crypto/engine/eng_dyn.c

   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 */
  70 static int dynamic_init(ENGINE *e);
  71 static int dynamic_finish(ENGINE *e);
  72 static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p,
  73                         void (*f) (void));
  74 /* Predeclare our context type */
  75 typedef struct st_dynamic_data_ctx dynamic_data_ctx;
  76 /* The implementation for the important control command */
  77 static 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 */
  88 static const char *engine_dynamic_id = "dynamic";
  89 static const char *engine_dynamic_name = "Dynamic engine loading support";
  90 static 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  */
 127 struct 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     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     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  */
 167 static int dynamic_ex_data_idx = -1;
 168
 169 static 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  */
 183 static 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         DSO_free(ctx->dynamic_dso);
 190         OPENSSL_free(ctx->DYNAMIC_LIBNAME);
 191         OPENSSL_free(ctx->engine_id);
 192         sk_OPENSSL_STRING_pop_free(ctx->dirs, int_free_str);
 193         OPENSSL_free(ctx);
 194     }
 195 }
 196
 197 /*
 198  * Construct the per-ENGINE context. We create it blindly and then use a lock
 199  * to check for a race - if so, all but one of the threads "racing" will have
 200  * wasted their time. The alternative involves creating everything inside the
 201  * lock which is far worse.
 202  */
 203 static int dynamic_set_data_ctx(ENGINE *e, dynamic_data_ctx **ctx)
 204 {
 205     dynamic_data_ctx *c = OPENSSL_zalloc(sizeof(*c));
 206
 207     if (c == NULL) {
 208         ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX, ERR_R_MALLOC_FAILURE);
 209         return 0;
 210     }
 211     c->dirs = sk_OPENSSL_STRING_new_null();
 212     if (c->dirs == NULL) {
 213         ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX, ERR_R_MALLOC_FAILURE);
 214         OPENSSL_free(c);
 215         return 0;
 216     }
 217     c->DYNAMIC_F1 = "v_check";
 218     c->DYNAMIC_F2 = "bind_engine";
 219     c->dir_load = 1;
 220     CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 221     if ((*ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e,
 222                                                        dynamic_ex_data_idx))
 223         == NULL) {
 224         /* Good, we're the first */
 225         ENGINE_set_ex_data(e, dynamic_ex_data_idx, c);
 226         *ctx = c;
 227         c = NULL;
 228     }
 229     CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 230     /*
 231      * If we lost the race to set the context, c is non-NULL and *ctx is the
 232      * context of the thread that won.
 233      */
 234     OPENSSL_free(c);
 235     return 1;
 236 }
 237
 238 /*
 239  * This function retrieves the context structure from an ENGINE's "ex_data",
 240  * or if it doesn't exist yet, sets it up.
 241  */
 242 static dynamic_data_ctx *dynamic_get_data_ctx(ENGINE *e)
 243 {
 244     dynamic_data_ctx *ctx;
 245     if (dynamic_ex_data_idx < 0) {
 246         /*
 247          * Create and register the ENGINE ex_data, and associate our "free"
 248          * function with it to ensure any allocated contexts get freed when
 249          * an ENGINE goes underground.
 250          */
 251         int new_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL,
 252                                               dynamic_data_ctx_free_func);
 253         if (new_idx == -1) {
 254             ENGINEerr(ENGINE_F_DYNAMIC_GET_DATA_CTX, ENGINE_R_NO_INDEX);
 255             return NULL;
 256         }
 257         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 258         /* Avoid a race by checking again inside this lock */
 259         if (dynamic_ex_data_idx < 0) {
 260             /* Good, someone didn't beat us to it */
 261             dynamic_ex_data_idx = new_idx;
 262             new_idx = -1;
 263         }
 264         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 265         /*
 266          * In theory we could "give back" the index here if (new_idx>-1), but
 267          * it's not possible and wouldn't gain us much if it were.
 268          */
 269     }
 270     ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, dynamic_ex_data_idx);
 271     /* Check if the context needs to be created */
 272     if ((ctx == NULL) && !dynamic_set_data_ctx(e, &ctx))
 273         /* "set_data" will set errors if necessary */
 274         return NULL;
 275     return ctx;
 276 }
 277
 278 static ENGINE *engine_dynamic(void)
 279 {
 280     ENGINE *ret = ENGINE_new();
 281     if (ret == NULL)
 282         return NULL;
 283     if (!ENGINE_set_id(ret, engine_dynamic_id) ||
 284         !ENGINE_set_name(ret, engine_dynamic_name) ||
 285         !ENGINE_set_init_function(ret, dynamic_init) ||
 286         !ENGINE_set_finish_function(ret, dynamic_finish) ||
 287         !ENGINE_set_ctrl_function(ret, dynamic_ctrl) ||
 288         !ENGINE_set_flags(ret, ENGINE_FLAGS_BY_ID_COPY) ||
 289         !ENGINE_set_cmd_defns(ret, dynamic_cmd_defns)) {
 290         ENGINE_free(ret);
 291         return NULL;
 292     }
 293     return ret;
 294 }
 295
 296 void ENGINE_load_dynamic(void)
 297 {
 298     ENGINE *toadd = engine_dynamic();
 299     if (!toadd)
 300         return;
 301     ENGINE_add(toadd);
 302     /*
 303      * If the "add" worked, it gets a structural reference. So either way, we
 304      * release our just-created reference.
