Re: [TLS] NULL cipher to become a MUST NOT in UTA BCP
Paul Lambert <paul@marvell.com> Tue, 02 September 2014 21:01 UTC
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From: Paul Lambert <paul@marvell.com>
To: "tls@ietf.org" <tls@ietf.org>
Date: Tue, 02 Sep 2014 14:01:22 -0700
Thread-Topic: [TLS] NULL cipher to become a MUST NOT in UTA BCP
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References: <54048985.1020005@net.in.tum.de> <20140902152308.GB14392@mournblade.imrryr.org> <54061EBC.5080909@net.in.tum.de> <20140902195148.GR14392@mournblade.imrryr.org>
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Archived-At: http://mailarchive.ietf.org/arch/msg/tls/IVfKcQ_RuB4UIZ4Fw4i9GJY3MIU
Subject: Re: [TLS] NULL cipher to become a MUST NOT in UTA BCP
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]-----Original Message----- ]From: TLS [mailto:tls-bounces@ietf.org] On Behalf Of Viktor Dukhovni ]Sent: Tuesday, September 02, 2014 12:52 PM ]To: tls@ietf.org ]Subject: Re: [TLS] NULL cipher to become a MUST NOT in UTA BCP ] ]On Tue, Sep 02, 2014 at 09:47:08PM +0200, Ralph Holz wrote: ] ]> > Postfix supports authenticated NULL ciphers for communication ]> > between an MTA and local (127.0.0.1 or ::1) LMTP server. Encrypting ]> > local IPC is just a waste of CPU. Yes, this is a specialized use- ]case. ]> > ]> > This can also be useful for access-controlled hand-off between ]> > reverse HTTP proxies, and web applications that support client ]> > certificates. These are sometimes used to implement GSSAPI SPNEGO ]> > support in front of application that don't support GSSAPI. The ]> > application is configured to listen on 127.0.0.1, but is then ]> > vulnerable to impersonation attacks from anything running on the ]> > host. With authenticated NULL ciphers, the connection can be ]> > restricted to just the front-end reverse proxy. ]> ]> Both seem to be real corner cases - wouldn't they be covered just as ]> well with encryption prescribed? ] ]Yes, these are "corner cases". A sufficiently broadly applicable tool ]has a lot of corners. ] ]While I agree that NULL ciphers should not be enabled *by default*, ]making NULL ciphers a "MUST NOT" seems rather too strong. Why burn ]limited CPU cycles doing nothing useful (encrypting local IPC). I disagree, and support the draft as written. 'MUST NOT' is the appropriate recommendation for NULL ciphers. Paul ] ]-- ] Viktor. ] ]_______________________________________________ ]TLS mailing list ]TLS@ietf.org ]https://www.ietf.org/mailman/listinfo/tls
- [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