1 files changed, 548 insertions, 0 deletions

diff --git a/src/lib/libcrypto/engine/eng_dyn.c b/src/lib/libcrypto/engine/eng_dyn.c
new file mode 100644
index 0000000000..807da7a5eb
--- /dev/null
+++ b/src/lib/libcrypto/engine/eng_dyn.c
@@ -0,0 +1,548 @@
+/* crypto/engine/eng_dyn.c */
+/* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
+ * project 2001.
+ */
+/* ====================================================================
+ * Copyright (c) 1999-2001 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    licensing@OpenSSL.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+
+#include "eng_int.h"
+#include <openssl/dso.h>
+
+/* Shared libraries implementing ENGINEs for use by the "dynamic" ENGINE loader
+ * should implement the hook-up functions with the following prototypes. */
+
+/* Our ENGINE handlers */
+static int dynamic_init(ENGINE *e);
+static int dynamic_finish(ENGINE *e);
+static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void));
+/* Predeclare our context type */
+typedef struct st_dynamic_data_ctx dynamic_data_ctx;
+/* The implementation for the important control command */
+static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx);
+
+#define DYNAMIC_CMD_SO_PATH             ENGINE_CMD_BASE
+#define DYNAMIC_CMD_NO_VCHECK           (ENGINE_CMD_BASE + 1)
+#define DYNAMIC_CMD_ID                  (ENGINE_CMD_BASE + 2)
+#define DYNAMIC_CMD_LIST_ADD            (ENGINE_CMD_BASE + 3)
+#define DYNAMIC_CMD_DIR_LOAD            (ENGINE_CMD_BASE + 4)
+#define DYNAMIC_CMD_DIR_ADD             (ENGINE_CMD_BASE + 5)
+#define DYNAMIC_CMD_LOAD                (ENGINE_CMD_BASE + 6)
+
+/* The constants used when creating the ENGINE */
+static const char *engine_dynamic_id = "dynamic";
+static const char *engine_dynamic_name = "Dynamic engine loading support";
+static const ENGINE_CMD_DEFN dynamic_cmd_defns[] = {
+        {DYNAMIC_CMD_SO_PATH,
+                "SO_PATH",
+                "Specifies the path to the new ENGINE shared library",
+                ENGINE_CMD_FLAG_STRING},
+        {DYNAMIC_CMD_NO_VCHECK,
+                "NO_VCHECK",
+                "Specifies to continue even if version checking fails (boolean)",
+                ENGINE_CMD_FLAG_NUMERIC},
+        {DYNAMIC_CMD_ID,
+                "ID",
+                "Specifies an ENGINE id name for loading",
+                ENGINE_CMD_FLAG_STRING},
+        {DYNAMIC_CMD_LIST_ADD,
+                "LIST_ADD",
+                "Whether to add a loaded ENGINE to the internal list (0=no,1=yes,2=mandatory)",
+                ENGINE_CMD_FLAG_NUMERIC},
+        {DYNAMIC_CMD_DIR_LOAD,
+                "DIR_LOAD",
+                "Specifies whether to load from 'DIR_ADD' directories (0=no,1=yes,2=mandatory)",
+                ENGINE_CMD_FLAG_NUMERIC},
+        {DYNAMIC_CMD_DIR_ADD,
+                "DIR_ADD",
+                "Adds a directory from which ENGINEs can be loaded",
+                ENGINE_CMD_FLAG_STRING},
+        {DYNAMIC_CMD_LOAD,
+                "LOAD",
+                "Load up the ENGINE specified by other settings",
+                ENGINE_CMD_FLAG_NO_INPUT},
+        {0, NULL, NULL, 0}
+        };
+static const ENGINE_CMD_DEFN dynamic_cmd_defns_empty[] = {
+        {0, NULL, NULL, 0}
+        };
+
+/* Loading code stores state inside the ENGINE structure via the "ex_data"
+ * element. We load all our state into a single structure and use that as a
+ * single context in the "ex_data" stack. */
+struct st_dynamic_data_ctx
+        {
+        /* The DSO object we load that supplies the ENGINE code */
+        DSO *dynamic_dso;
+        /* The function pointer to the version checking shared library function */
+        dynamic_v_check_fn v_check;
+        /* The function pointer to the engine-binding shared library function */
+        dynamic_bind_engine bind_engine;
+        /* The default name/path for loading the shared library */
+        const char *DYNAMIC_LIBNAME;
+        /* Whether to continue loading on a version check failure */
+        int no_vcheck;
+        /* If non-NULL, stipulates the 'id' of the ENGINE to be loaded */
+        const char *engine_id;
+        /* If non-zero, a successfully loaded ENGINE should be added to the internal
+         * ENGINE list. If 2, the add must succeed or the entire load should fail. */
+        int list_add_value;
+        /* The symbol name for the version checking function */
+        const char *DYNAMIC_F1;
