1 /* $OpenBSD: eng_init.c,v 1.9 2018/04/14 07:09:21 tb Exp $ */
2 /* ====================================================================
3  * Copyright (c) 1999-2001 The OpenSSL Project.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in
14  *    the documentation and/or other materials provided with the
15  *    distribution.
16  *
17  * 3. All advertising materials mentioning features or use of this
18  *    software must display the following acknowledgment:
19  *    "This product includes software developed by the OpenSSL Project
20  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
21  *
22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23  *    endorse or promote products derived from this software without
24  *    prior written permission. For written permission, please contact
25  *    licensing@OpenSSL.org.
26  *
27  * 5. Products derived from this software may not be called "OpenSSL"
28  *    nor may "OpenSSL" appear in their names without prior written
29  *    permission of the OpenSSL Project.
30  *
31  * 6. Redistributions of any form whatsoever must retain the following
32  *    acknowledgment:
33  *    "This product includes software developed by the OpenSSL Project
34  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
35  *
36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47  * OF THE POSSIBILITY OF SUCH DAMAGE.
48  * ====================================================================
49  *
50  * This product includes cryptographic software written by Eric Young
51  * (eay@cryptsoft.com).  This product includes software written by Tim
52  * Hudson (tjh@cryptsoft.com).
53  *
54  */
55 
56 #include <openssl/err.h>
57 
58 #include "eng_int.h"
59 
60 /* Initialise a engine type for use (or up its functional reference count
61  * if it's already in use). This version is only used internally. */
62 int
engine_unlocked_init(ENGINE * e)63 engine_unlocked_init(ENGINE *e)
64 {
65 	int to_return = 1;
66 
67 	if ((e->funct_ref == 0) && e->init)
68 		/* This is the first functional reference and the engine
69 		 * requires initialisation so we do it now. */
70 		to_return = e->init(e);
71 	if (to_return) {
72 		/* OK, we return a functional reference which is also a
73 		 * structural reference. */
74 		e->struct_ref++;
75 		e->funct_ref++;
76 		engine_ref_debug(e, 0, 1)
77 		engine_ref_debug(e, 1, 1)
78 	}
79 	return to_return;
80 }
81 
82 /* Free a functional reference to a engine type. This version is only used
83  * internally. */
84 int
engine_unlocked_finish(ENGINE * e,int unlock_for_handlers)85 engine_unlocked_finish(ENGINE *e, int unlock_for_handlers)
86 {
87 	int to_return = 1;
88 
89 	/* Reduce the functional reference count here so if it's the terminating
90 	 * case, we can release the lock safely and call the finish() handler
91 	 * without risk of a race. We get a race if we leave the count until
92 	 * after and something else is calling "finish" at the same time -
93 	 * there's a chance that both threads will together take the count from
94 	 * 2 to 0 without either calling finish(). */
95 	e->funct_ref--;
96 	engine_ref_debug(e, 1, -1);
97 	if ((e->funct_ref == 0) && e->finish) {
98 		if (unlock_for_handlers)
99 			CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
100 		to_return = e->finish(e);
101 		if (unlock_for_handlers)
102 			CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
103 		if (!to_return)
104 			return 0;
105 	}
106 
107 	/* Release the structural reference too */
108 	if (!engine_free_util(e, 0)) {
109 		ENGINEerror(ENGINE_R_FINISH_FAILED);
110 		return 0;
111 	}
112 	return to_return;
113 }
114 
115 /* The API (locked) version of "init" */
116 int
ENGINE_init(ENGINE * e)117 ENGINE_init(ENGINE *e)
118 {
119 	int ret;
120 
121 	if (e == NULL) {
122 		ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
123 		return 0;
124 	}
125 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
126 	ret = engine_unlocked_init(e);
127 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
128 	return ret;
129 }
130 
131 /* The API (locked) version of "finish" */
132 int
ENGINE_finish(ENGINE * e)133 ENGINE_finish(ENGINE *e)
134 {
135 	int to_return = 1;
136 
137 	if (e == NULL)
138 		return 1;
139 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
140 	to_return = engine_unlocked_finish(e, 1);
141 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
142 	if (!to_return) {
143 		ENGINEerror(ENGINE_R_FINISH_FAILED);
144 		return 0;
145 	}
146 	return to_return;
147 }
148