Merge "Fix bug about checking privilege" into tizen
[platform/core/uifw/stt.git] / client / stt.c
index 91f6fc1..163d67a 100644 (file)
@@ -1,5 +1,5 @@
 /*
-*  Copyright (c) 2011-2014 Samsung Electronics Co., Ltd All Rights Reserved
+*  Copyright (c) 2011-2016 Samsung Electronics Co., Ltd All Rights Reserved
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
@@ -12,6 +12,9 @@
 */
 
 #include <aul.h>
+#include <cynara-client.h>
+#include <cynara-error.h>
+#include <cynara-session.h>
 #include <dirent.h>
 #include <Ecore.h>
 #include <fcntl.h>
@@ -37,6 +40,11 @@ static float g_volume_db = 0;
 
 static int g_feature_enabled = -1;
 
+static int g_privilege_allowed = -1;
+static cynara *p_cynara = NULL;
+
+static bool g_err_callback_status = false;
+
 const char* stt_tag()
 {
        return "sttc";
@@ -72,6 +80,80 @@ static int __stt_get_feature_enabled()
        return 0;
 }
 
+static int __check_privilege_initialize()
+{
+       int ret = cynara_initialize(&p_cynara, NULL);
+       if (CYNARA_API_SUCCESS != ret)
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] fail to initialize");
+
+       return ret == CYNARA_API_SUCCESS;
+}
+
+static int __check_privilege(const char* uid, const char * privilege)
+{
+       FILE *fp = NULL;
+       char label_path[1024] = "/proc/self/attr/current";
+       char smack_label[1024] = {'\0',};
+
+       if (!p_cynara) {
+           return false;
+       }
+
+       fp = fopen(label_path, "r");
+       if (fp != NULL) {
+           if (fread(smack_label, 1, sizeof(smack_label), fp) <= 0)
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] fail to fread");
+
+           fclose(fp);
+       }
+
+       pid_t pid = getpid();
+       char *session = cynara_session_from_pid(pid);
+       int ret = cynara_check(p_cynara, smack_label, session, uid, privilege);
+       SLOG(LOG_DEBUG, TAG_STTC, "[Client]cynara_check returned %d(%s)", ret, (CYNARA_API_ACCESS_ALLOWED == ret) ? "Allowed" : "Denied");
+       if (session) {
+               free(session);
+               session = NULL;
+       }
+
+       if (ret != CYNARA_API_ACCESS_ALLOWED)
+           return false;
+       return true;
+}
+
+static void __check_privilege_deinitialize()
+{
+       if (p_cynara)
+               cynara_finish(p_cynara);
+       p_cynara = NULL;
+}
+
+static int __stt_check_privilege()
+{
+       char uid[16];
+
+       if (0 == g_privilege_allowed) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Permission is denied");
+               return STT_ERROR_PERMISSION_DENIED;
+       } else if (-1 == g_privilege_allowed) {
+               if (false == __check_privilege_initialize()) {
+                       SLOG(LOG_ERROR, TAG_STTC, "[ERROR] privilege initialize is failed");
+                       return STT_ERROR_PERMISSION_DENIED;
+               }
+               snprintf(uid, 16, "%d", getuid());
+               if (false == __check_privilege(uid, STT_PRIVILEGE)) {
+                       SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Permission is denied");
+                       g_privilege_allowed = 0;
+                       __check_privilege_deinitialize();
+                       return STT_ERROR_PERMISSION_DENIED;
+               }
+               __check_privilege_deinitialize();
+       }
+
+       g_privilege_allowed = 1;
+       return STT_ERROR_NONE;
+}
+
 static const char* __stt_get_error_code(stt_error_e err)
 {
        switch (err) {
@@ -89,6 +171,7 @@ static const char* __stt_get_error_code(stt_error_e err)
        case STT_ERROR_ENGINE_NOT_FOUND:        return "STT_ERROR_ENGINE_NOT_FOUND";
        case STT_ERROR_OPERATION_FAILED:        return "STT_ERROR_OPERATION_FAILED";
        case STT_ERROR_NOT_SUPPORTED_FEATURE:   return "STT_ERROR_NOT_SUPPORTED_FEATURE";
+       case STT_ERROR_SERVICE_RESET:           return "STT_ERROR_SERVICE_RESET";
        default:
                return "Invalid error code";
        }
@@ -145,11 +228,58 @@ void __stt_config_lang_changed_cb(const char* before_language, const char* curre
        return;
 }
 
+void __stt_config_engine_changed_cb(const char* engine_id, const char* setting, const char* language, bool support_silence, bool need_credential, void* user_data)
+{
+       stt_h stt = (stt_h)user_data;
+
+       stt_client_s* client = stt_client_get(stt);
+       if (NULL == client) {
+               SLOG(LOG_ERROR, TAG_STTC, "[WARNING] A handle is not valid");
+               return;
+       }
+
+       if (NULL != engine_id)  SLOG(LOG_DEBUG, TAG_STTC, "Engine id(%s)", engine_id);
+       if (NULL != setting)    SLOG(LOG_DEBUG, TAG_STTC, "Engine setting(%s)", setting);
+       if (NULL != language)   SLOG(LOG_DEBUG, TAG_STTC, "Language(%s)", language);
+       SLOG(LOG_DEBUG, TAG_STTC, "Silence(%s), Credential(%s)", support_silence ? "on" : "off", need_credential ? "need" : "no need");
+
+       /* call callback function */
+       if (NULL != client->engine_changed_cb) {
+               client->engine_changed_cb(stt, engine_id, language, support_silence, need_credential, client->engine_changed_user_data);
+       } else {
+               SLOG(LOG_WARN, TAG_STTC, "No registered callback function for engine change");
+       }
+       return;
+}
+
+static int __stt_check_handle(stt_h stt, stt_client_s** client)
+{
+       if (NULL == stt) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input handle is null");
+               return STT_ERROR_INVALID_PARAMETER;
+       }
+
+       stt_client_s* temp = NULL;
+       temp = stt_client_get(stt);
+
+       /* check handle */
+       if (NULL == temp) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+               return STT_ERROR_INVALID_PARAMETER;
+       }
+       *client = temp;
+
+       return STT_ERROR_NONE;
+}
+
 int stt_create(stt_h* stt)
 {
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
 
