How do I redirect www traffic without triggering browsers SSL check?

Question

I have a valid certificate for example.com. If users go to my site at http://example.com, they get redirected to https://example.com and all is good. If they go to https://e

Answer 1

If your certificate is for example.com only and not for www.example.com then any access to www.example.com will trigger a certificate warning, no matter if you want just redirect it or not. Redirection is done at the HTTP level and before it talks HTTP it first does the SSL handshake (which triggers the problem), because HTTPS is just HTTP inside SSL.

And before you ask, tricks with DNS (like CNAME) will not help either because the browser will compare the certificate against the name in the URL, not against possible DNS alias names. There is simply no way around getting a proper certificate.