Handle panic when invalid IP entered in sshd (#296)

ssh.go

@@ -463,7 +463,12 @@ func sshQueryLighthouse(ifce *Interface, fs interface{}, a []string, w sshd.Stri
 		return w.WriteLine("No vpn ip was provided")
 	}
 
-	vpnIp := ip2int(net.ParseIP(a[0]))
+	parsedIp := net.ParseIP(a[0])
+	if parsedIp == nil {
+		return w.WriteLine(fmt.Sprintf("The provided vpn ip could not be parsed: %s", a[0]))
+	}
+
+	vpnIp := ip2int(parsedIp)
 	if vpnIp == 0 {
 		return w.WriteLine(fmt.Sprintf("The provided vpn ip could not be parsed: %s", a[0]))
 	}
@@ -483,7 +488,12 @@ func sshCloseTunnel(ifce *Interface, fs interface{}, a []string, w sshd.StringWr
 		return w.WriteLine("No vpn ip was provided")
 	}
 
-	vpnIp := ip2int(net.ParseIP(a[0]))
+	parsedIp := net.ParseIP(a[0])
+	if parsedIp == nil {
+		return w.WriteLine(fmt.Sprintf("The provided vpn ip could not be parsed: %s", a[0]))
+	}
+
+	vpnIp := ip2int(parsedIp)
 	if vpnIp == 0 {
 		return w.WriteLine(fmt.Sprintf("The provided vpn ip could not be parsed: %s", a[0]))
 	}
@@ -521,7 +531,12 @@ func sshCreateTunnel(ifce *Interface, fs interface{}, a []string, w sshd.StringW
 		return w.WriteLine("No vpn ip was provided")
 	}
 
-	vpnIp := ip2int(net.ParseIP(a[0]))
+	parsedIp := net.ParseIP(a[0])
+	if parsedIp == nil {
+		return w.WriteLine(fmt.Sprintf("The provided vpn ip could not be parsed: %s", a[0]))
+	}
+
+	vpnIp := ip2int(parsedIp)
 	if vpnIp == 0 {
 		return w.WriteLine(fmt.Sprintf("The provided vpn ip could not be parsed: %s", a[0]))
 	}
@@ -573,7 +588,12 @@ func sshChangeRemote(ifce *Interface, fs interface{}, a []string, w sshd.StringW
 		return w.WriteLine("Address could not be parsed")
 	}
 
-	vpnIp := ip2int(net.ParseIP(a[0]))
+	parsedIp := net.ParseIP(a[0])
+	if parsedIp == nil {
+		return w.WriteLine(fmt.Sprintf("The provided vpn ip could not be parsed: %s", a[0]))
+	}
+
+	vpnIp := ip2int(parsedIp)
 	if vpnIp == 0 {
 		return w.WriteLine(fmt.Sprintf("The provided vpn ip could not be parsed: %s", a[0]))
 	}
@@ -649,7 +669,12 @@ func sshPrintCert(ifce *Interface, fs interface{}, a []string, w sshd.StringWrit
 
 	cert := ifce.certState.certificate
 	if len(a) > 0 {
-		vpnIp := ip2int(net.ParseIP(a[0]))
+		parsedIp := net.ParseIP(a[0])
+		if parsedIp == nil {
+			return w.WriteLine(fmt.Sprintf("The provided vpn ip could not be parsed: %s", a[0]))
+		}
+
+		vpnIp := ip2int(parsedIp)
 		if vpnIp == 0 {
 			return w.WriteLine(fmt.Sprintf("The provided vpn ip could not be parsed: %s", a[0]))
 		}
@@ -696,7 +721,12 @@ func sshPrintTunnel(ifce *Interface, fs interface{}, a []string, w sshd.StringWr
 		return w.WriteLine("No vpn ip was provided")
 	}
 
-	vpnIp := ip2int(net.ParseIP(a[0]))
+	parsedIp := net.ParseIP(a[0])
+	if parsedIp == nil {
+		return w.WriteLine(fmt.Sprintf("The provided vpn ip could not be parsed: %s", a[0]))
+	}
+
+	vpnIp := ip2int(parsedIp)
 	if vpnIp == 0 {
 		return w.WriteLine(fmt.Sprintf("The provided vpn ip could not be parsed: %s", a[0]))
 	}