feat: auto-generate upload dest path, add upload confirmation check

- --upload-dest is now optional; defaults to C:\Windows\Temp\<UUID> (same
  pattern as --out remote path generation)
- After upload, confirm file exists via SMB stat and log path + size
- Add --no-upload-confirm flag to skip the confirmation check
- Add UploadConfirmer optional interface in io.go
- Add ConfirmUpload method on FileStager (stats remote file, logs details)

Co-authored-by: Carter <carter-falconops@users.noreply.github.com>

cmd/args.go

@@ -51,7 +51,8 @@ func registerExecutionFlags(fs *pflag.FlagSet) {
 
 func registerExecutionUploadFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&uploadSource, "upload", "", "Upload local `file` to remote filesystem")
-	fs.StringVar(&uploadDest, "upload-dest", "", "Remote destination `path` for uploaded file")
+	fs.StringVar(&uploadDest, "upload-dest", "", "Remote destination `path` for uploaded file (default: random temp path)")
+	fs.BoolVar(&exec.Upload.NoConfirm, "no-upload-confirm", false, "Skip upload confirmation check")
 }
 
 func registerExecutionOutputFlags(fs *pflag.FlagSet) {
@@ -185,9 +186,6 @@ func argsUpload(methods ...string) func(cmd *cobra.Command, args []string) error
 	return args(append(as, func(*cobra.Command, []string) (err error) {
 
 		if uploadSource != "" {
-			if uploadDest == "" {
-				return fmt.Errorf("--upload-dest is required when --upload is set")
-			}
 			exec.Upload.Reader, err = os.Open(uploadSource)
 			if err != nil {
 				return fmt.Errorf("open upload file: %w", err)

cmd/root.go

@@ -185,6 +185,9 @@ Authors: FalconOps LLC (@FalconOpsLLC),
 		}
 
 		if uploadSource != "" {
+			if uploadDest == "" {
+				uploadDest = `C:\Windows\Temp\` + uuid.NewString()
+			}
 			exec.Upload.RemotePath = uploadDest
 			exec.Upload.Provider = &smb.FileStager{
 				Client:    &smbClient,

pkg/goexec/io.go

@@ -35,11 +35,18 @@ type ExecutionOutput struct {
 }
 
 type ExecutionUpload struct {
+	NoConfirm  bool
 	RemotePath string
 	Provider   InputProvider
 	Reader     io.ReadCloser
 }
 
+// UploadConfirmer is an optional interface that InputProvider implementations
+// can satisfy to confirm a file was successfully uploaded.
+type UploadConfirmer interface {
+	ConfirmUpload(ctx context.Context) error
+}
+
 type ExecutionInput struct {
   StageFile      io.ReadCloser
   Executable     string

pkg/goexec/method.go

@@ -124,7 +124,13 @@ func ExecuteCleanMethod(ctx context.Context, module CleanExecutionMethod, execIO
 			log.Error().Err(err).Msg("Upload failed")
 			return fmt.Errorf("upload: %w", err)
 		}
-		log.Info().Msg("Upload succeeded")
+		if !execIO.Upload.NoConfirm {
+			if confirmer, ok := execIO.Upload.Provider.(UploadConfirmer); ok {
+				if err = confirmer.ConfirmUpload(ctx); err != nil {
+					log.Warn().Err(err).Msg("Upload confirmation failed")
+				}
+			}
+		}
 	}
 
 	// Execute (only if a command/executable was provided)

pkg/goexec/smb/input.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 
 	"github.com/FalconOpsLLC/goexec/pkg/goexec"
+	"github.com/rs/zerolog"
 )
 
 type FileStager struct {
@@ -61,3 +62,26 @@ func (o *FileStager) Upload(ctx context.Context, reader io.Reader) (err error) {
 
 	return
 }
+
+// ConfirmUpload checks that the uploaded file exists on the remote filesystem
+// and logs the file path and size. The share must already be mounted from a
+// prior Upload call.
+func (o *FileStager) ConfirmUpload(ctx context.Context) error {
+	log := zerolog.Ctx(ctx)
+
+	if o.Client.mount == nil {
+		return fmt.Errorf("share not mounted")
+	}
+
+	info, err := o.Client.mount.Stat(o.relativePath)
+	if err != nil {
+		return fmt.Errorf("stat remote file: %w", err)
+	}
+
+	log.Info().
+		Str("path", o.File).
+		Int64("size", info.Size()).
+		Msg("Upload confirmed")
+
+	return nil
+}