Add features support to md4 plugin

src/libstrongswan/plugins/md4/md4_plugin.c

@@ -37,11 +37,20 @@ METHOD(plugin_t, get_name, char*,
 	return "md4";
 }
 
+METHOD(plugin_t, get_features, int,
+	private_md4_plugin_t *this, plugin_feature_t *features[])
+{
+	static plugin_feature_t f[] = {
+		PLUGIN_REGISTER(HASHER, md4_hasher_create),
+			PLUGIN_PROVIDE(HASHER, HASH_MD4),
+	};
+	*features = f;
+	return countof(f);
+}
+
 METHOD(plugin_t, destroy, void,
 	private_md4_plugin_t *this)
 {
-	lib->crypto->remove_hasher(lib->crypto,
-							   (hasher_constructor_t)md4_hasher_create);
 	free(this);
 }
 
@@ -56,15 +65,12 @@ plugin_t *md4_plugin_create()
 		.public = {
 			.plugin = {
 				.get_name = _get_name,
-				.reload = (void*)return_false,
+				.get_features = _get_features,
 				.destroy = _destroy,
 			},
 		},
 	);
 
-	lib->crypto->add_hasher(lib->crypto, HASH_MD4, get_name(this),
-							(hasher_constructor_t)md4_hasher_create);
-
 	return &this->public.plugin;
 }