new: implemented tcp.proxy (closes #33)

main.go

@@ -47,6 +47,7 @@ func main() {
 	sess.Register(modules.NewHttpServer(sess))
 	sess.Register(modules.NewHttpProxy(sess))
 	sess.Register(modules.NewHttpsProxy(sess))
+	sess.Register(modules.NewTcpProxy(sess))
 	sess.Register(modules.NewRestAPI(sess))
 	sess.Register(modules.NewWOL(sess))
 	sess.Register(modules.NewWiFiRecon(sess))

modules/base_proxy_script.go

@@ -2,8 +2,10 @@ package modules
 
 import (
 	"io/ioutil"
+	"sync"
 
 	"github.com/bettercap/bettercap/log"
+	"github.com/bettercap/bettercap/session"
 
 	"github.com/robertkrimen/otto"
 )
@@ -15,7 +17,68 @@ func errOtto(format string, args ...interface{}) otto.Value {
 	return nullOtto
 }
 
-// define functions available to proxy scripts
+type ProxyScript struct {
+	sync.Mutex
+
+	Path   string
+	Source string
+	VM     *otto.Otto
+
+	sess        *session.Session
+	cbCacheLock *sync.Mutex
+	cbCache     map[string]bool
+}
+
+func LoadProxyScriptSource(path, source string, sess *session.Session) (err error, s *ProxyScript) {
+	s = &ProxyScript{
+		Path:        path,
+		Source:      source,
+		VM:          otto.New(),
+		sess:        sess,
+		cbCacheLock: &sync.Mutex{},
+		cbCache:     make(map[string]bool),
+	}
+
+	// this will define callbacks and global objects
+	_, err = s.VM.Run(s.Source)
+	if err != nil {
+		return
+	}
+
+	// define session pointer
+	err = s.VM.Set("env", sess.Env.Data)
+	if err != nil {
+		log.Error("Error while defining environment: %s", err)
+		return
+	}
+
+	err = s.defineBuiltins()
+	if err != nil {
+		log.Error("Error while defining builtin functions: %s", err)
+		return
+	}
+
+	// run onLoad if defined
+	if s.hasCallback("onLoad") {
+		_, err = s.VM.Run("onLoad()")
+		if err != nil {
+			log.Error("Error while executing onLoad callback: %s", err)
+			return
+		}
+	}
+
+	return
+}
+
+func LoadProxyScript(path string, sess *session.Session) (err error, s *ProxyScript) {
+	raw, err := ioutil.ReadFile(path)
+	if err != nil {
+		return
+	}
+
+	return LoadProxyScriptSource(path, string(raw), sess)
+}
+
 func (s *ProxyScript) defineBuiltins() error {
 	// used to read a file ... doh
 	s.VM.Set("readFile", func(call otto.FunctionCall) otto.Value {
@@ -76,3 +139,23 @@ func (s *ProxyScript) defineBuiltins() error {
 
 	return nil
 }
+
+func (s *ProxyScript) hasCallback(name string) bool {
+	s.cbCacheLock.Lock()
+	defer s.cbCacheLock.Unlock()
+
+	// check the cache
+	has, found := s.cbCache[name]
+	if found == false {
+		// check the VM
+		cb, err := s.VM.Get(name)
+		if err == nil && cb.IsFunction() {
+			has = true
+		} else {
+			has = false
+		}
+		s.cbCache[name] = has
+	}
+
+	return has
+}

modules/http_proxy_base.go

@@ -36,7 +36,7 @@ type HTTPProxy struct {
 	Server      *http.Server
 	Redirection *firewall.Redirection
 	Proxy       *goproxy.ProxyHttpServer
-	Script      *ProxyScript
+	Script      *HttpProxyScript
 	CertFile    string
 	KeyFile     string
 
