Re: [TLS] Cipher suite values to indicate TLS capability

Yoav Nir <ynir@checkpoint.com> Wed, 06 June 2012 05:20 UTC

From: Yoav Nir <ynir@checkpoint.com>
To: Wan-Teh Chang <wtc@google.com>
Date: Wed, 06 Jun 2012 08:20:32 +0300
Thread-Topic: [TLS] Cipher suite values to indicate TLS capability
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Cc: Geoffrey Keating <geoffk@geoffk.org>, "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] Cipher suite values to indicate TLS capability
Precedence: list

On Jun 6, 2012, at 4:18 AM, Wan-Teh Chang wrote:

> ECDHE is not the only feature we lose when downgrading to SSLv3. We
> also lost all the features implemented using TLS extensions, such as
> server name indication, OCSP stapling, and the ability to negotiate
> SPDY.
> 
> It would be nice if the server could indicate support of TLS in a less
> destructive way than rejecting the handshake.  Perhaps a new alert
> message at the warning level?
> 
> As for TLS_1_1_CAPABLE_SCSV and TLS_1_2_CAPABLE_SCSV, it seems that
> TLS_1_2_CAPABLE_SCSV could be useful because TLS 1.2 is important to
> the people who want to avoid SHA-1 and MD5 or comply with NSA Suite B.

TLS 1.1 may also be important to people, because it is not vulnerable to the BEAST attack. With TLS 1.0 you have to use RC4 to avoid being flagged by PCI compliance scans and SSL Pulse.

And NIST has long recommended to avoid RC4.

Yoav

Re: [TLS] Cipher suite values to indicate TLS cap… Geoffrey Keating
[TLS] Cipher suite values to indicate TLS capabil… Adam Langley
Re: [TLS] Cipher suite values to indicate TLS cap… Adam Langley
Re: [TLS] Cipher suite values to indicate TLS cap… Geoffrey Keating
Re: [TLS] Cipher suite values to indicate TLS cap… Adam Langley
Re: [TLS] Cipher suite values to indicate TLS cap… Adam Langley
Re: [TLS] Cipher suite values to indicate TLS cap… Geoffrey Keating
Re: [TLS] Cipher suite values to indicate TLS cap… Adam Langley
Re: [TLS] Cipher suite values to indicate TLS cap… Chris Richardson
Re: [TLS] Cipher suite values to indicate TLS cap… Wan-Teh Chang
Re: [TLS] Cipher suite values to indicate TLS cap… Yoav Nir
Re: [TLS] Cipher suite values to indicate TLS cap… Yoav Nir
Re: [TLS] Cipher suite values to indicate TLS cap… Nikos Mavrogiannopoulos
Re: [TLS] Cipher suite values to indicate TLS cap… Geoffrey Keating
Re: [TLS] Cipher suite values to indicate TLS cap… Chris Richardson
Re: [TLS] Cipher suite values to indicate TLS cap… Tom Ritter
Re: [TLS] Cipher suite values to indicate TLS cap… Nikos Mavrogiannopoulos
Re: [TLS] Cipher suite values to indicate TLS cap… Adam Langley
Re: [TLS] Cipher suite values to indicate TLS cap… Nikos Mavrogiannopoulos
Re: [TLS] Cipher suite values to indicate TLS cap… Adam Langley
Re: [TLS] Cipher suite values to indicate TLS cap… Martin Rex