openssl: Move to a module and split thirdparty lib

Same rationale as the previous commits.

1 files changed, 570 insertions, 0 deletions

diff --git a/thirdparty/openssl/crypto/engine/eng_dyn.c b/thirdparty/openssl/crypto/engine/eng_dyn.c
new file mode 100644
index 0000000000..40f30e9d58
--- /dev/null
+++ b/thirdparty/openssl/crypto/engine/eng_dyn.c
@@ -0,0 +1,570 @@
+/* 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}
+};
+
+/*
+ * 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) {
+        sk_OPENSSL_STRING_free(c->dirs);
+        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;
+}