1/* crypto/engine/eng_list.c */
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#include <openssl/crypto.h>
60#include "cryptlib.h"
61#include "eng_int.h"
62#include <openssl/engine.h>
63
64/* The linked-list of pointers to engine types. engine_list_head
65 * incorporates an implicit structural reference but engine_list_tail
66 * does not - the latter is a computational niceity and only points
67 * to something that is already pointed to by its predecessor in the
68 * list (or engine_list_head itself). In the same way, the use of the
69 * "prev" pointer in each ENGINE is to save excessive list iteration,
70 * it doesn't correspond to an extra structural reference. Hence,
71 * engine_list_head, and each non-null "next" pointer account for
72 * the list itself assuming exactly 1 structural reference on each
73 * list member. */
74static ENGINE *engine_list_head = NULL;
75static ENGINE *engine_list_tail = NULL;
76
77/* This cleanup function is only needed internally. If it should be called, we
78 * register it with the "ENGINE_cleanup()" stack to be called during cleanup. */
79
80static void engine_list_cleanup(void)
81	{
82	ENGINE *iterator = engine_list_head;
83
84	while(iterator != NULL)
85		{
86		ENGINE_remove(iterator);
87		iterator = engine_list_head;
88		}
89	return;
90	}
91
92/* These static functions starting with a lower case "engine_" always
93 * take place when CRYPTO_LOCK_ENGINE has been locked up. */
94static int engine_list_add(ENGINE *e)
95	{
96	int conflict = 0;
97	ENGINE *iterator = NULL;
98
99	if(e == NULL)
100		{
101		ENGINEerr(ENGINE_F_ENGINE_LIST_ADD,
102			ERR_R_PASSED_NULL_PARAMETER);
103		return 0;
104		}
105	iterator = engine_list_head;
106	while(iterator && !conflict)
107		{
108		conflict = (strcmp(iterator->id, e->id) == 0);
109		iterator = iterator->next;
110		}
111	if(conflict)
112		{
113		ENGINEerr(ENGINE_F_ENGINE_LIST_ADD,
114			ENGINE_R_CONFLICTING_ENGINE_ID);
115		return 0;
116		}
117	if(engine_list_head == NULL)
118		{
119		/* We are adding to an empty list. */
120		if(engine_list_tail)
121			{
122			ENGINEerr(ENGINE_F_ENGINE_LIST_ADD,
123				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		}
132	else
133		{
134		/* We are adding to the tail of an existing list. */
135		if((engine_list_tail == NULL) ||
136				(engine_list_tail->next != NULL))
137			{
138			ENGINEerr(ENGINE_F_ENGINE_LIST_ADD,
139				ENGINE_R_INTERNAL_LIST_ERROR);
140			return 0;
141			}
142		engine_list_tail->next = e;
143		e->prev = engine_list_tail;
144		}
145	/* Having the engine in the list assumes a structural
146	 * reference. */
147	e->struct_ref++;
148	engine_ref_debug(e, 0, 1)
149	/* However it came to be, e is the last item in the list. */
150	engine_list_tail = e;
151	e->next = NULL;
152	return 1;
153	}
154
155static int engine_list_remove(ENGINE *e)
156	{
157	ENGINE *iterator;
158
159	if(e == NULL)
160		{
161		ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE,
162			ERR_R_PASSED_NULL_PARAMETER);
163		return 0;
164		}
165	/* We need to check that e is in our linked list! */
166	iterator = engine_list_head;
167	while(iterator && (iterator != e))
168		iterator = iterator->next;
169	if(iterator == NULL)
170		{
171		ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE,
172			ENGINE_R_ENGINE_IS_NOT_IN_LIST);
173		return 0;
174		}
175	/* un-link e from the chain. */
176	if(e->next)
177		e->next->prev = e->prev;
178	if(e->prev)
179		e->prev->next = e->next;
180	/* Correct our head/tail if necessary. */
181	if(engine_list_head == e)
182		engine_list_head = e->next;
183	if(engine_list_tail == e)
184		engine_list_tail = e->prev;
185	engine_free_util(e, 0);
186	return 1;
187	}
188
189/* Get the first/last "ENGINE" type available. */
190ENGINE *ENGINE_get_first(void)
191	{
192	ENGINE *ret;
193
194	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
195	ret = engine_list_head;
196	if(ret)
197		{
198		ret->struct_ref++;
199		engine_ref_debug(ret, 0, 1)
200		}
201	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
202	return ret;
203	}
204
205ENGINE *ENGINE_get_last(void)
206	{
207	ENGINE *ret;
208
209	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
210	ret = engine_list_tail;
211	if(ret)
212		{
213		ret->struct_ref++;
214		engine_ref_debug(ret, 0, 1)
215		}
216	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
217	return ret;
218	}
219
220/* Iterate to the next/previous "ENGINE" type (NULL = end of the list). */
