When the "dynamic" ENGINE loads another ENGINE from a shared-library, it

essentially overwrites itself with the new ENGINE, with the exception of reference counts, ex_data structures, and other 'admin' elements. However if the new ENGINE doesn't populate certain elements, there's the risk of the "dynamic" ENGINE's elements showing through - the "cmd_defns" were just one of the possibilities. This implements a more comprehensive cleanup.
openssl · Nov 22, 2001 · e4a6cf4 · e4a6cf4
1 parent 329636d
commit e4a6cf4
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Showing 3 changed files with 31 additions and 3 deletions.
diff --git a/crypto/engine/eng_dyn.c b/crypto/engine/eng_dyn.c
@@ -405,9 +405,9 @@ static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx)
 	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, initialise the command
-	   array to contain none */
-	ENGINE_set_cmd_defns(e, dynamic_cmd_defns_empty);
+	/* 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))

diff --git a/crypto/engine/eng_int.h b/crypto/engine/eng_int.h
@@ -129,6 +129,11 @@ int engine_unlocked_init(ENGINE *e);
 int engine_unlocked_finish(ENGINE *e, int unlock_for_handlers);
 int engine_free_util(ENGINE *e, int locked);
 
+/* This function will reset all "set"able values in an ENGINE to NULL. This
+ * won't touch reference counts or ex_data, but is equivalent to calling all the
+ * ENGINE_set_***() functions with a NULL value. */
+void engine_set_all_null(ENGINE *e);
+
 /* NB: Bitwise OR-able values for the "flags" variable in ENGINE are now exposed
  * in engine.h. */
 

diff --git a/crypto/engine/eng_lib.c b/crypto/engine/eng_lib.c
@@ -81,6 +81,29 @@ ENGINE *ENGINE_new(void)
 	return ret;
 	}
 
+/* Placed here (close proximity to ENGINE_new) so that modifications to the
+ * elements of the ENGINE structure are more likely to be caught and changed
+ * here. */
+void engine_set_all_null(ENGINE *e)
+	{
+	e->id = NULL;
+	e->name = NULL;
+	e->rsa_meth = NULL;
+	e->dsa_meth = NULL;
+	e->dh_meth = NULL;
+	e->rand_meth = NULL;
+	e->ciphers = NULL;
+	e->digests = NULL;
+	e->destroy = NULL;
+	e->init = NULL;
+	e->finish = NULL;
+	e->ctrl = NULL;
+	e->load_privkey = NULL;
+	e->load_pubkey = NULL;
+	e->cmd_defns = NULL;
+	e->flags = 0;
+	}
+
 int engine_free_util(ENGINE *e, int locked)
 	{
 	int i;