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Re: Win2000 IKE and 3des
In message <14620.26714.300239.321461@xedia.com>, Paul Koning writes:
>>>>>> "Sumi" == Sumi Singh <sumis@Exchange.Microsoft.com> writes:
>
> Sumi> Just to clarify the behaviour of Windows 2000 - Windows 2000
> Sumi> weakens 3DES policy to DES if you do not have the strong
> Sumi> encryption pack (128-bit) installed. This weakening is
> Sumi> announced by an event in the Audit log. So if you have 2 peers
> Sumi> with no encryption pack installed, and a policy to use 3DES,
> Sumi> they will talk DES since they cannot do 3DES.
>
>Clearly that's a major design error.
>
>If you ask for something that's not supported, it should be rejected.
>To change it (even with a message in some obscure log) is clearly
>wrong. You don't build secure systems that way.
Absolutely. If you can't handle a requested security policy, say so,
but don't lie to the application.
This is *seriously* brain-damaged. I've given up expecting good
software design from Microsoft (actually, from most vendors), since
they (and everyone else) are far too arrogant about their abilities to
design and write error-free code, but this goes above and beyond the
call of duty. Users who request 3DES do so because (rightly or
wrongly) they perceive a threat model that DES can't counter. Why is
their reasoning invalide? Certainly, they may decide to use DES instead
of being unable to communicate, but surely that's their decision, not
Microsoft's? Tell me, what do you do if the exportable
end system is old and doesn't even support DES? Use 40-bit toys? Send
authenticated plaintext?
I'm glad to hear that this fatally flawed decision will be fixed. But
it's not a simple upgrade; it's a glaring bug by the design team (as
opposed to the coding team), and should be treated as such, with an
immediate fix and corresponding public announcement.
--Steve Bellovin