Re: [Anima] CRLs in iDevID manufacturer signing certs?

[Michael Richardson]

Eliot Lear  wrote:
> What is the thinking on including CRL pointer in the manufacturer
> signing cert?  This question came up in industry discussions.

Kent Watsen  wrote:
> 802.1AR says that the IDevID secrets must be stored confidentially and
> be not available outside the module.  In practice, a crypto processor
> with tamper-resistant NVRAM is used (e.g., TPM).  As such, the
> likelihood of the credentials being stolen/discovered are near zero,
> but it is not zero, as a determined adversary with sufficient resources

While 802.1AR would like this, I think that the BRSKI mechanism we are
describing (and re-interpreting for constrained environments in 6tisch) are
very unlikely to have serious tamper-resistant mechanisms for the IDevID
that are seperate from the system in general.

Revoking the IDevID would be useful, but it might be that the MASA can
effect the same thing by refusing to issue an ownership voucher.
This only works if ownership vouchers are to be issued online, or
they can be revoked.   This doesn't solve the same problem, but it may have
the same result.

I am also concerned about how many bytes a CRL pointer requires.  I'm
guessing it's on the order of 50 bytes for the URL and container.



--
Michael Richardson , Sandelman Software Works
 -= IPv6 IoT consulting =-





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Re: [Anima] CRLs in iDevID manufacturer signing certs?

[Kent Watsen]

My view is that, if the IDevID has a CRL/OCSP URL listed, then the
validator SHOULD do the checking.  If the vendor didn't actually
want revocation checking done, then the vendor should've excluded
such information from their IDevID certs.

FWIW, 802.1AR takes a much neutral stance in Section 6.5.3 (Validation of 
DevIDs):

  The DevID is an X.509 credential and can be validated using the
  RFC 5280 defined mechanisms. IDevIDs are intended to have very
  long validity periods even exceeding what would normally be
  cryptographically acceptable. The manufacturer is not required
  to provide a Certificate Revocation List (CRL) although the
  validator may do CRL checking if the manufacturer provides CRLs.
  The validator may verify CRLs for LDevIDs as necessary.

Kent


-ORIGINAL MESSAGE-

Thanks, Kent.  Then it seems to me that we have a MAY floating around
for CRL checking on the part of the registrar for BRSKI.  Right?

Eliot


On 3/9/17 7:25 PM, Kent Watsen wrote:
> Hi Elliot,
>
>
>> What is the thinking on including CRL pointer in the manufacturer
>> signing cert?  This question came up in industry discussions.
> 802.1AR says that the IDevID secrets must be stored confidentially and be not 
> available outside the module.  In practice, a crypto processor with 
> tamper-resistant NVRAM is used (e.g., TPM).  As such, the likelihood of the 
> credentials being stolen/discovered are near zero, but it is not zero, as a 
> determined adversary with sufficient resources can still have their way with 
> it.  Still, vendors will likely conclude that protecting against that level 
> of attack isn't necessary.  That said, vendors face a more likely scenario, 
> of issues occurring by contract manufacturers, whether it be accidental or 
> intentional.  And as unlikely this scenario may seem, things happen and the 
> vendor would be without recourse if unable to issue revocations.  To this 
> extent, setting up the infrastructure to support revocations can be compared 
> to insurance - hopefully you never need it, but when you do, you're glad you 
> have it.
>
> Kent
>
>
>
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Re: [Anima] CRLs in iDevID manufacturer signing certs?

[Eliot Lear]

Thanks, Kent.  Then it seems to me that we have a MAY floating around
for CRL checking on the part of the registrar for BRSKI.  Right?

Eliot


On 3/9/17 7:25 PM, Kent Watsen wrote:
> Hi Elliot,
>
>
>> What is the thinking on including CRL pointer in the manufacturer
>> signing cert?  This question came up in industry discussions.
> 802.1AR says that the IDevID secrets must be stored confidentially and be not 
> available outside the module.  In practice, a crypto processor with 
> tamper-resistant NVRAM is used (e.g., TPM).  As such, the likelihood of the 
> credentials being stolen/discovered are near zero, but it is not zero, as a 
> determined adversary with sufficient resources can still have their way with 
> it.  Still, vendors will likely conclude that protecting against that level 
> of attack isn't necessary.  That said, vendors face a more likely scenario, 
> of issues occurring by contract manufacturers, whether it be accidental or 
> intentional.  And as unlikely this scenario may seem, things happen and the 
> vendor would be without recourse if unable to issue revocations.  To this 
> extent, setting up the infrastructure to support revocations can be compared 
> to insurance - hopefully you never need it, but when you do, you're glad you 
> have it.
>
> Kent
>
>
>
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> Anima mailing list
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> https://www.ietf.org/mailman/listinfo/anima
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Re: [Anima] CRLs in iDevID manufacturer signing certs?

[Kent Watsen]

Hi Elliot,


> What is the thinking on including CRL pointer in the manufacturer
> signing cert?  This question came up in industry discussions.

802.1AR says that the IDevID secrets must be stored confidentially and be not 
available outside the module.  In practice, a crypto processor with 
tamper-resistant NVRAM is used (e.g., TPM).  As such, the likelihood of the 
credentials being stolen/discovered are near zero, but it is not zero, as a 
determined adversary with sufficient resources can still have their way with 
it.  Still, vendors will likely conclude that protecting against that level of 
attack isn't necessary.  That said, vendors face a more likely scenario, of 
issues occurring by contract manufacturers, whether it be accidental or 
intentional.  And as unlikely this scenario may seem, things happen and the 
vendor would be without recourse if unable to issue revocations.  To this 
extent, setting up the infrastructure to support revocations can be compared to 
insurance - hopefully you never need it, but when you do, you're glad you have 
it.

Kent



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[Anima] CRLs in iDevID manufacturer signing certs?

[Eliot Lear]

Hi,

What is the thinking on including CRL pointer in the manufacturer
signing cert?  This question came up in industry discussions.

Eliot




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