 305      */
 306     ENGINE_free(toadd);
 307     /*
 308      * If the "add" didn't work, it was probably a conflict because it was
 309      * already added (eg. someone calling ENGINE_load_blah then calling
 310      * ENGINE_load_builtin_engines() perhaps).
 311      */
 312     ERR_clear_error();
 313 }
 314
 315 static int dynamic_init(ENGINE *e)
 316 {
 317     /*
 318      * We always return failure - the "dyanamic" engine itself can't be used
 319      * for anything.
 320      */
 321     return 0;
 322 }
 323
 324 static int dynamic_finish(ENGINE *e)
 325 {
 326     /*
 327      * This should never be called on account of "dynamic_init" always
 328      * failing.
 329      */
 330     return 0;
 331 }
 332
 333 static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
 334 {
 335     dynamic_data_ctx *ctx = dynamic_get_data_ctx(e);
 336     int initialised;
 337
 338     if (!ctx) {
 339         ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_NOT_LOADED);
 340         return 0;
 341     }
 342     initialised = ((ctx->dynamic_dso == NULL) ? 0 : 1);
 343     /* All our control commands require the ENGINE to be uninitialised */
 344     if (initialised) {
 345         ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_ALREADY_LOADED);
 346         return 0;
 347     }
 348     switch (cmd) {
 349     case DYNAMIC_CMD_SO_PATH:
 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         OPENSSL_free(ctx->DYNAMIC_LIBNAME);
 354         if (p)
 355             ctx->DYNAMIC_LIBNAME = OPENSSL_strdup(p);
 356         else
 357             ctx->DYNAMIC_LIBNAME = NULL;
 358         return (ctx->DYNAMIC_LIBNAME ? 1 : 0);
 359     case DYNAMIC_CMD_NO_VCHECK:
 360         ctx->no_vcheck = ((i == 0) ? 0 : 1);
 361         return 1;
 362     case DYNAMIC_CMD_ID:
 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         OPENSSL_free(ctx->engine_id);
 367         if (p)
 368             ctx->engine_id = OPENSSL_strdup(p);
 369         else
 370             ctx->engine_id = NULL;
 371         return (ctx->engine_id ? 1 : 0);
 372     case DYNAMIC_CMD_LIST_ADD:
 373         if ((i < 0) || (i > 2)) {
 374             ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
 375             return 0;
 376         }
 377         ctx->list_add_value = (int)i;
 378         return 1;
 379     case DYNAMIC_CMD_LOAD:
 380         return dynamic_load(e, ctx);
 381     case DYNAMIC_CMD_DIR_LOAD:
 382         if ((i < 0) || (i > 2)) {
 383             ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
 384             return 0;
 385         }
 386         ctx->dir_load = (int)i;
 387         return 1;
 388     case DYNAMIC_CMD_DIR_ADD:
 389         /* a NULL 'p' or a string of zero-length is the same thing */
 390         if (!p || (strlen((const char *)p) < 1)) {
 391             ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
 392             return 0;
 393         }
 394         {
 395             char *tmp_str = OPENSSL_strdup(p);
 396             if (!tmp_str) {
 397                 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ERR_R_MALLOC_FAILURE);
 398                 return 0;
 399             }
 400             sk_OPENSSL_STRING_insert(ctx->dirs, tmp_str, -1);
 401         }
 402         return 1;
 403     default:
 404         break;
 405     }
 406     ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED);
 407     return 0;
 408 }
 409
 410 static int int_load(dynamic_data_ctx *ctx)
 411 {
 412     int num, loop;
 413     /* Unless told not to, try a direct load */
 414     if ((ctx->dir_load != 2) && (DSO_load(ctx->dynamic_dso,
 415                                           ctx->DYNAMIC_LIBNAME, NULL,
 416                                           0)) != NULL)
 417         return 1;
 418     /* If we're not allowed to use 'dirs' or we have none, fail */
 419     if (!ctx->dir_load || (num = sk_OPENSSL_STRING_num(ctx->dirs)) < 1)
 420         return 0;
 421     for (loop = 0; loop < num; loop++) {
 422         const char *s = sk_OPENSSL_STRING_value(ctx->dirs, loop);
 423         char *merge = DSO_merge(ctx->dynamic_dso, ctx->DYNAMIC_LIBNAME, s);
 424         if (!merge)
 425             return 0;
 426         if (DSO_load(ctx->dynamic_dso, merge, NULL, 0)) {
 427             /* Found what we're looking for */
 428             OPENSSL_free(merge);
 429             return 1;
 430         }
 431         OPENSSL_free(merge);
 432     }
 433     return 0;
 434 }
 435
 436 static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx)
 437 {
 438     ENGINE cpy;
 439     dynamic_fns fns;
 440
 441     if (ctx->dynamic_dso == NULL)
 442         ctx->dynamic_dso = DSO_new();
 443     if (ctx->dynamic_dso == NULL)
 444         return 0;
 445     if (!ctx->DYNAMIC_LIBNAME) {
 446         if (!ctx->engine_id)
 447             return 0;
 448         ctx->DYNAMIC_LIBNAME =
 449             DSO_convert_filename(ctx->dynamic_dso, ctx->engine_id);
 450     }
 451     if (!int_load(ctx)) {
 452         ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_NOT_FOUND);
 453         DSO_free(ctx->dynamic_dso);
 454         ctx->dynamic_dso = NULL;
 455         return 0;
 456     }
 457     /* We have to find a bind function otherwise it'll always end badly */
 458     if (!