+        /* The symbol name for the "initialise ENGINE structure" function */
+        const char *DYNAMIC_F2;
+        /* Whether to never use 'dirs', use 'dirs' as a fallback, or only use
+         * 'dirs' for loading. Default is to use 'dirs' as a fallback. */
+        int dir_load;
+        /* A stack of directories from which ENGINEs could be loaded */
+        STACK_OF(OPENSSL_STRING) *dirs;
+        };
+
+/* This is the "ex_data" index we obtain and reserve for use with our context
+ * structure. */
+static int dynamic_ex_data_idx = -1;
+
+static void int_free_str(char *s) { OPENSSL_free(s); }
+/* Because our ex_data element may or may not get allocated depending on whether
+ * a "first-use" occurs before the ENGINE is freed, we have a memory leak
+ * problem to solve. We can't declare a "new" handler for the ex_data as we
+ * don't want a dynamic_data_ctx in *all* ENGINE structures of all types (this
+ * is a bug in the design of CRYPTO_EX_DATA). As such, we just declare a "free"
+ * handler and that will get called if an ENGINE is being destroyed and there
+ * was an ex_data element corresponding to our context type. */
+static void dynamic_data_ctx_free_func(void *parent, void *ptr,
+                        CRYPTO_EX_DATA *ad, int idx, long argl, void *argp)
+        {
+        if(ptr)
+                {
+                dynamic_data_ctx *ctx = (dynamic_data_ctx *)ptr;
+                if(ctx->dynamic_dso)
+                        DSO_free(ctx->dynamic_dso);
+                if(ctx->DYNAMIC_LIBNAME)
+                        OPENSSL_free((void*)ctx->DYNAMIC_LIBNAME);
+                if(ctx->engine_id)
+                        OPENSSL_free((void*)ctx->engine_id);
+                if(ctx->dirs)
+                        sk_OPENSSL_STRING_pop_free(ctx->dirs, int_free_str);
+                OPENSSL_free(ctx);
+                }
+        }
+
+/* Construct the per-ENGINE context. We create it blindly and then use a lock to
+ * check for a race - if so, all but one of the threads "racing" will have
+ * wasted their time. The alternative involves creating everything inside the
+ * lock which is far worse. */
+static int dynamic_set_data_ctx(ENGINE *e, dynamic_data_ctx **ctx)
+        {
+        dynamic_data_ctx *c;
+        c = OPENSSL_malloc(sizeof(dynamic_data_ctx));
+        if(!c)
+                {
+                ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX,ERR_R_MALLOC_FAILURE);
+                return 0;
+                }
+        memset(c, 0, sizeof(dynamic_data_ctx));
+        c->dynamic_dso = NULL;
+        c->v_check = NULL;
+        c->bind_engine = NULL;
+        c->DYNAMIC_LIBNAME = NULL;
+        c->no_vcheck = 0;
+        c->engine_id = NULL;
+        c->list_add_value = 0;
+        c->DYNAMIC_F1 = "v_check";
+        c->DYNAMIC_F2 = "bind_engine";
+        c->dir_load = 1;
+        c->dirs = sk_OPENSSL_STRING_new_null();
+        if(!c->dirs)
+                {
+                ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX,ERR_R_MALLOC_FAILURE);
+                OPENSSL_free(c);
+                return 0;
+                }
+        CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
+        if((*ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e,
+                                dynamic_ex_data_idx)) == NULL)
+                {
+                /* Good, we're the first */
+                ENGINE_set_ex_data(e, dynamic_ex_data_idx, c);
+                *ctx = c;
+                c = NULL;
+                }
+        CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
+        /* If we lost the race to set the context, c is non-NULL and *ctx is the
+         * context of the thread that won. */
+        if(c)
+                OPENSSL_free(c);
+        return 1;
+        }
+
+/* This function retrieves the context structure from an ENGINE's "ex_data", or
+ * if it doesn't exist yet, sets it up. */
+static dynamic_data_ctx *dynamic_get_data_ctx(ENGINE *e)
+        {
+        dynamic_data_ctx *ctx;
+        if(dynamic_ex_data_idx < 0)
+                {
+                /* Create and register the ENGINE ex_data, and associate our
+                 * "free" function with it to ensure any allocated contexts get
+                 * freed when an ENGINE goes underground. */
+                int new_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL,
+                                        dynamic_data_ctx_free_func);
