new: implemented http.proxy.injectjs and https.proxy.injectjs to inject javascript code, files or URLs without a proxy module

modules/http_proxy.go

@@ -33,6 +33,11 @@ func NewHttpProxy(s *session.Session) *HttpProxy {
 		"",
 		"Path of a proxy JS script."))
 
+	p.AddParam(session.NewStringParameter("http.proxy.injectjs",
+		"",
+		"",
+		"URL, path or javascript code to inject into every HTML page."))
+
 	p.AddParam(session.NewBoolParameter("http.proxy.sslstrip",
 		"false",
 		"Enable or disable SSL stripping."))
@@ -71,6 +76,7 @@ func (p *HttpProxy) Configure() error {
 	var httpPort int
 	var scriptPath string
 	var stripSSL bool
+	var jsToInject string
 
 	if p.Running() {
 		return session.ErrAlreadyStarted
@@ -84,9 +90,11 @@ func (p *HttpProxy) Configure() error {
 		return err
 	} else if err, stripSSL = p.BoolParam("http.proxy.sslstrip"); err != nil {
 		return err
+	} else if err, jsToInject = p.StringParam("http.proxy.injectjs"); err != nil {
+		return err
 	}
 
-	return p.proxy.Configure(address, proxyPort, httpPort, scriptPath, stripSSL)
+	return p.proxy.Configure(address, proxyPort, httpPort, scriptPath, jsToInject, stripSSL)
 }
 
 func (p *HttpProxy) Start() error {

modules/http_proxy_base.go

@@ -40,6 +40,7 @@ type HTTPProxy struct {
 	CertFile    string
 	KeyFile     string
 
+	jsHook      string
 	isTLS       bool
 	isRunning   bool
 	stripper    *SSLStripper
@@ -106,12 +107,29 @@ func (p *HTTPProxy) doProxy(req *http.Request) bool {
 	return true
 }
 
-func (p *HTTPProxy) Configure(address string, proxyPort int, httpPort int, scriptPath string, stripSSL bool) error {
+func (p *HTTPProxy) Configure(address string, proxyPort int, httpPort int, scriptPath string, jsToInject string, stripSSL bool) error {
 	var err error
 
 	p.stripper.Enable(stripSSL)
 	p.Address = address
 
+	if strings.HasPrefix(jsToInject, "http://") || strings.HasPrefix(jsToInject, "https://") {
+		p.jsHook = fmt.Sprintf("<script src=\"%s\" type=\"text/javascript\"></script></head>", jsToInject)
+	} else if core.Exists(jsToInject) {
+		if data, err := ioutil.ReadFile(jsToInject); err != nil {
+			return err
+		} else {
+			jsToInject = string(data)
+		}
+	}
+
+	if p.jsHook == "" && jsToInject != "" {
+		if strings.HasPrefix(jsToInject, "<script ") == false {
+			jsToInject = fmt.Sprintf("<script type=\"text/javascript\">%s</script>", jsToInject)
+		}
+		p.jsHook = fmt.Sprintf("%s</head>", jsToInject)
+	}
+
 	if scriptPath != "" {
 		if err, p.Script = LoadHttpProxyScript(scriptPath, p.sess); err != nil {
 			return err
@@ -187,8 +205,8 @@ func TLSConfigFromCA(ca *tls.Certificate) func(host string, ctx *goproxy.ProxyCt
 	}
 }
 
-func (p *HTTPProxy) ConfigureTLS(address string, proxyPort int, httpPort int, scriptPath string, certFile string, keyFile string, stripSSL bool) (err error) {
+func (p *HTTPProxy) ConfigureTLS(address string, proxyPort int, httpPort int, scriptPath string, certFile string, keyFile string, jsToInject string, stripSSL bool) (err error) {
-	if p.Configure(address, proxyPort, httpPort, scriptPath, stripSSL); err != nil {
+	if p.Configure(address, proxyPort, httpPort, scriptPath, jsToInject, stripSSL); err != nil {
 		return err
 	}
 

modules/http_proxy_base_filters.go

@@ -1,6 +1,7 @@
 package modules
 
 import (
+	"io/ioutil"
 	"net/http"
 	"strings"
 
