Meeting the InCommon Assurance profile criteria using Active Directory

["Capehart,Jeffrey D" <>]

Eric,

 

Nice work.  You are a Goodman**2.  (That’s my geek-speek for ‘Goodman, you’re a good man’)

 

I went back and read all the minutes from the previous cookbook discussion just so they would be fresh.  I had not realized that we had gone from 1.0 (NIST encryption) to 1.1 (industry standard) and now (1.2) back to NIST Approved Algorithm.  Interesting.

 

The entropy requirements seem to be leaned on heavily for the 2012 cookbook.  To me, it makes more sense to place the entropy in context, such that if someone can go out on the limb and say that an 8 character password with 10**14 entropy would be sufficient to mitigate the risks with Kerberos, then it becomes relevant to AD meeting “resist [replay, eavesdropper, hijack]” rather than resistance-is-futile.

 

I also thought that RC4 can come into play if SYSKEY is being used.  What I am still not clear on is whether the “password database” is encrypted if SYSKEY isn’t used.  Is the Password Encryption Key used (supposedly RC4) if SYSKEY isn’t turned on?

 

Just an overall comment about the document for the purposes of a “per-institution” version… the “fill-in-the-blank” areas need to be made more explicitly clear that they need to be filled out so that they actually get filled out, rather than being left “blank.”

 

Don’t forget to add a note on the version history when revisions are ready for broader review! J

Jeff

 

From: [mailto:] On Behalf Of David Walker
Sent: Friday, May 17, 2013 11:32 AM
To:
Subject: Re: [AD-Assurance] RE: Action Items from May 10

 

Eric,

This is good stuff.  As a general comment, I think it's fine for us to disagree with the earlier cookbook group.  I say we go ahead with the changes we feel are appropriate and ask them to review our version when we get to a point where it's reviewable.

Some further comments below...

David

On Fri, 2013-05-17 at 02:02 +0000, Eric Goodman wrote:

• Eric to take a first cut at reviewing the Cookbook and develop recommendations for what to keep, cut, and edit.

 

So this one turned out to be quite a bit more challenging than I expected. (It didn’t help that I didn’t really get started on it until today).

 

My edits were – probably unwisely – made on a second copy of the original cookbook (Called “Working copy of …” rather than just the AD cookbook title).

 

https://spaces.internet2.edu/display/InCAssurance/Working+copy+of+InCommon+Silver+with+Active+Directory+Domain+Services+Cookbook+-+May+2013

 

This resulted in page to be harder to find, without adding any value since Confluence would have saved the original pre-edit version anyway. If I can figure out how to move my copy back into the original one, I’ll do that and delete this alternate copy.

 

 

In any case, some major disagreement between the AD cookbook analysis and the Alternative Means strategies we identified around stored passwords. Specifically, the AD cookbook states that the specification of the use of salt is over-prescriptive and basically states that the entire requirement (of using a salt, or on access encryption) is unnecessary. Therefore there is no clear “stub” for us to note the need of Bitlocker (though the use of Bitlocker is encouraged). This conclusion is largely due to the Cookbook misapplying (in my estimation) the entropy requirements against brute force password guessing to the protection of passwords at rest (see my comments in the doc).

I agree that password entropy and encryption at rest are not interchangeable.  I think we can state that as a disagreement with the earlier group and make our Bitlocker statement.

Because the risk assessments are so out of phase with one another in the area of stored passwords, I didn’t see how to put in our commentary without completely rewriting (and revising) the original AD cookbook suggestions, which I think bears more discussion – or at least we should alert the original group that we disagree – before actually making any edits of that magnitude.

I think we agreed to keep a copy of the 2012 Cookbook.  We should feel free to make any changes we see as needed.  As I said, we can ask for the earlier group's input.

On the other areas, we mostly agreed; I added a couple of comments, but there’s still lots of room for editing what I added. E.g., I say “add some of Jeff’s references here” rather than actually having selected his best references. I’m willing to do that addition as well, I just didn’t get to it at this point.

 

I’d like to see the document better formatted to clarify what sections are background info, what are specific operating configuration recommendations, and what is language to use to assert (non-AM) compliance, but I haven’t quite sussed out how to do that yet. For now, I squeezed in our two main additional differences (Require Bitlocker, require invalidating subjects using insecure authentication protocols), and tagged the base disagreements between the two groups. In the doc, my comments are identified with text inside of <<double angle brackets>>.

 

--- Eric