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