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.