The three functions has been modeled after the arc4random family of
functions, and they will always return random bytes.
The isc_random family of functions internally use these CSPRNG (if available):
1. getrandom() libc call (might be available on Linux and Solaris)
2. SYS_getrandom syscall (might be available on Linux, detected at runtime)
3. arc4random(), arc4random_buf() and arc4random_uniform() (available on BSDs and Mac OS X)
4. crypto library function:
4a. RAND_bytes in case OpenSSL
4b. pkcs_C_GenerateRandom() in case PKCS#11 library
3535. [func] Add support for setting Differentiated Services Code
Point (DSCP) values in named. Most configuration
options which take a "port" option (e.g.,
listen-on, forwarders, also-notify, masters,
notify-source, etc) can now also take a "dscp"
option specifying a code point for use with
outgoing traffic, if supported by the underlying
OS. [RT #27596]
