From 9c5200fec290b3f5d12d061fe8c9b62f1a411f98 Mon Sep 17 00:00:00 2001
From: rc4 <isohyde@gmail.com>
Date: Wed, 22 Jun 2022 17:36:21 -0400
Subject: [PATCH] Fix authentication handling

Add handling of empty SERVERDATA_RESPONSE_VALUE packet before SERVERDATA_AUTH_RESPONSE packet
---
 lib/Net/RCON.pm | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/Net/RCON.pm b/lib/Net/RCON.pm
index 63608d3..ecd5c42 100644
--- a/lib/Net/RCON.pm
+++ b/lib/Net/RCON.pm
@@ -32,6 +32,12 @@ sub new {
 
 	# Send a SERVERDATA_AUTH packet
 	$object->_send_rcon( SERVERDATA_AUTH, $self->{password} );
+	
+	# We should get an empty SERVERDATA_RESPONSE_VALUE packet first
+	if( !$self->_recv_rcon( SERVERDATA_RESPONSE_VALUE ) ) {
+		warn "Authentication to the RCON server failed - no reply from server";
+		return undef;
+	}
 
 	# Check is SERVERDATA_AUTH_RESPONSE came back as valid
 	if( !$self->_recv_rcon( SERVERDATA_AUTH_RESPONSE ) ) {