        SLOG(LOG_DEBUG, TAG_STTC, "===== Create STT");
 
@@ -185,7 +315,7 @@ int stt_create(stt_h* stt)
                return ret;
        }
 
-       ret = stt_config_mgr_set_callback(client->uid, NULL, __stt_config_lang_changed_cb, NULL, NULL);
+       ret = stt_config_mgr_set_callback(client->uid, __stt_config_engine_changed_cb, __stt_config_lang_changed_cb, NULL, client->stt);
        ret = __stt_convert_config_error_code(ret);
        if (0 != ret) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to set config changed : %s", __stt_get_error_code(ret));
@@ -203,25 +333,19 @@ int stt_create(stt_h* stt)
 
 int stt_destroy(stt_h stt)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       SLOG(LOG_DEBUG, TAG_STTC, "===== Destroy STT");
-
-       if (NULL == stt) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input handle is null");
-               return STT_ERROR_INVALID_PARAMETER;
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
        }
-
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
+       SLOG(LOG_DEBUG, TAG_STTC, "===== Destroy STT");
+
        /* check used callback */
        if (0 != stt_client_get_use_callback(client)) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Cannot destroy in Callback function");
@@ -292,22 +416,21 @@ bool __stt_config_supported_engine_cb(const char* engine_id, const char* engine_
 
 int stt_foreach_supported_engines(stt_h stt, stt_supported_engine_cb callback, void* user_data)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       SLOG(LOG_DEBUG, TAG_STTC, "===== Foreach Supported engine");
-
-       if (NULL == stt || NULL == callback) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
-       stt_client_s* client = stt_client_get(stt);
+       SLOG(LOG_DEBUG, TAG_STTC, "===== Foreach Supported engine");
 
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (NULL == callback) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
                return STT_ERROR_INVALID_PARAMETER;
        }
 
@@ -337,22 +460,21 @@ int stt_foreach_supported_engines(stt_h stt, stt_supported_engine_cb callback, v
 
 int stt_get_engine(stt_h stt, char** engine_id)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       SLOG(LOG_DEBUG, TAG_STTC, "===== Get current engine");
-
-       if (NULL == stt || NULL == engine_id) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
-       stt_client_s* client = stt_client_get(stt);
+       SLOG(LOG_DEBUG, TAG_STTC, "===== Get current engine");
 
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (NULL == engine_id) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
                return STT_ERROR_INVALID_PARAMETER;
        }
 
@@ -385,22 +507,21 @@ int stt_get_engine(stt_h stt, char** engine_id)
 
 int stt_set_engine(stt_h stt, const char* engine_id)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       SLOG(LOG_DEBUG, TAG_STTC, "===== Set current engine");
-
-       if (NULL == stt || NULL == engine_id) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
-       stt_client_s* client = stt_client_get(stt);
+       SLOG(LOG_DEBUG, TAG_STTC, "===== Set current engine");
 
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (NULL == engine_id) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
                return STT_ERROR_INVALID_PARAMETER;
        }
 
@@ -412,8 +533,11 @@ int stt_set_engine(stt_h stt, const char* engine_id)
 
        if (NULL != client->current_engine_id) {
                free(client->current_engine_id);
+               client->current_engine_id = NULL;
        }
 
+       SLOG(LOG_DEBUG, TAG_STTC, "===== engined_id(%s)", engine_id);
+
        client->current_engine_id = strdup(engine_id);
 
        SLOG(LOG_DEBUG, TAG_STTC, "=====");
@@ -422,6 +546,152 @@ int stt_set_engine(stt_h stt, const char* engine_id)
        return 0;
 }
 
