bindings: artifact extract reject invalid names

The server already does validate this so this is not strictly needed and
the client must trust the server no matter what.

But adding an extra check here does not hurt and may help prevent future
bugs.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>
(cherry picked from commit 12bec19)
Signed-off-by: Paul Holzinger <pholzing@redhat.com>

Author: Luap99

pkg/bindings/artifacts/extract.go

@@ -73,7 +73,14 @@ func Extract(ctx context.Context, artifactName string, target string, options *E
 		// If destination isn't a file, extract to target/filename
 		fileTarget := target
 		if targetIsDirectory {
-			fileTarget = filepath.Join(target, header.Name)
+			filename := header.Name
+			// This matches the logic from generateArtifactBlobName().
+			for i := range len(filename) {
+				if os.IsPathSeparator(filename[i]) {
+					return fmt.Errorf("invalid filename: %q cannot contain %c", filename, filename[i])
+				}
+			}
+			fileTarget = filepath.Join(target, filename)
 		}
 
 		if header.Typeflag == tar.TypeReg {