90eb5cd6d58c9bc939e36caa5f635f2e845bdb6a
[openssl.git] / crypto / engine / engine_lib.c
1 /* crypto/engine/engine_lib.c */
2 /* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
3  * project 2000.
4  */
5 /* ====================================================================
6  * Copyright (c) 1999 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 "engine_int.h"
62 #include <openssl/engine.h>
63
64 /* These pointers each have their own "functional reference" when they
65  * are non-NULL. Similarly, when they are retrieved by a call to
66  * ENGINE_get_default_[RSA|DSA|...] the returned pointer is also a
67  * reference and the caller is responsible for freeing that when they
68  * are finished with it (with a call to ENGINE_finish() *NOT* just
69  * ENGINE_free()!!!!!!). */
70 #ifndef OPENSSL_NO_RSA
71 static ENGINE *engine_def_rsa = NULL;
72 #endif
73 #ifndef OPENSSL_NO_DSA
74 static ENGINE *engine_def_dsa = NULL;
75 #endif
76 #ifndef OPENSSL_NO_DH
77 static ENGINE *engine_def_dh = NULL;
78 #endif
79 static ENGINE *engine_def_rand = NULL;
80 static ENGINE *engine_def_bn_mod_exp = NULL;
81 static ENGINE *engine_def_bn_mod_exp_crt = NULL;
82 /* A static "once-only" flag used to control if/when the above were
83  * initialised to suitable start-up defaults. */
84 static int engine_def_flag = 0;
85
86 /* When querying a ENGINE-specific control command's 'description', this string
87  * is used if the ENGINE_CMD_DEFN has cmd_desc set to NULL. */
88 static const char *int_no_description = "";
89
90 /* This is used in certain static utility functions to save code
91  * repetition for per-algorithm functions. */
92 typedef enum {
93         ENGINE_TYPE_RSA,
94         ENGINE_TYPE_DSA,
95         ENGINE_TYPE_DH,
96         ENGINE_TYPE_RAND,
97         ENGINE_TYPE_BN_MOD_EXP,
98         ENGINE_TYPE_BN_MOD_EXP_CRT
99         } ENGINE_TYPE;
100
101 static void engine_def_check_util(ENGINE **def, ENGINE *val)
102         {
103         *def = val;
104         val->struct_ref++;
105         val->funct_ref++;
106         engine_ref_debug(val, 0, 1)
107         engine_ref_debug(val, 1, 1)
108         }
109
110 /* In a slight break with convention - this static function must be
111  * called *outside* any locking of CRYPTO_LOCK_ENGINE. */
112 static void engine_def_check(void)
113         {
114         ENGINE *e;
115         if(engine_def_flag)
116                 return;
117         e = ENGINE_get_first();
118         if(e == NULL)
119                 /* The list is empty ... not much we can do! */
120                 return;
121         /* We have a structural reference, see if getting a functional
122          * reference is possible. This is done to cope with init errors
123          * in the engine - the following locked code does a bunch of
124          * manual "ENGINE_init"s which do *not* allow such an init
125          * error so this is worth doing. */
126         if(ENGINE_init(e))
127                 {
128                 CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
129                 /* Doing another check here prevents an obvious race
130                  * condition because the whole function itself cannot
131                  * be locked. */
132                 if(engine_def_flag)
133                         goto skip_set_defaults;
134                 /* OK, we got a functional reference, so we get one each
135                  * for the defaults too. */
136 #ifndef OPENSSL_NO_RSA
137                 engine_def_check_util(&engine_def_rsa, e);
138 #endif
139 #ifndef OPENSSL_NO_RSA
140                 engine_def_check_util(&engine_def_dsa, e);
141 #endif
142 #ifndef OPENSSL_NO_DH
143                 engine_def_check_util(&engine_def_dh, e);
144 #endif
145                 engine_def_check_util(&engine_def_rand, e);
146                 engine_def_check_util(&engine_def_bn_mod_exp, e);
147                 engine_def_check_util(&engine_def_bn_mod_exp_crt, e);
148                 engine_def_flag = 1;
149 skip_set_defaults:
150                 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
151                 /* The "if" needs to be balanced out. */
152                 ENGINE_finish(e);
153                 }
154         /* We need to balance out the fact we obtained a structural
155          * reference to begin with from ENGINE_get_first(). */
156         ENGINE_free(e);
157         }
158
159 /* Initialise a engine type for use (or up its functional reference count
160  * if it's already in use). */
161 int ENGINE_init(ENGINE *e)
