On Friday, July 24, 2015 01:50:31 am Andrei Popov wrote:
> > I'm proposing renaming "insufficient_security" to 
> > "unsupported_cipher_suites", which is explicitly what it's been for since 
> > TLS 1.0.
> 
> Not quite. Insufficient_security alert is defined as follows:
> " Returned instead of handshake_failure when a negotiation has
>    failed specifically because the server requires ciphers more
>    secure than those supported by the client.  This message is always
>    fatal."
> 
> This is a very narrow and specific definition. The server says "I know all 
> the cipher suites the client advertises, and consider them too weak". By 
> contrast, unsupported_cipher_suites means something like "I don't have a 
> cipher suite in common with the client". The latter can happen when the 
> client's cipher suites are more secure than the server's.

Then if we wish to keep this as narrow as written, we can just have a separate 
one for unsupported with no judgment on strength:

insufficient_security(71),  // unchanged
unsupported_cipher_suites(72),  // new
unsupported_groups(73),  // new
client_authentication_failure(74),  // new

e.g. RC4 gets insufficient_security & Camellia gets unsupported_cipher_suites

Sounds good to me, if we prefer this.


Dave

_______________________________________________
TLS mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/tls

Reply via email to