bettercap/modules/http_proxy_base.go
evilsocket 0e9368cc61 balls
2018-02-08 06:19:55 +01:00

364 lines
8.4 KiB
Go

package modules
import (
"bufio"
"bytes"
"context"
"crypto/tls"
"crypto/x509"
"fmt"
"io/ioutil"
"net"
"net/http"
"net/url"
"strconv"
"strings"
"time"
"github.com/evilsocket/bettercap-ng/core"
"github.com/evilsocket/bettercap-ng/firewall"
"github.com/evilsocket/bettercap-ng/log"
"github.com/evilsocket/bettercap-ng/session"
btls "github.com/evilsocket/bettercap-ng/tls"
"github.com/elazarl/goproxy"
"github.com/inconshreveable/go-vhost"
)
const (
httpReadTimeout = 5 * time.Second
httpWriteTimeout = 10 * time.Second
)
type HTTPProxy struct {
Name string
Address string
Server *http.Server
Redirection *firewall.Redirection
Proxy *goproxy.ProxyHttpServer
Script *ProxyScript
CertFile string
KeyFile string
isTLS bool
isRunning bool
sniListener net.Listener
sess *session.Session
}
func stripPort(s string) string {
ix := strings.IndexRune(s, ':')
if ix == -1 {
return s
}
return s[:ix]
}
func NewHTTPProxy(s *session.Session) *HTTPProxy {
p := &HTTPProxy{
Name: "http.proxy",
Proxy: goproxy.NewProxyHttpServer(),
sess: s,
isTLS: false,
Server: nil,
}
p.Proxy.NonproxyHandler = http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
if p.doProxy(req) == true {
if p.isTLS == false {
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) {
log.Debug("(%s) < %s %s %s%s", core.Green(p.Name), req.RemoteAddr, req.Method, req.Host, req.URL.Path)
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 res != nil {
req := res.Request
log.Debug("(%s) > %s %s %s%s", core.Green(p.Name), req.RemoteAddr, req.Method, req.Host, req.URL.Path)
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.sess.Events.Add(p.Name+".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.sess); 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,
ReadTimeout: httpReadTimeout,
WriteTimeout: httpWriteTimeout,
}
if p.sess.Firewall.IsForwardingEnabled() == false {
log.Info("Enabling forwarding.")
p.sess.Firewall.EnableForwarding(true)
}
p.Redirection = firewall.NewRedirection(p.sess.Interface.Name(),
"TCP",
httpPort,
p.Address,
proxyPort)
if err := p.sess.Firewall.EnableRedirection(p.Redirection, true); err != nil {
return err
}
log.Debug("Applied redirection %s", p.Redirection.String())
return nil
}
func TLSConfigFromCA(ca *tls.Certificate) func(host string, ctx *goproxy.ProxyCtx) (*tls.Config, error) {
return func(host string, ctx *goproxy.ProxyCtx) (c *tls.Config, err error) {
parts := strings.SplitN(host, ":", 2)
hostname := parts[0]
port := 443
if len(parts) > 1 {
port, err = strconv.Atoi(parts[1])
if err != nil {
port = 443
}
}
cert := getCachedCert(hostname, port)
if cert == nil {
log.Info("Creating spoofed certificate for %s:%d", core.Yellow(hostname), port)
cert, err = btls.SignCertificateForHost(ca, hostname, port)
if err != nil {
log.Warning("Cannot sign host certificate with provided CA: %s", err)
return nil, err
}
setCachedCert(hostname, port, cert)
}
config := tls.Config{
InsecureSkipVerify: true,
Certificates: []tls.Certificate{*cert},
}
return &config, nil
}
}
func (p *HTTPProxy) ConfigureTLS(address string, proxyPort int, httpPort int, scriptPath string, certFile string, keyFile string) error {
err := p.Configure(address, proxyPort, httpPort, scriptPath)