+int stt_set_credential(stt_h stt, const char* credential)
+{
+       stt_client_s* client = NULL;
+       if (0 != __stt_get_feature_enabled()) {
+               return STT_ERROR_NOT_SUPPORTED;
+       }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
+               return STT_ERROR_INVALID_PARAMETER;
+       }
+
+       SLOG(LOG_DEBUG, TAG_STTC, "===== Set credential");
+
+       if (NULL == credential) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
+               return STT_ERROR_INVALID_PARAMETER;
+       }
+
+       /* check state */
+       if (client->current_state != STT_STATE_CREATED && client->current_state != STT_STATE_READY) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State: Current state(%d) is not CREATED or READY", client->current_state);
+               return STT_ERROR_INVALID_STATE;
+       }
+
+       if (NULL != client->credential) {
+               free(client->credential);
+               client->credential = NULL;
+       }
+       client->credential = strdup(credential);
+
+       SLOG(LOG_DEBUG, TAG_STTC, "=====");
+       SLOG(LOG_DEBUG, TAG_STTC, " ");
+
+       return STT_ERROR_NONE;
+}
+
+int stt_set_private_data(stt_h stt, const char* key, const char* data)
+{
+       stt_client_s* client = NULL;
+       if (0 != __stt_get_feature_enabled()) {
+               return STT_ERROR_NOT_SUPPORTED;
+       }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
+               return STT_ERROR_INVALID_PARAMETER;
+       }
+
+       SLOG(LOG_DEBUG, TAG_STTC, "===== Set private data");
+
+       if (NULL == key || NULL == data) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid parameter");
+               return STT_ERROR_INVALID_PARAMETER;
+       }
+
+       /* check state */
+       if (STT_STATE_READY != client->current_state) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State: Current state(%d) is not READY", client->current_state);
+               return STT_ERROR_INVALID_STATE;
+       }
+
+       int ret = -1;
+       int count = 0;
+       while (0 != ret) {
+               ret = stt_dbus_request_set_private_data(client->uid, key, data);
+               if (0 != ret) {
+                       if (STT_ERROR_TIMED_OUT != ret) {
+                               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to set private data : %s", __stt_get_error_code(ret));
+                               return ret;
+                       } else {
+                               SLOG(LOG_WARN, TAG_STTC, "[WARNING] retry : %s", __stt_get_error_code(ret));
+                               usleep(10000);
+                               count++;
+                               if (STT_RETRY_COUNT == count) {
+                                       SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to request");
+                                       return ret;
+                               }
+                       }
+               }
+       }
+
+       SLOG(LOG_DEBUG, TAG_STTC, "=====");
+       SLOG(LOG_DEBUG, TAG_STTC, "");
+
+       return STT_ERROR_NONE;
+
+}
+int stt_get_private_data(stt_h stt, const char* key, char** data)
+{
+       stt_client_s* client = NULL;
+       if (0 != __stt_get_feature_enabled()) {
+               return STT_ERROR_NOT_SUPPORTED;
+       }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
+               return STT_ERROR_INVALID_PARAMETER;
+       }
+
+       SLOG(LOG_DEBUG, TAG_STTC, "===== Get private data");
+
+       if (NULL == key || NULL == data) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid parameter");
+               return STT_ERROR_INVALID_PARAMETER;
+       }
+
+       /* check state */
+       if (STT_STATE_READY != client->current_state) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State: Current state(%d) is not READY", client->current_state);
+               return STT_ERROR_INVALID_STATE;
+       }
+
+       int ret = -1;
+       int count = 0;
+       while (0 != ret) {
+               ret = stt_dbus_request_get_private_data(client->uid, key, data);
+               if (0 != ret) {
+                       if (STT_ERROR_TIMED_OUT != ret) {
+                               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to get private data : %s", __stt_get_error_code(ret));
+                               return ret;
+                       } else {
+                               SLOG(LOG_WARN, TAG_STTC, "[WARNING] retry : %s", __stt_get_error_code(ret));
+                               usleep(10000);
+                               count++;
+                               if (STT_RETRY_COUNT == count) {
+                                       SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to request");
+                                       return ret;
+                               }
+                       }
+               }
+       }
+
+       if (0 == strncmp(*data, "NULL", strlen(*data))) {
+               free(*data);
+               *data = NULL;
+       }
+
+       SLOG(LOG_DEBUG, TAG_STTC, "=====");
+       SLOG(LOG_DEBUG, TAG_STTC, "");
+
+       return STT_ERROR_NONE;
+}
 static Eina_Bool __stt_connect_daemon(void *data)
 {
        stt_client_s* client = (stt_client_s*)data;
@@ -445,12 +715,13 @@ static Eina_Bool __stt_connect_daemon(void *data)
        }
 
        g_connect_timer = NULL;
-       SLOG(LOG_DEBUG, TAG_STTC, "===== Connect daemon");
+       SLOG(LOG_DEBUG, TAG_STTC, "===== Connect stt-service");
 
        /* request initialization */
        bool silence_supported = false;
+       bool credential_needed = false;
 
-       ret = stt_dbus_request_initialize(client->uid, &silence_supported);
+       ret = stt_dbus_request_initialize(client->uid, &silence_supported, &credential_needed);
 
        if (STT_ERROR_ENGINE_NOT_FOUND == ret) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to initialize : %s", __stt_get_error_code(ret));
@@ -464,17 +735,22 @@ static Eina_Bool __stt_connect_daemon(void *data)
                SLOG(LOG_ERROR, TAG_STTC, "[WARNING] Fail to connection. Retry to connect");
                return EINA_TRUE;
        } else {
-               /* success to connect stt-daemon */
+               /* success to connect stt-service */
                client->silence_supported = silence_supported;
-               SLOG(LOG_DEBUG, TAG_STTC, "Supported options : silence(%s)", silence_supported ? "true" : "false");
+               client->credential_needed = credential_needed;
+               SLOG(LOG_DEBUG, TAG_STTC, "Supported options : silence(%s), credential(%s)", silence_supported ? "support" : "no support", credential_needed ? "need" : "no need");
        }
 
+#ifdef __UNUSED_CODES__
        if (NULL != client->current_engine_id) {
                ret = -1;
                int count = 0;
                silence_supported = false;
+               credential_needed = false;
+               SLOG(LOG_DEBUG, TAG_STTC, "[WARNING] current_engine_id(%s)", client->current_engine_id);
+
                while (0 != ret) {
-                       ret = stt_dbus_request_set_current_engine(client->uid, client->current_engine_id, &silence_supported);
+                       ret = stt_dbus_request_set_current_engine(client->uid, client->current_engine_id, &silence_supported, &credential_needed);
                        if (0 != ret) {
                                if (STT_ERROR_TIMED_OUT != ret) {
                                        SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to set current engine : %s", __stt_get_error_code(ret));
@@ -493,11 +769,11 @@ static Eina_Bool __stt_connect_daemon(void *data)
 
                                /* success to change engine */
                                client->silence_supported = silence_supported;
-                               SLOG(LOG_DEBUG, TAG_STTC, "Supported options : silence(%s)", silence_supported ? "true" : "false");
+                               SLOG(LOG_DEBUG, TAG_STTC, "Supported options : silence(%s), credential(%s)", silence_supported ? "support" : "no support", credential_needed ? "need" : "no need");
                        }
                }
        }
-
+#endif
        SLOG(LOG_DEBUG, TAG_STTC, "[SUCCESS] uid(%d)", client->uid);
 
        client->before_state = client->current_state;
@@ -521,17 +797,14 @@ static Eina_Bool __stt_connect_daemon(void *data)
 
 int stt_prepare(stt_h stt)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       SLOG(LOG_DEBUG, TAG_STTC, "===== Prepare STT");
-
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
@@ -551,20 +824,19 @@ int stt_prepare(stt_h stt)
 
 int stt_unprepare(stt_h stt)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       SLOG(LOG_DEBUG, TAG_STTC, "===== Unprepare STT");
-
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
+       SLOG(LOG_DEBUG, TAG_STTC, "===== Unprepare STT");
+
        /* check state */
        if (client->current_state != STT_STATE_READY) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State: Current state(%d) is not 'READY'", client->current_state);
@@ -605,7 +877,7 @@ int stt_unprepare(stt_h stt)
                SLOG(LOG_WARN, TAG_STTC, "[WARNING] State changed callback is null");
        }
 
