pub fn encrypt_file(
path: &Path,
derived_key: &[u8; 32],
salt: &[u8; 16],
file_id: Option<[u8; 16]>,
zstd: Option<u8>,
) -> Result<Option<FileHeader>>Expand description
Encrypt a single file using streaming chunked encryption.
Returns Some(header) on success, or None if the file was already
encrypted and skipped.