@@ -147,7 +147,7 @@ func (p *HTTPProxy) Configure(address string, proxyPort int, httpPort int, scrip
 	p.Address = address
 
 	if scriptPath != "" {
-		if err, p.Script = LoadProxyScript(scriptPath, p.sess); err != nil {
+		if err, p.Script = LoadHttpProxyScript(scriptPath, p.sess); err != nil {
 			return err
 		} else {
 			log.Debug("Proxy script %s loaded.", scriptPath)

modules/http_proxy_script.go

@@ -3,7 +3,6 @@ package modules
 import (
 	"io/ioutil"
 	"net/http"
-	"sync"
 
 	"github.com/bettercap/bettercap/log"
 	"github.com/bettercap/bettercap/session"
@@ -11,59 +10,22 @@ import (
 	"github.com/robertkrimen/otto"
 )
 
-type ProxyScript struct {
-	sync.Mutex
-
-	Path   string
-	Source string
-	VM     *otto.Otto
-
-	sess             *session.Session
+type HttpProxyScript struct {
+	*ProxyScript
 	onRequestScript  *otto.Script
 	onResponseScript *otto.Script
-	cbCacheLock      *sync.Mutex
-	cbCache          map[string]bool
 }
 
-func LoadProxyScriptSource(path, source string, sess *session.Session) (err error, s *ProxyScript) {
-	s = &ProxyScript{
-		Path:   path,
-		Source: source,
-		VM:     otto.New(),
+func LoadHttpProxyScriptSource(path, source string, sess *session.Session) (err error, s *HttpProxyScript) {
+	err, ps := LoadProxyScriptSource(path, source, sess)
+	if err != nil {
+		return
+	}
 
-		sess:             sess,
+	s = &HttpProxyScript{
+		ProxyScript:      ps,
 		onRequestScript:  nil,
 		onResponseScript: nil,
-		cbCacheLock:      &sync.Mutex{},
-		cbCache:          make(map[string]bool),
-	}
-
-	// this will define callbacks and global objects
-	_, err = s.VM.Run(s.Source)
-	if err != nil {
-		return
-	}
-
-	// define session pointer
-	err = s.VM.Set("env", sess.Env.Data)
-	if err != nil {
-		log.Error("Error while defining environment: %s", err)
-		return
-	}
-
-	err = s.defineBuiltins()
-	if err != nil {
-		log.Error("Error while defining builtin functions: %s", err)
-		return
-	}
-
-	// run onLoad if defined
-	if s.hasCallback("onLoad") {
-		_, err = s.VM.Run("onLoad()")
-		if err != nil {
-			log.Error("Error while executing onLoad callback: %s", err)
-			return
-		}
 	}
 
 	// compile call to onRequest if defined
@@ -87,7 +49,7 @@ func LoadProxyScriptSource(path, source string, sess *session.Session) (err erro
 	return
 }
 
-func LoadProxyScript(path string, sess *session.Session) (err error, s *ProxyScript) {
+func LoadHttpProxyScript(path string, sess *session.Session) (err error, s *HttpProxyScript) {
 	log.Info("Loading proxy script %s ...", path)
 
 	raw, err := ioutil.ReadFile(path)
@@ -95,30 +57,10 @@ func LoadProxyScript(path string, sess *session.Session) (err error, s *ProxyScr
 		return
 	}
 
-	return LoadProxyScriptSource(path, string(raw), sess)
+	return LoadHttpProxyScriptSource(path, string(raw), sess)
 }
 
-func (s *ProxyScript) hasCallback(name string) bool {
-	s.cbCacheLock.Lock()
-	defer s.cbCacheLock.Unlock()
-
-	// check the cache
-	has, found := s.cbCache[name]
-	if found == false {
-		// check the VM
-		cb, err := s.VM.Get(name)
-		if err == nil && cb.IsFunction() {
-			has = true
-		} else {
-			has = false
-		}
-		s.cbCache[name] = has
-	}
-
-	return has
-}
-
-func (s *ProxyScript) doRequestDefines(req *http.Request) (err error, jsres *JSResponse) {
+func (s *HttpProxyScript) doRequestDefines(req *http.Request) (err error, jsres *JSResponse) {
 	// convert request and define empty response to be optionally filled
 	jsreq := NewJSRequest(req)
 	if err = s.VM.Set("req", &jsreq); err != nil {
@@ -134,7 +76,7 @@ func (s *ProxyScript) doRequestDefines(req *http.Request) (err error, jsres *JSR
 	return
 }
 
