From 29fa31370a3e45ac8013bacff6171179a4df6e35 Mon Sep 17 00:00:00 2001
From: Quinten <67589015+QuintenQVD0@users.noreply.github.com>
Date: Sat, 28 Sep 2024 00:11:53 +0200
Subject: [PATCH] Enforce the egg's file denylist more thoroughly (#29)

* draft: Enforce the egg's file denylist more thoroughly

* feat: Skip ignored files during compression instead of stopping with an error

* Fix: Skip ignored files in CompressFiles
---
 router/router_download.go     |  5 +++++
 router/router_server_files.go | 12 +++++++++++-
 server/filesystem/compress.go | 14 +++++++++++++-
 sftp/handler.go               | 11 +++++++++++
 4 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/router/router_download.go b/router/router_download.go
index b1ca5a0a..7d070a81 100644
--- a/router/router_download.go
+++ b/router/router_download.go
@@ -89,6 +89,11 @@ func getDownloadFile(c *gin.Context) {
 		return
 	}
 
+	if err := s.Filesystem().IsIgnored(token.FilePath); err != nil {
+		middleware.CaptureAndAbort(c, err)
+		return
+	}
+
 	f, st, err := s.Filesystem().File(token.FilePath)
 	if err != nil {
 		middleware.CaptureAndAbort(c, err)
diff --git a/router/router_server_files.go b/router/router_server_files.go
index ad6dd0c8..5d3ba78d 100644
--- a/router/router_server_files.go
+++ b/router/router_server_files.go
@@ -31,6 +31,10 @@ import (
 func getServerFileContents(c *gin.Context) {
 	s := middleware.ExtractServer(c)
 	p := strings.TrimLeft(c.Query("file"), "/")
+	if err := s.Filesystem().IsIgnored(p); err != nil {
+		middleware.CaptureAndAbort(c, err)
+		return
+	}
 	f, st, err := s.Filesystem().File(p)
 	if err != nil {
 		middleware.CaptureAndAbort(c, err)
@@ -214,6 +218,9 @@ func postServerDeleteFiles(c *gin.Context) {
 			case <-ctx.Done():
 				return ctx.Err()
 			default:
+				if err := s.Filesystem().IsIgnored(pi); err != nil {
+					return err
+				}
 				return s.Filesystem().Delete(pi)
 			}
 		})
@@ -324,7 +331,10 @@ func postServerPullRemoteFile(c *gin.Context) {
 		FileName:  data.FileName,
 		UseHeader: data.UseHeader,
 	})
-
+	if err := s.Filesystem().IsIgnored(dl.Path()); err != nil {
+		middleware.CaptureAndAbort(c, err)
+		return
+	}
 	download := func() error {
 		s.Log().WithField("download_id", dl.Identifier).WithField("url", u.String()).Info("starting pull of remote file to disk")
 		if err := dl.Execute(); err != nil {
diff --git a/server/filesystem/compress.go b/server/filesystem/compress.go
index 15f2d26e..efb8e11a 100644
--- a/server/filesystem/compress.go
+++ b/server/filesystem/compress.go
@@ -29,7 +29,19 @@ import (
 // and the compressed file will be placed at that location named
 // `archive-{date}.tar.gz`.
 func (fs *Filesystem) CompressFiles(dir string, paths []string) (ufs.FileInfo, error) {
-	a := &Archive{Filesystem: fs, BaseDirectory: dir, Files: paths}
+	var validPaths []string
+	for _, file := range paths {
+		if err := fs.IsIgnored(path.Join(dir, file)); err == nil {
+			validPaths = append(validPaths, file)
+		}
+	}
+
+	// If there are no valid paths, return an error
+	if len(validPaths) == 0 {
+		return nil, fmt.Errorf("no valid files to compress")
+	}
+
+	a := &Archive{Filesystem: fs, BaseDirectory: dir, Files: validPaths}
 	d := path.Join(
 		dir,
 		fmt.Sprintf("archive-%s.tar.gz", strings.ReplaceAll(time.Now().Format(time.RFC3339), ":", "")),
diff --git a/sftp/handler.go b/sftp/handler.go
index dacea401..aed12dbc 100644
--- a/sftp/handler.go
+++ b/sftp/handler.go
@@ -79,6 +79,9 @@ func (h *Handler) Fileread(request *sftp.Request) (io.ReaderAt, error) {
 	}
 	h.mu.Lock()
 	defer h.mu.Unlock()
+	if err := h.fs.IsIgnored(request.Filepath); err != nil {
+		return nil, err
+	}
 	f, _, err := h.fs.File(request.Filepath)
 	if err != nil {
 		if !errors.Is(err, os.ErrNotExist) {
@@ -104,6 +107,10 @@ func (h *Handler) Filewrite(request *sftp.Request) (io.WriterAt, error) {
 
 	h.mu.Lock()
 	defer h.mu.Unlock()
+	
+	if err := h.fs.IsIgnored(request.Filepath); err != nil {
+		return nil, err
+	}
 	// The specific permission required to perform this action. If the file exists on the
 	// system already it only needs to be an update, otherwise we'll check for a create.
 	permission := PermissionFileUpdate
@@ -148,6 +155,10 @@ func (h *Handler) Filecmd(request *sftp.Request) error {
 		l = l.WithField("target", request.Target)
 	}
 
+	if err := h.fs.IsIgnored(request.Filepath); err != nil {
+		return err
+	}
+	
 	switch request.Method {
 	// Allows a user to make changes to the permissions of a given file or directory
 	// on their server using their SFTP client.