BIND 9.18.6 disables RSASHA1 at runtime?

[Petr Menšík]

On 9/2/22 14:23, Bjørn Mork wrote:
> Mark Andrews <marka at isc.org> writes:
>
>> We don’t log rsamd5 is disabled now ec or ed curves when they are not
>> supported by the crypto provider. Why should rsasha1 based algs be
>> special?
> Because RSASHA1 validation still is a MUST in RFC8624? MD5 is and ED is
> not.
>
> I don't know if disabled EC curves is a real world problem, but
> ECDSAP256SHA256 is also a MUST and should get the same treatment.
>
> IMHO you should not allow the server to start up with a non-compliant
> configuration without making sure the adminstrator is aware of the
> problem.  A log warning is sort of a minimum.  Personally I'd prefer the
> server to die by default.  It is unsuitable as a validating resolver and
> forcing adminstrators to find that out the hard way is not very nice.
>
>
> Bjørn

I do not think all servers should fail to start on CentOS Stream 9, 
RHEL9 and derivates. Yes, I have hit too it does not report at all which 
algorithms are ready to use. But DEFAULT crypto policy on those 
distributions simply do not allow validation of SHA-1 based signatures 
to succeed. It is suitable for all other algorithms so I disagree that 
without algorithms 5 and 7 it is not usable at all. Majority of secured 
domains use stronger algorithms already.

I think it might report at least single line with a list of successfuly 
initialized algorithms. So it would not report RSASHA1 is not available, 
but a list of algorithms which are available in this build AND runtime 
environment. I think such list would be short enough.

Administrators should be aware of those issues by reading release notes 
on affected distributions. They should not be surprised so much.

Regards,
Petr