221ENGINE *ENGINE_get_next(ENGINE *e)
222	{
223	ENGINE *ret = NULL;
224	if(e == NULL)
225		{
226		ENGINEerr(ENGINE_F_ENGINE_GET_NEXT,
227			ERR_R_PASSED_NULL_PARAMETER);
228		return 0;
229		}
230	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
231	ret = e->next;
232	if(ret)
233		{
234		/* Return a valid structural refernce to the next ENGINE */
235		ret->struct_ref++;
236		engine_ref_debug(ret, 0, 1)
237		}
238	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
239	/* Release the structural reference to the previous ENGINE */
240	ENGINE_free(e);
241	return ret;
242	}
243
244ENGINE *ENGINE_get_prev(ENGINE *e)
245	{
246	ENGINE *ret = NULL;
247	if(e == NULL)
248		{
249		ENGINEerr(ENGINE_F_ENGINE_GET_PREV,
250			ERR_R_PASSED_NULL_PARAMETER);
251		return 0;
252		}
253	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
254	ret = e->prev;
255	if(ret)
256		{
257		/* Return a valid structural reference to the next ENGINE */
258		ret->struct_ref++;
259		engine_ref_debug(ret, 0, 1)
260		}
261	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
262	/* Release the structural reference to the previous ENGINE */
263	ENGINE_free(e);
264	return ret;
265	}
266
267/* Add another "ENGINE" type into the list. */
268int ENGINE_add(ENGINE *e)
269	{
270	int to_return = 1;
271	if(e == NULL)
272		{
273		ENGINEerr(ENGINE_F_ENGINE_ADD,
274			ERR_R_PASSED_NULL_PARAMETER);
275		return 0;
276		}
277	if((e->id == NULL) || (e->name == NULL))
278		{
279		ENGINEerr(ENGINE_F_ENGINE_ADD,
280			ENGINE_R_ID_OR_NAME_MISSING);
281		}
282	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
283	if(!engine_list_add(e))
284		{
285		ENGINEerr(ENGINE_F_ENGINE_ADD,
286			ENGINE_R_INTERNAL_LIST_ERROR);
287		to_return = 0;
288		}
289	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
290	return to_return;
291	}
292
293/* Remove an existing "ENGINE" type from the array. */
294int ENGINE_remove(ENGINE *e)
295	{
296	int to_return = 1;
297	if(e == NULL)
298		{
299		ENGINEerr(ENGINE_F_ENGINE_REMOVE,
300			ERR_R_PASSED_NULL_PARAMETER);
301		return 0;
302		}
303	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
304	if(!engine_list_remove(e))
305		{
306		ENGINEerr(ENGINE_F_ENGINE_REMOVE,
307			ENGINE_R_INTERNAL_LIST_ERROR);
308		to_return = 0;
309		}
310	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
311	return to_return;
312	}
313
314static void engine_cpy(ENGINE *dest, const ENGINE *src)
315	{
316	dest->id = src->id;
317	dest->name = src->name;
318#ifndef OPENSSL_NO_RSA
319	dest->rsa_meth = src->rsa_meth;
320#endif
321#ifndef OPENSSL_NO_DSA
322	dest->dsa_meth = src->dsa_meth;
323#endif
324#ifndef OPENSSL_NO_DH
325	dest->dh_meth = src->dh_meth;
326#endif
327	dest->rand_meth = src->rand_meth;
328	dest->ciphers = src->ciphers;
329	dest->digests = src->digests;
330	dest->destroy = src->destroy;
331	dest->init = src->init;
332	dest->finish = src->finish;
333	dest->ctrl = src->ctrl;
334	dest->load_privkey = src->load_privkey;
335	dest->load_pubkey = src->load_pubkey;
336	dest->cmd_defns = src->cmd_defns;
337	dest->flags = src->flags;
338	}
339
340ENGINE *ENGINE_by_id(const char *id)
341	{
342	ENGINE *iterator;
343	if(id == NULL)
344		{
345		ENGINEerr(ENGINE_F_ENGINE_BY_ID,
346			ERR_R_PASSED_NULL_PARAMETER);
347		return NULL;
348		}
349	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
350	iterator = engine_list_head;
351	while(iterator && (strcmp(id, iterator->id) != 0))
352		iterator = iterator->next;
353	if(iterator)
354		{
355		/* We need to return a structural reference. If this is an
356		 * ENGINE type that returns copies, make a duplicate - otherwise
357		 * increment the existing ENGINE's reference count. */
358		if(iterator->flags & ENGINE_FLAGS_BY_ID_COPY)
359			{
360			ENGINE *cp = ENGINE_new();
361			if(!cp)
362				iterator = NULL;
363			else
364				{
365				engine_cpy(cp, iterator);
366				iterator = cp;
367				}
368			}
369		else
370			{
371			iterator->struct_ref++;
372			engine_ref_debug(iterator, 0, 1)
373			}
374		}
375	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
376	if(iterator == NULL)
377		{
378		ENGINEerr(ENGINE_F_ENGINE_BY_ID,
379			ENGINE_R_NO_SUCH_ENGINE);
380		ERR_add_error_data(2, "id=", id);
381		}
382	return iterator;
383	}
384
385int ENGINE_up_ref(ENGINE *e)
386	{
387	if (e == NULL)
388		{
389		ENGINEerr(ENGINE_F_ENGINE_UP_REF,ERR_R_PASSED_NULL_PARAMETER);
390		return 0;
391		}
392	CRYPTO_add(&e->struct_ref,1,CRYPTO_LOCK_ENGINE);
393	return 1;
394	}
395