More type-checking.
[openssl.git] / crypto / engine / eng_table.c
1 /* ====================================================================
2  * Copyright (c) 2001 The OpenSSL Project.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer. 
10  *
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in
13  *    the documentation and/or other materials provided with the
14  *    distribution.
15  *
16  * 3. All advertising materials mentioning features or use of this
17  *    software must display the following acknowledgment:
18  *    "This product includes software developed by the OpenSSL Project
19  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
20  *
21  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22  *    endorse or promote products derived from this software without
23  *    prior written permission. For written permission, please contact
24  *    licensing@OpenSSL.org.
25  *
26  * 5. Products derived from this software may not be called "OpenSSL"
27  *    nor may "OpenSSL" appear in their names without prior written
28  *    permission of the OpenSSL Project.
29  *
30  * 6. Redistributions of any form whatsoever must retain the following
31  *    acknowledgment:
32  *    "This product includes software developed by the OpenSSL Project
33  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
34  *
35  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46  * OF THE POSSIBILITY OF SUCH DAMAGE.
47  * ====================================================================
48  *
49  * This product includes cryptographic software written by Eric Young
50  * (eay@cryptsoft.com).  This product includes software written by Tim
51  * Hudson (tjh@cryptsoft.com).
52  *
53  */
54
55 #include "cryptlib.h"
56 #include <openssl/evp.h>
57 #include <openssl/lhash.h>
58 #include "eng_int.h"
59
60 /* The type of the items in the table */
61 typedef struct st_engine_pile
62         {
63         /* The 'nid' of this algorithm/mode */
64         int nid;
65         /* ENGINEs that implement this algorithm/mode. */
66         STACK_OF(ENGINE) *sk;
67         /* The default ENGINE to perform this algorithm/mode. */
68         ENGINE *funct;
69         /* Zero if 'sk' is newer than the cached 'funct', non-zero otherwise */
70         int uptodate;
71         } ENGINE_PILE;
72
73 DECLARE_LHASH_OF(ENGINE_PILE);
74
75 /* The type exposed in eng_int.h */
76 struct st_engine_table
77         {
78         LHASH_OF(ENGINE_PILE) piles;
79         }; /* ENGINE_TABLE */
80
81
82 typedef struct st_engine_pile_doall
83         {
84         engine_table_doall_cb *cb;
85         void *arg;
86         } ENGINE_PILE_DOALL;
87         
88
89 /* Global flags (ENGINE_TABLE_FLAG_***). */
90 static unsigned int table_flags = 0;
91
92 /* API function manipulating 'table_flags' */
93 unsigned int ENGINE_get_table_flags(void)
94         {
95         return table_flags;
96         }
97
98 void ENGINE_set_table_flags(unsigned int flags)
99         {
100         table_flags = flags;
101         }
102
103 /* Internal functions for the "piles" hash table */
104 static unsigned long engine_pile_hash(const ENGINE_PILE *c)
105         {
106         return c->nid;
107         }
108
109 static int engine_pile_cmp(const ENGINE_PILE *a, const ENGINE_PILE *b)
110         {
111         return a->nid - b->nid;
112         }
113 static IMPLEMENT_LHASH_HASH_FN(engine_pile, ENGINE_PILE)
114 static IMPLEMENT_LHASH_COMP_FN(engine_pile, ENGINE_PILE)
115
116 static int int_table_check(ENGINE_TABLE **t, int create)
117         {
118         LHASH_OF(ENGINE_PILE) *lh;
119
120         if(*t) return 1;
121         if(!create) return 0;
122         if((lh = lh_ENGINE_PILE_new()) == NULL)
123                 return 0;
124         *t = (ENGINE_TABLE *)lh;
125         return 1;
126         }
127
128 /* Privately exposed (via eng_int.h) functions for adding and/or removing
129  * ENGINEs from the implementation table */
130 int engine_table_register(ENGINE_TABLE **table, ENGINE_CLEANUP_CB *cleanup,
131                 ENGINE *e, const int *nids, int num_nids, int setdefault)
132         {
133         int ret = 0, added = 0;
134         ENGINE_PILE tmplate, *fnd;
135         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
136         if(!(*table))
137                 added = 1;
138         if(!int_table_check(table, 1))
139                 goto end;
140         if(added)
141                 /* The cleanup callback needs to be added */
