This change replaces the ENGINE's underlying mechanics with the new
[openssl.git] / crypto / engine / eng_list.c
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. */
74 static ENGINE *engine_list_head = NULL;
75 static 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
80 static 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. */
94 static 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
155 static 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. */
190 ENGINE *ENGINE_get_first(void)
191         {
192         ENGINE *ret;
193
194         CRYPTO_r_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_r_unlock(CRYPTO_LOCK_ENGINE);
202         return ret;
203         }
204
205 ENGINE *ENGINE_get_last(void)
206         {
207         ENGINE *ret;
208
209         CRYPTO_r_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_r_unlock(CRYPTO_LOCK_ENGINE);
217         return ret;
218         }
219
220 /* Iterate to the next/previous "ENGINE" type (NULL = end of the list). */
221 ENGINE *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_r_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_r_unlock(CRYPTO_LOCK_ENGINE);
239         /* Release the structural reference to the previous ENGINE */
240         ENGINE_free(e);
241         return ret;
242         }
243
244 ENGINE *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_r_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_r_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. */
268 int 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. */
294 int 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
314 static 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->destroy = src->destroy;
329         dest->init = src->init;
330         dest->finish = src->finish;
331         dest->ctrl = src->ctrl;
332         dest->load_privkey = src->load_privkey;
333         dest->load_pubkey = src->load_pubkey;
334         dest->cmd_defns = src->cmd_defns;
335         dest->flags = src->flags;
336         }
337
338 ENGINE *ENGINE_by_id(const char *id)
339         {
340         ENGINE *iterator;
341         if(id == NULL)
342                 {
343                 ENGINEerr(ENGINE_F_ENGINE_BY_ID,
344                         ERR_R_PASSED_NULL_PARAMETER);
345                 return NULL;
346                 }
347         CRYPTO_r_lock(CRYPTO_LOCK_ENGINE);
348         iterator = engine_list_head;
349         while(iterator && (strcmp(id, iterator->id) != 0))
350                 iterator = iterator->next;
351         if(iterator)
352                 {
353                 /* We need to return a structural reference. If this is an
354                  * ENGINE type that returns copies, make a duplicate - otherwise
355                  * increment the existing ENGINE's reference count. */
356                 if(iterator->flags & ENGINE_FLAGS_BY_ID_COPY)
357                         {
358                         ENGINE *cp = ENGINE_new();
359                         if(!cp)
360                                 iterator = NULL;
361                         else
362                                 {
363                                 engine_cpy(cp, iterator);
364                                 iterator = cp;
365                                 }
366                         }
367                 else
368                         {
369                         iterator->struct_ref++;
370                         engine_ref_debug(iterator, 0, 1)
371                         }
372                 }
373         CRYPTO_r_unlock(CRYPTO_LOCK_ENGINE);
374         if(iterator == NULL)
375                 ENGINEerr(ENGINE_F_ENGINE_BY_ID,
376                         ENGINE_R_NO_SUCH_ENGINE);
377         return iterator;
378         }