if err != nil {
return err
}
p.isTLS = true
p.Name = "https.proxy"
p.CertFile = certFile
p.KeyFile = keyFile
rawCert, _ := ioutil.ReadFile(p.CertFile)
rawKey, _ := ioutil.ReadFile(p.KeyFile)
ourCa, err := tls.X509KeyPair(rawCert, rawKey)
if err != nil {
return err
}
if ourCa.Leaf, err = x509.ParseCertificate(ourCa.Certificate[0]); err != nil {
return err
}
goproxy.GoproxyCa = ourCa
goproxy.OkConnect = &goproxy.ConnectAction{Action: goproxy.ConnectAccept, TLSConfig: TLSConfigFromCA(&ourCa)}
goproxy.MitmConnect = &goproxy.ConnectAction{Action: goproxy.ConnectMitm, TLSConfig: TLSConfigFromCA(&ourCa)}
goproxy.HTTPMitmConnect = &goproxy.ConnectAction{Action: goproxy.ConnectHTTPMitm, TLSConfig: TLSConfigFromCA(&ourCa)}
goproxy.RejectConnect = &goproxy.ConnectAction{Action: goproxy.ConnectReject, TLSConfig: TLSConfigFromCA(&ourCa)}
return nil
}
func (p *HTTPProxy) httpWorker() error {
p.isRunning = true
return p.Server.ListenAndServe()
}
type dumbResponseWriter struct {
net.Conn
}
func (dumb dumbResponseWriter) Header() http.Header {
panic("Header() should not be called on this ResponseWriter")
}
func (dumb dumbResponseWriter) Write(buf []byte) (int, error) {
if bytes.Equal(buf, []byte("HTTP/1.0 200 OK\r\n\r\n")) {
return len(buf), nil // throw away the HTTP OK response from the faux CONNECT request
}
return dumb.Conn.Write(buf)
}
func (dumb dumbResponseWriter) WriteHeader(code int) {
panic("WriteHeader() should not be called on this ResponseWriter")
}
func (dumb dumbResponseWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
return dumb, bufio.NewReadWriter(bufio.NewReader(dumb), bufio.NewWriter(dumb)), nil
}
func (p *HTTPProxy) httpsWorker() error {
var err error
// listen to the TLS ClientHello but make it a CONNECT request instead
p.sniListener, err = net.Listen("tcp", p.Server.Addr)
if err != nil {
return err
}
p.isRunning = true
for p.isRunning {
c, err := p.sniListener.Accept()
if err != nil {
log.Warning("Error accepting connection: %s.", err)
continue
}
go func(c net.Conn) {
now := time.Now()
c.SetReadDeadline(now.Add(httpReadTimeout))
c.SetWriteDeadline(now.Add(httpWriteTimeout))
tlsConn, err := vhost.TLS(c)
if err != nil {
log.Warning("Error reading SNI: %s.", err)
return
}
hostname := tlsConn.Host()
if hostname == "" {
log.Warning("Client does not support SNI.")
return
}
log.Debug("Got new SNI from %s for %s", core.Bold(stripPort(c.RemoteAddr().String())), core.Yellow(hostname))
req := &http.Request{
Method: "CONNECT",
URL: &url.URL{
Opaque: hostname,
Host: net.JoinHostPort(hostname, "443"),
},
Host: hostname,
Header: make(http.Header),
}
resp := dumbResponseWriter{tlsConn}
p.Proxy.ServeHTTP(resp, req)
}(c)
}
return nil
}
func (p *HTTPProxy) Start() {
go func() {
var err error
if p.isTLS == true {
err = p.httpsWorker()
} else {
err = p.httpWorker()
}
if err != nil && err.Error() != "http: Server closed" {
log.Fatal("%s", err)
}
}()
}
func (p *HTTPProxy) Stop() error {
if p.Redirection != nil {
log.Debug("Disabling redirection %s", p.Redirection.String())
if err := p.sess.Firewall.EnableRedirection(p.Redirection, false); err != nil {
return err
}
p.Redirection = nil
}
if p.isTLS == true {
p.isRunning = false
p.sniListener.Close()
return nil
} else {
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
return p.Server.Shutdown(ctx)
}
}