bettercap/modules/dns_proxy/dns_proxy_script.go

127 lines
3.1 KiB
Go

package dns_proxy
import (
"strings"
"github.com/bettercap/bettercap/v2/log"
"github.com/bettercap/bettercap/v2/session"
"github.com/evilsocket/islazy/plugin"
"github.com/miekg/dns"
"github.com/robertkrimen/otto"
)
type DnsProxyScript struct {
*plugin.Plugin
doOnRequest bool
doOnResponse bool
doOnCommand bool
}
func LoadDnsProxyScript(path string, sess *session.Session) (err error, s *DnsProxyScript) {
log.Debug("loading proxy script %s ...", path)
plug, err := plugin.Load(path)
if err != nil {
return
}
// define session pointer
if err = plug.Set("env", sess.Env.Data); err != nil {
log.Error("Error while defining environment: %+v", err)
return
}
// define addSessionEvent function
err = plug.Set("addSessionEvent", func(call otto.FunctionCall) otto.Value {
if len(call.ArgumentList) < 2 {
log.Error("Failed to execute 'addSessionEvent' in DNS proxy: 2 arguments required, but only %d given.", len(call.ArgumentList))
return otto.FalseValue()
}
ottoTag := call.Argument(0)
if !ottoTag.IsString() {
log.Error("Failed to execute 'addSessionEvent' in DNS proxy: first argument must be a string.")
return otto.FalseValue()
}
tag := strings.TrimSpace(ottoTag.String())
if tag == "" {
log.Error("Failed to execute 'addSessionEvent' in DNS proxy: tag cannot be empty.")
return otto.FalseValue()
}
data := call.Argument(1)
sess.Events.Add(tag, data)
return otto.TrueValue()
})
if err != nil {
log.Error("Error while defining addSessionEvent function: %+v", err)
return
}
// run onLoad if defined
if plug.HasFunc("onLoad") {
if _, err = plug.Call("onLoad"); err != nil {
log.Error("Error while executing onLoad callback: %s", "\nTraceback:\n "+err.(*otto.Error).String())
return
}
}
s = &DnsProxyScript{
Plugin: plug,
doOnRequest: plug.HasFunc("onRequest"),
doOnResponse: plug.HasFunc("onResponse"),
doOnCommand: plug.HasFunc("onCommand"),
}
return
}
func (s *DnsProxyScript) OnRequest(req *dns.Msg, clientIP string) (jsreq, jsres *JSQuery) {
if s.doOnRequest {
jsreq := NewJSQuery(req, clientIP)
jsres := NewJSQuery(req, clientIP)
if _, err := s.Call("onRequest", jsreq, jsres); err != nil {
log.Error("%s", err)
return nil, nil
} else if jsreq.WasModified() {
jsreq.UpdateHash()
return jsreq, nil
} else if jsres.WasModified() {
jsres.UpdateHash()
return nil, jsres
}
}
return nil, nil
}
func (s *DnsProxyScript) OnResponse(req, res *dns.Msg, clientIP string) (jsreq, jsres *JSQuery) {
if s.doOnResponse {
jsreq := NewJSQuery(req, clientIP)
jsres := NewJSQuery(res, clientIP)
if _, err := s.Call("onResponse", jsreq, jsres); err != nil {
log.Error("%s", err)
return nil, nil
} else if jsres.WasModified() {
jsres.UpdateHash()
return nil, jsres
}
}
return nil, nil
}
func (s *DnsProxyScript) OnCommand(cmd string) bool {
if s.doOnCommand {
if ret, err := s.Call("onCommand", cmd); err != nil {
log.Error("Error while executing onCommand callback: %+v", err)
return false
} else if v, ok := ret.(bool); ok {
return v
}
}
return false
}