Fix broker sending duplicate CONNACK on failed MQTT v5 reauthentication.

Closes #2339. Thanks to hvxl.

ChangeLog.txt

@@ -10,6 +10,8 @@ Broker:
 - Don't send retained messages when a shared subscription is made.
 - Fix log being truncated in Windows.
 - Fix client id not showing in log on failed connections, where possible.
+- Fix broker sending duplicate CONNACK on failed MQTT v5 reauthentication.
+  Closes #2339.
 
 Client library:
 - Initialise sockpairR/W to invalid in `mosquitto_reinitialise()` to avoid

src/handle_auth.c

@@ -129,18 +129,22 @@ int handle__auth(struct mosquitto *context)
 			will__clear(context);
 		}
 		if(rc == MOSQ_ERR_AUTH){
-			send__connack(context, 0, MQTT_RC_NOT_AUTHORIZED, NULL);
 			if(context->state == mosq_cs_authenticating){
+				send__connack(context, 0, MQTT_RC_NOT_AUTHORIZED, NULL);
 				mosquitto__free(context->id);
 				context->id = NULL;
+			}else{
+				send__disconnect(context, MQTT_RC_NOT_AUTHORIZED, NULL);
 			}
 			return MOSQ_ERR_PROTOCOL;
 		}else if(rc == MOSQ_ERR_NOT_SUPPORTED){
 			/* Client has requested extended authentication, but we don't support it. */
-			send__connack(context, 0, MQTT_RC_BAD_AUTHENTICATION_METHOD, NULL);
 			if(context->state == mosq_cs_authenticating){
+				send__connack(context, 0, MQTT_RC_BAD_AUTHENTICATION_METHOD, NULL);
 				mosquitto__free(context->id);
 				context->id = NULL;
+			}else{
+				send__disconnect(context, MQTT_RC_BAD_AUTHENTICATION_METHOD, NULL);
 			}
 			return MOSQ_ERR_PROTOCOL;
 		}else{

test/broker/09-extended-auth-reauth.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python3
+
+from mosq_test_helper import *
+
+def write_config(filename, port):
+    with open(filename, 'w') as f:
+        f.write("port %d\n" % (port))
+        f.write("auth_plugin c/auth_plugin_extended_reauth.so\n")
+
+port = mosq_test.get_port()
+conf_file = os.path.basename(__file__).replace('.py', '.conf')
+write_config(conf_file, port)
+
+rc = 1
+
+# First authentication succeeds
+props = mqtt5_props.gen_string_prop(mqtt5_props.PROP_AUTHENTICATION_METHOD, "repeat")
+props += mqtt5_props.gen_string_prop(mqtt5_props.PROP_AUTHENTICATION_DATA, "repeat")
+connect_packet = mosq_test.gen_connect("client-params-test", keepalive=42, proto_ver=5, properties=props)
+
+props = mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_TOPIC_ALIAS_MAXIMUM, 10)
+props += mqtt5_props.gen_string_prop(mqtt5_props.PROP_AUTHENTICATION_METHOD, "repeat")
+props += mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_RECEIVE_MAXIMUM, 20)
+connack_packet = mosq_test.gen_connack(rc=0, proto_ver=5, properties=props, property_helper=False)
+
+# Reauthentication fails
+props = mqtt5_props.gen_string_prop(mqtt5_props.PROP_AUTHENTICATION_METHOD, "repeat")
+props += mqtt5_props.gen_string_prop(mqtt5_props.PROP_AUTHENTICATION_DATA, "repeat")
+auth_packet = mosq_test.gen_auth(reason_code=mqtt5_rc.MQTT_RC_REAUTHENTICATE, properties=props)
+disconnect_packet = mosq_test.gen_disconnect(reason_code=mqtt5_rc.MQTT_RC_NOT_AUTHORIZED, proto_ver=5)
+
+broker = mosq_test.start_broker(filename=os.path.basename(__file__), use_conf=True, port=port)
+
+try:
+    sock = mosq_test.do_client_connect(connect_packet, connack_packet, timeout=20, port=port)
+    mosq_test.do_send_receive(sock, auth_packet, disconnect_packet)
+    sock.close()
+
+    rc = 0
+except mosq_test.TestError:
+    pass
+finally:
+    os.remove(conf_file)
+    broker.terminate()
+    broker.wait()
+    (stdo, stde) = broker.communicate()
+    if rc:
+        print(stde.decode('utf-8'))
+
+
+exit(rc)
+

test/broker/Makefile

@@ -168,6 +168,7 @@ endif
 	./09-extended-auth-change-username.py
 	./09-extended-auth-multistep-reauth.py
 	./09-extended-auth-multistep.py
+	./09-extended-auth-reauth.py
 	./09-extended-auth-single.py
 	./09-plugin-acl-change.py
 	./09-plugin-auth-acl-pub.py

test/broker/c/Makefile

@@ -8,6 +8,7 @@ PLUGIN_SRC = \
 	auth_plugin_acl_sub_denied.c \
 	auth_plugin_context_params.c \
 	auth_plugin_extended_multiple.c \
+	auth_plugin_extended_reauth.c \
 	auth_plugin_extended_single.c \
 	auth_plugin_extended_single2.c \
 	auth_plugin_msg_params.c \

test/broker/c/auth_plugin_extended_reauth.c

@@ -0,0 +1,54 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <mosquitto.h>
+#include <mosquitto_broker.h>
+#include <mosquitto_plugin.h>
+
+static int auth_count = 0;
+
+int mosquitto_auth_plugin_version(void)
+{
+	return 4;
+}
+
+int mosquitto_auth_plugin_init(void **user_data, struct mosquitto_opt *auth_opts, int auth_opt_count)
+{
+	return MOSQ_ERR_SUCCESS;
+}
+
+int mosquitto_auth_plugin_cleanup(void *user_data, struct mosquitto_opt *auth_opts, int auth_opt_count)
+{
+	return MOSQ_ERR_SUCCESS;
+}
+
+int mosquitto_auth_security_init(void *user_data, struct mosquitto_opt *auth_opts, int auth_opt_count, bool reload)
+{
+	return MOSQ_ERR_SUCCESS;
+}
+
+int mosquitto_auth_security_cleanup(void *user_data, struct mosquitto_opt *auth_opts, int auth_opt_count, bool reload)
+{
+	return MOSQ_ERR_SUCCESS;
+}
+
+int mosquitto_auth_acl_check(void *user_data, int access, struct mosquitto *client, const struct mosquitto_acl_msg *msg)
+{
+	return MOSQ_ERR_PLUGIN_DEFER;
+}
+
+
+int mosquitto_auth_start(void *user_data, struct mosquitto *client, const char *method, bool reauth, const void *data, uint16_t data_len, void **data_out, uint16_t *data_out_len)
+{
+	if(auth_count == 0){
+		auth_count++;
+		return MOSQ_ERR_SUCCESS;
+	}else{
+		return MOSQ_ERR_AUTH;
+	}
+}
+
+int mosquitto_auth_continue(void *user_data, struct mosquitto *client, const char *method, const void *data, uint16_t data_len, void **data_out, uint16_t *data_out_len)
+{
+	return MOSQ_ERR_AUTH;
+}

test/broker/test.py

@@ -138,6 +138,7 @@ tests = [
     (1, './09-extended-auth-change-username.py'),
     (1, './09-extended-auth-multistep-reauth.py'),
     (1, './09-extended-auth-multistep.py'),
+    (1, './09-extended-auth-reauth.py'),
     (1, './09-extended-auth-single.py'),
     (1, './09-plugin-acl-change.py'),
     (1, './09-plugin-auth-acl-pub.py'),