This library provides message digest functions found on BSD systems either on
their libc (NetBSD, OpenBSD) or libmd (FreeBSD, DragonflyBSD, macOS, Solaris) 
libraries and lacking on others like GNU systems.

The intention here is to have a library with extremely permissive licenses
(see below), that can be used by any project; that has a very small scope
and as such can be part of the base system on most distributions; and that 
has a compatible API with the implementations on other systems and those 
that other projects are embedding, so that they can switch to use the 
system library instead of duplicating the same code all over the place.

The currently provided message digest algorithms are:

* MD2
* MD4
* MD5
* RIPEMD-160
* SHA-1
* SHA-2 (SHA-256, SHA-384 and SHA-512)