Re: [PATCH v43 01/15] Linux Random Number Generator

[Jason A. Donenfeld]

On Mon, Jan 10, 2022 at 9:18 PM Theodore Ts'o <tytso@xxxxxxx> wrote:
> In general, you need FIPS
> certification for some specific use cases / application.  For example,
> if you're going for PCI compliance, then you might only need FIPS
> compliance for your OpenSSL library.  What the FIPS certification lab
> might consider acceptable for its entropy for its DRBG is an
> interesting question.  For some, simply having the OpenSSL library use
> RDSEED or RDRAND might be sufficient.  Or it could talk to an actual
> physical RNG device.
>
> So disabling getrandom() is probably not necessary, just so long as
> you can demonstrate that the FIPS cryptographic module --- i.e., the
> OpenSSL library --- is getting its entropy from an acceptable source.

I don't know exactly what these people think they want, but what you
say seems probably correct.

> I suspect what's actually going on is that some enterprise customers
> have FIPS complaince on a check-off list, and they aren't actually
> getting a formal FIPS certification.  Or they only need something to
> wave under the noses of their PCI certification company, and so the
> question is what makes them happy.

Right.

> And this is why some FIPS certification have gotten by just *fine*
> with a pure userspace OpenSSL library as their FIPS cryptographic
> module.  Where you draw the line between a "blessed" entropy source
> and one that's just hand-waving is really at the discretion of the
> certification lab.

Hah, probably correct.

So, seen this way, and combined with the solution provided at [1] (or
similar) for people who think they need something there, it seems like
the FIPS people can likely get what they need without really needing
to involve the kernel anyway.

Jason

[1] https://lore.kernel.org/lkml/YdynXjhhuQfbYuSb@xxxxxxxxx/