fix: support zero-length clientId

Ryan-CW-Code · Ryan-CW-Code · commit 8be845da6b89 · 2025-10-25T01:21:43.000+08:00
diff --git a/source/core_mqtt_serializer.c b/source/core_mqtt_serializer.c
@@ -1706,9 +1706,15 @@ MQTTStatus_t MQTT_GetConnectPacketSize( const MQTTConnectInfo_t * pConnectInfo,
                     ( void * ) pPacketSize ) );
         status = MQTTBadParameter;
     }
-    else if( ( pConnectInfo->clientIdentifierLength == 0U ) || ( pConnectInfo->pClientIdentifier == NULL ) )
+    else if( ( ( pConnectInfo->clientIdentifierLength == 0U ) || ( pConnectInfo->pClientIdentifier == NULL ) || ( *( pConnectInfo->pClientIdentifier ) == '\0' ) ) &&
+             ( pConnectInfo->cleanSession == false ) )
     {
-        LogError( ( "Mqtt_GetConnectPacketSize() client identifier must be set." ) );
+        LogError( ( "Zero-length client identifier requires cleanSession=true per MQTT 3.1.1." ) );
+        status = MQTTBadParameter;
+    }
+    else if( ( pConnectInfo->clientIdentifierLength == 0U ) ^ ( ( pConnectInfo->pClientIdentifier == NULL )  || ( *( pConnectInfo->pClientIdentifier ) == '\0' ) ) )
+    {
+        LogError( ( "Client ID length and value mismatch." ) );
         status = MQTTBadParameter;
     }
     else if( ( pWillInfo != NULL ) && ( pWillInfo->payloadLength > ( size_t ) UINT16_MAX ) )

Original file line number	Diff line number	Diff line change
`@@ -1706,9 +1706,15 @@ MQTTStatus_t MQTT_GetConnectPacketSize( const MQTTConnectInfo_t * pConnectInfo,`
`1706`	`1706`	`( void * ) pPacketSize ) );`
`1707`	`1707`	`status = MQTTBadParameter;`
`1708`	`1708`	`}`
`1709`		`- else if( ( pConnectInfo->clientIdentifierLength == 0U ) \|\| ( pConnectInfo->pClientIdentifier == NULL ) )`
	`1709`	`+ else if( ( ( pConnectInfo->clientIdentifierLength == 0U ) \|\| ( pConnectInfo->pClientIdentifier == NULL ) \|\| ( *( pConnectInfo->pClientIdentifier ) == '\0' ) ) &&`
	`1710`	`+ ( pConnectInfo->cleanSession == false ) )`
`1710`	`1711`	`{`
`1711`		`- LogError( ( "Mqtt_GetConnectPacketSize() client identifier must be set." ) );`
	`1712`	`+ LogError( ( "Zero-length client identifier requires cleanSession=true per MQTT 3.1.1." ) );`
	`1713`	`+ status = MQTTBadParameter;`
	`1714`	`+ }`
	`1715`	`+ else if( ( pConnectInfo->clientIdentifierLength == 0U ) ^ ( ( pConnectInfo->pClientIdentifier == NULL ) \|\| ( *( pConnectInfo->pClientIdentifier ) == '\0' ) ) )`
	`1716`	`+ {`
	`1717`	`+ LogError( ( "Client ID length and value mismatch." ) );`
`1712`	`1718`	`status = MQTTBadParameter;`
`1713`	`1719`	`}`
`1714`	`1720`	`else if( ( pWillInfo != NULL ) && ( pWillInfo->payloadLength > ( size_t ) UINT16_MAX ) )`