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         if (ctx->dirs)
 193             sk_OPENSSL_STRING_pop_free(ctx->dirs, int_free_str);
 194         OPENSSL_free(ctx);
 195     }
 196 }
 197
 198 /*
 199  * Construct the per-ENGINE context. We create it blindly and then use a lock
 200  * to check for a race - if so, all but one of the threads "racing" will have
 201  * wasted their time. The alternative involves creating everything inside the
 202  * lock which is far worse.
 203  */
 204 static int dynamic_set_data_ctx(ENGINE *e, dynamic_data_ctx **ctx)
 205 {
 206     dynamic_data_ctx *c;
 207     c = OPENSSL_malloc(sizeof(dynamic_data_ctx));
 208     if (!c) {
 209         ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX, ERR_R_MALLOC_FAILURE);
 210         return 0;
 211     }
 212     memset(c, 0, sizeof(dynamic_data_ctx));
 213     c->dynamic_dso = NULL;
 214     c->v_check = NULL;
 215     c->bind_engine = NULL;
 216     c->DYNAMIC_LIBNAME = NULL;
 217     c->no_vcheck = 0;
 218     c->engine_id = NULL;
 219     c->list_add_value = 0;
 220     c->DYNAMIC_F1 = "v_check";
 221     c->DYNAMIC_F2 = "bind_engine";
 222     c->dir_load = 1;
 223     c->dirs = sk_OPENSSL_STRING_new_null();
 224     if (!c->dirs) {
 225         ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX, ERR_R_MALLOC_FAILURE);
 226         OPENSSL_free(c);
 227         return 0;
 228     }
 229     CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 230     if ((*ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e,
 231                                                        dynamic_ex_data_idx))
 232         == NULL) {
 233         /* Good, we're the first */
 234         ENGINE_set_ex_data(e, dynamic_ex_data_idx, c);
 235         *ctx = c;
 236         c = NULL;
 237     }
 238     CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 239     /*
 240      * If we lost the race to set the context, c is non-NULL and *ctx is the
 241      * context of the thread that won.
 242      */
 243     OPENSSL_free(c);
 244     return 1;
 245 }
 246
 247 /*
 248  * This function retrieves the context structure from an ENGINE's "ex_data",
 249  * or if it doesn't exist yet, sets it up.
 250  */
 251 static dynamic_data_ctx *dynamic_get_data_ctx(ENGINE *e)
 252 {
 253     dynamic_data_ctx *ctx;
 254     if (dynamic_ex_data_idx < 0) {
 255         /*
 256          * Create and register the ENGINE ex_data, and associate our "free"
 257          * function with it to ensure any allocated contexts get freed when
 258          * an ENGINE goes underground.
 259          */
 260         int new_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL,
 261                                               dynamic_data_ctx_free_func);
 262         if (new_idx == -1) {
 263             ENGINEerr(ENGINE_F_DYNAMIC_GET_DATA_CTX, ENGINE_R_NO_INDEX);
 264             return NULL;
 265         }
 266         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 267         /* Avoid a race by checking again inside this lock */
 268         if (dynamic_ex_data_idx < 0) {
 269             /* Good, someone didn't beat us to it */
 270             dynamic_ex_data_idx = new_idx;
 271             new_idx = -1;
 272         }
 273         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 274         /*
 275          * In theory we could "give back" the index here if (new_idx>-1), but
 276          * it's not possible and wouldn't gain us much if it were.
 277          */
 278     }
 279     ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, dynamic_ex_data_idx);
 280     /* Check if the context needs to be created */
 281     if ((ctx == NULL) && !dynamic_set_data_ctx(e, &ctx))
 282         /* "set_data" will set errors if necessary */
 283         return NULL;
 284     return ctx;
 285 }
 286
 287 static ENGINE *engine_dynamic(void)
 288 {
 289     ENGINE *ret = ENGINE_new();
 290     if (!ret)
 291         return NULL;
 292     if (!ENGINE_set_id(ret, engine_dynamic_id) ||
 293         !ENGINE_set_name(ret, engine_dynamic_name) ||
 294         !ENGINE_set_init_function(ret, dynamic_init) ||
 295         !ENGINE_set_finish_function(ret, dynamic_finish) ||
 296         !ENGINE_set_ctrl_function(ret, dynamic_ctrl) ||
 297         !ENGINE_set_flags(ret, ENGINE_FLAGS_BY_ID_COPY) ||
 298         !ENGINE_set_cmd_defns(ret, dynamic_cmd_defns)) {
 299         ENGINE_free(ret);
 300         return NULL;
 301     }
 302     return ret;
 303 }
 304
 305 void ENGINE_load_dynamic(void)
 306 {
 307     ENGINE *toadd = engine_dynamic();
 308     if (!toadd)
 309         return;
 310     ENGINE_add(toadd);
 311     /*
 312      * If the "add" worked, it gets a structural reference. So either way, we
 313      * release our just-created reference.
