I’m just one of the many many users of the SSL/TLS protocols on a HTTPS site.
For good security reasons I'd like to restrict the TLS negotiation to minimum TLS1.1 with AES ciphers. Reasons are available at SSLLabs and OWASP.
But I know that older browsers (IE on WinXP etc.) will have issues in that case connecting to my website (negotiation will fail, thus no website will be shown).
My issue is that I'd rather like to provide my visitors with a fallback page (on a insecure line) about updating the browser than leaving them in the blank about what happend (and getting loads of calls on the helpdesk about this).
There is of course the option enabling the older protocols and ciphers and afterwards putting them into some quarantaine site like the link below suggests. This however feels like a workaround, for which a load of extra work devices are involved. https://devcentral.f5.com/questions/how-do-i-restrict-tls-negotiation-to-minimum-tls-v12
My question is:
- Is there another way that I do not know to send browsers to a 'fallback' page in case the negotiation fails?
- If not, would it be possible to put something into the TLS protocol version 1.3 to fix this issue? Such as a 'fallback' decryption field that is open for the application layer to fill in with some way of informing browsers that if the handshake would not be possible the browser knows it should fallback to some other resource? (maybe more of a question for the IETF, but since they also read this forum, I'll just ask it here :)).
Note. I've seen websites that actually allow connecting on http like http://example[.]com:443/ and providing a message in that case you should retry with https-protocol. Something like that ;).