, ENGINE_R_FINISH_FAILED);
  74         return 0;
  75     }
  76     return to_return;
  77 }
  78
  79 /* The API (locked) version of "init" */
  80 int ENGINE_init(ENGINE *e)
  81 {
  82     int ret;
  83     if (e == NULL) {
  84         ERR_raise(ERR_LIB_ENGINE, ERR_R_PASSED_NULL_PARAMETER);
  85         return 0;
  86     }
  87     if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
  88         ERR_raise(ERR_LIB_ENGINE, ERR_R_MALLOC_FAILURE);
  89         return 0;
  90     }
  91     CRYPTO_THREAD_write_lock(global_engine_lock);
  92     ret = engine_unlocked_init(e);
  93     CRYPTO_THREAD_unlock(global_engine_lock);
  94     return ret;
  95 }
  96
  97 /* The API (locked) version of "finish" */
  98 int ENGINE_finish(ENGINE *e)
  99 {
 100     int to_return = 1;
 101
 102     if (e == NULL)
 103         return 1;
 104     CRYPTO_THREAD_write_lock(global_engine_lock);
 105     to_return = engine_unlocked_finish(e, 1);
 106     CRYPTO_THREAD_unlock(global_engine_lock);
 107     if (!to_return) {
 108         ERR_raise(ERR_LIB_ENGINE, ENGINE_R_FINISH_FAILED);
 109         return 0;
 110     }
 111     return to_return;
 112 }