 314      */
 315     ENGINE_free(toadd);
 316     /*
 317      * If the "add" didn't work, it was probably a conflict because it was
 318      * already added (eg. someone calling ENGINE_load_blah then calling
 319      * ENGINE_load_builtin_engines() perhaps).
 320      */
 321     ERR_clear_error();
 322 }
 323
 324 static int dynamic_init(ENGINE *e)
 325 {
 326     /*
 327      * We always return failure - the "dyanamic" engine itself can't be used
 328      * for anything.
 329      */
 330     return 0;
 331 }
 332
 333 static int dynamic_finish(ENGINE *e)
 334 {
 335     /*
 336      * This should never be called on account of "dynamic_init" always
 337      * failing.
 338      */
 339     return 0;
 340 }
 341
 342 static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
 343 {
 344     dynamic_data_ctx *ctx = dynamic_get_data_ctx(e);
 345     int initialised;
 346
 347     if (!ctx) {
 348         ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_NOT_LOADED);
 349         return 0;
 350     }
 351     initialised = ((ctx->dynamic_dso == NULL) ? 0 : 1);
 352     /* All our control commands require the ENGINE to be uninitialised */
 353     if (initialised) {
 354         ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_ALREADY_LOADED);
 355         return 0;
 356     }
 357     switch (cmd) {
 358     case DYNAMIC_CMD_SO_PATH:
 359         /* a NULL 'p' or a string of zero-length is the same thing */
 360         if (p && (strlen((const char *)p) < 1))
 361             p = NULL;
 362         OPENSSL_free(ctx->DYNAMIC_LIBNAME);
 363         if (p)
 364             ctx->DYNAMIC_LIBNAME = BUF_strdup(p);
 365         else
 366             ctx->DYNAMIC_LIBNAME = NULL;
 367         return (ctx->DYNAMIC_LIBNAME ? 1 : 0);
 368     case DYNAMIC_CMD_NO_VCHECK:
 369         ctx->no_vcheck = ((i == 0) ? 0 : 1);
 370         return 1;
 371     case DYNAMIC_CMD_ID:
 372         /* a NULL 'p' or a string of zero-length is the same thing */
 373         if (p && (strlen((const char *)p) < 1))
 374             p = NULL;
 375         OPENSSL_free(ctx->engine_id);
 376         if (p)
 377             ctx->engine_id = BUF_strdup(p);
 378         else
 379             ctx->engine_id = NULL;
 380         return (ctx->engine_id ? 1 : 0);
 381     case DYNAMIC_CMD_LIST_ADD:
 382         if ((i < 0) || (i > 2)) {
 383             ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
 384             return 0;
 385         }
 386         ctx->list_add_value = (int)i;
 387         return 1;
 388     case DYNAMIC_CMD_LOAD:
 389         return dynamic_load(e, ctx);
 390     case DYNAMIC_CMD_DIR_LOAD:
 391         if ((i < 0) || (i > 2)) {
 392             ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
 393             return 0;
 394         }
 395         ctx->dir_load = (int)i;
 396         return 1;
 397     case DYNAMIC_CMD_DIR_ADD:
 398         /* a NULL 'p' or a string of zero-length is the same thing */
 399         if (!p || (strlen((const char *)p) < 1)) {
 400             ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
 401             return 0;
 402         }
 403         {
 404             char *tmp_str = BUF_strdup(p);
 405             if (!tmp_str) {
 406                 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ERR_R_MALLOC_FAILURE);
 407                 return 0;
 408             }
 409             sk_OPENSSL_STRING_insert(ctx->dirs, tmp_str, -1);
 410         }
 411         return 1;
 412     default:
 413         break;
 414     }
 415     ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED);
 416     return 0;
 417 }
 418
 419 static int int_load(dynamic_data_ctx *ctx)
 420 {
 421     int num, loop;
 422     /* Unless told not to, try a direct load */
 423     if ((ctx->dir_load != 2) && (DSO_load(ctx->dynamic_dso,
 424                                           ctx->DYNAMIC_LIBNAME, NULL,
 425                                           0)) != NULL)
 426         return 1;
 427     /* If we're not allowed to use 'dirs' or we have none, fail */
 428     if (!ctx->dir_load || (num = sk_OPENSSL_STRING_num(ctx->dirs)) < 1)
 429         return 0;
 430     for (loop = 0; loop < num; loop++) {
 431         const char *s = sk_OPENSSL_STRING_value(ctx->dirs, loop);
 432         char *merge = DSO_merge(ctx->dynamic_dso, ctx->DYNAMIC_LIBNAME, s);
 433         if (!merge)
 434             return 0;
 435         if (DSO_load(ctx->dynamic_dso, merge, NULL, 0)) {
 436             /* Found what we're looking for */
 437             OPENSSL_free(merge);
 438             return 1;
 439         }
 440         OPENSSL_free(merge);
 441     }
 442     return 0;
 443 }
 444
 445 static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx)
 446 {
 447     ENGINE cpy;
 448     dynamic_fns fns;
 449
 450     if (!ctx->dynamic_dso)
 451         ctx->dynamic_dso = DSO_new();
 452     if (!ctx->DYNAMIC_LIBNAME) {
 453         if (!ctx->engine_id)
 454             return 0;
 455         ctx->DYNAMIC_LIBNAME =
 456             DSO_convert_filename(ctx->dynamic_dso, ctx->engine_id);
 457     }
 458     if (!int_load(ctx)) {
 459         ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_NOT_FOUND);
 460         DSO_free(ctx->dynamic_dso);
 461         ctx->dynamic_dso = NULL;
 462         return 0;
 463     }
 464     /* We have to find a bind function otherwise it'll always end badly */
 465     if (!
