1/*
2 * Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
4 *
5 * Licensed under the Apache License 2.0 (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
9 */
10
11#include "eng_local.h"
12
13/*
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.
23 */
24static ENGINE *engine_list_head = NULL;
25static ENGINE *engine_list_tail = NULL;
26
27/*
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
30 * cleanup.
31 */
32
33static void engine_list_cleanup(void)
34{
35 ENGINE *iterator = engine_list_head;
36
37 while (iterator != NULL) {
38 ENGINE_remove(iterator);
39 iterator = engine_list_head;
40 }
41 return;
42}
43
44/*
45 * These static functions starting with a lower case "engine_" always take
46 * place when global_engine_lock has been locked up.
47 */
48static int engine_list_add(ENGINE *e)
49{
50 int conflict = 0;
51 ENGINE *iterator = NULL;
52
53 if (e == NULL) {
54 ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ERR_R_PASSED_NULL_PARAMETER);
55 return 0;
56 }
57 iterator = engine_list_head;
58 while (iterator && !conflict) {
59 conflict = (strcmp(iterator->id, e->id) == 0);
60 iterator = iterator->next;
61 }
62 if (conflict) {
63 ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_CONFLICTING_ENGINE_ID);
64 return 0;
65 }
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);
70 return 0;
71 }
72 engine_list_head = e;
73 e->prev = NULL;
74 /*
75 * The first time the list allocates, we should register the cleanup.
76 */
77 engine_cleanup_add_last(engine_list_cleanup);
78 } else {
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);
82 return 0;
83 }
84 engine_list_tail->next = e;
85 e->prev = engine_list_tail;
86 }
87 /*
88 * Having the engine in the list assumes a structural reference.
89 */
90 e->struct_ref++;
91 engine_ref_debug(e, 0, 1);
92 /* However it came to be, e is the last item in the list. */
93 engine_list_tail = e;
94 e->next = NULL;
95 return 1;
96}
97
98static int engine_list_remove(ENGINE *e)
99{
100 ENGINE *iterator;
101
102 if (e == NULL) {
103 ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE, ERR_R_PASSED_NULL_PARAMETER);
104 return 0;
105 }
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);
113 return 0;
114 }
115 /* un-link e from the chain. */
116 if (e->next)
117 e->next->prev = e->prev;
118 if (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);
126 return 1;
127}
128
129/* Get the first/last "ENGINE" type available. */
130ENGINE *ENGINE_get_first(void)
131{
132 ENGINE *ret;
133
134 if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
135 ENGINEerr(ENGINE_F_ENGINE_GET_FIRST, ERR_R_MALLOC_FAILURE);
136 return NULL;
137 }
138
139 CRYPTO_THREAD_write_lock(global_engine_lock);
140 ret = engine_list_head;
141 if (ret) {
142 ret->struct_ref++;
143 engine_ref_debug(ret, 0, 1);
144 }
145 CRYPTO_THREAD_unlock(global_engine_lock);
146 return ret;
147}
148
149ENGINE *ENGINE_get_last(void)
150{
151 ENGINE *ret;
152
153 if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
154 ENGINEerr(ENGINE_F_ENGINE_GET_LAST, ERR_R_MALLOC_FAILURE);
155 return NULL;
156 }
157
158 CRYPTO_THREAD_write_lock(global_engine_lock);
159 ret = engine_list_tail;
160 if (ret) {
161 ret->struct_ref++;
162 engine_ref_debug(ret, 0, 1);
163 }
164 CRYPTO_THREAD_unlock(global_engine_lock);
165 return ret;
166}
167
168/* Iterate to the next/previous "ENGINE" type (NULL = end of the list). */
169ENGINE *ENGINE_get_next(ENGINE *e)
170{
171 ENGINE *ret = NULL;
172 if (e == NULL) {
173 ENGINEerr(ENGINE_F_ENGINE_GET_NEXT, ERR_R_PASSED_NULL_PARAMETER);
174 return 0;
175 }
176 CRYPTO_THREAD_write_lock(global_engine_lock);
177 ret = e->next;
178 if (ret) {
179 /* Return a valid structural reference to the next ENGINE */
180 ret->struct_ref++;
