stdlib/digest.mli

   1 (***********************************************************************)
   2 (*                                                                     *)
   3 (*                           Objective Caml                            *)
   4 (*                                                                     *)
   5 (*            Xavier Leroy, projet Cristal, INRIA Rocquencourt         *)
   6 (*                                                                     *)
   7 (*  Copyright 1996 Institut National de Recherche en Informatique et   *)
   8 (*  en Automatique.  All rights reserved.  This file is distributed    *)
   9 (*  under the terms of the GNU Library General Public License, with    *)
  10 (*  the special exception on linking described in file ../LICENSE.     *)
  11 (*                                                                     *)
  12 (***********************************************************************)
  13
  14 (* $Id$ *)
  15
  16 (** MD5 message digest.
  17
  18    This module provides functions to compute 128-bit ``digests'' of
  19    arbitrary-length strings or files. The digests are of cryptographic
  20    quality: it is very hard, given a digest, to forge a string having
  21    that digest. The algorithm used is MD5.
  22 *)
  23
  24 type t = string
  25 (** The type of digests: 16-character strings. *)
  26
  27 val string : string -> t
  28 (** Return the digest of the given string. *)
  29
  30 val substring : string -> int -> int -> t
  31 (** [Digest.substring s ofs len] returns the digest of the substring
  32    of [s] starting at character number [ofs] and containing [len]
  33    characters. *)
  34
  35 external channel : in_channel -> int -> t = "caml_md5_chan"
  36 (** If [len] is nonnegative, [Digest.channel ic len] reads [len]
  37    characters from channel [ic] and returns their digest, or raises
  38    [End_of_file] if end-of-file is reached before [len] characters
  39    are read.  If [len] is negative, [Digest.channel ic len] reads
  40    all characters from [ic] until end-of-file is reached and return
  41    their digest. *)
  42
  43 val file : string -> t
  44 (** Return the digest of the file whose name is given. *)
  45
  46 val output : out_channel -> t -> unit
  47 (** Write a digest on the given output channel. *)
  48
  49 val input : in_channel -> t
  50 (** Read a digest from the given input channel. *)
  51
  52 val to_hex : t -> string
  53 (** Return the printable hexadecimal representation of the given digest. *)