Re: [xmpp] #39: prohibition on TLS renegotiation

Kurt Zeilenga <Kurt.Zeilenga@Isode.com> Tue, 06 July 2010 19:58 UTC

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From: Kurt Zeilenga <Kurt.Zeilenga@Isode.com>
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Date: Tue, 06 Jul 2010 12:58:19 -0700
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To: Peter Saint-Andre <stpeter@stpeter.im>
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Subject: Re: [xmpp] #39: prohibition on TLS renegotiation
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On Jul 6, 2010, at 12:04 PM, Peter Saint-Andre wrote:

> I'd be amenable to that. Basically: support for renegotiation is
> strictly optional, and you really shouldn't use it unless you know what
> you're doing.

'strictly optional' != 'shouldn't', which means you Therefore needs some word smithing.  I suggest:

  1.  XMPP entities SHOULD NOT attempt TLS renegotiation.
  2.  If a party that does not support TLS renegotiation detects a TLS
      renegotiation attempt, it SHOULD immediately close the underlying
      TCP connection without returning a stream error (since the
      violation has occurred at the TLS layer, not the XMPP layer; see
      Section 13.3).
  3.  If a party that does support TLS Renegotiation Extension [TLS-NEG] detects a TLS
      renegotiation attempt not using the TLS Renegotiation Extension, it SHOULD
      immediately close the underlying TCP connection without returning a
      stream error (since the violation has occurred at the TLS layer, not
      the XMPP layer; see Section 13.3).
  4.  This specification does not require any implementation to support
      TLS Renegotiation.  However, implementations that support TLS Renegotiation
      MUST implement and use the TLS Renegotiation Extension.  

-- Kurt