+                if(new_idx == -1)
+                        {
+                        ENGINEerr(ENGINE_F_DYNAMIC_GET_DATA_CTX,ENGINE_R_NO_INDEX);
+                        return NULL;
+                        }
+                CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
+                /* Avoid a race by checking again inside this lock */
+                if(dynamic_ex_data_idx < 0)
+                        {
+                        /* Good, someone didn't beat us to it */
+                        dynamic_ex_data_idx = new_idx;
+                        new_idx = -1;
+                        }
+                CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
+                /* In theory we could "give back" the index here if
+                 * (new_idx>-1), but it's not possible and wouldn't gain us much
+                 * if it were. */
+                }
+        ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, dynamic_ex_data_idx);
+        /* Check if the context needs to be created */
+        if((ctx == NULL) && !dynamic_set_data_ctx(e, &ctx))
+                /* "set_data" will set errors if necessary */
+                return NULL;
+        return ctx;
+        }
+
+static ENGINE *engine_dynamic(void)
+        {
+        ENGINE *ret = ENGINE_new();
+        if(!ret)
+                return NULL;
+        if(!ENGINE_set_id(ret, engine_dynamic_id) ||
+                        !ENGINE_set_name(ret, engine_dynamic_name) ||
+                        !ENGINE_set_init_function(ret, dynamic_init) ||
+                        !ENGINE_set_finish_function(ret, dynamic_finish) ||
+                        !ENGINE_set_ctrl_function(ret, dynamic_ctrl) ||
+                        !ENGINE_set_flags(ret, ENGINE_FLAGS_BY_ID_COPY) ||
+                        !ENGINE_set_cmd_defns(ret, dynamic_cmd_defns))
+                {
+                ENGINE_free(ret);
+                return NULL;
+                }
+        return ret;
+        }
+
+void ENGINE_load_dynamic(void)
+        {
+        ENGINE *toadd = engine_dynamic();
+        if(!toadd) return;
+        ENGINE_add(toadd);
+        /* If the "add" worked, it gets a structural reference. So either way,
+         * we release our just-created reference. */
+        ENGINE_free(toadd);
+        /* If the "add" didn't work, it was probably a conflict because it was
+         * already added (eg. someone calling ENGINE_load_blah then calling
+         * ENGINE_load_builtin_engines() perhaps). */
+        ERR_clear_error();
+        }
+
+static int dynamic_init(ENGINE *e)
+        {
+        /* We always return failure - the "dyanamic" engine itself can't be used
+         * for anything. */
+        return 0;
+        }
+
+static int dynamic_finish(ENGINE *e)
+        {
+        /* This should never be called on account of "dynamic_init" always
+         * failing. */
+        return 0;
+        }
+
+static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
+        {
+        dynamic_data_ctx *ctx = dynamic_get_data_ctx(e);
+        int initialised;
+        
+        if(!ctx)
+                {
+                ENGINEerr(ENGINE_F_DYNAMIC_CTRL,ENGINE_R_NOT_LOADED);
+                return 0;
+                }
+        initialised = ((ctx->dynamic_dso == NULL) ? 0 : 1);
+        /* All our control commands require the ENGINE to be uninitialised */
+        if(initialised)
+                {
+                ENGINEerr(ENGINE_F_DYNAMIC_CTRL,
+                        ENGINE_R_ALREADY_LOADED);
+                return 0;
+                }
+        switch(cmd)
+                {
+        case DYNAMIC_CMD_SO_PATH:
+                /* a NULL 'p' or a string of zero-length is the same thing */
+                if(p && (strlen((const char *)p) < 1))
+                        p = NULL;
+                if(ctx->DYNAMIC_LIBNAME)
+                        OPENSSL_free((void*)ctx->DYNAMIC_LIBNAME);
+                if(p)
+                        ctx->DYNAMIC_LIBNAME = BUF_strdup(p);
+                else
+                        ctx->DYNAMIC_LIBNAME = NULL;
+                return (ctx->DYNAMIC_LIBNAME ? 1 : 0);
+        case DYNAMIC_CMD_NO_VCHECK:
+                ctx->no_vcheck = ((i == 0) ? 0 : 1);
+                return 1;
+        case DYNAMIC_CMD_ID:
+                /* a NULL 'p' or a string of zero-length is the same thing */
+                if(p && (strlen((const char *)p) < 1))