-       if(g_connect_timer) {
+       if (g_connect_timer) {
                ecore_timer_del(g_connect_timer);
                g_connect_timer = NULL;
        }
@@ -638,22 +910,21 @@ bool __stt_config_supported_language_cb(const char* engine_id, const char* langu
 
 int stt_foreach_supported_languages(stt_h stt, stt_supported_language_cb callback, void* user_data)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       SLOG(LOG_DEBUG, TAG_STTC, "===== Foreach Supported Language");
-
-       if (NULL == stt || NULL == callback) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
-       stt_client_s* client = stt_client_get(stt);
+       SLOG(LOG_DEBUG, TAG_STTC, "===== Foreach Supported Language");
 
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (NULL == callback) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
                return STT_ERROR_INVALID_PARAMETER;
        }
 
@@ -686,6 +957,7 @@ int stt_foreach_supported_languages(stt_h stt, stt_supported_language_cb callbac
 
        if (NULL != current_engine_id) {
                free(current_engine_id);
+               current_engine_id = NULL;
        }
 
        client->supported_lang_cb = NULL;
@@ -699,23 +971,24 @@ int stt_foreach_supported_languages(stt_h stt, stt_supported_language_cb callbac
 
 int stt_get_default_language(stt_h stt, char** language)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
+               return STT_ERROR_INVALID_PARAMETER;
+       }
 
        SLOG(LOG_DEBUG, TAG_STTC, "===== Get Default Language");
 
-       if (NULL == stt || NULL == language) {
+       if (NULL == language) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
                return STT_ERROR_INVALID_PARAMETER;
        }
 
-       stt_client_s* client = stt_client_get(stt);
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
-               return STT_ERROR_INVALID_PARAMETER;
-       }
-
        int ret = 0;
        ret = stt_config_mgr_get_default_language(language);
        ret = __stt_convert_config_error_code(ret);
@@ -733,48 +1006,86 @@ int stt_get_default_language(stt_h stt, char** language)
 
 int stt_get_state(stt_h stt, stt_state_e* state)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       if (NULL == stt || NULL == state) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
-       stt_client_s* client = stt_client_get(stt);
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Get state : A handle is not valid");
+       if (NULL == state) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
                return STT_ERROR_INVALID_PARAMETER;
        }
 
        *state = client->current_state;
 
        switch (*state) {
-               case STT_STATE_CREATED:         SLOG(LOG_DEBUG, TAG_STTC, "Current state is 'CREATED'");        break;
-               case STT_STATE_READY:           SLOG(LOG_DEBUG, TAG_STTC, "Current state is 'Ready'");          break;
-               case STT_STATE_RECORDING:       SLOG(LOG_DEBUG, TAG_STTC, "Current state is 'Recording'");      break;
-               case STT_STATE_PROCESSING:      SLOG(LOG_DEBUG, TAG_STTC, "Current state is 'Processing'");     break;
-               default:                        SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid value");             break;
+       case STT_STATE_CREATED:         SLOG(LOG_DEBUG, TAG_STTC, "Current state is 'CREATED'");        break;
+       case STT_STATE_READY:           SLOG(LOG_DEBUG, TAG_STTC, "Current state is 'Ready'");          break;
+       case STT_STATE_RECORDING:       SLOG(LOG_DEBUG, TAG_STTC, "Current state is 'Recording'");      break;
+       case STT_STATE_PROCESSING:      SLOG(LOG_DEBUG, TAG_STTC, "Current state is 'Processing'");     break;
+       default:                        SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid value");             break;
        }
 
        return STT_ERROR_NONE;
 }
 
-int stt_is_recognition_type_supported(stt_h stt, const char* type, bool* support)
+int stt_get_error_message(stt_h stt, char** err_msg)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
+               return STT_ERROR_INVALID_PARAMETER;
+       }
 
-       if (NULL == stt || NULL == type || NULL == support) {
+       if (NULL == err_msg) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
                return STT_ERROR_INVALID_PARAMETER;
        }
 
-       stt_client_s* client = stt_client_get(stt);
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not valid");
+       if (false == g_err_callback_status) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] This callback should be called during an err_callback");
+               return STT_ERROR_OPERATION_FAILED;
+       }
+
+       if (NULL != client->err_msg) {
+               *err_msg = strdup(client->err_msg);
+               SLOG(LOG_DEBUG, TAG_STTC, "[SUCCESS] Error msg (%s)", *err_msg);
+       } else {
+               SLOG(LOG_DEBUG, TAG_STTC, "[SUCCESS] Error msg (NULL)");
+       }
+
+       SLOG(LOG_DEBUG, TAG_STTC, "=====");
+       SLOG(LOG_DEBUG, TAG_STTC, " ");
+
+       return STT_ERROR_NONE;
+}
+
+int stt_is_recognition_type_supported(stt_h stt, const char* type, bool* support)
+{
+       stt_client_s* client = NULL;
+       if (0 != __stt_get_feature_enabled()) {
+               return STT_ERROR_NOT_SUPPORTED;
+       }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
+               return STT_ERROR_INVALID_PARAMETER;
+       }
+
+       if (NULL == type || NULL == support) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
                return STT_ERROR_INVALID_PARAMETER;
        }
 
@@ -812,18 +1123,14 @@ int stt_is_recognition_type_supported(stt_h stt, const char* type, bool* support
 
 int stt_set_silence_detection(stt_h stt, stt_option_silence_detection_e type)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       if (NULL == stt) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
-               return STT_ERROR_INVALID_PARAMETER;
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
        }
-
-       stt_client_s* client = stt_client_get(stt);
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Get state : A handle is not valid");
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
@@ -849,13 +1156,20 @@ int stt_set_silence_detection(stt_h stt, stt_option_silence_detection_e type)
 
 int stt_set_start_sound(stt_h stt, const char* filename)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
+               return STT_ERROR_INVALID_PARAMETER;
+       }
 