162         {
163         int to_return = 1;
164
165         if(e == NULL)
166                 {
167                 ENGINEerr(ENGINE_F_ENGINE_INIT,ERR_R_PASSED_NULL_PARAMETER);
168                 return 0;
169                 }
170         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
171         if((e->funct_ref == 0) && e->init)
172                 /* This is the first functional reference and the engine
173                  * requires initialisation so we do it now. */
174                 to_return = e->init(e);
175         if(to_return)
176                 {
177                 /* OK, we return a functional reference which is also a
178                  * structural reference. */
179                 e->struct_ref++;
180                 e->funct_ref++;
181                 engine_ref_debug(e, 0, 1)
182                 engine_ref_debug(e, 1, 1)
183                 }
184         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
185         return to_return;
186         }
187
188 /* Free a functional reference to a engine type */
189 int ENGINE_finish(ENGINE *e)
190         {
191         int to_return = 1;
192
193         if(e == NULL)
194                 {
195                 ENGINEerr(ENGINE_F_ENGINE_FINISH,ERR_R_PASSED_NULL_PARAMETER);
196                 return 0;
197                 }
198         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
199         /* Reduce the functional reference count here so if it's the terminating
200          * case, we can release the lock safely and call the finish() handler
201          * without risk of a race. We get a race if we leave the count until
202          * after and something else is calling "finish" at the same time -
203          * there's a chance that both threads will together take the count from
204          * 2 to 0 without either calling finish(). */
205         e->funct_ref--;
206         engine_ref_debug(e, 1, -1)
207         if((e->funct_ref == 0) && e->finish)
208                 {
209                 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
210                 if(!(to_return = e->finish(e)))
211                         {
212                         ENGINEerr(ENGINE_F_ENGINE_FINISH,ENGINE_R_FINISH_FAILED);
213                         return 0;
214                         }
215                 }
216         else
217                 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
218 #ifdef REF_CHECK
219         if(e->funct_ref < 0)
220                 {
221                 fprintf(stderr,"ENGINE_finish, bad functional reference count\n");
222                 abort();
223                 }
224 #endif
225         /* Release the structural reference too */
226         if(!ENGINE_free(e))
227                 {
228                 ENGINEerr(ENGINE_F_ENGINE_FINISH,ENGINE_R_FINISH_FAILED);
229                 return 0;
230                 }
231         return to_return;
232         }
233
234 EVP_PKEY *ENGINE_load_private_key(ENGINE *e, const char *key_id,
235         const char *passphrase)
236         {
237         EVP_PKEY *pkey;
238
239         if(e == NULL)
240                 {
241                 ENGINEerr(ENGINE_F_ENGINE_LOAD_PRIVATE_KEY,
242                         ERR_R_PASSED_NULL_PARAMETER);
243                 return 0;
244                 }
245         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
246         if(e->funct_ref == 0)
247                 {
248                 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
249                 ENGINEerr(ENGINE_F_ENGINE_LOAD_PRIVATE_KEY,
250                         ENGINE_R_NOT_INITIALISED);
251                 return 0;
252                 }
253         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
254         if (!e->load_privkey)
255                 {
256                 ENGINEerr(ENGINE_F_ENGINE_LOAD_PRIVATE_KEY,
257                         ENGINE_R_NO_LOAD_FUNCTION);
258                 return 0;
259                 }
260         pkey = e->load_privkey(e, key_id, passphrase);
261         if (!pkey)
262                 {
263                 ENGINEerr(ENGINE_F_ENGINE_LOAD_PRIVATE_KEY,
264                         ENGINE_R_FAILED_LOADING_PRIVATE_KEY);
265                 return 0;
266                 }
267         return pkey;
268         }
269
270 EVP_PKEY *ENGINE_load_public_key(ENGINE *e, const char *key_id,
271         const char *passphrase)
272         {
273         EVP_PKEY *pkey;
274
275         if(e == NULL)
276                 {
