SSL certificates are system time sensitive (did you suspend your virtual machine?).
First thing you do is check if your timedate is up to date, if not, use this to set your timedate:
Second might be that your certificates are not up to date, use yum to update it.
yum update openssl -y
If it still does not work, try to add the certificate manually:
Getting the certificate.
Method 1 Download the certificate from Firefox,
click on the lock left to the https:// and "view certificate", "details", "export".
Method 2 From the command line you could do:
echo -n|openssl s_client -connect forgeapi.puppetlabs.com:443 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > /tmp/forgeapi.puppetlabs.com.cert
Install the ca-certificates package
yum install ca-certificates
Enable the dynamic CA configuration feature:
Add it as a new file to /etc/pki/ca-trust/source/anchors/:
cp /tmp/forgeapi.puppetlabs.com.cert /etc/pki/ca-trust/source/anchors/
For other suggestions, see also