19.6 Module Digest: MD5 message digest

This module provides functions to compute 128-bit ``digests'' of arbitrary-length strings or files. The digests are of cryptographic quality: it is very hard, given a digest, to forge a string having that digest. The algorithm used is MD5.
type t = string
The type of digests: 16-character strings.
val string: string -> t
Return the digest of the given string.
val substring: string -> pos:int -> len:int -> t
Digest.substring s ofs len returns the digest of the substring of s starting at character number ofs and containing len characters.
val channel: in_channel -> len:int -> t
Digest.channel ic len reads len characters from channel ic and returns their digest.
val file: string -> t
Return the digest of the file whose name is given.
val output: out_channel -> t -> unit
Write a digest on the given output channel.
val input: in_channel -> t
Read a digest from the given input channel.