277                 ENGINEerr(ENGINE_F_ENGINE_LOAD_PUBLIC_KEY,
278                         ERR_R_PASSED_NULL_PARAMETER);
279                 return 0;
280                 }
281         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
282         if(e->funct_ref == 0)
283                 {
284                 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
285                 ENGINEerr(ENGINE_F_ENGINE_LOAD_PUBLIC_KEY,
286                         ENGINE_R_NOT_INITIALISED);
287                 return 0;
288                 }
289         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
290         if (!e->load_pubkey)
291                 {
292                 ENGINEerr(ENGINE_F_ENGINE_LOAD_PUBLIC_KEY,
293                         ENGINE_R_NO_LOAD_FUNCTION);
294                 return 0;
295                 }
296         pkey = e->load_pubkey(e, key_id, passphrase);
297         if (!pkey)
298                 {
299                 ENGINEerr(ENGINE_F_ENGINE_LOAD_PUBLIC_KEY,
300                         ENGINE_R_FAILED_LOADING_PUBLIC_KEY);
301                 return 0;
302                 }
303         return pkey;
304         }
305
306 /* These internal functions handle 'CMD'-related control commands when the
307  * ENGINE in question has asked us to take care of it (ie. the ENGINE did not
308  * set the ENGINE_FLAGS_MANUAL_CMD_CTRL flag. */
309
310 static int int_ctrl_cmd_is_null(const ENGINE_CMD_DEFN *defn)
311         {
312         if((defn->cmd_num == 0) || (defn->cmd_name == NULL))
313                 return 1;
314         return 0;
315         }
316
317 static int int_ctrl_cmd_by_name(const ENGINE_CMD_DEFN *defn, const char *s)
318         {
319         int idx = 0;
320         while(!int_ctrl_cmd_is_null(defn) && (strcmp(defn->cmd_name, s) != 0))
321                 {
322                 idx++;
323                 defn++;
324                 }
325         if(int_ctrl_cmd_is_null(defn))
326                 /* The given name wasn't found */
327                 return -1;
328         return idx;
329         }
330
331 static int int_ctrl_cmd_by_num(const ENGINE_CMD_DEFN *defn, unsigned int num)
332         {
333         int idx = 0;
334         /* NB: It is stipulated that 'cmd_defn' lists are ordered by cmd_num. So
335          * our searches don't need to take any longer than necessary. */
336         while(!int_ctrl_cmd_is_null(defn) && (defn->cmd_num < num))
337                 {
338                 idx++;
339                 defn++;
340                 }
341         if(defn->cmd_num == num)
342                 return idx;
343         /* The given cmd_num wasn't found */
344         return -1;
345         }
346
347 static int int_ctrl_helper(ENGINE *e, int cmd, long i, void *p, void (*f)())
348         {
349         int idx;
350         char *s = (char *)p;
351         /* Take care of the easy one first (eg. it requires no searches) */
352         if(cmd == ENGINE_CTRL_GET_FIRST_CMD_TYPE)
353                 {
354                 if((e->cmd_defns == NULL) || int_ctrl_cmd_is_null(e->cmd_defns))
355                         return 0;
356                 return e->cmd_defns->cmd_num;
357                 }
358         /* One or two commands require that "p" be a valid string buffer */
359         if((cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) ||
360                         (cmd == ENGINE_CTRL_GET_NAME_FROM_CMD) ||
361                         (cmd == ENGINE_CTRL_GET_DESC_FROM_CMD))
362                 {
363                 if(s == NULL)
364                         {
365                         ENGINEerr(ENGINE_F_INT_CTRL_HELPER,
366                                 ERR_R_PASSED_NULL_PARAMETER);
367                         return -1;
368                         }
369                 }
370         /* Now handle cmd_name -> cmd_num conversion */
371         if(cmd == ENGINE_CTRL_GET_CMD_FROM_NAME)
372                 {
373                 if((e->cmd_defns == NULL) || ((idx = int_ctrl_cmd_by_name(
374                                                 e->cmd_defns, s)) < 0))
375                         {
376                         ENGINEerr(ENGINE_F_INT_CTRL_HELPER,
377                                 ENGINE_R_INVALID_CMD_NAME);
378                         return -1;
379                         }
380                 return e->cmd_defns[idx].cmd_num;
381                 }
382         /* For the rest of the commands, the 'long' argument must specify a
383          * valie command number - so we need to conduct a search. */
