An array passed as a function argument is just a cosmetic ay to pass just a
pointer. Therefore sizeof(array) will only return the pointer length, not
the array length, and on 32 bit pointers are 4 bytes long.

Fix payload calculation by passing in the known correct length instead of using
fancy sizeofs ...

Openssl detects at runtime the CPU type and on some 32 bit CPUs will
automatically switch to a compressed schedule for the RC4_KEY.
Don't try to be too smart nd just copy all the data even if it takes
4 times the space.

The code still assumes sizeof(RC4_INT) == sizeof(uint32_t)

Do this by removing directives that we do not really depend on.

This allows people to put in an email address as the source name and
have i treated automatically as an enterprise name as well.

Although technically NetBIOS names can have dots it is unlikely and the
user@domain form is generally undestood to be used with UPNs and email
like addresses which use the DNS Domain Name.

The fallback case for NetBIOS domain names with a dot is to configure the
client to use the DOMAIN\user name form instead.