Looking for a sha1 library

[Goswin von Brederlow <goswin-v-b@web.de>]

Hi,

I'm looking for a library that can compute sha1 sums for ocaml.
I currently need the following interface:

type t

(* Compute the sha1 sum of a string or substring, only one of them *)
sha1_of_string str : string -> t
sha1_of_string str start length : string -> int -> int -> t

(* Compute the sha1 sum of a file *)
sha1_of_file fd start length: Unix.file_descr -> Int64.t -> Int64.t -> t

(* Input output functions *)
(* human readable form *)
sha1_to_string sha1 : t -> string
sha1_from_string str : string -> t

(* machine readable form *)
sha1_to_binary sha1 : t -> string
sha1_from_binary str : string -> t


Anyone know some ocmal bindings that would fit those?

MfG
        Goswin