384         if((e->cmd_defns == NULL) || ((idx = int_ctrl_cmd_by_num(e->cmd_defns,
385                                         (unsigned int)i)) < 0))
386                 {
387                 ENGINEerr(ENGINE_F_INT_CTRL_HELPER,
388                         ENGINE_R_INVALID_CMD_NUMBER);
389                 return -1;
390                 }
391         /* Now the logic splits depending on command type */
392         switch(cmd)
393                 {
394         case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
395                 idx++;
396                 if(int_ctrl_cmd_is_null(e->cmd_defns + idx))
397                         /* end-of-list */
398                         return 0;
399                 else
400                         return e->cmd_defns[idx].cmd_num;
401         case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
402                 return strlen(e->cmd_defns[idx].cmd_name);
403         case ENGINE_CTRL_GET_NAME_FROM_CMD:
404                 return sprintf(s, "%s", e->cmd_defns[idx].cmd_name);
405         case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
406                 if(e->cmd_defns[idx].cmd_desc)
407                         return strlen(e->cmd_defns[idx].cmd_desc);
408                 return strlen(int_no_description);
409         case ENGINE_CTRL_GET_DESC_FROM_CMD:
410                 if(e->cmd_defns[idx].cmd_desc)
411                         return sprintf(s, "%s", e->cmd_defns[idx].cmd_desc);
412                 return sprintf(s, "%s", int_no_description);
413         case ENGINE_CTRL_GET_CMD_FLAGS:
414                 return e->cmd_defns[idx].cmd_flags;
415                 }
416         /* Shouldn't really be here ... */
417         ENGINEerr(ENGINE_F_INT_CTRL_HELPER,ENGINE_R_INTERNAL_LIST_ERROR);
418         return -1;
419         }
420
421 int ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)())
422         {
423         int ctrl_exists, ref_exists;
424         if(e == NULL)
425                 {
426                 ENGINEerr(ENGINE_F_ENGINE_CTRL,ERR_R_PASSED_NULL_PARAMETER);
427                 return 0;
428                 }
429         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
430         ref_exists = ((e->struct_ref > 0) ? 1 : 0);
431         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
432         ctrl_exists = ((e->ctrl == NULL) ? 0 : 1);
433         if(!ref_exists)
434                 {
435                 ENGINEerr(ENGINE_F_ENGINE_CTRL,ENGINE_R_NO_REFERENCE);
436                 return 0;
437                 }
438         /* Intercept any "root-level" commands before trying to hand them on to
439          * ctrl() handlers. */
440         switch(cmd)
441                 {
442         case ENGINE_CTRL_HAS_CTRL_FUNCTION:
443                 return ctrl_exists;
444         case ENGINE_CTRL_GET_FIRST_CMD_TYPE:
445         case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
446         case ENGINE_CTRL_GET_CMD_FROM_NAME:
447         case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
448         case ENGINE_CTRL_GET_NAME_FROM_CMD:
449         case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
450         case ENGINE_CTRL_GET_DESC_FROM_CMD:
451         case ENGINE_CTRL_GET_CMD_FLAGS:
452                 if(ctrl_exists && !(e->flags & ENGINE_FLAGS_MANUAL_CMD_CTRL))
453                         return int_ctrl_helper(e,cmd,i,p,f);
454                 if(!ctrl_exists)
455                         {
456                         ENGINEerr(ENGINE_F_ENGINE_CTRL,ENGINE_R_NO_CONTROL_FUNCTION);
457                         /* For these cmd-related functions, failure is indicated
458                          * by a -1 return value (because 0 is used as a valid
459                          * return in some places). */
460                         return -1;
461                         }
462         default:
463                 break;
464                 }
465         /* Anything else requires a ctrl() handler to exist. */
466         if(!ctrl_exists)
467                 {
468                 ENGINEerr(ENGINE_F_ENGINE_CTRL,ENGINE_R_NO_CONTROL_FUNCTION);
469                 return 0;
470                 }
471         return e->ctrl(e, cmd, i, p, f);
472         }
473
474 int ENGINE_cmd_is_executable(ENGINE *e, int cmd)
475         {
476         int flags;
477         if((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, cmd, NULL, NULL)) < 0)
478                 {
479                 ENGINEerr(ENGINE_F_ENGINE_CMD_IS_EXECUTABLE,
480                         ENGINE_R_INVALID_CMD_NUMBER);
