Re: [PATCH] crypto: HMAC - disallow keys < 112 bits in FIPS mode

["Stephan Müller" <smueller@chronox.de>]

Am Samstag, 8. Januar 2022, 00:28:31 CET schrieb Eric Biggers:

Hi Eric,

> Hi Stephan,
> 
> On Fri, Jan 07, 2022 at 08:25:24PM +0100, Stephan Müller wrote:
> > FIPS 140 requires a minimum security strength of 112 bits. This implies
> > that the HMAC key must not be smaller than 112 in FIPS mode.
> > 
> > This restriction implies that the test vectors for HMAC that have a key
> > that is smaller than 112 bits must be disabled when FIPS support is
> > compiled.
> > 
> > Signed-off-by: Stephan Mueller <smueller@chronox.de>
> 
> This could make sense, but the weird thing is that the HMAC code has been
> like this from the beginning, yet many companies have already gotten this
> exact same HMAC implementation FIPS-certified.  What changed?

FIPS 140-3 (which is now mandatory) requires this based on SP800-131A.
> 
> - Eric


Ciao
Stephan