1 /* $OpenBSD: eng_list.c,v 1.24 2019/01/19 01:07:00 tb Exp $ */
2 /* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
3  * project 2000.
4  */
5 /* ====================================================================
6  * Copyright (c) 1999-2001 The OpenSSL Project.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. All advertising materials mentioning features or use of this
21  *    software must display the following acknowledgment:
22  *    "This product includes software developed by the OpenSSL Project
23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24  *
25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26  *    endorse or promote products derived from this software without
27  *    prior written permission. For written permission, please contact
28  *    licensing@OpenSSL.org.
29  *
30  * 5. Products derived from this software may not be called "OpenSSL"
31  *    nor may "OpenSSL" appear in their names without prior written
32  *    permission of the OpenSSL Project.
33  *
34  * 6. Redistributions of any form whatsoever must retain the following
35  *    acknowledgment:
36  *    "This product includes software developed by the OpenSSL Project
37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38  *
39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50  * OF THE POSSIBILITY OF SUCH DAMAGE.
51  * ====================================================================
52  *
53  * This product includes cryptographic software written by Eric Young
54  * (eay@cryptsoft.com).  This product includes software written by Tim
55  * Hudson (tjh@cryptsoft.com).
56  *
57  */
58 /* ====================================================================
59  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
60  * ECDH support in OpenSSL originally developed by
61  * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
62  */
63 
64 #include <string.h>
65 #include <unistd.h>
66 
67 #include <openssl/opensslconf.h>
68 
69 #include <openssl/err.h>
70 
71 #include "cryptlib.h"
72 #include "eng_int.h"
73 
74 /* The linked-list of pointers to engine types. engine_list_head
75  * incorporates an implicit structural reference but engine_list_tail
76  * does not - the latter is a computational niceity and only points
77  * to something that is already pointed to by its predecessor in the
78  * list (or engine_list_head itself). In the same way, the use of the
79  * "prev" pointer in each ENGINE is to save excessive list iteration,
80  * it doesn't correspond to an extra structural reference. Hence,
81  * engine_list_head, and each non-null "next" pointer account for
82  * the list itself assuming exactly 1 structural reference on each
83  * list member. */
84 static ENGINE *engine_list_head = NULL;
85 static ENGINE *engine_list_tail = NULL;
86 
87 /* This cleanup function is only needed internally. If it should be called, we
88  * register it with the "ENGINE_cleanup()" stack to be called during cleanup. */
89 
90 static void
91 engine_list_cleanup(void)
92 {
93 	ENGINE *iterator = engine_list_head;
94 
95 	while (iterator != NULL && ENGINE_remove(iterator))
96 		iterator = engine_list_head;
97 }
98 
99 /* These static functions starting with a lower case "engine_" always
100  * take place when CRYPTO_LOCK_ENGINE has been locked up. */
101 static int
102 engine_list_add(ENGINE *e)
103 {
104 	int conflict = 0;
105 	ENGINE *iterator = NULL;
106 
107 	if (e == NULL) {
108 		ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
109 		return 0;
110 	}
111 	iterator = engine_list_head;
112 	while (iterator && !conflict) {
113 		conflict = (strcmp(iterator->id, e->id) == 0);
114 		iterator = iterator->next;
115 	}
