Re: [TLS] NULL cipher to become a MUST NOT in UTA BCP
Viktor Dukhovni <ietf-dane@dukhovni.org> Fri, 05 September 2014 21:49 UTC
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Date: Fri, 05 Sep 2014 21:49:09 +0000
From: Viktor Dukhovni <ietf-dane@dukhovni.org>
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Subject: Re: [TLS] NULL cipher to become a MUST NOT in UTA BCP
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On Fri, Sep 05, 2014 at 11:27:27PM +0200, Bodo Moeller wrote: > > This is why my suggestion was specifically about the initiator > > (client): > > > > What is much more reasonable is that initiators (clients) should > > refuse to negotiate (should suppress any configured) NULL cipher > > suites when any non NULL cipher suite is enabled. This prevents > > accidents, without breaking carefully considered NULL to NULL > > deployments. > > > > It leaves room for dual-purpose servers. > > > > Thanks for the clarification -- so I should have expanded the very terse "Same > for clients": A client content with NULL encryption may want to offer > non-NULL cipher suites in the same ClientHello in case the server doesn't > accept NULL encryption for whatever reason (e.g., because the implementor > doesn't like NULL encryption). My thinking is that clients SHOULD NOT offer NULL, unless they explicitly want NULL and know that it will be excepted. Clients that are laissez-faire about whether they get no encryption or not seem negligent to me. If they don't need whatever performance or transparency for troubleshoots they might get from NULL, they should just always go with non-NULL. This is not a proof that the mixed case has no compelling scenarios, just can't think of any as yet. > As noted before, I think the BCP doesn't have to deal with issues like > this, and instead should provide recommendations just for applications that > want to achieve confidentiality. That's fine too. I was mostly trying to non-destructively accommodate the impulse to do something normative along the lines of the original proposal. -- Viktor.
- [TLS] NULL cipher to become a MUST NOT in UTA BCP Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Blumenthal, Uri - 0558 - MITLL
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Viktor Dukhovni
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Paul Hoffman
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Salz, Rich
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Viktor Dukhovni
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Blumenthal, Uri - 0558 - MITLL
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Viktor Dukhovni
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Viktor Dukhovni
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Paul Lambert
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Bodo Moeller
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Blumenthal, Uri - 0558 - MITLL
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Nico Williams
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Nikos Mavrogiannopoulos
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Yutaka OIWA
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Blumenthal, Uri - 0558 - MITLL
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Viktor Dukhovni
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Blumenthal, Uri - 0668 - MITLL
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Viktor Dukhovni
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Geoffrey Keating
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Blumenthal, Uri - 0668 - MITLL
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Nico Williams
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Nico Williams
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Nico Williams
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Blumenthal, Uri - 0668 - MITLL
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Blumenthal, Uri - 0558 - MITLL
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Yutaka OIWA
- [TLS] uta-tls-bcp-02 thoughts (was: NULL cipher t… Viktor Dukhovni
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Bodo Moeller
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Yutaka OIWA
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Nico Williams
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Blumenthal, Uri - 0558 - MITLL
- Re: [TLS] uta-tls-bcp-02 thoughts (was: NULL ciph… Blumenthal, Uri - 0558 - MITLL
- Re: [TLS] uta-tls-bcp-02 thoughts (was: NULL ciph… Nico Williams
- Re: [TLS] uta-tls-bcp-02 thoughts (was: NULL ciph… Blumenthal, Uri - 0558 - MITLL
- Re: [TLS] uta-tls-bcp-02 thoughts Ralph Holz
- Re: [TLS] uta-tls-bcp-02 thoughts Blumenthal, Uri - 0558 - MITLL
- Re: [TLS] uta-tls-bcp-02 thoughts Ralph Holz
- Re: [TLS] uta-tls-bcp-02 thoughts (was: NULL ciph… Barry Leiba
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Bill Frantz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Daniel Kahn Gillmor
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Bodo Moeller
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Manuel Pégourié-Gonnard
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Viktor Dukhovni
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Manuel Pégourié-Gonnard
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ilari Liusvaara
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Nico Williams
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Blumenthal, Uri - 0668 - MITLL
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Ralph Holz
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Bodo Moeller
- Re: [TLS] NULL cipher to become a MUST NOT in UTA… Viktor Dukhovni