By default, OpenSSL doesn't always use a SP800-90A compliant random number generator.
A way to configure OpenSSL to always use a strong source is to setup a wrapper that
defines a shell function that shadows the actual openssl binary,
and that ensures that the -rand /dev/random option is added to every openssl invocation.
To do so, place the following shell snippet exactly as-is to /etc/profile.d/openssl-rand.sh:
# provide a default -rand /dev/random option to openssl commands that
# support it
# written inefficiently for maximum shell compatibility
openssl()
(
openssl_bin=/usr/bin/openssl
case "$*" in
# if user specified -rand, honor it
*\ -rand\ *|*\ -help*) exec $openssl_bin "$@" ;;
esac
cmds=`$openssl_bin list -digest-commands -cipher-commands | tr '\n' ' '`
for i in `$openssl_bin list -commands`; do
if $openssl_bin list -options "$i" | grep -q '^rand '; then
cmds=" $i $cmds"
fi
done
case "$cmds" in
*\ "$1"\ *)
cmd="$1"; shift
exec $openssl_bin "$cmd" -rand /dev/random "$@" ;;
esac
exec $openssl_bin "$@"
)