116 	if (conflict) {
117 		ENGINEerror(ENGINE_R_CONFLICTING_ENGINE_ID);
118 		return 0;
119 	}
120 	if (engine_list_head == NULL) {
121 		/* We are adding to an empty list. */
122 		if (engine_list_tail) {
123 			ENGINEerror(ENGINE_R_INTERNAL_LIST_ERROR);
124 			return 0;
125 		}
126 		engine_list_head = e;
127 		e->prev = NULL;
128 		/* The first time the list allocates, we should register the
129 		 * cleanup. */
130 		engine_cleanup_add_last(engine_list_cleanup);
131 	} else {
132 		/* We are adding to the tail of an existing list. */
133 		if ((engine_list_tail == NULL) ||
134 		    (engine_list_tail->next != NULL)) {
135 			ENGINEerror(ENGINE_R_INTERNAL_LIST_ERROR);
136 			return 0;
137 		}
138 		engine_list_tail->next = e;
139 		e->prev = engine_list_tail;
140 	}
141 	/* Having the engine in the list assumes a structural
142 	 * reference. */
143 	e->struct_ref++;
144 	engine_ref_debug(e, 0, 1)
145 	/* However it came to be, e is the last item in the list. */
146 	engine_list_tail = e;
147 	e->next = NULL;
148 	return 1;
149 }
150 
151 static int
152 engine_list_remove(ENGINE *e)
153 {
154 	ENGINE *iterator;
155 
156 	if (e == NULL) {
157 		ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
158 		return 0;
159 	}
160 	/* We need to check that e is in our linked list! */
161 	iterator = engine_list_head;
162 	while (iterator && (iterator != e))
163 		iterator = iterator->next;
164 	if (iterator == NULL) {
165 		ENGINEerror(ENGINE_R_ENGINE_IS_NOT_IN_LIST);
166 		return 0;
167 	}
168 	/* un-link e from the chain. */
169 	if (e->next)
170 		e->next->prev = e->prev;
171 	if (e->prev)
172 		e->prev->next = e->next;
173 	/* Correct our head/tail if necessary. */
174 	if (engine_list_head == e)
175 		engine_list_head = e->next;
176 	if (engine_list_tail == e)
177 		engine_list_tail = e->prev;
178 	engine_free_util(e, 0);
179 	return 1;
180 }
181 
182 /* Get the first/last "ENGINE" type available. */
183 ENGINE *
184 ENGINE_get_first(void)
185 {
186 	ENGINE *ret;
187 
188 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
189 	ret = engine_list_head;
190 	if (ret) {
191 		ret->struct_ref++;
192 		engine_ref_debug(ret, 0, 1)
193 	}
194 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
195 	return ret;
196 }
197 
198 ENGINE *
199 ENGINE_get_last(void)
200 {
201 	ENGINE *ret;
202 
203 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
204 	ret = engine_list_tail;
205 	if (ret) {
206 		ret->struct_ref++;
207 		engine_ref_debug(ret, 0, 1)
208 	}
209 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
210 	return ret;
211 }
212 
213 /* Iterate to the next/previous "ENGINE" type (NULL = end of the list). */
214 ENGINE *
215 ENGINE_get_next(ENGINE *e)
216 {
217 	ENGINE *ret = NULL;
218 
219 	if (e == NULL) {
220 		ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
221 		return 0;
222 	}
223 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
224 	ret = e->next;
225 	if (ret) {
226 		/* Return a valid structural refernce to the next ENGINE */
227 		ret->struct_ref++;
228 		engine_ref_debug(ret, 0, 1)
229 	}
230 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
231 	/* Release the structural reference to the previous ENGINE */
232 	ENGINE_free(e);
233 	return ret;
234 }
235 
236 ENGINE *
237 ENGINE_get_prev(ENGINE *e)
238 {
239 	ENGINE *ret = NULL;
240 
241 	if (e == NULL) {
242 		ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
243 		return 0;
244 	}
245 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
246 	ret = e->prev;
247 	if (ret) {
248 		/* Return a valid structural reference to the next ENGINE */
249 		ret->struct_ref++;
250 		engine_ref_debug(ret, 0, 1)
251 	}
