This one took me about 45 minutes. Kept getting hanging errors while trying to connect mysql workbench to amazon’s RDS services. So here’s what I did. Not sure what fixed it.
I followed the tutorial here: http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithSecurityGroups.html
And then added a rule (which is probably really dangerous): CIDR/IP: 0.0.0.0/0 to allo connections from all sources.
Woohoo! it works.