[cabfpub] Microsoft SHA-1 deprecation problem for Kernel Mode Code Signing

Rob Stradling rob.stradling at comodo.com
Wed Nov 13 12:18:17 UTC 2013

Tom, Kelvin,

I know you're already aware that Windows Vista and Windows 7 are unable 
to use SHA-2 certificates for Kernel Mode Code Signing.

Your SHA-1 deprecation advisory [1] says:
"Recommendation: Microsoft recommends that certificate authorities no 
longer sign newly generated certificates using the SHA-1 hashing 
algorithm and begin migrating to SHA-2. Microsoft also recommends that 
customers replace their SHA-1 certificates with SHA-2 certificates at 
the earliest opportunity."

I understand this to mean that, ideally, you'd like us to switch from 
SHA-1 to SHA-2 _today_, for the issuance of new SSL certificates and 
Code Signing Certificates.

Does this mean that you've managed to hotfix all deployed Vista/7 boxes 
on the planet, so that SHA-2 certificates can now be used for Kernel 
Mode Code Signing?

If not, how do you intend to address this issue?

(I presume you're not phasing out Windows 7 at the same time as phasing 
out SHA-1!!)

[1] https://technet.microsoft.com/en-us/security/advisory/2880823

Rob Stradling
Senior Research & Development Scientist
COMODO - Creating Trust Online

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