481                 return 0;
482                 }
483         if(!(flags & ENGINE_CMD_FLAG_NO_INPUT) &&
484                         !(flags & ENGINE_CMD_FLAG_NUMERIC) &&
485                         !(flags & ENGINE_CMD_FLAG_STRING))
486                 return 0;
487         return 1;
488         }
489
490 int ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
491                                 int cmd_optional)
492         {
493         int num, flags;
494         long l;
495         char *ptr;
496         if((e == NULL) || (cmd_name == NULL))
497                 {
498                 ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
499                         ERR_R_PASSED_NULL_PARAMETER);
500                 return 0;
501                 }
502         if((e->ctrl == NULL) || ((num = ENGINE_ctrl(e,
503                                         ENGINE_CTRL_GET_CMD_FROM_NAME,
504                                         0, (void *)cmd_name, NULL)) <= 0))
505                 {
506                 /* If the command didn't *have* to be supported, we fake
507                  * success. This allows certain settings to be specified for
508                  * multiple ENGINEs and only require a change of ENGINE id
509                  * (without having to selectively apply settings). Eg. changing
510                  * from a hardware device back to the regular software ENGINE
511                  * without editing the config file, etc. */
512                 if(cmd_optional)
513                         {
514                         ERR_clear_error();
515                         return 1;
516                         }
517                 ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
518                         ENGINE_R_INVALID_CMD_NAME);
519                 return 0;
520                 }
521         if(!ENGINE_cmd_is_executable(e, num))
522                 {
523                 ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
524                         ENGINE_R_CMD_NOT_EXECUTABLE);
525                 return 0;
526                 }
527         if((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num, NULL, NULL)) < 0)
528                 {
529                 /* Shouldn't happen, given that ENGINE_cmd_is_executable()
530                  * returned success. */
531                 ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
532                         ENGINE_R_INTERNAL_LIST_ERROR);
533                 return 0;
534                 }
535         /* If the command takes no input, there must be no input. And vice
536          * versa. */
537         if(flags & ENGINE_CMD_FLAG_NO_INPUT)
538                 {
539                 if(arg != NULL)
540                         {
541                         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
542                                 ENGINE_R_COMMAND_TAKES_NO_INPUT);
543                         return 0;
544                         }
545                 /* We deliberately force the result of ENGINE_ctrl() to 0 or 1
546                  * rather than returning it as "return data". This is to ensure
547                  * usage of these commands is consistent across applications and
548                  * that certain applications don't understand it one way, and
549                  * others another. */
550                 if(ENGINE_ctrl(e, num, 0, (void *)arg, NULL))
551                         return 1;
552                 return 0;
553                 }
554         /* So, we require input */
555         if(arg == NULL)
556                 {
557                 ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
558                         ENGINE_R_COMMAND_TAKES_INPUT);
559                 return 0;
560                 }
561         /* If it takes string input, that's easy */
562         if(flags & ENGINE_CMD_FLAG_STRING)
563                 {
564                 /* Same explanation as above */
565                 if(ENGINE_ctrl(e, num, 0, (void *)arg, NULL))
566                         return 1;
567                 return 0;
568                 }
569         /* If it doesn't take numeric either, then it is unsupported for use in
570          * a config-setting situation, which is what this function is for. This
571          * should never happen though, because ENGINE_cmd_is_executable() was
572          * used. */
573         if(!(flags & ENGINE_CMD_FLAG_NUMERIC))
574                 {
575                 ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