-func (s *ProxyScript) doResponseDefines(res *http.Response) (err error, jsres *JSResponse) {
+func (s *HttpProxyScript) doResponseDefines(res *http.Response) (err error, jsres *JSResponse) {
 	// convert both request and response
 	jsreq := NewJSRequest(res.Request)
 	if err = s.VM.Set("req", jsreq); err != nil {
@@ -151,7 +93,7 @@ func (s *ProxyScript) doResponseDefines(res *http.Response) (err error, jsres *J
 	return
 }
 
-func (s *ProxyScript) OnRequest(req *http.Request) *JSResponse {
+func (s *HttpProxyScript) OnRequest(req *http.Request) *JSResponse {
 	if s.onRequestScript != nil {
 		s.Lock()
 		defer s.Unlock()
@@ -177,7 +119,7 @@ func (s *ProxyScript) OnRequest(req *http.Request) *JSResponse {
 	return nil
 }
 
-func (s *ProxyScript) OnResponse(res *http.Response) *JSResponse {
+func (s *HttpProxyScript) OnResponse(res *http.Response) *JSResponse {
 	if s.onResponseScript != nil {
 		s.Lock()
 		defer s.Unlock()

modules/http_proxy_script_test.go

@@ -8,11 +8,11 @@ import (
 	"github.com/bettercap/bettercap/session"
 )
 
-func getScript(src string) *ProxyScript {
+func getScript(src string) *HttpProxyScript {
 	sess := session.Session{}
 	sess.Env = session.NewEnvironment(&sess)
 
-	err, script := LoadProxyScriptSource("", src, &sess)
+	err, script := LoadHttpProxyScriptSource("", src, &sess)
 	if err != nil {
 		log.Fatal("%s", err)
 	}