+                        p = NULL;
+                if(ctx->engine_id)
+                        OPENSSL_free((void*)ctx->engine_id);
+                if(p)
+                        ctx->engine_id = BUF_strdup(p);
+                else
+                        ctx->engine_id = NULL;
+                return (ctx->engine_id ? 1 : 0);
+        case DYNAMIC_CMD_LIST_ADD:
+                if((i < 0) || (i > 2))
+                        {
+                        ENGINEerr(ENGINE_F_DYNAMIC_CTRL,
+                                ENGINE_R_INVALID_ARGUMENT);
+                        return 0;
+                        }
+                ctx->list_add_value = (int)i;
+                return 1;
+        case DYNAMIC_CMD_LOAD:
+                return dynamic_load(e, ctx);
+        case DYNAMIC_CMD_DIR_LOAD:
+                if((i < 0) || (i > 2))
+                        {
+                        ENGINEerr(ENGINE_F_DYNAMIC_CTRL,
+                                ENGINE_R_INVALID_ARGUMENT);
+                        return 0;
+                        }
+                ctx->dir_load = (int)i;
+                return 1;
+        case DYNAMIC_CMD_DIR_ADD:
+                /* a NULL 'p' or a string of zero-length is the same thing */
+                if(!p || (strlen((const char *)p) < 1))
+                        {
+                        ENGINEerr(ENGINE_F_DYNAMIC_CTRL,
+                                ENGINE_R_INVALID_ARGUMENT);
+                        return 0;
+                        }
+                {
+                char *tmp_str = BUF_strdup(p);
+                if(!tmp_str)
+                        {
+                        ENGINEerr(ENGINE_F_DYNAMIC_CTRL,
+                                ERR_R_MALLOC_FAILURE);
+                        return 0;
+                        }
+                sk_OPENSSL_STRING_insert(ctx->dirs, tmp_str, -1);
+                }
+                return 1;
+        default:
+                break;
+                }
+        ENGINEerr(ENGINE_F_DYNAMIC_CTRL,ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED);
+        return 0;
+        }
+
+static int int_load(dynamic_data_ctx *ctx)
+        {
+        int num, loop;
+        /* Unless told not to, try a direct load */
+        if((ctx->dir_load != 2) && (DSO_load(ctx->dynamic_dso,
+                                ctx->DYNAMIC_LIBNAME, NULL, 0)) != NULL)
+                return 1;
+        /* If we're not allowed to use 'dirs' or we have none, fail */
+        if(!ctx->dir_load || (num = sk_OPENSSL_STRING_num(ctx->dirs)) < 1)
+                return 0;
+        for(loop = 0; loop < num; loop++)
+                {
+                const char *s = sk_OPENSSL_STRING_value(ctx->dirs, loop);
+                char *merge = DSO_merge(ctx->dynamic_dso, ctx->DYNAMIC_LIBNAME, s);
+                if(!merge)
+                        return 0;
+                if(DSO_load(ctx->dynamic_dso, merge, NULL, 0))
+                        {
+                        /* Found what we're looking for */
+                        OPENSSL_free(merge);
+                        return 1;
+                        }
+                OPENSSL_free(merge);
+                }
+        return 0;
+        }
+
+static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx)
+        {
+        ENGINE cpy;
+        dynamic_fns fns;
+
+        if(!ctx->dynamic_dso)
+                ctx->dynamic_dso = DSO_new();
+        if(!ctx->DYNAMIC_LIBNAME)
+                {
+                if(!ctx->engine_id)
+                        return 0;
+                ctx->DYNAMIC_LIBNAME =
+                        DSO_convert_filename(ctx->dynamic_dso, ctx->engine_id);
+                }
+        if(!int_load(ctx))
+                {
+                ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
+                        ENGINE_R_DSO_NOT_FOUND);
+                DSO_free(ctx->dynamic_dso);
+                ctx->dynamic_dso = NULL;
+                return 0;
+                }
+        /* We have to find a bind function otherwise it'll always end badly */
+        if(!(ctx->bind_engine = (dynamic_bind_engine)DSO_bind_func(
+                                        ctx->dynamic_dso, ctx->DYNAMIC_F2)))
+                {
+                ctx->bind_engine = NULL;
+                DSO_free(ctx->dynamic_dso);
+                ctx->dynamic_dso = NULL;
+                ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
