eng_dyn.c revision 280304
1/* crypto/engine/eng_dyn.c */ 2/* 3 * Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL project 4 * 2001. 5 */ 6/* ==================================================================== 7 * Copyright (c) 1999-2001 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * licensing@OpenSSL.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay@cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh@cryptsoft.com). 57 * 58 */ 59 60#include "eng_int.h" 61#include <openssl/dso.h> 62 63/* 64 * Shared libraries implementing ENGINEs for use by the "dynamic" ENGINE 65 * loader should implement the hook-up functions with the following 66 * prototypes. 67 */ 68 69/* Our ENGINE handlers */ 70static int dynamic_init(ENGINE *e); 71static int dynamic_finish(ENGINE *e); 72static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, 73 void (*f) (void)); 74/* Predeclare our context type */ 75typedef struct st_dynamic_data_ctx dynamic_data_ctx; 76/* The implementation for the important control command */ 77static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx); 78 79#define DYNAMIC_CMD_SO_PATH ENGINE_CMD_BASE 80#define DYNAMIC_CMD_NO_VCHECK (ENGINE_CMD_BASE + 1) 81#define DYNAMIC_CMD_ID (ENGINE_CMD_BASE + 2) 82#define DYNAMIC_CMD_LIST_ADD (ENGINE_CMD_BASE + 3) 83#define DYNAMIC_CMD_DIR_LOAD (ENGINE_CMD_BASE + 4) 84#define DYNAMIC_CMD_DIR_ADD (ENGINE_CMD_BASE + 5) 85#define DYNAMIC_CMD_LOAD (ENGINE_CMD_BASE + 6) 86 87/* The constants used when creating the ENGINE */ 88static const char *engine_dynamic_id = "dynamic"; 89static const char *engine_dynamic_name = "Dynamic engine loading support"; 90static const ENGINE_CMD_DEFN dynamic_cmd_defns[] = { 91 {DYNAMIC_CMD_SO_PATH, 92 "SO_PATH", 93 "Specifies the path to the new ENGINE shared library", 94 ENGINE_CMD_FLAG_STRING}, 95 {DYNAMIC_CMD_NO_VCHECK, 96 "NO_VCHECK", 97 "Specifies to continue even if version checking fails (boolean)", 98 ENGINE_CMD_FLAG_NUMERIC}, 99 {DYNAMIC_CMD_ID, 100 "ID", 101 "Specifies an ENGINE id name for loading", 102 ENGINE_CMD_FLAG_STRING}, 103 {DYNAMIC_CMD_LIST_ADD, 104 "LIST_ADD", 105 "Whether to add a loaded ENGINE to the internal list (0=no,1=yes,2=mandatory)", 106 ENGINE_CMD_FLAG_NUMERIC}, 107 {DYNAMIC_CMD_DIR_LOAD, 108 "DIR_LOAD", 109 "Specifies whether to load from 'DIR_ADD' directories (0=no,1=yes,2=mandatory)", 110 ENGINE_CMD_FLAG_NUMERIC}, 111 {DYNAMIC_CMD_DIR_ADD, 112 "DIR_ADD", 113 "Adds a directory from which ENGINEs can be loaded", 114 ENGINE_CMD_FLAG_STRING}, 115 {DYNAMIC_CMD_LOAD, 116 "LOAD", 117 "Load up the ENGINE specified by other settings", 118 ENGINE_CMD_FLAG_NO_INPUT}, 119 {0, NULL, NULL, 0} 120}; 121 122/* 123 * Loading code stores state inside the ENGINE structure via the "ex_data" 124 * element. We load all our state into a single structure and use that as a 125 * single context in the "ex_data" stack. 126 */ 127struct st_dynamic_data_ctx { 128 /* The DSO object we load that supplies the ENGINE code */ 129 DSO *dynamic_dso; 130 /* 131 * The function pointer to the version checking shared library function 132 */ 133 dynamic_v_check_fn v_check; 134 /* 135 * The function pointer to the engine-binding shared library function 136 */ 137 dynamic_bind_engine bind_engine; 138 /* The default name/path for loading the shared library */ 139 const char *DYNAMIC_LIBNAME; 140 /* Whether to continue loading on a version check failure */ 141 int