modules/tcp_proxy.go

@@ -0,0 +1,214 @@
+package modules
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"sync"
+
+	"github.com/bettercap/bettercap/firewall"
+	"github.com/bettercap/bettercap/log"
+	"github.com/bettercap/bettercap/session"
+)
+
+type TcpProxy struct {
+	session.SessionModule
+	Redirection *firewall.Redirection
+	localAddr   *net.TCPAddr
+	remoteAddr  *net.TCPAddr
+	listener    *net.TCPListener
+	script      *TcpProxyScript
+}
+
+func NewTcpProxy(s *session.Session) *TcpProxy {
+	p := &TcpProxy{
+		SessionModule: session.NewSessionModule("tcp.proxy", s),
+	}
+
+	p.AddParam(session.NewIntParameter("tcp.port",
+		"443",
+		"Remote port to redirect when the TCP proxy is activated."))
+
+	p.AddParam(session.NewStringParameter("tcp.address",
+		"",
+		session.IPv4Validator,
+		"Remote address of the TCP proxy."))
+
+	p.AddParam(session.NewStringParameter("tcp.proxy.address",
+		session.ParamIfaceAddress,
+		session.IPv4Validator,
+		"Address to bind the TCP proxy to."))
+
+	p.AddParam(session.NewIntParameter("tcp.proxy.port",
+		"8443",
+		"Port to bind the TCP proxy to."))
+
+	p.AddParam(session.NewStringParameter("tcp.proxy.script",
+		"",
+		"",
+		"Path of a TCP proxy JS script."))
+
+	p.AddHandler(session.NewModuleHandler("tcp.proxy on", "",
+		"Start HTTP proxy.",
+		func(args []string) error {
+			return p.Start()
+		}))
+
+	p.AddHandler(session.NewModuleHandler("tcp.proxy off", "",
+		"Stop HTTP proxy.",
+		func(args []string) error {
+			return p.Stop()
+		}))
+
+	return p
+}
+
+func (p *TcpProxy) Name() string {
+	return "tcp.proxy"
+}
+
+func (p *TcpProxy) Description() string {
+	return "A full featured TCP proxy, all TCP traffic to a given remote address and port will be redirected to it."
+}
+
+func (p *TcpProxy) Author() string {
+	return "Simone Margaritelli <evilsocket@protonmail.com>"
+}
+
+func (p *TcpProxy) Configure() error {
+	var err error
+	var port int
+	var proxyPort int
+	var address string
+	var proxyAddress string
+	var scriptPath string
+
+	if err, address = p.StringParam("tcp.address"); err != nil {
+		return err
+	} else if err, proxyAddress = p.StringParam("tcp.proxy.address"); err != nil {
+		return err
+	} else if err, proxyPort = p.IntParam("tcp.proxy.port"); err != nil {
+		return err
+	} else if err, port = p.IntParam("tcp.port"); err != nil {
+		return err
+	} else if err, scriptPath = p.StringParam("tcp.proxy.script"); err != nil {
+		return err
+	} else if p.localAddr, err = net.ResolveTCPAddr("tcp", fmt.Sprintf("%s:%d", proxyAddress, proxyPort)); err != nil {
+		return err
+	} else if p.remoteAddr, err = net.ResolveTCPAddr("tcp", fmt.Sprintf("%s:%d", address, port)); err != nil {
+		return err
+	} else if p.listener, err = net.ListenTCP("tcp", p.localAddr); err != nil {
+		return err
+	}
+
+	if scriptPath != "" {
+		if err, p.script = LoadTcpProxyScript(scriptPath, p.Session); err != nil {
+			return err
+		} else {
+			log.Debug("TCP proxy script %s loaded.", scriptPath)
+		}
+	}
+
+	if p.Session.Firewall.IsForwardingEnabled() == false {
+		log.Info("Enabling forwarding.")
+		p.Session.Firewall.EnableForwarding(true)
+	}
+
+	p.Redirection = firewall.NewRedirection(p.Session.Interface.Name(),
+		"TCP",
+		port,
+		proxyAddress,
+		proxyPort)
+
+	p.Redirection.SrcAddress = address
+
+	if err := p.Session.Firewall.EnableRedirection(p.Redirection, true); err != nil {
+		return err
+	}
+
+	log.Debug("Applied redirection %s", p.Redirection.String())
+
+	return nil
+}
+
+func (p *TcpProxy) doPipe(from, to net.Addr, src, dst io.ReadWriter, wg *sync.WaitGroup) {
+	defer wg.Done()
+
+	buff := make([]byte, 0xffff)
+	for {
+		n, err := src.Read(buff)
+		if err != nil {
+			if err.Error() != "EOF" {
+				log.Warning("Read failed: %s", err)
+			}
+			return
+		}
+		b := buff[:n]
+
+		ret := p.script.OnData(from, to, b)
+		if ret != nil {
+			nret := len(ret)
+			log.Info("Overriding %d bytes of data from %s to %s with %d bytes of new data.", n, from.String(), to.String(), nret)
+			b = make([]byte, nret)
+			copy(b, ret)
+		}
+
+		n, err = dst.Write(b)
+		if err != nil {
+			log.Warning("Write failed: %s", err)
+			return
+		}
+
+		log.Debug("%s -> %s : %d bytes", from.String(), to.String(), n)
+	}
+}
+
+func (p *TcpProxy) handleConnection(c *net.TCPConn) {
+	defer c.Close()
+
+	log.Info("TCP proxy got a connection from %s", c.RemoteAddr().String())
+
+	remote, err := net.DialTCP("tcp", nil, p.remoteAddr)
+	if err != nil {
+		log.Warning("Error while connecting to remote %s: %s", p.remoteAddr.String(), err)
+		return
+	}
+	defer remote.Close()
+
+	wg := sync.WaitGroup{}
+	wg.Add(2)
+
+	// start pipeing
+	go p.doPipe(c.RemoteAddr(), p.remoteAddr, c, remote, &wg)
+	go p.doPipe(p.remoteAddr, c.RemoteAddr(), remote, c, &wg)
+
+	wg.Wait()
+}
+
+func (p *TcpProxy) Start() error {
+	if p.Running() == true {
+		return session.ErrAlreadyStarted
+	} else if err := p.Configure(); err != nil {
+		return err
+	}
+
+	return p.SetRunning(true, func() {
+		log.Info("TCP proxy started ( x -> %s -> %s )", p.localAddr, p.remoteAddr)
+
+		for p.Running() {
+			conn, err := p.listener.AcceptTCP()
+			if err != nil {
+				log.Warning("Error while accepting TCP connection: %s", err)
+				continue
+			}
+
+			go p.handleConnection(conn)
+		}
+	})
+}
+
+func (p *TcpProxy) Stop() error {
+	return p.SetRunning(false, func() {
+		p.listener.Close()
+	})
+}

