Chacha20 (p.noise.0.1.0.doc.noise.

val quarter_round : 
  (int32 * int32 * int32 * int32) ->
  int32 * int32 * int32 * int32

type state

val equal_state : state -> state -> Ppx_deriving_runtime.bool

val pp_state : 
  Ppx_deriving_runtime.Format.formatter ->
  state ->
  Ppx_deriving_runtime.unit

val show_state : state -> Ppx_deriving_runtime.string

val make_state : int32 list -> state

val quarter_round_state : state -> (int * int * int * int) -> state

val make_state_for_encryption : 
  key:Cstruct.t ->
  nonce:Cstruct.t ->
  count:int32 ->
  (state, string) result

val process : state -> state

val serialize : state -> Cstruct.t

val encrypt : 
  key:Cstruct.t ->
  counter:int32 ->
  nonce:Cstruct.t ->
  Cstruct.t ->
  (Cstruct.t, string) result