@@ -40,6 +41,17 @@ func (p *HTTPProxy) onRequestFilter(req *http.Request, ctx *goproxy.ProxyCtx) (*
 	return req, nil
 }
 
+func getContentType(res *http.Response) string {
+	for name, values := range res.Header {
+		for _, value := range values {
+			if strings.ToLower(name) == "content-type" {
+				return value
+			}
+		}
+	}
+	return ""
+}
+
 func (p *HTTPProxy) onResponseFilter(res *http.Response, ctx *goproxy.ProxyCtx) *http.Response {
 	// sometimes it happens ¯\_(ツ)_/¯
 	if res == nil {
@@ -52,16 +64,32 @@ func (p *HTTPProxy) onResponseFilter(res *http.Response, ctx *goproxy.ProxyCtx)
 	p.stripper.Process(res, ctx)
 
 	// do we have a proxy script?
-	if p.Script == nil {
+	if p.Script != nil {
-		return res
-	}
-
 		_, jsres := p.Script.OnResponse(res)
 		if jsres != nil {
 			// the response has been changed by the script
 			p.logResponseAction(res.Request, jsres)
 			return jsres.ToResponse(res.Request)
 		}
+	}
+
+	// inject javascript code if specified and needed
+	if cType := getContentType(res); p.jsHook != "" && strings.Contains(cType, "text/html") {
+		log.Info("(%s) > injecting javascript (%d bytes) into %s for %s", core.Green(p.Name), len(p.jsHook), core.Yellow(req.Host+req.URL.Path), core.Bold(req.RemoteAddr))
+		defer res.Body.Close()
+
+		raw, _ := ioutil.ReadAll(res.Body)
+		html := strings.Replace(string(raw), "</head>", p.jsHook, -1)
+
+		newResp := goproxy.NewResponse(req, cType, res.StatusCode, html)
+		for k, vv := range res.Header {
+			for _, v := range vv {
+				newResp.Header.Add(k, v)
+			}
+		}
+
+		return newResp
+	}
 
 	return res
 }

modules/https_proxy.go

@@ -35,6 +35,11 @@ func NewHttpsProxy(s *session.Session) *HttpsProxy {
 		"false",
 		"Enable or disable SSL stripping."))
 
+	p.AddParam(session.NewStringParameter("https.proxy.injectjs",
+		"",
+		"",
+		"URL, path or javascript code to inject into every HTML page."))
+
 	p.AddParam(session.NewStringParameter("https.proxy.certificate",
 		"~/.bettercap-ca.cert.pem",
 		"",
@@ -86,6 +91,7 @@ func (p *HttpsProxy) Configure() error {
 	var certFile string
 	var keyFile string
 	var stripSSL bool
+	var jsToInject string
 
 	if p.Running() {
 		return session.ErrAlreadyStarted
@@ -107,6 +113,8 @@ func (p *HttpsProxy) Configure() error {
 		return err
 	} else if err, scriptPath = p.StringParam("https.proxy.script"); err != nil {
 		return err
+	} else if err, jsToInject = p.StringParam("https.proxy.injectjs"); err != nil {
+		return err
 	}
 
 	if !core.Exists(certFile) || !core.Exists(keyFile) {
@@ -120,7 +128,7 @@ func (p *HttpsProxy) Configure() error {
 		log.Info("Loading proxy certification authority TLS certificate from %s", certFile)
 	}
 
-	return p.proxy.ConfigureTLS(address, proxyPort, httpPort, scriptPath, certFile, keyFile, stripSSL)
+	return p.proxy.ConfigureTLS(address, proxyPort, httpPort, scriptPath, certFile, keyFile, jsToInject, stripSSL)
 }
 
 func (p *HttpsProxy) Start() error {