        SLOG(LOG_DEBUG, TAG_STTC, "===== STT SET START SOUND");
 
-       if (NULL == stt || NULL == filename) {
+       if (NULL == filename) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
                return STT_ERROR_INVALID_PARAMETER;
        }
@@ -865,12 +1179,6 @@ int stt_set_start_sound(stt_h stt, const char* filename)
                return STT_ERROR_INVALID_PARAMETER;
        }
 
-       stt_client_s* client = stt_client_get(stt);
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Get state : A handle is not valid");
-               return STT_ERROR_INVALID_PARAMETER;
-       }
-
        /* check state */
        if (client->current_state != STT_STATE_READY) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State: Current state(%d) is not READY", client->current_state);
@@ -905,24 +1213,19 @@ int stt_set_start_sound(stt_h stt, const char* filename)
 
 int stt_unset_start_sound(stt_h stt)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       SLOG(LOG_DEBUG, TAG_STTC, "===== STT UNSET START SOUND");
-
-       if (NULL == stt) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
-               return STT_ERROR_INVALID_PARAMETER;
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
        }
-
-       stt_client_s* client = stt_client_get(stt);
-
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Get state : A handle is not valid");
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
+       SLOG(LOG_DEBUG, TAG_STTC, "===== STT UNSET START SOUND");
+
        /* check state */
        if (client->current_state != STT_STATE_READY) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State: Current state(%d) is not READY", client->current_state);
@@ -957,13 +1260,20 @@ int stt_unset_start_sound(stt_h stt)
 
 int stt_set_stop_sound(stt_h stt, const char* filename)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
+               return STT_ERROR_INVALID_PARAMETER;
+       }
 
        SLOG(LOG_DEBUG, TAG_STTC, "===== STT SET STOP SOUND");
 
-       if (NULL == stt || NULL == filename) {
+       if (NULL == filename) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
                return STT_ERROR_INVALID_PARAMETER;
        }
@@ -973,13 +1283,6 @@ int stt_set_stop_sound(stt_h stt, const char* filename)
                return STT_ERROR_INVALID_PARAMETER;
        }
 
-       stt_client_s* client = stt_client_get(stt);
-
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Get state : A handle is not valid");
-               return STT_ERROR_INVALID_PARAMETER;
-       }
-
        /* check state */
        if (client->current_state != STT_STATE_READY) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State: Current state(%d) is not READY", client->current_state);
@@ -1014,24 +1317,19 @@ int stt_set_stop_sound(stt_h stt, const char* filename)
 
 int stt_unset_stop_sound(stt_h stt)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       SLOG(LOG_DEBUG, TAG_STTC, "===== STT UNSET STOP SOUND");
-
-       if (NULL == stt) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
-               return STT_ERROR_INVALID_PARAMETER;
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
        }
-
-       stt_client_s* client = stt_client_get(stt);
-
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Get state : A handle is not valid");
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
+       SLOG(LOG_DEBUG, TAG_STTC, "===== STT UNSET STOP SOUND");
+
        /* check state */
        if (client->current_state != STT_STATE_READY) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State: Current state(%d) is not READY", client->current_state);
@@ -1066,23 +1364,19 @@ int stt_unset_stop_sound(stt_h stt)
 
 int stt_start(stt_h stt, const char* language, const char* type)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       SLOG(LOG_DEBUG, TAG_STTC, "===== STT START");
-
-       if (NULL == stt) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
-               return STT_ERROR_INVALID_PARAMETER;
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
        }
-
-       stt_client_s* client = stt_client_get(stt);
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
+       SLOG(LOG_DEBUG, TAG_STTC, "===== STT START");
+
        /* check state */
        if (client->current_state != STT_STATE_READY) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State: Current state(%d) is not READY", client->current_state);
@@ -1091,7 +1385,7 @@ int stt_start(stt_h stt, const char* language, const char* type)
 
        if (STT_INTERNAL_STATE_NONE != client->internal_state) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State : Internal state is NOT none : %d", client->internal_state);
-               return STT_ERROR_INVALID_STATE;
+               return STT_ERROR_IN_PROGRESS_TO_RECORDING;
        }
 
        int ret = -1;
@@ -1111,55 +1405,12 @@ int stt_start(stt_h stt, const char* language, const char* type)
                temp = strdup(language);
        }
 
-#if 0
-       ret = -1;
-       /* do request */
-       int count = 0;
-       while (0 != ret) {
-               ret = stt_dbus_request_start(client->uid, temp, type, client->silence, appid);
-               if (0 > ret) {
-                       /* Failure */
-                       if (STT_ERROR_TIMED_OUT != ret) {
-                               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to start : %s", __stt_get_error_code(ret));
-                               if (NULL != temp)       free(temp);
-                               return ret;
-                       } else {
-                               SLOG(LOG_WARN, TAG_STTC, "[WARNING] retry to start");
-                               usleep(10000);
-                               count++;
-                               if (STT_RETRY_COUNT == count) {
-                                       SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to request");
-                                       if (NULL != temp)       free(temp);
-                                       return ret;
-                               }
-                       }
-               } else {
-                       /* Success */
-                       if (NULL != temp)       free(temp);
-
-                       if (STT_RESULT_STATE_DONE == ret) {
-                               SLOG(LOG_DEBUG, TAG_STTC, "[SUCCESS] Start is done : %d", ret);
-                               client->before_state = client->current_state;
-                               client->current_state = STT_STATE_RECORDING;
-
-                               if (NULL != client->state_changed_cb) {
-                                       ecore_main_loop_thread_safe_call_async(__stt_notify_state_changed, client);
-                               } else {
-                                       SLOG(LOG_WARN, TAG_STTC, "[WARNING] State changed callback is null");
-                               }
-                       } else if (STT_RESULT_STATE_NOT_DONE == ret) {
-                               SLOG(LOG_DEBUG, TAG_STTC, "[SUCCESS] Start is not done : %d", ret);
-                               client->internal_state = STT_INTERNAL_STATE_STARTING;
-                       } else {
-                               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid result : %d", ret);
-                       }
-
-                       ret = STT_ERROR_NONE;
-                       break;
-               }
+       if (true == client->credential_needed && NULL == client->credential) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Do not have app credential for this engine(%s)", client->current_engine_id);
+               return STT_ERROR_PERMISSION_DENIED;
        }
-#else
-       ret = stt_dbus_request_start(client->uid, temp, type, client->silence, appid);
+
+       ret = stt_dbus_request_start(client->uid, temp, type, client->silence, appid, client->credential);
        if (0 != ret) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to start : %s", __stt_get_error_code(ret));
        } else {
@@ -1168,7 +1419,7 @@ int stt_start(stt_h stt, const char* language, const char* type)
        }
 
