refact: refactored proxy specific code in a http proxy base object, preparing for https.proxy module

modules/http_proxy_base.go

@@ -0,0 +1,162 @@
+package modules
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/evilsocket/bettercap-ng/firewall"
+	"github.com/evilsocket/bettercap-ng/log"
+	"github.com/evilsocket/bettercap-ng/session"
+
+	"github.com/elazarl/goproxy"
+)
+
+type HTTPProxy struct {
+	Address     string
+	Server      http.Server
+	Redirection *firewall.Redirection
+	Proxy       *goproxy.ProxyHttpServer
+	Script      *ProxyScript
+
+	s *session.Session
+}
+
+func NewHTTPProxy(s *session.Session) *HTTPProxy {
+	p := &HTTPProxy{
+		Proxy: goproxy.NewProxyHttpServer(),
+		s:     s,
+	}
+
+	p.Proxy.NonproxyHandler = http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		if p.doProxy(req) == true {
+			req.URL.Scheme = "http"
+			req.URL.Host = req.Host
+			p.Proxy.ServeHTTP(w, req)
+		}
+	})
+
+	p.Proxy.OnRequest().HandleConnect(goproxy.AlwaysMitm)
+	p.Proxy.OnRequest().DoFunc(func(req *http.Request, ctx *goproxy.ProxyCtx) (*http.Request, *http.Response) {
+		if p.Script != nil {
+			jsres := p.Script.OnRequest(req)
+			if jsres != nil {
+				p.logAction(req, jsres)
+				return req, jsres.ToResponse(req)
+			}
+		}
+		return req, nil
+	})
+
+	p.Proxy.OnResponse().DoFunc(func(res *http.Response, ctx *goproxy.ProxyCtx) *http.Response {
+		if p.Script != nil {
+			jsres := p.Script.OnResponse(res)
+			if jsres != nil {
+				p.logAction(res.Request, jsres)
+				return jsres.ToResponse(res.Request)
+			}
+		}
+		return res
+	})
+
+	return p
+}
+
+func (p *HTTPProxy) logAction(req *http.Request, jsres *JSResponse) {
+	p.s.Events.Add("http.proxy.spoofed-response", struct {
+		To     string
+		Method string
+		Host   string
+		Path   string
+		Size   int
+	}{
+		strings.Split(req.RemoteAddr, ":")[0],
+		req.Method,
+		req.Host,
+		req.URL.Path,
+		len(jsres.Body),
+	})
+}
+
+func (p *HTTPProxy) doProxy(req *http.Request) bool {
+	blacklist := []string{
+		"localhost",
+		"127.0.0.1",
+	}
+
+	if req.Host == "" {
+		log.Error("Got request with empty host: %v", req)
+		return false
+	}
+
+	for _, blacklisted := range blacklist {
+		if strings.HasPrefix(req.Host, blacklisted) {
+			log.Error("Got request with blacklisted host: %s", req.Host)
+			return false
+		}
+	}
+
+	return true
+}
+
+func (p *HTTPProxy) Configure(address string, proxyPort int, httpPort int, scriptPath string) error {
+	var err error
+
+	p.Address = address
+
+	if scriptPath != "" {
+		if err, p.Script = LoadProxyScript(scriptPath, p.s); err != nil {
+			return err
+		} else {
+			log.Debug("Proxy script %s loaded.", scriptPath)
+		}
+	}
+
+	p.Server = http.Server{
+		Addr:    fmt.Sprintf("%s:%d", p.Address, proxyPort),
+		Handler: p.Proxy,
+	}
+
+	if p.s.Firewall.IsForwardingEnabled() == false {
+		log.Info("Enabling forwarding.")
+		p.s.Firewall.EnableForwarding(true)
+	}
+
+	p.Redirection = firewall.NewRedirection(p.s.Interface.Name(),
+		"TCP",
+		httpPort,
+		p.Address,
+		proxyPort)
+
+	if err := p.s.Firewall.EnableRedirection(p.Redirection, true); err != nil {
+		return err
+	}
+
+	log.Debug("Applied redirection %s", p.Redirection.String())
+
+	return nil
+}
+
+func (p *HTTPProxy) Start() {
+	go func() {
+		if err := p.Server.ListenAndServe(); err != nil {
+			log.Warning("%s", err)
+		}
+	}()
+}
+
+func (p *HTTPProxy) Stop() error {
+	if p.Redirection != nil {
+		log.Debug("Disabling redirection %s", p.Redirection.String())
+		if err := p.s.Firewall.EnableRedirection(p.Redirection, false); err != nil {
+			return err
+		}
+		p.Redirection = nil
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	return p.Server.Shutdown(ctx)
+}