Cryptokit.transform

`object method available_output : int method finish : unit method flush : unit method get_byte : int method get_char : char method get_string : string method get_substring : string * int * int method input_block_size : int method output_block_size : int method put_byte : int -> unit method put_char : char -> unit method put_string : string -> unit method put_substring : string -> int -> int -> unit method wipe : unit end`