142                 engine_cleanup_add_first(cleanup);
143         while(num_nids--)
144                 {
145                 tmplate.nid = *nids;
146                 fnd = lh_ENGINE_PILE_retrieve(&(*table)->piles, &tmplate);
147                 if(!fnd)
148                         {
149                         fnd = OPENSSL_malloc(sizeof(ENGINE_PILE));
150                         if(!fnd) goto end;
151                         fnd->uptodate = 1;
152                         fnd->nid = *nids;
153                         fnd->sk = sk_ENGINE_new_null();
154                         if(!fnd->sk)
155                                 {
156                                 OPENSSL_free(fnd);
157                                 goto end;
158                                 }
159                         fnd->funct = NULL;
160                         lh_ENGINE_PILE_insert(&(*table)->piles, fnd);
161                         }
162                 /* A registration shouldn't add duplciate entries */
163                 (void)sk_ENGINE_delete_ptr(fnd->sk, e);
164                 /* if 'setdefault', this ENGINE goes to the head of the list */
165                 if(!sk_ENGINE_push(fnd->sk, e))
166                         goto end;
167                 /* "touch" this ENGINE_PILE */
168                 fnd->uptodate = 0;
169                 if(setdefault)
170                         {
171                         if(!engine_unlocked_init(e))
172                                 {
173                                 ENGINEerr(ENGINE_F_ENGINE_TABLE_REGISTER,
174                                                 ENGINE_R_INIT_FAILED);
175                                 goto end;
176                                 }
177                         if(fnd->funct)
178                                 engine_unlocked_finish(fnd->funct, 0);
179                         fnd->funct = e;
180                         fnd->uptodate = 1;
181                         }
182                 nids++;
183                 }
184         ret = 1;
185 end:
186         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
187         return ret;
188         }
189 static void int_unregister_cb_doall_arg(ENGINE_PILE *pile, ENGINE *e)
190         {
191         int n;
192         /* Iterate the 'c->sk' stack removing any occurance of 'e' */
193         while((n = sk_ENGINE_find(pile->sk, e)) >= 0)
194                 {
195                 (void)sk_ENGINE_delete(pile->sk, n);
196                 pile->uptodate = 0;
197                 }
198         if(pile->funct == e)
199                 {
200                 engine_unlocked_finish(e, 0);
201                 pile->funct = NULL;
202                 }
203         }
204 static IMPLEMENT_LHASH_DOALL_ARG_FN(int_unregister_cb, ENGINE_PILE, ENGINE)
205
206 void engine_table_unregister(ENGINE_TABLE **table, ENGINE *e)
207         {
208         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
209         if(int_table_check(table, 0))
210                 lh_ENGINE_PILE_doall_arg(&(*table)->piles,
211                                          LHASH_DOALL_ARG_FN(int_unregister_cb),
212                                          ENGINE, e);
213         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
214         }
215
216 static void int_cleanup_cb_doall(ENGINE_PILE *p)
217         {
218         sk_ENGINE_free(p->sk);
219         if(p->funct)
220                 engine_unlocked_finish(p->funct, 0);
221         OPENSSL_free(p);
222         }
223 static IMPLEMENT_LHASH_DOALL_FN(int_cleanup_cb, ENGINE_PILE)
224
225 void engine_table_cleanup(ENGINE_TABLE **table)
226         {
227         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
228         if(*table)
229                 {
230                 lh_ENGINE_PILE_doall(&(*table)->piles,
231                                      LHASH_DOALL_FN(int_cleanup_cb));
232                 lh_ENGINE_PILE_free(&(*table)->piles);
233                 *table = NULL;
234                 }
235         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
236         }
237
238 /* return a functional reference for a given 'nid' */
239 #ifndef ENGINE_TABLE_DEBUG
240 ENGINE *engine_table_select(ENGINE_TABLE **table, int nid)
241 #else
242 ENGINE *engine_table_select_tmp(ENGINE_TABLE **table, int nid, const char *f, int l)
243 #endif
244         {
245         ENGINE *ret = NULL;
246         ENGINE_PILE tmplate, *fnd=NULL;
