See lavarnd.org for a modernized (2003) version.

If the machine truly has little entropy to start, it might have trouble establishing a secure TLS connection to the remote source.

That said, here is my little "wwwrand" script, that assumes Google News will return unpredictable and unrepeatable content. You could also throttle curl using --limit-rate to generate more interrupts for strace to log.

nice -n 19 strace -CTiv -ttt curl -LNv https://news.google.com 2>&1 | shasum -a 512

I see random.org has an api https://api.random.org/json-rpc/1/