Re: [I2nsf] Comments/questions about draft-ietf-i2nsf-problem-and-use-cases

-----Original Message-----
From: I2nsf [mailto:i2nsf-bounces@ietf.org] On Behalf Of Rafa Marin Lopez
Sent: Monday, October 3, 2016 5:33 PM
To: i2nsf@ietf.org
Cc: Rafa Marin Lopez
Subject: [I2nsf] Comments/questions about draft-ietf-i2nsf-problem-and-use-cases

Dear all:

I have reviewed draft-ietf-i2nsf-problem-and-use-cases and I have a few comments/questions (my apologies if these have been already discussed in the past).

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Section 3.1.1

[Rafa]
-Security Functions in a DMZ. You refer to authentication and authorization but also AAA. Is this not redundant?

Sue: New text 
Security Functions in a DMZ: Examples of this
              function are firewall/ACLs, IDS/IPS, one or all of AAA services		  
              NAT, forwarding proxies, and application filtering. 
              These functions may be physically on-premise
              in a server provider's network at the DMZ spots or located in a
              "virtual" DMZ.

[Rafa #2]  
- At first sight, there is no example of NSFs with flow based protection. That is, those that participate in the establishment of a security association to protect data traffic.

[Sue #2]  Can you suggest an example NSF with flow protection.  I will be gald 

[Rafa #3 Section 3.1.10] 

- A general comment about this section is that the text seems to pay attention to routing. In our case, for example, we have an I-D to manage IPSec SAs based on SDNs (https://tools.ietf.org/html/draft-abad-i2nsf-sdn-ipsec-flow-protection-00). I guess this use case we present in our I-D is somehow included in the text “Conceptually, there must be an interface defined for routing/signaling protocols…” but I am not sure. Could you clarify?

[Sue #3]: 
I have modified the text to state: 
Conceptually, there must be an interface defined for routing/signaling protocols to make requests for automated key management when it is being used, to notify the protocols when keys become available in the key table. One potential use of such an interface is to manage IPSec security associations on SDN networks.

[Rafa #4:] 
- A suggestion I have is to revise this paragraph:

“While there are many key management methods and
   key derivation functions (KDF), there is a lack of standard interface
   to provision and manage keys.”

There is a lack not only to provision and manage keys but also to specify additional information (e.g. low level policies) or to fill certain information to manage, in the end, a security association. Additionally, I am not sure about the initial sentence "While there are many key management methods and key derivation functions (KDF)”… what do you mean with this?

Perhaps a possible modification would say:

 —-> While there are many key management methods and
   cryptographic suites (e.g. encryption algorithms, key derivation functions, etc…), there is a lack of standard interface
   to provision and manage security associations.

[Sue #4]: I have changed the text 

[Rafa #5] 
Regarding this paragraph:

“The ability to utilize keys when routing protocols send or receive
   messages will be enhanced by having an abstract key table maintained
   by a security service.  Conceptually, there must be an interface
   defined for routing/signaling protocols to make requests for
   automated key management when it is being used, to notify the
   protocols when keys become available in the key table.”
]
In my opinion, it seems going into a solution space: “an abstract key table” and a mechanism to “pull” the keys, is this correct?. Why using this key table? Why using pull method so that the protocols know when the keys are available in the table?. Also, the text refers to routing protocols at the beginning. I would say that there must be an interface to configure security associations of any nature, no?

[Sue]: I agree.  I have removed the first sentence.  I believe this addresses your comment. 

[Rafa #6] 

Section 4. In the use cases, there is no explicit text where key distribution is required. One may think that section 4.3.2 and, most probably, 4.3.3 may be related with key management (section 3.1.10). I mention this because our I-D focused on key management for IPSec SAs and VPNs is a term that may be associated to this.

[Sue]: You are right.  I have changed the following paragraph to mention the distribution of keys. 

       Interface 1 is used for receiving security requirements from client
        and translating them into commands that NSFs can understand and
        execute. The security controller also passes back NSF security reports
        (e.g., statistics) to the client which the control has gathered from
        NSFs. Interface 2 is used for interacting with NSFs according to
        commands (e.g. enact policy and distribute key), and collecting 
		status information about NSFs.

[Rafa #7]
Section 7.

When you mention AAA, are you referring to https://tools.ietf.org/html/rfc2904 ? 

[Sue # 7]:  I've included a reference to the AAA document at that point. 

Rafa - Thanks for all the comments - Let me know if the above resolution works for you.  I'll respond to your other message, and then send you a copy of the file. 

-------------------------------------------------------
Rafael Marin Lopez, PhD
Dept. Information and Communications Engineering (DIIC) Faculty of Computer Science-University of Murcia
30100 Murcia - Spain
Telf: +34868888501 Fax: +34868884151 e-mail: rafa@um.es
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