<br><br><div class="gmail_quote">On Thu, Feb 14, 2013 at 10:38 AM, Caitlin Bestler <span dir="ltr"><<a href="mailto:caitlin.bestler@nexenta.com" target="_blank">caitlin.bestler@nexenta.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div>On 2/14/2013 8:23 AM, Nate Reller
wrote:<br>
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<div><span>Malini, I was happy to learn about a key manager
discussion at the summit. Do you know what track this would
be under? I can't decide if this should be in Keystone or
maybe a whole new service. I like the idea of a whole new
service myself because I think it helps to have the
separation and prevent bloating of functionality for
components. On the other hand, I probably don't want a
dozen services.</span></div>
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<div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman,new york,times,serif"><span>I like the idea of the
key-id. I think we may end up using that idea. This will
help us to support snapshot operations.</span></div>
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<span></span></div>
<div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman,new york,times,serif"><span>One item we have yet
to tackle is cloning. I think there are a few options for
this.</span></div>
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<div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman,new york,times,serif"><span>1) Don't support clone
operations for encrypted volumes. This is easy to implement
and prevents key reuse, but it limits functionality.<br>
</span></div>
<div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman,new york,times,serif"><span>2) Support clone with
same key. This should be easy to implement as well. We
could use the metadata key-id and set it to the same value
for the clone. The drawback to this is that the key has
multiple uses, and it could be used to decrypt many
different volumes. I don't like the idea of that. If the
key is compromised then what do you do?</span></div>
<div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman,new york,times,serif"><span>3) Support clone with
different key. You could do this by decrypting the bytes
from the original volume and encrypting them with a new
key. If we are going to support cloning then I think I like
this approach the best. The drawback on this is time.</span></div>
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<span></span></div>
<div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman,new york,times,serif"><span>There are similar
issues for snapshots, but I am not as opposed to option 2
for snapshots. Any thoughts on this?</span></div>
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<span></span></div>
<div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman,new york,times,serif"><span>-Nate<br>
</span></div>
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Great outline, it zeroes in on the most critical issue.<br>
<br>
Nexenta favors option 2, which shouldn't be surprising since we
on-the-fly snapshotting and cloning<br>
is one of the key strengths of ZFS.<br>
<br>
When you have to decrypt and re-encrypt a volume the process is no
longer a "snapshot", but something<br>
that resembled Civil War era photography.<br>
<br>
However, I do not see Keystone as being a key repository that is up
to supporting distributed keys.<br>
Any would-be attacker would immediately target the encryption of
communicating with keystone<br>
as being a far more vulnerable target than the encryption used on
the volumes themselves.<br>
<br>
I believe what we need is to allow the encryption keys to be stored
by the storage servers themselves<br>
in secure lock boxes, and the role of OpenStack should be to
authorize secure transfers between those<br>
lockboxes (which could be encrypted by far more than SSL).<br>
<br>
<br>
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<br></blockquote></div>I've been pretty much silent through most of this discussion and I'm fine with the direction everybody's taking here. The concerns that I had regarding the implementation itself; I raised in the review for the code and the responses/solution were addressed so I don't have a problem.<div>
<br></div><div>I just want to urge folks to make sure we document this VERY well. There are all sorts of corner cases, caveats etc that this has the potential to raise. For example, if somebody is using a back-end device that has internal encryption features, then you turn around and try to overlay the nova encryption changes on top of it. The absolute destruction that this will cause on some de-duplication algorithms depending again on the back-end.</div>
<div><br></div><div>I really could care less about what algorithm is used etc, I think the folks involved in this thread have plenty of expertise in this area and I leave that up to them. I just think as has been pointed out we need to stress via documentation and communication to folks that there are significant risks and possible issues if they choose to turn this on without a good understanding of exactly how it works etc.</div>
<div><br></div><div>John</div>