 466         (ctx->bind_engine =
 467          (dynamic_bind_engine) DSO_bind_func(ctx->dynamic_dso,
 468                                              ctx->DYNAMIC_F2))) {
 469         ctx->bind_engine = NULL;
 470         DSO_free(ctx->dynamic_dso);
 471         ctx->dynamic_dso = NULL;
 472         ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_FAILURE);
 473         return 0;
 474     }
 475     /* Do we perform version checking? */
 476     if (!ctx->no_vcheck) {
 477         unsigned long vcheck_res = 0;
 478         /*
 479          * Now we try to find a version checking function and decide how to
 480          * cope with failure if/when it fails.
 481          */
 482         ctx->v_check =
 483             (dynamic_v_check_fn) DSO_bind_func(ctx->dynamic_dso,
 484                                                ctx->DYNAMIC_F1);
 485         if (ctx->v_check)
 486             vcheck_res = ctx->v_check(OSSL_DYNAMIC_VERSION);
 487         /*
 488          * We fail if the version checker veto'd the load *or* if it is
 489          * deferring to us (by returning its version) and we think it is too
 490          * old.
 491          */
 492         if (vcheck_res < OSSL_DYNAMIC_OLDEST) {
 493             /* Fail */
 494             ctx->bind_engine = NULL;
 495             ctx->v_check = NULL;
 496             DSO_free(ctx->dynamic_dso);
 497             ctx->dynamic_dso = NULL;
 498             ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
 499                       ENGINE_R_VERSION_INCOMPATIBILITY);
 500             return 0;
 501         }
 502     }
 503     /*
 504      * First binary copy the ENGINE structure so that we can roll back if the
 505      * hand-over fails
 506      */
 507     memcpy(&cpy, e, sizeof(ENGINE));
 508     /*
 509      * Provide the ERR, "ex_data", memory, and locking callbacks so the
 510      * loaded library uses our state rather than its own. FIXME: As noted in
 511      * engine.h, much of this would be simplified if each area of code
 512      * provided its own "summary" structure of all related callbacks. It
 513      * would also increase opaqueness.
 514      */
 515     fns.static_state = ENGINE_get_static_state();
 516     fns.ex_data_fns = CRYPTO_get_ex_data_implementation();
 517     CRYPTO_get_mem_functions(&fns.mem_fns.malloc_cb,
 518                              &fns.mem_fns.realloc_cb, &fns.mem_fns.free_cb);
 519     fns.lock_fns.lock_locking_cb = CRYPTO_get_locking_callback();
 520     fns.lock_fns.lock_add_lock_cb = CRYPTO_get_add_lock_callback();
 521     fns.lock_fns.dynlock_create_cb = CRYPTO_get_dynlock_create_callback();
 522     fns.lock_fns.dynlock_lock_cb = CRYPTO_get_dynlock_lock_callback();
 523     fns.lock_fns.dynlock_destroy_cb = CRYPTO_get_dynlock_destroy_callback();
 524     /*
 525      * Now that we've loaded the dynamic engine, make sure no "dynamic"
 526      * ENGINE elements will show through.
 527      */
 528     engine_set_all_null(e);
 529
 530     /* Try to bind the ENGINE onto our own ENGINE structure */
 531     if (!ctx->bind_engine(e, ctx->engine_id, &fns)) {
 532         ctx->bind_engine = NULL;
 533         ctx->v_check = NULL;
 534         DSO_free(ctx->dynamic_dso);
 535         ctx->dynamic_dso = NULL;
 536         ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_INIT_FAILED);
 537         /* Copy the original ENGINE structure back */
 538         memcpy(e, &cpy, sizeof(ENGINE));
 539         return 0;
 540     }
 541     /* Do we try to add this ENGINE to the internal list too? */
 542     if (ctx->list_add_value > 0) {
 543         if (!ENGINE_add(e)) {
 544             /* Do we tolerate this or fail? */
 545             if (ctx->list_add_value > 1) {
 546                 /*
 547                  * Fail - NB: By this time, it's too late to rollback, and
 548                  * trying to do so allows the bind_engine() code to have
 549                  * created leaks. We just have to fail where we are, after
 550                  * the ENGINE has changed.
 551                  */
 552                 ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
 553                           ENGINE_R_CONFLICTING_ENGINE_ID);
 554                 return 0;
 555             }
 556             /* Tolerate */
 557             ERR_clear_error();
 558         }
 559     }
 560     return 1;
 561 }