The library implements the SHA-256, SHA-384, and SHA-512 hash algorithms. The
interface is similar to the interface to SHA-1 found in the OpenSSL library.
sha2 is a simple program that accepts input from either STDIN or reads one or
more files specified on the command line, and then generates the specified hash
(either SHA-256, SHA-384, SHA-512, or any combination thereof, including all
three at once).