no_vcheck; 142 /* If non-NULL, stipulates the 'id' of the ENGINE to be loaded */ 143 const char *engine_id; 144 /* 145 * If non-zero, a successfully loaded ENGINE should be added to the 146 * internal ENGINE list. If 2, the add must succeed or the entire load 147 * should fail. 148 */ 149 int list_add_value; 150 /* The symbol name for the version checking function */ 151 const char *DYNAMIC_F1; 152 /* The symbol name for the "initialise ENGINE structure" function */ 153 const char *DYNAMIC_F2; 154 /* 155 * Whether to never use 'dirs', use 'dirs' as a fallback, or only use 156 * 'dirs' for loading. Default is to use 'dirs' as a fallback. 157 */ 158 int dir_load; 159 /* A stack of directories from which ENGINEs could be loaded */ 160 STACK_OF(OPENSSL_STRING) *dirs; 161}; 162 163/* 164 * This is the "ex_data" index we obtain and reserve for use with our context 165 * structure. 166 */ 167static int dynamic_ex_data_idx = -1; 168 169static void int_free_str(char *s) 170{ 171 OPENSSL_free(s); 172} 173 174/* 175 * Because our ex_data element may or may not get allocated depending on 176 * whether a "first-use" occurs before the ENGINE is freed, we have a memory 177 * leak problem to solve. We can't declare a "new" handler for the ex_data as 178 * we don't want a dynamic_data_ctx in *all* ENGINE structures of all types 179 * (this is a bug in the design of CRYPTO_EX_DATA). As such, we just declare 180 * a "free" handler and that will get called if an ENGINE is being destroyed 181 * and there was an ex_data element corresponding to our context type. 182 */ 183static void dynamic_data_ctx_free_func(void *parent, void *ptr, 184 CRYPTO_EX_DATA *ad, int idx, long argl, 185 void *argp) 186{ 187 if (ptr) { 188 dynamic_data_ctx *ctx = (dynamic_data_ctx *)ptr; 189 if (ctx->dynamic_dso) 190 DSO_free(ctx->dynamic_dso); 191 if (ctx->DYNAMIC_LIBNAME) 192 OPENSSL_free((void *)ctx->DYNAMIC_LIBNAME); 193 if (ctx->engine_id) 194 OPENSSL_free((void *)ctx->engine_id); 195 if (ctx->dirs) 196 sk_OPENSSL_STRING_pop_free(ctx->dirs, int_free_str); 197 OPENSSL_free(ctx); 198 } 199} 200 201/* 202 * Construct the per-ENGINE context. We create it blindly and then use a lock 203 * to check for a race - if so, all but one of the threads "racing" will have 204 * wasted their time. The alternative involves creating everything inside the 205 * lock which is far worse. 206 */ 207static int dynamic_set_data_ctx(ENGINE *e, dynamic_data_ctx **ctx) 208{ 209 dynamic_data_ctx *c; 210 c = OPENSSL_malloc(sizeof(dynamic_data_ctx)); 211 if (!c) { 212 ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX, ERR_R_MALLOC_FAILURE); 213 return 0; 214 } 215 memset(c, 0, sizeof(dynamic_data_ctx)); 216 c->dynamic_dso = NULL; 217 c->v_check = NULL; 218 c->bind_engine = NULL; 219 c->DYNAMIC_LIBNAME = NULL; 220 c->no_vcheck = 0; 221 c->engine_id = NULL; 222 c->list_add_value = 0; 223 c->DYNAMIC_F1 = "v_check"; 224 c->DYNAMIC_F2 = "bind_engine"; 225 c->dir_load = 1; 226 c->dirs = sk_OPENSSL_STRING_new_null(); 227 if (!c->dirs) { 228 ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX, ERR_R_MALLOC_FAILURE); 229 OPENSSL_free(c); 230 return 0; 231 } 232 CRYPTO_w_lock(CRYPTO_LOCK_ENGINE); 233 if ((*ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, 234 dynamic_ex_data_idx)) 235 == NULL) { 236 /* Good, we're the first */ 237 ENGINE_set_ex_data(e, dynamic_ex_data_idx, c); 238 *ctx = c; 239 c = NULL; 240 } 