        if (NULL != temp)       free(temp);
-#endif
+
        SLOG(LOG_DEBUG, TAG_STTC, "=====");
        SLOG(LOG_DEBUG, TAG_STTC, " ");
 
@@ -1177,85 +1428,45 @@ int stt_start(stt_h stt, const char* language, const char* type)
 
 int stt_stop(stt_h stt)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       SLOG(LOG_DEBUG, TAG_STTC, "===== STT STOP");
-
-       if (NULL == stt) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
-               return STT_ERROR_INVALID_PARAMETER;
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
        }
-
-       stt_client_s* client = stt_client_get(stt);
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
+       SLOG(LOG_DEBUG, TAG_STTC, "===== STT STOP");
+
        /* check state */
        if (client->current_state != STT_STATE_RECORDING) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State : Current state(%d) is NOT RECORDING", client->current_state);
                return STT_ERROR_INVALID_STATE;
        }
 
-       if (STT_INTERNAL_STATE_NONE != client->internal_state) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State : Internal state is NOT none : %d", client->internal_state);
-               return STT_ERROR_INVALID_STATE;
-       }
-#if 0
-       int ret = -1;
-       /* do request */
-       int count = 0;
-       while (0 != ret) {
-               ret = stt_dbus_request_stop(client->uid);
-               if (0 > ret) {
-                       /* Failure */
-                       if (STT_ERROR_TIMED_OUT != ret) {
-                               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to stop : %s", __stt_get_error_code(ret));
-                               return ret;
-                       } else {
-                               SLOG(LOG_WARN, TAG_STTC, "[WARNING] retry stop");
-                               usleep(10000);
-                               count++;
-                               if (STT_RETRY_COUNT == count) {
-                                       SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to request");
-                                       return ret;
-                               }
-                       }
-               } else {
-                       if (STT_RESULT_STATE_DONE == ret) {
-                               SLOG(LOG_DEBUG, TAG_STTC, "[SUCCESS] Stop is done : %d", ret);
-                               client->before_state = client->current_state;
-                               client->current_state = STT_STATE_PROCESSING;
-
-                               if (NULL != client->state_changed_cb) {
-                                       ecore_main_loop_thread_safe_call_async(__stt_notify_state_changed, client);
-                                       SLOG(LOG_DEBUG, TAG_STTC, "State changed callback is called");
-                               } else {
-                                       SLOG(LOG_WARN, TAG_STTC, "[WARNING] State changed callback is null");
-                               }
-                       } else if (STT_RESULT_STATE_NOT_DONE == ret) {
-                               SLOG(LOG_DEBUG, TAG_STTC, "[SUCCESS] Stop is not done : %d", ret);
-                               client->internal_state = STT_INTERNAL_STATE_STOPING;
-                       } else {
-                               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid result : %d", ret);
-                       }
-                       ret = STT_ERROR_NONE;
-                       break;
-               }
+       if (STT_INTERNAL_STATE_STARTING == client->internal_state) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State : Internal state is STARTING : %d", client->internal_state);
+               return STT_ERROR_IN_PROGRESS_TO_RECORDING;
+       } else if (STT_INTERNAL_STATE_CANCELING == client->internal_state) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State : Internal state is CANCELING : %d", client->internal_state);
+               return STT_ERROR_IN_PROGRESS_TO_READY;
+       } else if (STT_INTERNAL_STATE_STOPPING == client->internal_state) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State : Internal state is STOPPING : %d", client->internal_state);
+               return STT_ERROR_IN_PROGRESS_TO_PROCESSING;
        }
-#else
+
        int ret = stt_dbus_request_stop(client->uid);
 
        if (0 != ret) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to stop : %s", __stt_get_error_code(ret));
        } else {
                SLOG(LOG_DEBUG, TAG_STTC, "[SUCCESS] Stop is successful but not done");
-               client->internal_state = STT_INTERNAL_STATE_STOPING;
+               client->internal_state = STT_INTERNAL_STATE_STOPPING;
        }
-#endif
+
        SLOG(LOG_DEBUG, TAG_STTC, "=====");
        SLOG(LOG_DEBUG, TAG_STTC, " ");
 
@@ -1265,72 +1476,36 @@ int stt_stop(stt_h stt)
 
 int stt_cancel(stt_h stt)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       SLOG(LOG_DEBUG, TAG_STTC, "===== STT CANCEL");
-
-       if (NULL == stt) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input handle is null");
-               return STT_ERROR_INVALID_PARAMETER;
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
        }
-
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
+       SLOG(LOG_DEBUG, TAG_STTC, "===== STT CANCEL");
+
        /* check state */
        if (STT_STATE_RECORDING != client->current_state && STT_STATE_PROCESSING != client->current_state) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid state : Current state(%d) is 'Ready'", client->current_state);
                return STT_ERROR_INVALID_STATE;
        }
 
