(** Poly1305 message authentication code. *)

(** The signature of a Poly1305 MAC. *)
module type S = sig
  type 'a iter = 'a Uncommon.iter
  (** An iterator. *)

  type t
  (** MAC computation state. *)

  val mac_size : int
  (** The MAC output size in bytes. *)

  val empty : key:string -> t
  (** [empty ~key] is a fresh MAC state keyed with [key].

      @raise Invalid_argument if [key] is not 32 bytes. *)

  val feed : t -> string -> t
  (** [feed t data] feeds [data] into [t]. *)

  val feedi : t -> string iter -> t
  (** [feedi t iter] feeds an iterator of strings into [t]. *)

  val get : t -> string
  (** [get t] finalises and returns the MAC. *)

  val mac : key:string -> string -> string
  (** [mac ~key data] is the MAC of [data] under [key]. *)

  val maci : key:string -> string iter -> string
  (** [maci ~key iter] is the MAC of the concatenation of strings from [iter].
  *)

  val mac_into :
    key:string -> (string * int * int) list -> bytes -> dst_off:int -> unit
  (** [mac_into ~key datas dst ~dst_off] computes the MAC of [datas] into [dst]
      at [dst_off] with bounds checking. *)

  val unsafe_mac_into :
    key:string -> (string * int * int) list -> bytes -> dst_off:int -> unit
  (** Like {!mac_into} without bounds checking. *)
end

module It : S
(** Poly1305 MAC using the C implementation. *)