181 engine_ref_debug(ret, 0, 1);
182 }
183 CRYPTO_THREAD_unlock(global_engine_lock);
184 /* Release the structural reference to the previous ENGINE */
185 ENGINE_free(e);
186 return ret;
187}
188
189ENGINE *ENGINE_get_prev(ENGINE *e)
190{
191 ENGINE *ret = NULL;
192 if (e == NULL) {
193 ENGINEerr(ENGINE_F_ENGINE_GET_PREV, ERR_R_PASSED_NULL_PARAMETER);
194 return 0;
195 }
196 CRYPTO_THREAD_write_lock(global_engine_lock);
197 ret = e->prev;
198 if (ret) {
199 /* Return a valid structural reference to the next ENGINE */
200 ret->struct_ref++;
201 engine_ref_debug(ret, 0, 1);
202 }
203 CRYPTO_THREAD_unlock(global_engine_lock);
204 /* Release the structural reference to the previous ENGINE */
205 ENGINE_free(e);
206 return ret;
207}
208
209/* Add another "ENGINE" type into the list. */
210int ENGINE_add(ENGINE *e)
211{
212 int to_return = 1;
213 if (e == NULL) {
214 ENGINEerr(ENGINE_F_ENGINE_ADD, ERR_R_PASSED_NULL_PARAMETER);
215 return 0;
216 }
217 if ((e->id == NULL) || (e->name == NULL)) {
218 ENGINEerr(ENGINE_F_ENGINE_ADD, ENGINE_R_ID_OR_NAME_MISSING);
219 return 0;
220 }
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);
224 to_return = 0;
225 }
226 CRYPTO_THREAD_unlock(global_engine_lock);
227 return to_return;
228}
229
230/* Remove an existing "ENGINE" type from the array. */
231int ENGINE_remove(ENGINE *e)
232{
233 int to_return = 1;
234 if (e == NULL) {
235 ENGINEerr(ENGINE_F_ENGINE_REMOVE, ERR_R_PASSED_NULL_PARAMETER);
236 return 0;
237 }
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);
241 to_return = 0;
242 }
243 CRYPTO_THREAD_unlock(global_engine_lock);
244 return to_return;
245}
246
247static void engine_cpy(ENGINE *dest, const ENGINE *src)
248{
249 dest->id = src->id;
250 dest->name = src->name;
251#ifndef OPENSSL_NO_RSA
252 dest->rsa_meth = src->rsa_meth;
253#endif
254#ifndef OPENSSL_NO_DSA
255 dest->dsa_meth = src->dsa_meth;
256#endif
257#ifndef OPENSSL_NO_DH
258 dest->dh_meth = src->dh_meth;
259#endif
260#ifndef OPENSSL_NO_EC
261 dest->ec_meth = src->ec_meth;
262#endif
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;
275}
276
277ENGINE *ENGINE_by_id(const char *id)
278{
279 ENGINE *iterator;
280 char *load_dir = NULL;
281 if (id == NULL) {
282 ENGINEerr(ENGINE_F_ENGINE_BY_ID, ERR_R_PASSED_NULL_PARAMETER);
283 return NULL;
284 }
285 if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
286 ENGINEerr(ENGINE_F_ENGINE_BY_ID, ERR_R_MALLOC_FAILURE);
287 return NULL;
288 }
289
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) {
295 /*
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.
299 */
300 if (iterator->flags & ENGINE_FLAGS_BY_ID_COPY) {
301 ENGINE *cp = ENGINE_new();
302 if (cp == NULL)
303 iterator = NULL;
304 else {
305 engine_cpy(cp, iterator);
306 iterator = cp;
307 }
308 } else {
309 iterator->struct_ref++;
310 engine_ref_debug(iterator, 0, 1);
311 }
312 }
313 CRYPTO_THREAD_unlock(global_engine_lock);
314 if (iterator != NULL)
315 return iterator;
316 /*
317 * Prevent infinite recursion if we're looking for the dynamic engine.
318 */
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",
326 load_dir, 0) ||
327 !ENGINE_ctrl_cmd_string(iterator, "LIST_ADD", "1", 0) ||
328 !ENGINE_ctrl_cmd_string(iterator, "LOAD", NULL, 0))
329 goto notfound;
330 return iterator;
331 }
332 notfound:
333 ENGINE_free(iterator);
334 ENGINEerr(ENGINE_F_ENGINE_BY_ID, ENGINE_R_NO_SUCH_ENGINE);
335 ERR_add_error_data(2, "id=", id);
336 return NULL;
337 /* EEK! Experimental code ends */
338}
339
340int ENGINE_up_ref(ENGINE *e)
341{
342 int i;
343 if (e == NULL) {
344 ENGINEerr(ENGINE_F_ENGINE_UP_REF, ERR_R_PASSED_NULL_PARAMETER);
345 return 0;
346 }
347 CRYPTO_UP_REF(&e->struct_ref, &i, global_engine_lock);
348 return 1;
349}
350