Make the VNC authentication build with LibreSSL on HardenedBSD and TrueOS.

[araujo]

Summary

HardenedBSD and TrueOS has LibreSSL in the base system, to make it compatible is better use the unsigned char const_DES_cblock[8];

There is a PR[0] with a patch to fix it.
[0] https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=219790

Test Plan

• Built on TrueOS.
• Tested on FreeBSD HEAD and TrueOS.

[rgrimes]

As pointed on in the PR is it possible to totally remove all this casting?
It would make the code much cleaner.

[araujo]

In D11071#229273, @rgrimes wrote:

As pointed on in the PR is it possible to totally remove all this casting?
It would make the code much cleaner.

Actually need to make the cast, the DES_* expect a parameter of type DES_cblock or const_DES_cblock:

/usr/src/usr.sbin/bhyve/rfb.c:845:15: error: incompatible pointer types passing 'unsigned char [8]' to parameter of type 'const_DES_cblock *'
      (aka 'unsigned char (*)[8]'); take the address with & [-Werror,-Wincompatible-pointer-types]
                DES_set_key(keystr, &ks);
                            ^~~~~~
                            &
/usr/include/openssl/des.h:230:35: note: passing argument to parameter 'key' here
int DES_set_key(const_DES_cblock *key, DES_key_schedule *schedule);