modules/tcp_proxy_script.go

@@ -0,0 +1,92 @@
+package modules
+
+import (
+	"io/ioutil"
+	"net"
+	"strings"
+
+	"github.com/bettercap/bettercap/log"
+	"github.com/bettercap/bettercap/session"
+
+	"github.com/robertkrimen/otto"
+)
+
+type TcpProxyScript struct {
+	*ProxyScript
+	onDataScript *otto.Script
+}
+
+func LoadTcpProxyScriptSource(path, source string, sess *session.Session) (err error, s *TcpProxyScript) {
+	err, ps := LoadProxyScriptSource(path, source, sess)
+	if err != nil {
+		return
+	}
+
+	s = &TcpProxyScript{
+		ProxyScript:  ps,
+		onDataScript: nil,
+	}
+
+	if s.hasCallback("onData") {
+		s.onDataScript, err = s.VM.Compile("", "onData(from, to, data)")
+		if err != nil {
+			log.Error("Error while compiling onData callback: %s", err)
+			return
+		}
+	}
+
+	return
+}
+
+func LoadTcpProxyScript(path string, sess *session.Session) (err error, s *TcpProxyScript) {
+	log.Info("Loading TCP proxy script %s ...", path)
+
+	raw, err := ioutil.ReadFile(path)
+	if err != nil {
+		return
+	}
+
+	return LoadTcpProxyScriptSource(path, string(raw), sess)
+}
+
+func (s *TcpProxyScript) doDefines(from, to net.Addr, data []byte) (err error) {
+	addrFrom := strings.Split(from.String(), ":")[0]
+	addrTo := strings.Split(to.String(), ":")[0]
+
+	if err = s.VM.Set("from", addrFrom); err != nil {
+		log.Error("Error while defining from: %s", err)
+		return
+	} else if err = s.VM.Set("to", addrTo); err != nil {
+		log.Error("Error while defining to: %s", err)
+		return
+	} else if err = s.VM.Set("data", string(data)); err != nil {
+		log.Error("Error while defining data: %s", err)
+		return
+	}
+	return
+}
+
+func (s *TcpProxyScript) OnData(from, to net.Addr, data []byte) []byte {
+	if s.onDataScript != nil {
+		s.Lock()
+		defer s.Unlock()
+
+		err := s.doDefines(from, to, data)
+		if err != nil {
+			log.Error("Error while running bootstrap definitions: %s", err)
+			return nil
+		}
+
+		ret, err := s.VM.Run(s.onDataScript)
+		if err != nil {
+			log.Error("Error while executing onData callback: %s", err)
+			return nil
+		}
+
+		if ret.IsUndefined() == false && ret.IsString() {
+			return []byte(ret.String())
+		}
+	}
+
+	return nil
+}