-       if (STT_INTERNAL_STATE_NONE != client->internal_state) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State : Internal state is NOT none : %d", client->internal_state);
-               return STT_ERROR_INVALID_STATE;
+       if (STT_INTERNAL_STATE_STARTING == client->internal_state) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State : Internal state is STARTING : %d", client->internal_state);
+               return STT_ERROR_IN_PROGRESS_TO_RECORDING;
+       } else if (STT_INTERNAL_STATE_STOPPING == client->internal_state) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State : Internal state is STOPPING : %d", client->internal_state);
+               return STT_ERROR_IN_PROGRESS_TO_PROCESSING;
+       } else if (STT_INTERNAL_STATE_CANCELING == client->internal_state) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Invalid State : Internal state is CANCELING : %d", client->internal_state);
+               return STT_ERROR_IN_PROGRESS_TO_READY;
        }
-#if 0
-       int ret = -1;
-       /* do request */
-       int count = 0;
-       while (0 != ret) {
-               ret = stt_dbus_request_cancel(client->uid);
-               if (0 != ret) {
-                       /* Failure */
-                       if (STT_ERROR_TIMED_OUT != ret) {
-                               SLOG(LOG_DEBUG, TAG_STTC, "[ERROR] Fail to cancel : %s", __stt_get_error_code(ret));
-                               return ret;
-                       } else {
-                               SLOG(LOG_WARN, TAG_STTC, "[WARNING] retry");
-                               usleep(10000);
-                               count++;
-                               if (STT_RETRY_COUNT == count) {
-                                       SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to request");
-                                       return ret;
-                               }
-                       }
-               } else {
-                       SLOG(LOG_DEBUG, TAG_STTC, "[SUCCESS]");
 
-                       client->before_state = client->current_state;
-                       client->current_state = STT_STATE_READY;
-
-                       if (NULL != client->state_changed_cb) {
-                               ecore_main_loop_thread_safe_call_async(__stt_notify_state_changed, client);
-                               SLOG(LOG_DEBUG, TAG_STTC, "State changed callback is called");
-                       } else {
-                               SLOG(LOG_WARN, TAG_STTC, "[WARNING] State changed callback is null");
-                       }
-                       ret = STT_ERROR_NONE;
-                       break;
-               }
-       }
-#else
        int ret = stt_dbus_request_cancel(client->uid);
        if (0 != ret) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to cancel : %s", __stt_get_error_code(ret));
@@ -1338,7 +1513,7 @@ int stt_cancel(stt_h stt)
                SLOG(LOG_DEBUG, TAG_STTC, "[SUCCESS] Cancel is successful but not done");
                client->internal_state = STT_INTERNAL_STATE_CANCELING;
        }
-#endif
+
        SLOG(LOG_DEBUG, TAG_STTC, "=====");
        SLOG(LOG_DEBUG, TAG_STTC, " ");
 
@@ -1368,20 +1543,19 @@ int __stt_cb_set_volume(int uid, float volume)
 
 int stt_get_recording_volume(stt_h stt, float* volume)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       if (NULL == stt || NULL == volume) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (NULL == volume) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Input parameter is NULL");
                return STT_ERROR_INVALID_PARAMETER;
        }
 
@@ -1420,9 +1594,16 @@ bool __stt_result_time_cb(int index, int event, const char* text, long start_tim
 
 int stt_foreach_detailed_result(stt_h stt, stt_result_time_cb callback, void* user_data)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
+               return STT_ERROR_INVALID_PARAMETER;
+       }
 
        SLOG(LOG_DEBUG, TAG_STTC, "===== STT FOREACH DETAILED RESULT");
 
@@ -1431,14 +1612,6 @@ int stt_foreach_detailed_result(stt_h stt, stt_result_time_cb callback, void* us
                return STT_ERROR_INVALID_PARAMETER;
        }
 
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail : A handle is not valid");
-               return STT_ERROR_INVALID_PARAMETER;
-       }
-
        client->result_time_cb = callback;
        client->result_time_user_data = user_data;
 
@@ -1475,7 +1648,9 @@ static Eina_Bool __stt_notify_error(void *data)
 
        if (NULL != client->error_cb) {
                stt_client_use_callback(client);
+               g_err_callback_status = true;
                client->error_cb(client->stt, client->reason, client->error_user_data);
+               g_err_callback_status = false;
                stt_client_not_use_callback(client);
                SLOG(LOG_WARN, TAG_STTC, "[WARNING] Error callback is called : reason [%d]", client->reason);
        } else {
@@ -1485,16 +1660,22 @@ static Eina_Bool __stt_notify_error(void *data)
        return EINA_FALSE;
 }
 
-int __stt_cb_error(int uid, int reason)
+int __stt_cb_error(int uid, int reason, char* err_msg)
 {
        stt_client_s* client = stt_client_get_by_uid(uid);
-       if( NULL == client ) {
+       if (NULL == client) {
                SLOG(LOG_ERROR, TAG_STTC, "Handle not found");
                return -1;
        }
 
        client->reason = reason;
        client->internal_state = STT_INTERNAL_STATE_NONE;
+       if (NULL != client->err_msg) {
+               free(client->err_msg);
+               client->err_msg = NULL;
+       }
+       client->err_msg = strdup(err_msg);
+
        SLOG(LOG_INFO, TAG_STTC, "internal state is initialized to 0");
 
        if (NULL != client->error_cb) {
@@ -1503,6 +1684,15 @@ int __stt_cb_error(int uid, int reason)
                SLOG(LOG_WARN, TAG_STTC, "[WARNING] Error callback is null");
        }
 
+       if (STT_ERROR_SERVICE_RESET == reason) {
+               SLOG(LOG_WARN, TAG_STTC, "[WARNING] Service reset");
+
+               client->current_state = STT_STATE_CREATED;
+               if (0 != stt_prepare(client->stt)) {
+                       SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Fail to prepare");
+               }
+       }
+
        return 0;
 }
 
