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