URL: https://github.com/SSSD/sssd/pull/837
Title: #837: p11_child: make OCSP digest configurable

alexey-tikhonov commented:
"""
> 
> @alexey-tikhonov -
> 
> Re you comment https://bugzilla.redhat.com/show_bug.cgi?id=1718478#c2
> 
> OCSP responders are NOT guaranteed to accept SHA2 hash types, and depends on 
> the deployment's configuration. We have encountered an issue where an OCSP 
> responder configured for only SHA1 will deny entry to a system when SHA256 is 
> not enabled.

Could you please check if using `ocsp_dgst=sha1` helps?

> Looking thru the RFC, I don't see mention of a responder to be required to 
> answer for all hash types.
> 
> I'm sure we're not the only ones noticing this change has broken PKI 
> authentication, and it may be prudent for p11_child to attempt a fallback 
> back down to SHA1 if SHA2 OCSP request fails unauthorized.

But that would be against our intent.


> Also, I've not been able to locate the language in FIPS140 that bans SHA1's 
> use. Could you please refer to this in the standards document?

I think strictly speaking SHA-1 is still allowed for a limited uses (like 
`HMAC-SHA-1`) by FIPS 140-2, but intention is clearly to ged rid of it.
Quick search yields things like 
https://www.stigviewer.com/stig/application_security_and_development/2017-12-18/finding/V-70193
 :
```
While SHA1 is currently FIPS-140-2 approved, due to known vulnerabilities with 
this algorithm, DoD PKI policy prohibits the use of SHA1 as of December 2016.
```
etc.

For this reason it was made configurable, defaults changed to more secure 
option, but sha-1 is still allowed to be configured explicitly.
"""

See the full comment at 
https://github.com/SSSD/sssd/pull/837#issuecomment-672847772
_______________________________________________
sssd-devel mailing list -- [email protected]
To unsubscribe send an email to [email protected]
Fedora Code of Conduct: 
https://docs.fedoraproject.org/en-US/project/code-of-conduct/
List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
List Archives: 
https://lists.fedorahosted.org/archives/list/[email protected]

Reply via email to