In case anybody else comes across this issue, this reply on the Homebrew GitHub issues page was able to fix it BUT requires switching to the development version of Brew.
It looks like you're being connected elsewhere for some reason. It sounds more like a network-related issue. Are you running a firewall/packet analyser/etc (e.g. Little Snitch)? You might ...
You temporary disable verifying ssl in yum with the following.
echo "sslverify=0" >> /etc/yum.conf
yum reinstall -y ca-certificates
Remove temporary hack with editor of your choice from /etc/yum.conf
If for some reason, this still doesn't work, you might try the following:
Find the package. In the case of RPM packages, I recommend ...