252 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
253 	/* Release the structural reference to the previous ENGINE */
254 	ENGINE_free(e);
255 	return ret;
256 }
257 
258 /* Add another "ENGINE" type into the list. */
259 int
260 ENGINE_add(ENGINE *e)
261 {
262 	int to_return = 1;
263 
264 	if (e == NULL) {
265 		ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
266 		return 0;
267 	}
268 	if ((e->id == NULL) || (e->name == NULL)) {
269 		ENGINEerror(ENGINE_R_ID_OR_NAME_MISSING);
270 	}
271 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
272 	if (!engine_list_add(e)) {
273 		ENGINEerror(ENGINE_R_INTERNAL_LIST_ERROR);
274 		to_return = 0;
275 	}
276 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
277 	return to_return;
278 }
279 
280 /* Remove an existing "ENGINE" type from the array. */
281 int
282 ENGINE_remove(ENGINE *e)
283 {
284 	int to_return = 1;
285 
286 	if (e == NULL) {
287 		ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
288 		return 0;
289 	}
290 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
291 	if (!engine_list_remove(e)) {
292 		ENGINEerror(ENGINE_R_INTERNAL_LIST_ERROR);
293 		to_return = 0;
294 	}
295 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
296 	return to_return;
297 }
298 
299 static void
300 engine_cpy(ENGINE *dest, const ENGINE *src)
301 {
302 	dest->id = src->id;
303 	dest->name = src->name;
304 #ifndef OPENSSL_NO_RSA
305 	dest->rsa_meth = src->rsa_meth;
306 #endif
307 #ifndef OPENSSL_NO_DSA
308 	dest->dsa_meth = src->dsa_meth;
309 #endif
310 #ifndef OPENSSL_NO_DH
311 	dest->dh_meth = src->dh_meth;
312 #endif
313 #ifndef OPENSSL_NO_ECDH
314 	dest->ecdh_meth = src->ecdh_meth;
315 #endif
316 #ifndef OPENSSL_NO_ECDSA
317 	dest->ecdsa_meth = src->ecdsa_meth;
318 #endif
319 #ifndef OPENSSL_NO_EC
320 	dest->ec_meth = src->ec_meth;
321 #endif
322 	dest->rand_meth = src->rand_meth;
323 	dest->store_meth = src->store_meth;
324 	dest->ciphers = src->ciphers;
325 	dest->digests = src->digests;
326 	dest->pkey_meths = src->pkey_meths;
327 	dest->destroy = src->destroy;
328 	dest->init = src->init;
329 	dest->finish = src->finish;
330 	dest->ctrl = src->ctrl;
331 	dest->load_privkey = src->load_privkey;
332 	dest->load_pubkey = src->load_pubkey;
333 	dest->cmd_defns = src->cmd_defns;
334 	dest->flags = src->flags;
335 }
336 
337 ENGINE *
338 ENGINE_by_id(const char *id)
339 {
340 	ENGINE *iterator;
341 
342 	if (id == NULL) {
343 		ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
344 		return NULL;
345 	}
346 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
347 	iterator = engine_list_head;
348 	while (iterator && (strcmp(id, iterator->id) != 0))
349 		iterator = iterator->next;
350 	if (iterator) {
351 		/* We need to return a structural reference. If this is an
352 		 * ENGINE type that returns copies, make a duplicate - otherwise
353 		 * increment the existing ENGINE's reference count. */
354 		if (iterator->flags & ENGINE_FLAGS_BY_ID_COPY) {
355 			ENGINE *cp = ENGINE_new();
356 			if (!cp)
357 				iterator = NULL;
358 			else {
359 				engine_cpy(cp, iterator);
360 				iterator = cp;
361 			}
362 		} else {
363 			iterator->struct_ref++;
364 			engine_ref_debug(iterator, 0, 1)
365 		}
366 	}
367 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
368 
369 	if (iterator == NULL) {
370 		ENGINEerror(ENGINE_R_NO_SUCH_ENGINE);
371 		ERR_asprintf_error_data("id=%s", id);
372 	}
373 	return iterator;
374 }
375 
376 int
377 ENGINE_up_ref(ENGINE *e)
378 {
379 	int refs;
380 
381 	if (e == NULL) {
382 		ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
383 		return 0;
384 	}
385 	refs = CRYPTO_add(&e->struct_ref, 1, CRYPTO_LOCK_ENGINE);
386 	return refs > 1 ? 1 : 0;
387 }
388