241 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE); 242 /* 243 * If we lost the race to set the context, c is non-NULL and *ctx is the 244 * context of the thread that won. 245 */ 246 if (c) 247 OPENSSL_free(c); 248 return 1; 249} 250 251/* 252 * This function retrieves the context structure from an ENGINE's "ex_data", 253 * or if it doesn't exist yet, sets it up. 254 */ 255static dynamic_data_ctx *dynamic_get_data_ctx(ENGINE *e) 256{ 257 dynamic_data_ctx *ctx; 258 if (dynamic_ex_data_idx < 0) { 259 /* 260 * Create and register the ENGINE ex_data, and associate our "free" 261 * function with it to ensure any allocated contexts get freed when 262 * an ENGINE goes underground. 263 */ 264 int new_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL, 265 dynamic_data_ctx_free_func); 266 if (new_idx == -1) { 267 ENGINEerr(ENGINE_F_DYNAMIC_GET_DATA_CTX, ENGINE_R_NO_INDEX); 268 return NULL; 269 } 270 CRYPTO_w_lock(CRYPTO_LOCK_ENGINE); 271 /* Avoid a race by checking again inside this lock */ 272 if (dynamic_ex_data_idx < 0) { 273 /* Good, someone didn't beat us to it */ 274 dynamic_ex_data_idx = new_idx; 275 new_idx = -1; 276 } 277 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE); 278 /* 279 * In theory we could "give back" the index here if (new_idx>-1), but 280 * it's not possible and wouldn't gain us much if it were. 281 */ 282 } 283 ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, dynamic_ex_data_idx); 284 /* Check if the context needs to be created */ 285 if ((ctx == NULL) && !dynamic_set_data_ctx(e, &ctx)) 286 /* "set_data" will set errors if necessary */ 287 return NULL; 288 return ctx; 289} 290 291static ENGINE *engine_dynamic(void) 292{ 293 ENGINE *ret = ENGINE_new(); 294 if (!ret) 295 return NULL; 296 if (!ENGINE_set_id(ret, engine_dynamic_id) || 297 !ENGINE_set_name(ret, engine_dynamic_name) || 298 !ENGINE_set_init_function(ret, dynamic_init) || 299 !ENGINE_set_finish_function(ret, dynamic_finish) || 300 !ENGINE_set_ctrl_function(ret, dynamic_ctrl) || 301 !ENGINE_set_flags(ret, ENGINE_FLAGS_BY_ID_COPY) || 302 !ENGINE_set_cmd_defns(ret, dynamic_cmd_defns)) { 303 ENGINE_free(ret); 304 return NULL; 305 } 306 return ret; 307} 308 309void ENGINE_load_dynamic(void) 310{ 311 ENGINE *toadd = engine_dynamic(); 312 if (!toadd) 313 return; 314 ENGINE_add(toadd); 315 /* 316 * If the "add" worked, it gets a structural reference. So either way, we 317 * release our just-created reference. 318 */ 319 ENGINE_free(toadd); 320 /* 321 * If the "add" didn't work, it was probably a conflict because it was 322 * already added (eg. someone calling ENGINE_load_blah then calling 323 * ENGINE_load_builtin_engines() perhaps). 324 */ 325 ERR_clear_error(); 326} 327 328static int dynamic_init(ENGINE *e) 329{ 330 /* 331 * We always return failure - the "dyanamic" engine itself can't be used 332 * for anything. 333 */ 334 return 0; 335} 336 337static int dynamic_finish(ENGINE *e) 338{ 339 /* 340 * This should never be called on account of "dynamic_init" always 341 * failing. 342 */ 343 return 0; 344} 345 346static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void)) 347{ 348 dynamic_data_ctx *ctx = dynamic_get_data_ctx(e); 349 int initialised; 350 351 if (!ctx) { 352 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_NOT_LOADED); 353 return 0; 354 } 355 initialised = ((ctx->dynamic_dso == NULL) ? 