Add native protocol service plugins

plugins/services/mqtt.go

@@ -0,0 +1,114 @@
+//go:build plugin_mqtt || !plugin_selective
+
+package services
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"io"
+	"net"
+	"time"
+
+	"github.com/shadow1ng/fscan/common"
+	"github.com/shadow1ng/fscan/plugins"
+)
+
+var mqttConnectPacket = []byte{
+	0x10, 0x0c,
+	0x00, 0x04, 'M', 'Q', 'T', 'T',
+	0x04,
+	0x02,
+	0x00, 0x00,
+	0x00, 0x00,
+}
+
+type MQTTPlugin struct {
+	plugins.BasePlugin
+}
+
+func NewMQTTPlugin() *MQTTPlugin {
+	return &MQTTPlugin{BasePlugin: plugins.NewBasePlugin("mqtt")}
+}
+
+func (p *MQTTPlugin) Scan(ctx context.Context, info *common.HostInfo, session *common.ScanSession) *ScanResult {
+	timeout := session.Config.Timeout
+	if timeout <= 0 {
+		timeout = 3 * time.Second
+	}
+
+	addr := fmt.Sprintf("%s:%d", info.Host, info.Port)
+	conn, err := session.DialTCP(ctx, "tcp", addr, timeout)
+	if err != nil {
+		return &ScanResult{Success: false, Service: "mqtt"}
+	}
+	defer conn.Close()
+
+	if info.Port == 8883 {
+		_ = conn.SetDeadline(time.Now().Add(timeout))
+		conn, err = p.wrapTLS(ctx, conn)
+		if err != nil {
+			return &ScanResult{Success: false, Service: "mqtt"}
+		}
+		defer conn.Close()
+	}
+
+	_ = conn.SetDeadline(time.Now().Add(timeout))
+	if _, err := conn.Write(mqttConnectPacket); err != nil {
+		return &ScanResult{Success: false, Service: "mqtt"}
+	}
+
+	header := make([]byte, 4)
+	if _, err := io.ReadFull(conn, header); err != nil {
+		return &ScanResult{Success: false, Service: "mqtt"}
+	}
+
+	banner, ok := parseMQTTConnack(header)
+	if !ok {
+		return &ScanResult{Success: false, Service: "mqtt"}
+	}
+
+	return &ScanResult{
+		Success: true,
+		Type:    plugins.ResultTypeService,
+		Service: "mqtt",
+		Banner:  banner,
+	}
+}
+
+func (p *MQTTPlugin) wrapTLS(ctx context.Context, conn net.Conn) (net.Conn, error) {
+	tlsConn := tls.Client(conn, &tls.Config{InsecureSkipVerify: true})
+	if err := tlsConn.HandshakeContext(ctx); err != nil {
+		return nil, err
+	}
+	return tlsConn, nil
+}
+
+func parseMQTTConnack(data []byte) (string, bool) {
+	if len(data) < 4 || data[0] != 0x20 || data[1] != 0x02 {
+		return "", false
+	}
+
+	switch data[3] {
+	case 0x00:
+		return "MQTT CONNACK accepted", true
+	case 0x01:
+		return "MQTT CONNACK unacceptable protocol version", true
+	case 0x02:
+		return "MQTT CONNACK identifier rejected", true
+	case 0x03:
+		return "MQTT CONNACK server unavailable", true
+	case 0x04:
+		return "MQTT CONNACK bad username or password", true
+	case 0x05:
+		return "MQTT CONNACK not authorized", true
+	default:
+		return fmt.Sprintf("MQTT CONNACK return_code=%d", data[3]), true
+	}
+}
+
+func init() {
+	RegisterPluginWithPorts("mqtt", func() Plugin {
+		return NewMQTTPlugin()
+	}, []int{1883, 8883})
+}