576                         ENGINE_R_INTERNAL_LIST_ERROR);
577                 return 0;
578                 }
579         l = strtol(arg, &ptr, 10);
580         if((arg == ptr) || (*ptr != '\0'))
581                 {
582                 ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
583                         ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);
584                 return 0;
585                 }
586         /* Force the result of the control command to 0 or 1, for the reasons
587          * mentioned before. */
588         if(ENGINE_ctrl(e, num, l, NULL, NULL))
589                 return 1;
590         return 0;
591         }
592
593 static ENGINE *engine_get_default_type(ENGINE_TYPE t)
594         {
595         ENGINE *ret = NULL;
596
597         /* engine_def_check is lean and mean and won't replace any
598          * prior default engines ... so we must ensure that it is always
599          * the first function to get to touch the default values. */
600         engine_def_check();
601         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
602         switch(t)
603                 {
604 #ifndef OPENSSL_NO_RSA
605         case ENGINE_TYPE_RSA:
606                 ret = engine_def_rsa; break;
607 #endif
608 #ifndef OPENSSL_NO_DSA
609         case ENGINE_TYPE_DSA:
610                 ret = engine_def_dsa; break;
611 #endif
612 #ifndef OPENSSL_NO_DH
613         case ENGINE_TYPE_DH:
614                 ret = engine_def_dh; break;
615 #endif
616         case ENGINE_TYPE_RAND:
617                 ret = engine_def_rand; break;
618         case ENGINE_TYPE_BN_MOD_EXP:
619                 ret = engine_def_bn_mod_exp; break;
620         case ENGINE_TYPE_BN_MOD_EXP_CRT:
621                 ret = engine_def_bn_mod_exp_crt; break;
622         default:
623                 break;
624                 }
625         /* Unforunately we can't do this work outside the lock with a
626          * call to ENGINE_init() because that would leave a race
627          * condition open. */
628         if(ret)
629                 {
630                 ret->struct_ref++;
631                 ret->funct_ref++;
632                 engine_ref_debug(ret, 0, 1)
633                 engine_ref_debug(ret, 1, 1)
634                 }
635         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
636         return ret;
637         }
638
639 #ifndef OPENSSL_NO_RSA
640 ENGINE *ENGINE_get_default_RSA(void)
641         {
642         return engine_get_default_type(ENGINE_TYPE_RSA);
643         }
644 #endif
645
646 #ifndef OPENSSL_NO_DSA
647 ENGINE *ENGINE_get_default_DSA(void)
648         {
649         return engine_get_default_type(ENGINE_TYPE_DSA);
650         }
651 #endif
652
653 #ifndef OPENSSL_NO_DH
654 ENGINE *ENGINE_get_default_DH(void)
655         {
656         return engine_get_default_type(ENGINE_TYPE_DH);
657         }
658 #endif
659
660 ENGINE *ENGINE_get_default_RAND(void)
661         {
662         return engine_get_default_type(ENGINE_TYPE_RAND);
663         }
664
665 ENGINE *ENGINE_get_default_BN_mod_exp(void)
666         {
667         return engine_get_default_type(ENGINE_TYPE_BN_MOD_EXP);
668         }
669
670 ENGINE *ENGINE_get_default_BN_mod_exp_crt(void)
671         {
672         return engine_get_default_type(ENGINE_TYPE_BN_MOD_EXP_CRT);
673         }
674
675 static int engine_set_default_type(ENGINE_TYPE t, ENGINE *e)
676         {
677         ENGINE *old = NULL;
678
679         /* engine_def_check is lean and mean and won't replace any
680          * prior default engines ... so we must ensure that it is always
681          * the first function to get to touch the default values. */
682         engine_def_check();
683         /* Attempt to get a functional reference (we need one anyway, but
684          * also, 'e' may be just a structural reference being passed in so
685          * this call may actually be the first). */
686         if(e && !ENGINE_init(e))
687                 {
688                 ENGINEerr(ENGINE_F_ENGINE_SET_DEFAULT_TYPE,
689                         ENGINE_R_INIT_FAILED);
690                 return 0;
691                 }
692         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
693         switch(t)
694                 {
695 #ifndef OPENSSL_NO_RSA
696         case ENGINE_TYPE_RSA:
697                 old = engine_def_rsa;
698                 engine_def_rsa = e; break;
699 #endif
700 #ifndef OPENSSL_NO_DSA
701         case ENGINE_TYPE_DSA:
702                 old = engine_def_dsa;