+                        ENGINE_R_DSO_FAILURE);
+                return 0;
+                }
+        /* Do we perform version checking? */
+        if(!ctx->no_vcheck)
+                {
+                unsigned long vcheck_res = 0;
+                /* Now we try to find a version checking function and decide how
+                 * to cope with failure if/when it fails. */
+                ctx->v_check = (dynamic_v_check_fn)DSO_bind_func(
+                                ctx->dynamic_dso, ctx->DYNAMIC_F1);
+                if(ctx->v_check)
+                        vcheck_res = ctx->v_check(OSSL_DYNAMIC_VERSION);
+                /* We fail if the version checker veto'd the load *or* if it is
+                 * deferring to us (by returning its version) and we think it is
+                 * too old. */
+                if(vcheck_res < OSSL_DYNAMIC_OLDEST)
+                        {
+                        /* Fail */
+                        ctx->bind_engine = NULL;
+                        ctx->v_check = NULL;
+                        DSO_free(ctx->dynamic_dso);
+                        ctx->dynamic_dso = NULL;
+                        ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
+                                ENGINE_R_VERSION_INCOMPATIBILITY);
+                        return 0;
+                        }
+                }
+        /* First binary copy the ENGINE structure so that we can roll back if
+         * the hand-over fails */
+        memcpy(&cpy, e, sizeof(ENGINE));
+        /* Provide the ERR, "ex_data", memory, and locking callbacks so the
+         * loaded library uses our state rather than its own. FIXME: As noted in
+         * engine.h, much of this would be simplified if each area of code
+         * provided its own "summary" structure of all related callbacks. It
+         * would also increase opaqueness. */
+        fns.static_state = ENGINE_get_static_state();
+        fns.err_fns = ERR_get_implementation();
+        fns.ex_data_fns = CRYPTO_get_ex_data_implementation();
+        CRYPTO_get_mem_functions(&fns.mem_fns.malloc_cb,
+                                &fns.mem_fns.realloc_cb,
+                                &fns.mem_fns.free_cb);
+        fns.lock_fns.lock_locking_cb = CRYPTO_get_locking_callback();
+        fns.lock_fns.lock_add_lock_cb = CRYPTO_get_add_lock_callback();
+        fns.lock_fns.dynlock_create_cb = CRYPTO_get_dynlock_create_callback();
+        fns.lock_fns.dynlock_lock_cb = CRYPTO_get_dynlock_lock_callback();
+        fns.lock_fns.dynlock_destroy_cb = CRYPTO_get_dynlock_destroy_callback();
+        /* Now that we've loaded the dynamic engine, make sure no "dynamic"
+         * ENGINE elements will show through. */
+        engine_set_all_null(e);
+
+        /* Try to bind the ENGINE onto our own ENGINE structure */
+        if(!ctx->bind_engine(e, ctx->engine_id, &fns))
+                {
+                ctx->bind_engine = NULL;
+                ctx->v_check = NULL;
+                DSO_free(ctx->dynamic_dso);
+                ctx->dynamic_dso = NULL;
+                ENGINEerr(ENGINE_F_DYNAMIC_LOAD,ENGINE_R_INIT_FAILED);
+                /* Copy the original ENGINE structure back */
+                memcpy(e, &cpy, sizeof(ENGINE));
+                return 0;
+                }
+        /* Do we try to add this ENGINE to the internal list too? */
+        if(ctx->list_add_value > 0)
+                {
+                if(!ENGINE_add(e))
+                        {
+                        /* Do we tolerate this or fail? */
+                        if(ctx->list_add_value > 1)
+                                {
+                                /* Fail - NB: By this time, it's too late to
+                                 * rollback, and trying to do so allows the
+                                 * bind_engine() code to have created leaks. We
+                                 * just have to fail where we are, after the
+                                 * ENGINE has changed. */
+                                ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
+                                        ENGINE_R_CONFLICTING_ENGINE_ID);
+                                return 0;
+                                }
+                        /* Tolerate */
+                        ERR_clear_error();
+                        }
+                }
+        return 1;
+        }