Re: [TLS] Rizzo claims implementation attach, should be interesting
"Yngve N. Pettersen" <yngve@opera.com> Thu, 29 September 2011 13:53 UTC
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To: Marsh Ray <marsh@extendedsubset.com>, Martin Rex <mrex@sap.com>
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Date: Thu, 29 Sep 2011 15:55:49 +0200
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From: "Yngve N. Pettersen" <yngve@opera.com>
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Cc: asteingruebl@paypal-inc.com, tls@ietf.org
Subject: Re: [TLS] Rizzo claims implementation attach, should be interesting
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On Thu, 29 Sep 2011 15:44:31 +0200, Martin Rex <mrex@sap.com> wrote: > Marsh Ray wrote: >> >> > - avoid CBC-based cipher suites (at least when SSLv3 or TLSv1.0 >> > is negotiated), and use RC4-128 instead. >> >> Does TLS's use of RC4 still take the first bytes after initialization >> with the key? Or does it discard the proper amount? >> >> I believe there was a mitigation put in place by OpenSSL: sending an >> empty (just padding) message before each app data message. The document >> at eprint.iacr.org/2006/136 suggests that this could be a server-side >> only change. I don't see how that would work since the session cookie >> recovery attack is clearly happening on the client->server channel. >> >> I read somewhere that this mitigation was off by default in OpenSSL >> because it some software (an old MSIE IIRC). > > Why using a EMPTY (just padding) SSL record? That looks like an > obvious untested border case. > > How about using an initial SSL record with one byte of real data > for SSLv3 and TLSv1.0 SSL with CBC cipher suites? According to my testing, this breaks about as many websites, unfortunately, approximately 0.15% of tested websites. There is some uncertainty in the numbers, as I have observed sites that has been reported as breaking still work with the patched versions, whil others doesn't work. At present I do not why this is happening. -- Sincerely, Yngve N. Pettersen ******************************************************************** Senior Developer Email: yngve@opera.com Opera Software ASA http://www.opera.com/ Phone: +47 24 16 42 60 Fax: +47 24 16 40 01 ********************************************************************
- Re: [TLS] Rizzo claims implementation attach, sho… David Wagner
- [TLS] Rizzo claims implementation attach, should … Tim Dierks
- Re: [TLS] Rizzo claims implementation attach, sho… Peter Gutmann
- Re: [TLS] Rizzo claims implementation attach, sho… =JeffH
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Steingruebl, Andy
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Marsh Ray
- Re: [TLS] Rizzo claims implementation attach, sho… Eric Rescorla
- Re: [TLS] Rizzo claims implementation attach, sho… Eric Rescorla
- Re: [TLS] Rizzo claims implementation attach, sho… Yoav Nir
- Re: [TLS] Rizzo claims implementation attach, sho… Marsh Ray
- Re: [TLS] Rizzo claims implementation attach, sho… Yoav Nir
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Marsh Ray
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Eric Rescorla
- Re: [TLS] Rizzo claims implementation attach, sho… Phillip Hallam-Baker
- Re: [TLS] Rizzo claims implementation attach, sho… Nico Williams
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Marsh Ray
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Geoffrey Keating
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… =JeffH
- Re: [TLS] Rizzo claims implementation attach, sho… Nico Williams
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Nico Williams
- Re: [TLS] Rizzo claims implementation attach, sho… Marsh Ray
- Re: [TLS] Rizzo claims implementation attach, sho… Nico Williams
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Eric Rescorla
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Yngve N. Pettersen
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Yngve N. Pettersen
- Re: [TLS] Rizzo claims implementation attach, sho… Martin Rex
- Re: [TLS] Rizzo claims implementation attach, sho… Yoav Nir