 459         (ctx->bind_engine =
 460          (dynamic_bind_engine) DSO_bind_func(ctx->dynamic_dso,
 461                                              ctx->DYNAMIC_F2))) {
 462         ctx->bind_engine = NULL;
 463         DSO_free(ctx->dynamic_dso);
 464         ctx->dynamic_dso = NULL;
 465         ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_FAILURE);
 466         return 0;
 467     }
 468     /* Do we perform version checking? */
 469     if (!ctx->no_vcheck) {
 470         unsigned long vcheck_res = 0;
 471         /*
 472          * Now we try to find a version checking function and decide how to
 473          * cope with failure if/when it fails.
 474          */
 475         ctx->v_check =
 476             (dynamic_v_check_fn) DSO_bind_func(ctx->dynamic_dso,
 477                                                ctx->DYNAMIC_F1);
 478         if (ctx->v_check)
 479             vcheck_res = ctx->v_check(OSSL_DYNAMIC_VERSION);
 480         /*
 481          * We fail if the version checker veto'd the load *or* if it is
 482          * deferring to us (by returning its version) and we think it is too
 483          * old.
 484          */
 485         if (vcheck_res < OSSL_DYNAMIC_OLDEST) {
 486             /* Fail */
 487             ctx->bind_engine = NULL;
 488             ctx->v_check = NULL;
 489             DSO_free(ctx->dynamic_dso);
 490             ctx->dynamic_dso = NULL;
 491             ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
 492                       ENGINE_R_VERSION_INCOMPATIBILITY);
 493             return 0;
 494         }
 495     }
 496     /*
 497      * First binary copy the ENGINE structure so that we can roll back if the
 498      * hand-over fails
 499      */
 500     memcpy(&cpy, e, sizeof(ENGINE));
 501     /*
 502      * Provide the ERR, "ex_data", memory, and locking callbacks so the
 503      * loaded library uses our state rather than its own. FIXME: As noted in
 504      * engine.h, much of this would be simplified if each area of code
 505      * provided its own "summary" structure of all related callbacks. It
 506      * would also increase opaqueness.
 507      */
 508     fns.static_state = ENGINE_get_static_state();
 509     CRYPTO_get_mem_functions(&fns.mem_fns.malloc_cb,
 510                              &fns.mem_fns.realloc_cb, &fns.mem_fns.free_cb);
 511     fns.lock_fns.lock_locking_cb = CRYPTO_get_locking_callback();
 512     fns.lock_fns.lock_add_lock_cb = CRYPTO_get_add_lock_callback();
 513     fns.lock_fns.dynlock_create_cb = CRYPTO_get_dynlock_create_callback();
 514     fns.lock_fns.dynlock_lock_cb = CRYPTO_get_dynlock_lock_callback();
 515     fns.lock_fns.dynlock_destroy_cb = CRYPTO_get_dynlock_destroy_callback();
 516     /*
 517      * Now that we've loaded the dynamic engine, make sure no "dynamic"
 518      * ENGINE elements will show through.
 519      */
 520     engine_set_all_null(e);
 521
 522     /* Try to bind the ENGINE onto our own ENGINE structure */
 523     if (!ctx->bind_engine(e, ctx->engine_id, &fns)) {
 524         ctx->bind_engine = NULL;
 525         ctx->v_check = NULL;
 526         DSO_free(ctx->dynamic_dso);
 527         ctx->dynamic_dso = NULL;
 528         ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_INIT_FAILED);
 529         /* Copy the original ENGINE structure back */
 530         memcpy(e, &cpy, sizeof(ENGINE));
 531         return 0;
 532     }
 533     /* Do we try to add this ENGINE to the internal list too? */
 534     if (ctx->list_add_value > 0) {
 535         if (!ENGINE_add(e)) {
 536             /* Do we tolerate this or fail? */
 537             if (ctx->list_add_value > 1) {
 538                 /*
 539                  * Fail - NB: By this time, it's too late to rollback, and
 540                  * trying to do so allows the bind_engine() code to have
 541                  * created leaks. We just have to fail where we are, after
 542                  * the ENGINE has changed.
 543                  */
 544                 ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
 545                           ENGINE_R_CONFLICTING_ENGINE_ID);
 546                 return 0;
 547             }
 548             /* Tolerate */
 549             ERR_clear_error();
 550         }
 551     }
 552     return 1;
 553 }