./configure --with-nettle to use Nettle crypto lib for algorithms,
instead of OpenSSL or wolfSSL. Note: Nettle does not provide TLS.
x-ref:
"How to use SHA-256 without OpenSSL?"
https://redmine.lighttpd.net/boards/2/topics/8903
add public domain SHA1() if not linking with crypto lib
obtained from https://github.com/nori0428/mod_websocket
* Originally written by Steve Reid <steve@edmweb.com>
*
* Modified by Aaron D. Gifford <agifford@infowest.com>
*
* NO COPYRIGHT - THIS IS 100% IN THE PUBLIC DOMAIN
*
* The original unmodified version is available at:
* ftp://ftp.funet.fi/pub/crypt/hash/sha/sha1.c