2 * Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
5 * Licensed under the OpenSSL license (the "License"). You may not use
6 * this file except in compliance with the License. You can obtain a copy
7 * in the file LICENSE in the source distribution or at
8 * https://www.openssl.org/source/license.html
14 * The linked-list of pointers to engine types. engine_list_head incorporates
15 * an implicit structural reference but engine_list_tail does not - the
16 * latter is a computational optimization and only points to something that
17 * is already pointed to by its predecessor in the list (or engine_list_head
18 * itself). In the same way, the use of the "prev" pointer in each ENGINE is
19 * to save excessive list iteration, it doesn't correspond to an extra
20 * structural reference. Hence, engine_list_head, and each non-null "next"
21 * pointer account for the list itself assuming exactly 1 structural
22 * reference on each list member.
24 static ENGINE *engine_list_head = NULL;
25 static ENGINE *engine_list_tail = NULL;
28 * This cleanup function is only needed internally. If it should be called,
29 * we register it with the "engine_cleanup_int()" stack to be called during
33 static void engine_list_cleanup(void)
35 ENGINE *iterator = engine_list_head;
37 while (iterator != NULL) {
38 ENGINE_remove(iterator);
39 iterator = engine_list_head;
45 * These static functions starting with a lower case "engine_" always take
46 * place when global_engine_lock has been locked up.
48 static int engine_list_add(ENGINE *e)
51 ENGINE *iterator = NULL;
54 ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ERR_R_PASSED_NULL_PARAMETER);
57 iterator = engine_list_head;
58 while (iterator && !conflict) {
59 conflict = (strcmp(iterator->id, e->id) == 0);
60 iterator = iterator->next;
63 ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_CONFLICTING_ENGINE_ID);
66 if (engine_list_head == NULL) {
67 /* We are adding to an empty list. */
68 if (engine_list_tail) {
69 ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
75 * The first time the list allocates, we should register the cleanup.
77 engine_cleanup_add_last(engine_list_cleanup);
79 /* We are adding to the tail of an existing list. */
80 if ((engine_list_tail == NULL) || (engine_list_tail->next != NULL)) {
81 ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
84 engine_list_tail->next = e;
85 e->prev = engine_list_tail;
88 * Having the engine in the list assumes a structural reference.
91 engine_ref_debug(e, 0, 1);
92 /* However it came to be, e is the last item in the list. */
98 static int engine_list_remove(ENGINE *e)
103 ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE, ERR_R_PASSED_NULL_PARAMETER);
106 /* We need to check that e is in our linked list! */
107 iterator = engine_list_head;
108 while (iterator && (iterator != e))
109 iterator = iterator->next;
110 if (iterator == NULL) {
111 ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE,
112 ENGINE_R_ENGINE_IS_NOT_IN_LIST);
115 /* un-link e from the chain. */
117 e->next->prev = e->prev;
119 e->prev->next = e->next;
120 /* Correct our head/tail if necessary. */
121 if (engine_list_head == e)
122 engine_list_head = e->next;
123 if (engine_list_tail == e)
124 engine_list_tail = e->prev;
125 engine_free_util(e, 0);
129 /* Get the first/last "ENGINE" type available. */
130 ENGINE *ENGINE_get_first(void)
134 if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
135 ENGINEerr(ENGINE_F_ENGINE_GET_FIRST, ERR_R_MALLOC_FAILURE);
139 CRYPTO_THREAD_write_lock(global_engine_lock);
140 ret = engine_list_head;
143 engine_ref_debug(ret, 0, 1);
145 CRYPTO_THREAD_unlock(global_engine_lock);
149 ENGINE *ENGINE_get_last(void)
153 if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
154 ENGINEerr(ENGINE_F_ENGINE_GET_LAST, ERR_R_MALLOC_FAILURE);
158 CRYPTO_THREAD_write_lock(global_engine_lock);
159 ret = engine_list_tail;
162 engine_ref_debug(ret, 0, 1);
164 CRYPTO_THREAD_unlock(global_engine_lock);
168 /* Iterate to the next/previous "ENGINE" type (NULL = end of the list). */
