Re: [dnssd] [DNSOP] Working Group Last Call - draft-ietf-dnsop-session-signal

"Jan Komissar (jkomissa)" <jkomissa@cisco.com> Wed, 14 February 2018 22:12 UTC

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From: "Jan Komissar (jkomissa)" <jkomissa@cisco.com>
To: Paul Hoffman <paul.hoffman@vpnc.org>, dnsop <dnsop@ietf.org>
CC: "dnssd@ietf.org" <dnssd@ietf.org>, "doh@ietf.org" <doh@ietf.org>
Thread-Topic: [DNSOP] Working Group Last Call - draft-ietf-dnsop-session-signal
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Date: Wed, 14 Feb 2018 22:12:29 +0000
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Subject: Re: [dnssd] [DNSOP] Working Group Last Call - draft-ietf-dnsop-session-signal
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Two items related to this:

1: I think that it would be better to require TLS for all DSO connections. This document (DSO) specifies that it should use TCP or TLS for connections, but the DNS Push Notification (DPN) draft requires TLS. This would complicate matters if a standard TCP connection was opened for one purpose and later a DPN operation over the same connection was attempted. Also, it improves security for all DSO operations.

2: I also believe this document should only support DSO over TLS, not session based protocols in general. If there is a need/desire for doing DSO over other protocols, a new RFC allowing each protocol would be required. This requirement will ensure that all implementations of this draft would interoperate. (If DSO-over-X and DSO-over-Y both are compliant with this document, they are not likely to interoperate even if both X and Y are session based, which would defeat the purpose of a standard.)

Regards,

Jan.

On 2/2/18, 4:58 PM, "DNSOP on behalf of Paul Hoffman" <dnsop-bounces@ietf.org on behalf of paul.hoffman@vpnc.org> wrote:

    The current draft is hand-wavy when it comes to which transports DSO can 
    run on.
    
    Section 2 says "such as":
        The term "connection" means a bidirectional byte stream of reliable,
        in-order messages, such as provided by using DNS over TCP
        [RFC1035][RFC7766] or DNS over TLS [RFC7858].
    Section 4.1 says "are suitable":
        Standard DNS over TCP [RFC1035][RFC7766], and DNS over TLS [RFC7858]
        are suitable protocols.
    
    The document should explicitly list which protocols are currently 
    acceptable, and say that the list can change in the future based on 
    standards-track documents. Proposed wording for both of these above are:
    
    Section 2:
        The term "connection" means a bidirectional byte stream of reliable,
        in-order messages.
    Section 4.1 says "are suitable":
        DSO MUST be run as standard DNS over TCP [RFC1035][RFC7766]
        or DNS over TLS [RFC7858]. This list might expand in the future, 
    such
        an expansion MUST be in standards-track RFCs.
    
    Having developers know exactly which protocols can be used is important 
    so that they do not use protocols that they accidentally think are 
    reliable and in-order. For example, the DOH WG is working on a protocol 
    that might initially seem attractive, but it does *not* qualify for DSO.
    
    --Paul Hoffman
    
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