Fix the non-C2 spun up shutdown case (scanner only) (#369)

* Fix the non-C2 spun up shutdown case (scanner only)

Author: terrorbyte

c2/httpservefile/httpservefile.go

@@ -105,6 +105,10 @@ func (httpServer *Server) Channel() *channel.Channel {
 
 // Shutdown the C2 server and cleanup all the sessions.
 func (httpServer *Server) Shutdown() bool {
+	// Account for non-running case
+	if httpServer.Channel() == nil {
+		return true
+	}
 	output.PrintFrameworkStatus("Shutting down the HTTP Server")
 	if len(httpServer.Channel().Sessions) > 0 {
 		for k := range httpServer.Channel().Sessions {

c2/httpserveshell/httpserveshell.go

@@ -119,6 +119,10 @@ func (serveShell *Server) Init(ch *channel.Channel) bool {
 
 // Shutdown triggers the shutdown for all running C2s.
 func (serveShell *Server) Shutdown() bool {
+	// Account for non-running case
+	if serveShell.Channel() == nil {
+		return true
+	}
 	// This is a bit confusing at first glance, but it solves the fact that this c2 doesn't directly
 	// keep track of sessions and we can't differentiate between a timeout "done" and a signal "done".
 	// What this means is that if a underlying shell server has sessions that we want to keep open for

c2/httpshellserver/httpshellserver.go

@@ -131,6 +131,10 @@ func (httpServer *Server) Channel() *channel.Channel {
 
 // Shutdown the C2 server and cleanup all the sessions.
 func (httpServer *Server) Shutdown() bool {
+	// Account for non-running case
+	if httpServer.Channel() == nil {
+		return true
+	}
 	output.PrintFrameworkStatus("Shutting down the HTTP Server")
 	if len(httpServer.Channel().Sessions) > 0 {
 		for k := range httpServer.Channel().Sessions {

c2/shelltunnel/shelltunnel.go

@@ -159,6 +159,10 @@ func (shellTunnel *Server) Init(channel *channel.Channel) bool {
 }
 
 func (shellTunnel *Server) Shutdown() bool {
+	// Account for non-running case
+	if shellTunnel.Channel() == nil {
+		return true
+	}
 	output.PrintFrameworkStatus("C2 received shutdown, killing server and client sockets for shell tunnel")
 	if len(shellTunnel.Channel().Sessions) > 0 {
 		for k, session := range shellTunnel.Channel().Sessions {

c2/simpleshell/simpleshellclient.go

@@ -31,6 +31,10 @@ func (shellClient *Client) CreateFlags() {
 }
 
 func (shellClient *Client) Shutdown() bool {
+	// Account for non-running case
+	if shellClient.Channel() == nil {
+		return true
+	}
 	ok := shellClient.Channel().RemoveSessions()
 
 	// we done here

c2/simpleshell/simpleshellserver.go

@@ -45,6 +45,10 @@ func (shellServer *Server) Channel() *channel.Channel {
 
 // Shutdown the C2 and cleanup any active connections.
 func (shellServer *Server) Shutdown() bool {
+	// Account for non-running case
+	if shellServer.Channel() == nil {
+		return true
+	}
 	output.PrintFrameworkStatus("C2 received shutdown, killing server and client sockets for shell server")
 	if len(shellServer.Channel().Sessions) > 0 {
 		for k, session := range shellServer.Channel().Sessions {

c2/sslshell/sslshellserver.go

@@ -66,6 +66,10 @@ func (shellServer *Server) CreateFlags() {
 
 // Shutdown the C2 and close server and client connections when applicable.
 func (shellServer *Server) Shutdown() bool {
+	// Account for non-running case
+	if shellServer.Channel() == nil {
+		return true
+	}
 	output.PrintFrameworkStatus("C2 received shutdown, killing server and client sockets for SSL shell server")
 	if len(shellServer.channel.Sessions) > 0 {
 		for k, session := range shellServer.channel.Sessions {