0 : 1); 356 /* All our control commands require the ENGINE to be uninitialised */ 357 if (initialised) { 358 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_ALREADY_LOADED); 359 return 0; 360 } 361 switch (cmd) { 362 case DYNAMIC_CMD_SO_PATH: 363 /* a NULL 'p' or a string of zero-length is the same thing */ 364 if (p && (strlen((const char *)p) < 1)) 365 p = NULL; 366 if (ctx->DYNAMIC_LIBNAME) 367 OPENSSL_free((void *)ctx->DYNAMIC_LIBNAME); 368 if (p) 369 ctx->DYNAMIC_LIBNAME = BUF_strdup(p); 370 else 371 ctx->DYNAMIC_LIBNAME = NULL; 372 return (ctx->DYNAMIC_LIBNAME ? 1 : 0); 373 case DYNAMIC_CMD_NO_VCHECK: 374 ctx->no_vcheck = ((i == 0) ? 0 : 1); 375 return 1; 376 case DYNAMIC_CMD_ID: 377 /* a NULL 'p' or a string of zero-length is the same thing */ 378 if (p && (strlen((const char *)p) < 1)) 379 p = NULL; 380 if (ctx->engine_id) 381 OPENSSL_free((void *)ctx->engine_id); 382 if (p) 383 ctx->engine_id = BUF_strdup(p); 384 else 385 ctx->engine_id = NULL; 386 return (ctx->engine_id ? 1 : 0); 387 case DYNAMIC_CMD_LIST_ADD: 388 if ((i < 0) || (i > 2)) { 389 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT); 390 return 0; 391 } 392 ctx->list_add_value = (int)i; 393 return 1; 394 case DYNAMIC_CMD_LOAD: 395 return dynamic_load(e, ctx); 396 case DYNAMIC_CMD_DIR_LOAD: 397 if ((i < 0) || (i > 2)) { 398 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT); 399 return 0; 400 } 401 ctx->dir_load = (int)i; 402 return 1; 403 case DYNAMIC_CMD_DIR_ADD: 404 /* a NULL 'p' or a string of zero-length is the same thing */ 405 if (!p || (strlen((const char *)p) < 1)) { 406 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT); 407 return 0; 408 } 409 { 410 char *tmp_str = BUF_strdup(p); 411 if (!tmp_str) { 412 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ERR_R_MALLOC_FAILURE); 413 return 0; 414 } 415 sk_OPENSSL_STRING_insert(ctx->dirs, tmp_str, -1); 416 } 417 return 1; 418 default: 419 break; 420 } 421 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED); 422 return 0; 423} 424 425static int int_load(dynamic_data_ctx *ctx) 426{ 427 int num, loop; 428 /* Unless told not to, try a direct load */ 429 if ((ctx->dir_load != 2) && (DSO_load(ctx->dynamic_dso, 430 ctx->DYNAMIC_LIBNAME, NULL, 431 0)) != NULL) 432 return 1; 433 /* If we're not allowed to use 'dirs' or we have none, fail */ 434 if (!ctx->dir_load || (num = sk_OPENSSL_STRING_num(ctx->dirs)) < 1) 435 return 0; 436 for (loop = 0; loop < num; loop++) { 437 const char *s = sk_OPENSSL_STRING_value(ctx->dirs, loop); 438 char *merge = DSO_merge(ctx->dynamic_dso, ctx->DYNAMIC_LIBNAME, s); 439 if (!merge) 440 return 0; 441 if (DSO_load(ctx->dynamic_dso, merge, NULL, 0)) { 442 /* Found what we're looking for */ 443 OPENSSL_free(merge); 444 return 1; 445 } 446 OPENSSL_free(merge); 447 } 448 return 0; 449} 450 451static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx) 452{ 453 ENGINE cpy; 454 dynamic_fns fns; 455 456 if (!ctx->dynamic_dso) 457 ctx->dynamic_dso = DSO_new(); 458 if (!ctx->DYNAMIC_LIBNAME) { 459 if (!ctx->engine_id) 460 return 0; 461 ctx->DYNAMIC_LIBNAME = 462 DSO_convert_filename(ctx->dynamic_dso, ctx->engine_id); 463 } 464 if (!int_load(ctx)) { 465 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_NOT_FOUND); 466 DSO_free(ctx->dynamic_dso); 467 ctx->dynamic_dso = NULL; 468 return 0; 469 } 470 /* We have to find a bind function otherwise it'll always end badly */ 471 if (! 