Re: [RFC PATCH v7 07/16] ipe: add auditing support

[Deven Bowers]

On 10/15/2021 12:50 PM, Randy Dunlap wrote:
> On 10/15/21 12:25 PM, Deven Bowers wrote:
> > On 10/13/2021 3:54 PM, Randy Dunlap wrote:
> > > Hi,
> > >
> > > On 10/13/21 12:06 PM, deven.desai@xxxxxxxxxxxxxxxxxxx wrote:
> > > > diff --git a/security/ipe/Kconfig b/security/ipe/Kconfig
> > > > index c4503083e92d..ef556b66e674 100644
> > > > --- a/security/ipe/Kconfig
> > > > +++ b/security/ipe/Kconfig
> > > > @@ -17,3 +17,55 @@ menuconfig SECURITY_IPE
> > > >         requirements on the fly.
> > > >           If unsure, answer N.
> > > > +
> > > > +if SECURITY_IPE
> > > > +
> > > > +choice
> > > > +    prompt "Hash algorithm used in auditing policies"
> > > > +    default IPE_AUDIT_HASH_SHA1
> > > > +    depends on AUDIT
> > > > +    help
> > > > +        Specify the hash algorithm used when auditing policies.
> > > > +        The hash is used to uniquely identify a policy from other
> > > > +        policies on the system.
> > > > +
> > > > +        If unsure, leave default.
> > > > +
> > > > +    config IPE_AUDIT_HASH_SHA1
> > > > +        bool "sha1"
> > > > +        depends on CRYPTO_SHA1
> > > > +        help
> > > > +            Use the SHA128 algorithm to hash policies
> > > > +            in the audit records.
> > > > +
> > > > +    config IPE_AUDIT_HASH_SHA256
> > > > +        bool "sha256"
> > > > +        depends on CRYPTO_SHA256
> > > > +        help
> > > > +            Use the SHA256 algorithm to hash policies
> > > > +            in the audit records.
> > > > +
> > > > +    config IPE_AUDIT_HASH_SHA384
> > > > +        bool "sha384"
> > > > +        depends on CRYPTO_SHA512
> > > > +        help
> > > > +            Use the SHA384 algorithm to hash policies
> > > > +            in the audit records
> > > > +
> > > > +    config IPE_AUDIT_HASH_SHA512
> > > > +        bool "sha512"
> > > > +        depends on CRYPTO_SHA512
> > > > +        help
> > > > +            Use the SHA512 algorithm to hash policies
> > > > +            in the audit records
> > > > +endchoice
> > > > +
> > > > +config IPE_AUDIT_HASH_ALG
> > > > +    string
> > > > +    depends on AUDIT
> > > > +    default "sha1" if IPE_AUDIT_HASH_SHA1
> > > > +    default "sha256" if IPE_AUDIT_HASH_SHA256
> > > > +    default "sha384" if IPE_AUDIT_HASH_SHA384
> > > > +    default "sha512" if IPE_AUDIT_HASH_SHA512
> > > > +
> > > > +endif
> > >
> > > Please follow coding-style for Kconfig files:
> > >
> > > (from Documentation/process/coding-style.rst, section 10):
> > >
> > > For all of the Kconfig* configuration files throughout the source tree,
> > > the indentation is somewhat different.  Lines under a ``config`` 
> > > definition
> > > are indented with one tab, while help text is indented an additional 
> > > two
> > > spaces.
> > Oof. That's embarrassing. Sorry, I'll fix this for v8.
> >
> > While I'm at it, is the help text required for choice configs?
> > checkpatch --strict complains with a warning without them, but
> > I see other places in the tree where help text is omitted for
> > these configs attached to a choice.
>
> Does checkpatch complain about what you have above
> or did you add that help text to keep it from complaining?

I added the help text to keep it from complaining (and added it incorrectly,
clearly).

> > Documentation/process/* doesn't seem to have any guidance, nor
> > Documentation/kbuild/* on whether it is safe to ignore that
> > checkpatch warning.
>
> Yeah, I don't think that we have any good guidance on that.
>
> I would say that if the choice prompt provides good/adequate
> help info, then each 'config' inside the choice block does not
> need help text. OTOH, if the choice prompt has little/no help
> info, then each 'config' under it should have some useful info.
>
> I only looked in arch/x86/Kconfig, init/Kconfig, and lib/Kconfig.debug,
> but you can see either help text method being used in those.
>
> And then if the help text is adequate in either one of those
> methods, I would just ignore the checkpatch complaints.
> It's just a guidance tool.

Alright. I think the choice guidance is pretty clear:

   Specify the hash algorithm used when auditing policies.
   The hash is used to uniquely identify a policy from other
   policies on the system.

So I'll remove the help text for these choices.

At worst, I can make the choice text more clear.
> HTH.