703                 engine_def_dsa = e; break;
704 #endif
705 #ifndef OPENSSL_NO_DH
706         case ENGINE_TYPE_DH:
707                 old = engine_def_dh;
708                 engine_def_dh = e; break;
709 #endif
710         case ENGINE_TYPE_RAND:
711                 old = engine_def_rand;
712                 engine_def_rand = e; break;
713         case ENGINE_TYPE_BN_MOD_EXP:
714                 old = engine_def_bn_mod_exp;
715                 engine_def_bn_mod_exp = e; break;
716         case ENGINE_TYPE_BN_MOD_EXP_CRT:
717                 old = engine_def_bn_mod_exp_crt;
718                 engine_def_bn_mod_exp_crt = e; break;
719         default:
720                 break;
721                 }
722         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
723         /* If we've replaced a previous value, then we need to remove the
724          * functional reference we had. */
725         if(old && !ENGINE_finish(old))
726                 {
727                 ENGINEerr(ENGINE_F_ENGINE_SET_DEFAULT_TYPE,
728                         ENGINE_R_FINISH_FAILED);
729                 return 0;
730                 }
731         return 1;
732         }
733
734 #ifndef OPENSSL_NO_RSA
735 int ENGINE_set_default_RSA(ENGINE *e)
736         {
737         return engine_set_default_type(ENGINE_TYPE_RSA, e);
738         }
739 #endif
740
741 #ifndef OPENSSL_NO_DSA
742 int ENGINE_set_default_DSA(ENGINE *e)
743         {
744         return engine_set_default_type(ENGINE_TYPE_DSA, e);
745         }
746 #endif
747
748 #ifndef OPENSSL_NO_DH
749 int ENGINE_set_default_DH(ENGINE *e)
750         {
751         return engine_set_default_type(ENGINE_TYPE_DH, e);
752         }
753 #endif
754
755 int ENGINE_set_default_RAND(ENGINE *e)
756         {
757         return engine_set_default_type(ENGINE_TYPE_RAND, e);
758         }
759
760 int ENGINE_set_default_BN_mod_exp(ENGINE *e)
761         {
762         return engine_set_default_type(ENGINE_TYPE_BN_MOD_EXP, e);
763         }
764
765 int ENGINE_set_default_BN_mod_exp_crt(ENGINE *e)
766         {
767         return engine_set_default_type(ENGINE_TYPE_BN_MOD_EXP_CRT, e);
768         }
769
770 int ENGINE_set_default(ENGINE *e, unsigned int flags)
771         {
772 #ifndef OPENSSL_NO_RSA
773         if((flags & ENGINE_METHOD_RSA) && e->rsa_meth &&
774                         !ENGINE_set_default_RSA(e))
775                 return 0;
776 #endif
777 #ifndef OPENSSL_NO_DSA
778         if((flags & ENGINE_METHOD_DSA) && e->dsa_meth &&
779                         !ENGINE_set_default_DSA(e))
780                 return 0;
781 #endif
782 #ifndef OPENSSL_NO_DH
783         if((flags & ENGINE_METHOD_DH) && e->dh_meth &&
784                         !ENGINE_set_default_DH(e))
785                 return 0;
786 #endif
787         if((flags & ENGINE_METHOD_RAND) && e->rand_meth &&
788                         !ENGINE_set_default_RAND(e))
789                 return 0;
790         if((flags & ENGINE_METHOD_BN_MOD_EXP) && e->bn_mod_exp &&
791                         !ENGINE_set_default_BN_mod_exp(e))
792                 return 0;
793         if((flags & ENGINE_METHOD_BN_MOD_EXP_CRT) && e->bn_mod_exp_crt &&
794                         !ENGINE_set_default_BN_mod_exp_crt(e))
795                 return 0;
796         return 1;
797         }
798
799 int ENGINE_clear_defaults(void)
800         {
801         /* If the defaults haven't even been set yet, don't bother. Any kind of
802          * "cleanup" has a kind of implicit race-condition if another thread is
803          * trying to keep going, so we don't address that with locking. The
804          * first ENGINE_set_default_*** call will actually *create* a standard
805          * set of default ENGINEs (including init() and functional reference
806          * counts aplenty) before the rest of this function undoes them all. So
807          * save some hassle ... */
808         if(!engine_def_flag)
809                 return 1;
810         if((0 == 1) ||
811 #ifndef OPENSSL_NO_RSA
812                         !ENGINE_set_default_RSA(NULL) ||
813 #endif
814 #ifndef OPENSSL_NO_DSA
815                         !ENGINE_set_default_DSA(NULL) ||
816 #endif
817 #ifndef OPENSSL_NO_DH
818                         !ENGINE_set_default_DH(NULL) ||
819 #endif
820                         !ENGINE_set_default_RAND(NULL) ||
821                         !ENGINE_set_default_BN_mod_exp(NULL) ||
822                         !ENGINE_set_default_BN_mod_exp_crt(NULL))
823                 return 0;
824         return 1;
825         }
826