472 (ctx->bind_engine = 473 (dynamic_bind_engine) DSO_bind_func(ctx->dynamic_dso, 474 ctx->DYNAMIC_F2))) { 475 ctx->bind_engine = NULL; 476 DSO_free(ctx->dynamic_dso); 477 ctx->dynamic_dso = NULL; 478 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_FAILURE); 479 return 0; 480 } 481 /* Do we perform version checking? */ 482 if (!ctx->no_vcheck) { 483 unsigned long vcheck_res = 0; 484 /* 485 * Now we try to find a version checking function and decide how to 486 * cope with failure if/when it fails. 487 */ 488 ctx->v_check = 489 (dynamic_v_check_fn) DSO_bind_func(ctx->dynamic_dso, 490 ctx->DYNAMIC_F1); 491 if (ctx->v_check) 492 vcheck_res = ctx->v_check(OSSL_DYNAMIC_VERSION); 493 /* 494 * We fail if the version checker veto'd the load *or* if it is 495 * deferring to us (by returning its version) and we think it is too 496 * old. 497 */ 498 if (vcheck_res < OSSL_DYNAMIC_OLDEST) { 499 /* Fail */ 500 ctx->bind_engine = NULL; 501 ctx->v_check = NULL; 502 DSO_free(ctx->dynamic_dso); 503 ctx->dynamic_dso = NULL; 504 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, 505 ENGINE_R_VERSION_INCOMPATIBILITY); 506 return 0; 507 } 508 } 509 /* 510 * First binary copy the ENGINE structure so that we can roll back if the 511 * hand-over fails 512 */ 513 memcpy(&cpy, e, sizeof(ENGINE)); 514 /* 515 * Provide the ERR, "ex_data", memory, and locking callbacks so the 516 * loaded library uses our state rather than its own. FIXME: As noted in 517 * engine.h, much of this would be simplified if each area of code 518 * provided its own "summary" structure of all related callbacks. It 519 * would also increase opaqueness. 520 */ 521 fns.static_state = ENGINE_get_static_state(); 522 fns.err_fns = ERR_get_implementation(); 523 fns.ex_data_fns = CRYPTO_get_ex_data_implementation(); 524 CRYPTO_get_mem_functions(&fns.mem_fns.malloc_cb, 525 &fns.mem_fns.realloc_cb, &fns.mem_fns.free_cb); 526 fns.lock_fns.lock_locking_cb = CRYPTO_get_locking_callback(); 527 fns.lock_fns.lock_add_lock_cb = CRYPTO_get_add_lock_callback(); 528 fns.lock_fns.dynlock_create_cb = CRYPTO_get_dynlock_create_callback(); 529 fns.lock_fns.dynlock_lock_cb = CRYPTO_get_dynlock_lock_callback(); 530 fns.lock_fns.dynlock_destroy_cb = CRYPTO_get_dynlock_destroy_callback(); 531 /* 532 * Now that we've loaded the dynamic engine, make sure no "dynamic" 533 * ENGINE elements will show through. 534 */ 535 engine_set_all_null(e); 536 537 /* Try to bind the ENGINE onto our own ENGINE structure */ 538 if (!ctx->bind_engine(e, ctx->engine_id, &fns)) { 539 ctx->bind_engine = NULL; 540 ctx->v_check = NULL; 541 DSO_free(ctx->dynamic_dso); 542 ctx->dynamic_dso = NULL; 543 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_INIT_FAILED); 544 /* Copy the original ENGINE structure back */ 545 memcpy(e, &cpy, sizeof(ENGINE)); 546 return 0; 547 } 548 /* Do we try to add this ENGINE to the internal list too? */ 549 if (ctx->list_add_value > 0) { 550 if (!ENGINE_add(e)) { 551 /* Do we tolerate this or fail? */ 552 if (ctx->list_add_value > 1) { 553 /* 554 * Fail - NB: By this time, it's too late to rollback, and 555 * trying to do so allows the bind_engine() code to have 556 * created leaks. We just have to fail where we are, after 557 * the ENGINE has changed. 558 */ 559 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, 560 ENGINE_R_CONFLICTING_ENGINE_ID); 561 return 0; 562 } 563 /* Tolerate */ 564 ERR_clear_error(); 565 } 566 } 567 return 1; 568} 569