Re: Fix hibernation in FIPS mode?

On Tue, 2021-03-30 at 16:46 +0200, Rafael J. Wysocki wrote:

On Tue, Mar 30, 2021 at 12:14 AM Dexuan Cui [off-list ref] wrote:

quoted

Hi,
MD5 was marked incompliant with FIPS in 2009:
a3bef3a31a19 ("crypto: testmgr - Skip algs not flagged fips_allowed in fips mode")
a1915d51e8e7 ("crypto: testmgr - Mark algs allowed in fips mode")

But hibernation_e820_save() is still using MD5, and fails in FIPS mode
due to the 2018 patch:
749fa17093ff ("PM / hibernate: Check the success of generating md5 digest before hibernation")

As a result, hibernation doesn't work when FIPS is on.

Do you think if hibernation_e820_save() should be changed to use a
FIPS-compliant algorithm like SHA-1?

I would say yes, it should.

quoted

PS, currently it looks like FIPS mode is broken in the mainline:
https://www.mail-archive.com/linux-crypto@vger.kernel.org/msg49414.html

FYI, SHA-1 is not a good choice, it is only permitted in HMAC
constructions and only for specified uses. If you need to change
algorithm you should go straight to SHA-2 or SHA-3 based hashes.

HTH,
Simo.

-- 
Simo Sorce
RHEL Crypto Team
Red Hat, Inc