247         int initres, loop = 0;
248
249         if(!(*table))
250                 {
251 #ifdef ENGINE_TABLE_DEBUG
252                 fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, nothing "
253                         "registered!\n", f, l, nid);
254 #endif
255                 return NULL;
256                 }
257         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
258         /* Check again inside the lock otherwise we could race against cleanup
259          * operations. But don't worry about a fprintf(stderr). */
260         if(!int_table_check(table, 0)) goto end;
261         tmplate.nid = nid;
262         fnd = lh_ENGINE_PILE_retrieve(&(*table)->piles, &tmplate);
263         if(!fnd) goto end;
264         if(fnd->funct && engine_unlocked_init(fnd->funct))
265                 {
266 #ifdef ENGINE_TABLE_DEBUG
267                 fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, using "
268                         "ENGINE '%s' cached\n", f, l, nid, fnd->funct->id);
269 #endif
270                 ret = fnd->funct;
271                 goto end;
272                 }
273         if(fnd->uptodate)
274                 {
275                 ret = fnd->funct;
276                 goto end;
277                 }
278 trynext:
279         ret = sk_ENGINE_value(fnd->sk, loop++);
280         if(!ret)
281                 {
282 #ifdef ENGINE_TABLE_DEBUG
283                 fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, no "
284                                 "registered implementations would initialise\n",
285                                 f, l, nid);
286 #endif
287                 goto end;
288                 }
289         /* Try to initialise the ENGINE? */
290         if((ret->funct_ref > 0) || !(table_flags & ENGINE_TABLE_FLAG_NOINIT))
291                 initres = engine_unlocked_init(ret);
292         else
293                 initres = 0;
294         if(initres)
295                 {
296                 /* Update 'funct' */
297                 if((fnd->funct != ret) && engine_unlocked_init(ret))
298                         {
299                         /* If there was a previous default we release it. */
300                         if(fnd->funct)
301                                 engine_unlocked_finish(fnd->funct, 0);
302                         fnd->funct = ret;
303 #ifdef ENGINE_TABLE_DEBUG
304                         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, "
305                                 "setting default to '%s'\n", f, l, nid, ret->id);
306 #endif
307                         }
308 #ifdef ENGINE_TABLE_DEBUG
309                 fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, using "
310                                 "newly initialised '%s'\n", f, l, nid, ret->id);
311 #endif
312                 goto end;
313                 }
314         goto trynext;
315 end:
316         /* If it failed, it is unlikely to succeed again until some future
317          * registrations have taken place. In all cases, we cache. */
318         if(fnd) fnd->uptodate = 1;
319 #ifdef ENGINE_TABLE_DEBUG
320         if(ret)
321                 fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, caching "
322                                 "ENGINE '%s'\n", f, l, nid, ret->id);
323         else
324                 fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, caching "
325                                 "'no matching ENGINE'\n", f, l, nid);
326 #endif
327         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
328         /* Whatever happened, any failed init()s are not failures in this
329          * context, so clear our error state. */
330         ERR_clear_error();
331         return ret;
332         }
333
334 /* Table enumeration */
335
336 static void int_cb_doall_arg(ENGINE_PILE *pile, ENGINE_PILE_DOALL *dall)
337         {
338         dall->cb(pile->nid, pile->sk, pile->funct, dall->arg);
339         }
340 static IMPLEMENT_LHASH_DOALL_ARG_FN(int_cb, ENGINE_PILE,ENGINE_PILE_DOALL)
341
342 void engine_table_doall(ENGINE_TABLE *table, engine_table_doall_cb *cb,
343                                                                 void *arg)
344         {
345         ENGINE_PILE_DOALL dall;
346         dall.cb = cb;
347         dall.arg = arg;
348         lh_ENGINE_PILE_doall_arg(&table->piles, LHASH_DOALL_ARG_FN(int_cb),
349                                  ENGINE_PILE_DOALL, &dall);
350         }