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From: Chris von Recklinghausen <crecklin@redhat.com>
To: David Laight <David.Laight@ACULAB.COM>,
	"ardb@kernel.org" <ardb@kernel.org>,
	"simo@redhat.com" <simo@redhat.com>,
	"rafael@kernel.org" <rafael@kernel.org>,
	"decui@microsoft.com" <decui@microsoft.com>,
	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
	"linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4 1/1] use crc32 instead of md5 for hibernation e820 integrity check
Date: Fri, 9 Apr 2021 15:28:15 -0400	[thread overview]
Message-ID: <822eaebf-4ef9-d469-4238-54107c8ba6a6@redhat.com> (raw)
In-Reply-To: <6be63531313d46caa7161697bf240dfc@AcuMS.aculab.com>

On 4/9/21 12:56 PM, David Laight wrote:
> From: Chris von Recklinghausen
>> Sent: 08 April 2021 11:46
>>
>> Suspend fails on a system in fips mode because md5 is used for the e820
>> integrity check and is not available. Use crc32 instead.
>>
>> Prior to this patch, MD5 is used only to create a digest to ensure integrity of
>> the region, no actual encryption is done. This patch set changes the integrity
>> check to use crc32 instead of md5 since crc32 is available in both FIPS and
>> non-FIPS modes.
>>
>> Note that the digest is only used as an integrity check. No actual encryption
>> is done.
> If crc32 is good enough, would a 1's compliment sum be good enough?
> It is likely to be faster to calculate and not need special
> functions be built into the kernel at all.


Eric Biggers <ebiggers@kernel.org> suggested using crc32_le() which is 
in the library interface (lib/crc32.c) and will always be available 
without any special ifdefs. That's what my next version will be based on.

Thanks,

Chris


>
> 	David
>
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)
>


      reply	other threads:[~2021-04-09 19:28 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-08 10:46 [PATCH v4 1/1] use crc32 instead of md5 for hibernation e820 integrity check Chris von Recklinghausen
2021-04-08 13:01 ` Simo Sorce
2021-04-09 16:56 ` David Laight
2021-04-09 19:28   ` Chris von Recklinghausen [this message]

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