libgocryptfs/internal/nametransform/valid.go

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package nametransform
import (
"fmt"
"strings"
)
// IsValidName checks if `name` is a valid name for a normal file
// (does not contain null bytes or "/" etc...).
func IsValidName(name string) error {
if name == "" {
return fmt.Errorf("empty input")
}
if len(name) > NameMax {
return fmt.Errorf("too long")
}
// A name can never contain a null byte or "/". Make sure we never return those
// to the kernel, even when we read a corrupted (or fuzzed) filesystem.
if strings.Contains(name, "\000") || strings.Contains(name, "/") {
return fmt.Errorf("contains forbidden bytes")
}
// The name should never be "." or "..".
if name == "." || name == ".." {
return fmt.Errorf(". and .. are forbidden names")
}
return nil
}