1 /*
2 * Copyright 2001-2017 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (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 #include "e_os.h"
11 #include "eng_local.h"
12
13 /*
14 * Initialise a engine type for use (or up its functional reference count if
15 * it's already in use). This version is only used internally.
16 */
engine_unlocked_init(ENGINE * e)17 int engine_unlocked_init(ENGINE *e)
18 {
19 int to_return = 1;
20
21 if ((e->funct_ref == 0) && e->init)
22 /*
23 * This is the first functional reference and the engine requires
24 * initialisation so we do it now.
25 */
26 to_return = e->init(e);
27 if (to_return) {
28 /*
29 * OK, we return a functional reference which is also a structural
30 * reference.
31 */
32 e->struct_ref++;
33 e->funct_ref++;
34 engine_ref_debug(e, 0, 1);
35 engine_ref_debug(e, 1, 1);
36 }
37 return to_return;
38 }
39
40 /*
41 * Free a functional reference to a engine type. This version is only used
42 * internally.
43 */
engine_unlocked_finish(ENGINE * e,int unlock_for_handlers)44 int engine_unlocked_finish(ENGINE *e, int unlock_for_handlers)
45 {
46 int to_return = 1;
47
48 /*
49 * Reduce the functional reference count here so if it's the terminating
50 * case, we can release the lock safely and call the finish() handler
51 * without risk of a race. We get a race if we leave the count until
52 * after and something else is calling "finish" at the same time -
53 * there's a chance that both threads will together take the count from 2
54 * to 0 without either calling finish().
55 */
56 e->funct_ref--;
57 engine_ref_debug(e, 1, -1);
58 if ((e->funct_ref == 0) && e->finish) {
59 if (unlock_for_handlers)
60 CRYPTO_THREAD_unlock(global_engine_lock);
61 to_return = e->finish(e);
62 if (unlock_for_handlers)
63 CRYPTO_THREAD_write_lock(global_engine_lock);
64 if (!to_return)
65 return 0;
66 }
67 REF_ASSERT_ISNT(e->funct_ref < 0);
68 /* Release the structural reference too */
69 if (!engine_free_util(e, 0)) {
70 ENGINEerr(ENGINE_F_ENGINE_UNLOCKED_FINISH, ENGINE_R_FINISH_FAILED);
71 return 0;
72 }
73 return to_return;
74 }
75
76 /* The API (locked) version of "init" */
ENGINE_init(ENGINE * e)77 int ENGINE_init(ENGINE *e)
78 {
79 int ret;
80 if (e == NULL) {
81 ENGINEerr(ENGINE_F_ENGINE_INIT, ERR_R_PASSED_NULL_PARAMETER);
82 return 0;
83 }
84 if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
85 ENGINEerr(ENGINE_F_ENGINE_INIT, ERR_R_MALLOC_FAILURE);
86 return 0;
87 }
88 CRYPTO_THREAD_write_lock(global_engine_lock);
89 ret = engine_unlocked_init(e);
90 CRYPTO_THREAD_unlock(global_engine_lock);
91 return ret;
92 }
93
94 /* The API (locked) version of "finish" */
ENGINE_finish(ENGINE * e)95 int ENGINE_finish(ENGINE *e)
96 {
97 int to_return = 1;
98
99 if (e == NULL)
100 return 1;
101 CRYPTO_THREAD_write_lock(global_engine_lock);
102 to_return = engine_unlocked_finish(e, 1);
103 CRYPTO_THREAD_unlock(global_engine_lock);
104 if (!to_return) {
105 ENGINEerr(ENGINE_F_ENGINE_FINISH, ENGINE_R_FINISH_FAILED);
106 return 0;
107 }
108 return to_return;
109 }
110