Hi Luigi!

Thanks for publishing -28/-29.  It addresses my feedback per our discussion 
below.  I've cleared my ballot.

Roman

> -----Original Message-----
> From: iesg <[email protected]> On Behalf Of Roman Danyliw
> Sent: Wednesday, June 29, 2022 4:35 PM
> To: Luigi Iannone <[email protected]>
> Cc: The IESG <[email protected]>; [email protected]; 
> [email protected];
> [email protected]
> Subject: RE: Roman Danyliw's Discuss on draft-ietf-lisp-sec-27: (with DISCUSS
> and COMMENT)
> 
> Hi Luigi!
> 
> Thanks for the quick response.  To your direct question, yes, the proposed 
> edits
> described below address my feedback.
> 
> Roman
> 
> > -----Original Message-----
> > From: Luigi Iannone <[email protected]>
> > Sent: Wednesday, June 29, 2022 7:42 AM
> > To: Roman Danyliw <[email protected]>
> > Cc: The IESG <[email protected]>; [email protected];
> > [email protected]; [email protected]
> > Subject: Re: Roman Danyliw's Discuss on draft-ietf-lisp-sec-27: (with
> > DISCUSS and COMMENT)
> >
> > Hi Roman,
> >
> > Thank you very much for your review.
> >
> > A few proposed changes  inline.
> >
> > > On 29 Jun 2022, at 03:47, Roman Danyliw via Datatracker
> > > <[email protected]>
> > wrote:
> > >
> > > Roman Danyliw has entered the following ballot position for
> > > draft-ietf-lisp-sec-27: Discuss
> > >
> > > When responding, please keep the subject line intact and reply to
> > > all email addresses included in the To and CC lines. (Feel free to
> > > cut this introductory paragraph, however.)
> > >
> > >
> > > Please refer to
> > > https://www.ietf.org/about/groups/iesg/statements/handling-ballot-po
> > > si tions/ for more information about how to handle DISCUSS and
> > > COMMENT positions.
> > >
> > >
> > > The document, along with other ballot positions, can be found here:
> > > https://datatracker.ietf.org/doc/draft-ietf-lisp-sec/
> > >
> > >
> > >
> > > --------------------------------------------------------------------
> > > --
> > > DISCUSS:
> > > --------------------------------------------------------------------
> > > --
> > >
> > > ** Since originally scheduled for the telechat in version -26, thank
> > > you for adding the following text about preferring HMAC-SHA256 for
> > > new deployments in
> > > -27:
> > >
> > >   The HMAC
> > >   function AUTH-HMAC-SHA-256-128 [RFC6234] MUST be supported in
> LISP-
> > >   SEC implementations.  LISP-SEC deployments SHOULD use AUTH-HMAC-
> > SHA-
> > >   256-128 HMAC function, unless older implementations using AUTH-
> HMAC-
> > >   SHA-1-96 are present in the same deployment [RFC2104].
> > >
> > > Could this same approach be applied for the algorithms set by KDF ID.
> > > Specifically:
> > >
> > > -- Section 6.9 says:
> > >
> > >   The key derivation function
> > >   HKDF-SHA1-128 [RFC5869] MUST be supported.
> > > ...
> > >  However, since HKDF-SHA1-128 is mandatory to implement, the process
> > >   will eventually converge.
> > >
> > > Could it say something to the effect of:
> > >
> > > The key derivation function HKDF-SHA256 MUST be supported in
> > > LISP-SEC implementations.  LISP-SEC deployments SHOULD use the
> > > HKDF-SHA256
> > HKDF
> > > function, unless older implementations using HKDF-SHA1-128 are
> > > present in the same deployment.
> > >
> > > However, since HKDF-SHA1-128 and HKDF-SHA256 are supported, the
> > > process will eventually converge.
> >
> > Yes, good idea. THe text makes sense and makes LISP-Sec even more robust.
> >
> >
> > >
> > > -- Section 8.5.  Add HKDF-SHA256 to the "LISP-SEC Authentication Data Key
> > >   Derivation Function ID" registry
> > >
> >
> > Yep.
> >
> >
> > >
> > > --------------------------------------------------------------------
> > > --
> > > COMMENT:
> > > --------------------------------------------------------------------
> > > --
> > >
> > > Thank you to Alexey Melnikov for the SECDIR review.
> > >
> > > ** Section 4.
> > >   In this
> > >   way the ETR can maliciously redirect traffic directed to a large
> > >   number of hosts.
> > >
> > > Does the number of impact host matter so much as the generic ability
> > > to redirect traffic?  I’m imagining that a “surgical” or targeted
> > > attack might be equally interesting – for example, if there was a
> > > particular services on a given prefix that an attacker wanted to redirect.
> >
> > You are right. It works both ways.
> > The text can simply state: “… the ETR can maliciously redirect traffic."
> >
> >
> > >
> > > ** Section 5.
> > >
> > >   Those trust relationships are used to securely
> > >   distribute, as described in Section 8.4, ...
> > >
> > > Is Section 8.4, really the right reference here?
> > >
> > > ** Section 6.5
> > >   Implementations of this specification MUST support OTK Wrapping ID
> > >   AES-KEY-WRAP-128+HKDF-SHA256 that specifies the use of the HKDF-
> > >   SHA256 Key Derivation Function specified in [RFC4868]
> > >
> > > RFC4868 doesn’t define a HKDF with SHA256.  Do you mean RFC5869?
> > > Same issue in Section 8.4 (IANA table)
> >
> > Will be replaced.
> >
> > >
> > > ** Section 6.5
> > >   4.  The per-message encryption key is computed as:
> > >
> > >       *  per-msg-key = KDF( nonce + s + PSK[Key ID] )
> > >       where the nonce is the value in the Nonce field of the Map-
> > >       Request, 's' is the string "OTK-Key-Wrap", and the operation'+'
> > >       just indicates string concatenation.
> > >
> > > HKDFs typically take one more input, L, the output size.  Since this
> > > is tied to a particular key wrap the options are more constrained.
> > > AES-KEY-WRAP-128 can have both a 128-bit and 192-bit KEK, please
> > > explicitly state the expected output size.
> >
> >
> > 128 bits is the expected output size.
> >
> > >
> > > ** Section 7.4
> > >
> > >   As an example, in certain closed and controlled deployments, it is
> > >   possible that the threat associated with an on-path attacker between
> > >   the xTR and the Mapping System is very low, and after careful
> > >   consideration it may be decided to allow a NULL key wrapping
> > >   algorithm while carrying the OTKs between the xTR and the Mapping
> > >   System.
> >
> >
> > >
> > > Wouldn’t this violate:
> > > -- Section 6.4, “ITR-OTK confidentiality and integrity protection
> > > MUST be provided in the path between the ITR and the Map-Resolver”
> > >
> > > -- Section 6.4, “If the NULL-KEY-WRAP-128 algorithm (see Section
> > > 8.4) is selected and no other encryption mechanism (e.g.  DTLS) is
> > > enabled, in the path between the ITR and the Map-Resolver, the
> > > Map-Request MUST be dropped and an appropriate log action SHOULD be
> taken”
> > >
> > > -- Section 6.5, “MS-OTK confidentiality and integrity protection MUST be
> > > provided in    the path between the Map-Server and the ETR.”
> > >
> >
> > Yes it would. The text in section 7.4 needs to be changed, actually
> > dropping altogether the paragraph you are citing.
> >
> >
> > > ** Section 7.7.  Recommend adding that when DTLS is used it
> > > confirmed to RFC7525, or even better would be draft-ietf-uta-rfc7525bis.
> >
> > Will be updated
> >
> > >
> > > ** Editorial
> > > -- Section 6.2.  Typo. s/authetification/authentication/
> > >
> > > -- Section 6.3.  Typo. s/Extentions/Extensions/
> > >
> > >
> > >
> >
> > Thanks will be fixed.
> >
> > Do the above proposed changes address your comments?
> >
> > Ciao
> >
> > L.

_______________________________________________
lisp mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/lisp

Reply via email to