From 34f50c5a0618df088a844b4ff76b4378eda1ac02 Mon Sep 17 00:00:00 2001
From: Nicola Murino <nicola.murino@gmail.com>
Date: Sun, 7 Dec 2025 18:21:43 +0100
Subject: [PATCH] refactor: minor improvements to ResolvePath

Make ResolvePath more robust by avoiding implicit reliance on path
normalization performed by external libraries such as pkg/sftp and
ftpserverlib

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>
---
 internal/vfs/azblobfs.go | 5 ++---
 internal/vfs/gcsfs.go    | 5 ++---
 internal/vfs/httpfs.go   | 5 ++---
 internal/vfs/osfs.go     | 1 +
 internal/vfs/s3fs.go     | 5 ++---
 internal/vfs/sftpfs.go   | 5 ++---
 6 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/internal/vfs/azblobfs.go b/internal/vfs/azblobfs.go
index 83f55b52..ac25d392 100644
--- a/internal/vfs/azblobfs.go
+++ b/internal/vfs/azblobfs.go
@@ -668,12 +668,11 @@ func (*AzureBlobFs) HasVirtualFolders() bool {
 
 // ResolvePath returns the matching filesystem path for the specified sftp path
 func (fs *AzureBlobFs) ResolvePath(virtualPath string) (string, error) {
+	virtualPath = strings.ReplaceAll(virtualPath, "\\", "/")
 	if fs.mountPath != "" {
 		virtualPath = strings.TrimPrefix(virtualPath, fs.mountPath)
 	}
-	if !path.IsAbs(virtualPath) {
-		virtualPath = path.Clean("/" + virtualPath)
-	}
+	virtualPath = path.Clean("/" + virtualPath)
 	return fs.Join(fs.config.KeyPrefix, strings.TrimPrefix(virtualPath, "/")), nil
 }
 
diff --git a/internal/vfs/gcsfs.go b/internal/vfs/gcsfs.go
index 895eacb0..9e6cd3fa 100644
--- a/internal/vfs/gcsfs.go
+++ b/internal/vfs/gcsfs.go
@@ -637,12 +637,11 @@ func (*GCSFs) HasVirtualFolders() bool {
 
 // ResolvePath returns the matching filesystem path for the specified virtual path
 func (fs *GCSFs) ResolvePath(virtualPath string) (string, error) {
+	virtualPath = strings.ReplaceAll(virtualPath, "\\", "/")
 	if fs.mountPath != "" {
 		virtualPath = strings.TrimPrefix(virtualPath, fs.mountPath)
 	}
-	if !path.IsAbs(virtualPath) {
-		virtualPath = path.Clean("/" + virtualPath)
-	}
+	virtualPath = path.Clean("/" + virtualPath)
 	return fs.Join(fs.config.KeyPrefix, strings.TrimPrefix(virtualPath, "/")), nil
 }
 
diff --git a/internal/vfs/httpfs.go b/internal/vfs/httpfs.go
index f9550924..2d800b4a 100644
--- a/internal/vfs/httpfs.go
+++ b/internal/vfs/httpfs.go
@@ -637,12 +637,11 @@ func (*HTTPFs) HasVirtualFolders() bool {
 
 // ResolvePath returns the matching filesystem path for the specified virtual path
 func (fs *HTTPFs) ResolvePath(virtualPath string) (string, error) {
+	virtualPath = strings.ReplaceAll(virtualPath, "\\", "/")
 	if fs.mountPath != "" {
 		virtualPath = strings.TrimPrefix(virtualPath, fs.mountPath)
 	}
-	if !path.IsAbs(virtualPath) {
-		virtualPath = path.Clean("/" + virtualPath)
-	}
+	virtualPath = path.Clean("/" + virtualPath)
 	return virtualPath, nil
 }
 
diff --git a/internal/vfs/osfs.go b/internal/vfs/osfs.go
index 3746a443..26aab2d4 100644
--- a/internal/vfs/osfs.go
+++ b/internal/vfs/osfs.go
@@ -378,6 +378,7 @@ func (*OsFs) Join(elem ...string) string {
 
 // ResolvePath returns the matching filesystem path for the specified sftp path
 func (fs *OsFs) ResolvePath(virtualPath string) (string, error) {
+	virtualPath = strings.ReplaceAll(virtualPath, "\\", "/")
 	if !filepath.IsAbs(fs.rootDir) {
 		return "", fmt.Errorf("invalid root path %q", fs.rootDir)
 	}
diff --git a/internal/vfs/s3fs.go b/internal/vfs/s3fs.go
index d330133a..fd7cc28e 100644
--- a/internal/vfs/s3fs.go
+++ b/internal/vfs/s3fs.go
@@ -635,12 +635,11 @@ func (*S3Fs) HasVirtualFolders() bool {
 
 // ResolvePath returns the matching filesystem path for the specified virtual path
 func (fs *S3Fs) ResolvePath(virtualPath string) (string, error) {
+	virtualPath = strings.ReplaceAll(virtualPath, "\\", "/")
 	if fs.mountPath != "" {
 		virtualPath = strings.TrimPrefix(virtualPath, fs.mountPath)
 	}
-	if !path.IsAbs(virtualPath) {
-		virtualPath = path.Clean("/" + virtualPath)
-	}
+	virtualPath = path.Clean("/" + virtualPath)
 	return fs.Join(fs.config.KeyPrefix, strings.TrimPrefix(virtualPath, "/")), nil
 }
 
diff --git a/internal/vfs/sftpfs.go b/internal/vfs/sftpfs.go
index 13e182cd..6b1a897a 100644
--- a/internal/vfs/sftpfs.go
+++ b/internal/vfs/sftpfs.go
@@ -730,12 +730,11 @@ func (*SFTPFs) HasVirtualFolders() bool {
 
 // ResolvePath returns the matching filesystem path for the specified virtual path
 func (fs *SFTPFs) ResolvePath(virtualPath string) (string, error) {
+	virtualPath = strings.ReplaceAll(virtualPath, "\\", "/")
 	if fs.mountPath != "" {
 		virtualPath = strings.TrimPrefix(virtualPath, fs.mountPath)
 	}
-	if !path.IsAbs(virtualPath) {
-		virtualPath = path.Clean("/" + virtualPath)
-	}
+	virtualPath = path.Clean("/" + virtualPath)
 	fsPath := fs.Join(fs.config.Prefix, virtualPath)
 	if fs.config.Prefix != "/" && fsPath != "/" {
 		// we need to check if this path is a symlink outside the given prefix