@@ -1523,7 +1713,7 @@ static void __stt_notify_state_changed(void *data)
        if (STT_INTERNAL_STATE_STARTING == client->internal_state && STT_STATE_RECORDING == client->current_state) {
                client->internal_state = STT_INTERNAL_STATE_NONE;
                SLOG(LOG_DEBUG, TAG_STTC, "Internal state change to NONE");
-       } else if (STT_INTERNAL_STATE_STOPING == client->internal_state && STT_STATE_PROCESSING == client->current_state) {
+       } else if (STT_INTERNAL_STATE_STOPPING == client->internal_state && STT_STATE_PROCESSING == client->current_state) {
                client->internal_state = STT_INTERNAL_STATE_NONE;
                SLOG(LOG_DEBUG, TAG_STTC, "Internal state change to NONE");
        } else if (STT_INTERNAL_STATE_CANCELING == client->internal_state && STT_STATE_READY == client->current_state) {
@@ -1685,20 +1875,19 @@ int __stt_cb_set_state(int uid, int state)
 
 int stt_set_recognition_result_cb(stt_h stt, stt_recognition_result_cb callback, void* user_data)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       if (stt == NULL || callback == NULL)
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
+       }
 
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (callback == NULL)
                return STT_ERROR_INVALID_PARAMETER;
-       }
 
        if (STT_STATE_CREATED != client->current_state) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Current state(%d) is not 'Created'", client->current_state);
@@ -1713,18 +1902,14 @@ int stt_set_recognition_result_cb(stt_h stt, stt_recognition_result_cb callback,
 
 int stt_unset_recognition_result_cb(stt_h stt)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       if (NULL == stt)
-               return STT_ERROR_INVALID_PARAMETER;
-
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
@@ -1741,20 +1926,19 @@ int stt_unset_recognition_result_cb(stt_h stt)
 
 int stt_set_state_changed_cb(stt_h stt, stt_state_changed_cb callback, void* user_data)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       if (NULL == stt || NULL == callback)
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
+       }
 
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (NULL == callback)
                return STT_ERROR_INVALID_PARAMETER;
-       }
 
        if (STT_STATE_CREATED != client->current_state) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Current state(%d) is not 'Created'", client->current_state);
@@ -1769,18 +1953,14 @@ int stt_set_state_changed_cb(stt_h stt, stt_state_changed_cb callback, void* use
 
 int stt_unset_state_changed_cb(stt_h stt)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       if (NULL == stt)
-               return STT_ERROR_INVALID_PARAMETER;
-
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
@@ -1797,20 +1977,19 @@ int stt_unset_state_changed_cb(stt_h stt)
 
 int stt_set_error_cb(stt_h stt, stt_error_cb callback, void* user_data)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       if (NULL == stt || NULL == callback)
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
+       }
 
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (NULL == callback)
                return STT_ERROR_INVALID_PARAMETER;
-       }
 
        if (STT_STATE_CREATED != client->current_state) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Current state(%d) is not 'Created'", client->current_state);
@@ -1825,18 +2004,14 @@ int stt_set_error_cb(stt_h stt, stt_error_cb callback, void* user_data)
 
 int stt_unset_error_cb(stt_h stt)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       if (NULL == stt)
-               return STT_ERROR_INVALID_PARAMETER;
-
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
@@ -1853,20 +2028,19 @@ int stt_unset_error_cb(stt_h stt)
 
 int stt_set_default_language_changed_cb(stt_h stt, stt_default_language_changed_cb callback, void* user_data)
 {
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
-
-       if (NULL == stt || NULL == callback)
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
+       }
 
-       stt_client_s* client = stt_client_get(stt);
-
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       if (NULL == callback)
                return STT_ERROR_INVALID_PARAMETER;
-       }
 
        if (STT_STATE_CREATED != client->current_state) {
                SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Current state(%d) is not 'Created'", client->current_state);
@@ -1881,18 +2055,65 @@ int stt_set_default_language_changed_cb(stt_h stt, stt_default_language_changed_
 
 int stt_unset_default_language_changed_cb(stt_h stt)
 {
+       stt_client_s* client = NULL;
+       if (0 != __stt_get_feature_enabled()) {
+               return STT_ERROR_NOT_SUPPORTED;
+       }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
+               return STT_ERROR_INVALID_PARAMETER;
+       }
+
+       if (STT_STATE_CREATED != client->current_state) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Current state(%d) is not 'Created'", client->current_state);
+               return STT_ERROR_INVALID_STATE;
+       }
+
+       client->default_lang_changed_cb = NULL;
+       client->default_lang_changed_user_data = NULL;
+
+       return 0;
+}
+
+int stt_set_engine_changed_cb(stt_h stt, stt_engine_changed_cb callback, void* user_data)
+{
+       stt_client_s* client = NULL;
        if (0 != __stt_get_feature_enabled()) {
                return STT_ERROR_NOT_SUPPORTED;
        }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
+               return STT_ERROR_INVALID_PARAMETER;
+       }
 
-       if (NULL == stt)
+       if (NULL == callback)
                return STT_ERROR_INVALID_PARAMETER;
 
-       stt_client_s* client = stt_client_get(stt);
+       if (STT_STATE_CREATED != client->current_state) {
+               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] Current state(%d) is not 'Created'", client->current_state);
+               return STT_ERROR_INVALID_STATE;
+       }
 
-       /* check handle */
-       if (NULL == client) {
-               SLOG(LOG_ERROR, TAG_STTC, "[ERROR] A handle is not available");
+       client->engine_changed_cb = callback;
+       client->engine_changed_user_data = user_data;
+
+       return 0;
+}
+
+int stt_unset_engine_changed_cb(stt_h stt)
+{
+       stt_client_s* client = NULL;
+       if (0 != __stt_get_feature_enabled()) {
+               return STT_ERROR_NOT_SUPPORTED;
+       }
+       if (0 != __stt_check_privilege()) {
+               return STT_ERROR_PERMISSION_DENIED;
+       }
+       if (0 != __stt_check_handle(stt, &client)) {
                return STT_ERROR_INVALID_PARAMETER;
        }
 
@@ -1901,8 +2122,8 @@ int stt_unset_default_language_changed_cb(stt_h stt)
                return STT_ERROR_INVALID_STATE;
        }
 
-       client->default_lang_changed_cb = NULL;
-       client->default_lang_changed_user_data = NULL;
+       client->engine_changed_cb = NULL;
+       client->engine_changed_user_data = NULL;
 
        return 0;
 }