169 ENGINE *ENGINE_get_next(ENGINE *e)
173 ENGINEerr(ENGINE_F_ENGINE_GET_NEXT, ERR_R_PASSED_NULL_PARAMETER);
176 CRYPTO_THREAD_write_lock(global_engine_lock);
179 /* Return a valid structural reference to the next ENGINE */
181 engine_ref_debug(ret, 0, 1);
183 CRYPTO_THREAD_unlock(global_engine_lock);
184 /* Release the structural reference to the previous ENGINE */
189 ENGINE *ENGINE_get_prev(ENGINE *e)
193 ENGINEerr(ENGINE_F_ENGINE_GET_PREV, ERR_R_PASSED_NULL_PARAMETER);
196 CRYPTO_THREAD_write_lock(global_engine_lock);
199 /* Return a valid structural reference to the next ENGINE */
201 engine_ref_debug(ret, 0, 1);
203 CRYPTO_THREAD_unlock(global_engine_lock);
204 /* Release the structural reference to the previous ENGINE */
209 /* Add another "ENGINE" type into the list. */
210 int ENGINE_add(ENGINE *e)
214 ENGINEerr(ENGINE_F_ENGINE_ADD, ERR_R_PASSED_NULL_PARAMETER);
217 if ((e->id == NULL) || (e->name == NULL)) {
218 ENGINEerr(ENGINE_F_ENGINE_ADD, ENGINE_R_ID_OR_NAME_MISSING);
221 CRYPTO_THREAD_write_lock(global_engine_lock);
222 if (!engine_list_add(e)) {
223 ENGINEerr(ENGINE_F_ENGINE_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
226 CRYPTO_THREAD_unlock(global_engine_lock);
230 /* Remove an existing "ENGINE" type from the array. */
231 int ENGINE_remove(ENGINE *e)
235 ENGINEerr(ENGINE_F_ENGINE_REMOVE, ERR_R_PASSED_NULL_PARAMETER);
238 CRYPTO_THREAD_write_lock(global_engine_lock);
239 if (!engine_list_remove(e)) {
240 ENGINEerr(ENGINE_F_ENGINE_REMOVE, ENGINE_R_INTERNAL_LIST_ERROR);
243 CRYPTO_THREAD_unlock(global_engine_lock);
247 static void engine_cpy(ENGINE *dest, const ENGINE *src)
250 dest->name = src->name;
251 #ifndef OPENSSL_NO_RSA
252 dest->rsa_meth = src->rsa_meth;
254 #ifndef OPENSSL_NO_DSA
255 dest->dsa_meth = src->dsa_meth;
257 #ifndef OPENSSL_NO_DH
258 dest->dh_meth = src->dh_meth;
260 #ifndef OPENSSL_NO_EC
261 dest->ec_meth = src->ec_meth;
263 dest->rand_meth = src->rand_meth;
264 dest->ciphers = src->ciphers;
265 dest->digests = src->digests;
266 dest->pkey_meths = src->pkey_meths;
267 dest->destroy = src->destroy;
268 dest->init = src->init;
269 dest->finish = src->finish;
270 dest->ctrl = src->ctrl;
271 dest->load_privkey = src->load_privkey;
272 dest->load_pubkey = src->load_pubkey;
273 dest->cmd_defns = src->cmd_defns;
274 dest->flags = src->flags;
277 ENGINE *ENGINE_by_id(const char *id)
280 char *load_dir = NULL;
282 ENGINEerr(ENGINE_F_ENGINE_BY_ID, ERR_R_PASSED_NULL_PARAMETER);
285 if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
286 ENGINEerr(ENGINE_F_ENGINE_BY_ID, ERR_R_MALLOC_FAILURE);
290 CRYPTO_THREAD_write_lock(global_engine_lock);
291 iterator = engine_list_head;
292 while (iterator && (strcmp(id, iterator->id) != 0))
293 iterator = iterator->next;
294 if (iterator != NULL) {
296 * We need to return a structural reference. If this is an ENGINE
297 * type that returns copies, make a duplicate - otherwise increment
298 * the existing ENGINE's reference count.
300 if (iterator->flags & ENGINE_FLAGS_BY_ID_COPY) {
301 ENGINE *cp = ENGINE_new();
305 engine_cpy(cp, iterator);
309 iterator->struct_ref++;
310 engine_ref_debug(iterator, 0, 1);
313 CRYPTO_THREAD_unlock(global_engine_lock);
314 if (iterator != NULL)
317 * Prevent infinite recursion if we're looking for the dynamic engine.
319 if (strcmp(id, "dynamic")) {
320 if ((load_dir = ossl_safe_getenv("OPENSSL_ENGINES")) == NULL)
321 load_dir = ENGINESDIR;
322 iterator = ENGINE_by_id("dynamic");
323 if (!iterator || !ENGINE_ctrl_cmd_string(iterator, "ID", id, 0) ||
324 !ENGINE_ctrl_cmd_string(iterator, "DIR_LOAD", "2", 0) ||
325 !ENGINE_ctrl_cmd_string(iterator, "DIR_ADD",
327 !ENGINE_ctrl_cmd_string(iterator, "LIST_ADD", "1", 0) ||
328 !ENGINE_ctrl_cmd_string(iterator, "LOAD", NULL, 0))
333 ENGINE_free(iterator);
334 ENGINEerr(ENGINE_F_ENGINE_BY_ID, ENGINE_R_NO_SUCH_ENGINE);
335 ERR_add_error_data(2, "id=", id);
337 /* EEK! Experimental code ends */
340 int ENGINE_up_ref(ENGINE *e)
344 ENGINEerr(ENGINE_F_ENGINE_UP_REF, ERR_R_PASSED_NULL_PARAMETER);
347 CRYPTO_UP_REF(&e->struct_ref, &i, global_engine_lock);