Re: [certid] Domain Components

[Paul Hoffman <[e-mail]>]

At 2:54 PM -0600 6/11/10, Peter Saint-Andre wrote:
>Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1; boundary="------------ms020609010501090708040406"
>
>Version -05 of draft-saintandre-tls-server-id-check has some warning
>text about Domain Components (DCs). However, the more I delve the matter
>the less I think that we need to warn people away from using DCs from a
>security perspective. The problem with them would arise from confusion
>about the order of DCs based on the string representation, however that
>kind of confusion is possible for any RDNs and is not limited to DCs (so
>follow the DER order, not the string order). There might be other
>reasons to discourage DCs, but so far I have not heard them, so I'm
>inclined to remove the warnings from -06.
>
>Do speak up if you're concerned about this proposal.

Finally decloaking after being off this topic for a while.

I am *quite* concerned about this. The DC ordering problem is not "based on the string representation": it is because the set of DCs can be read *by the program* in two directions. For example, think about  a cert with "dc=com dc=net". Both net.com and com.net exist today. For different applications, that one cert could apply to two completely different domains.