From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.jvdsn.com (smtp.jvdsn.com [129.153.194.31]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0B90D235358; Thu, 10 Sep 2026 03:33:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=129.153.194.31 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789011233; cv=none; b=SA823bCacqyN9vnurS8GiS+IRGCoK8scyu9jJZbVIdsTOtwdg0u4PeoxZ/TgaTzdFDkUAdU582kw80Gv24A5FpqDG1JPAg8+OYlXFuFhe4STjEBq0lTC0Wzy5yd5fZVbo7KmztKKxrvosRHn1NLonAt4Igon5AdDj0wODe5igdw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789011233; c=relaxed/simple; bh=OSmlZrTtowYwV7CqDLWVt9GCCCLsHOffm7LbDvdbciM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=T8CSBBRAUzwHJODZNxUOnVMkMqETejnLhX4aDBDmxaVrPm0k3zISw0a53fXaSk9jqa+mH2SDqJLfgHHnylAZjdcSx/+tFWidl03Z9qf0DO61lu52b+/5DN6JUxypjfm34DFXxVukdUuEbLsufn4BfUq44LU1sgFbnLQ3i5w5VTY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=jvdsn.com; spf=pass smtp.mailfrom=jvdsn.com; dkim=pass (2048-bit key) header.d=jvdsn.com header.i=@jvdsn.com header.b=HMl5re/5; arc=none smtp.client-ip=129.153.194.31 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=jvdsn.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=jvdsn.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=jvdsn.com header.i=@jvdsn.com header.b="HMl5re/5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=jvdsn.com; s=mail; t=1789010683; bh=OSmlZrTtowYwV7CqDLWVt9GCCCLsHOffm7LbDvdbciM=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=HMl5re/5pdfhQrloFTxpSn/Wk9I1N8fBDHCI6Ld7/Mg7K+E2nnE8xYPUFEzyE2KRY u0NV9bNtzXgBAKx7ZRR/FsDbpZQSYHWx42SDjwhEVFbr5ylQBqcMCSPLFX1L/lmv7Y hh8iWN+Zr6v1wDM9hD/iSLa73K00w4EJyM2tWF9xB8oFOQhiM5KWtY6do013FIdpCJ kYTfsi+G219Xs1QFuj6tTQ8O3qPSzJDAvaqNj4I5zwDc0/JnoNhHN+/ZxhsgRzIuYF RrKLLKluVok3nHmgNN18D5yI59CfAFvWCbdZcPLR4dq78IoP2vuAAMECDfYLSGEKXw yg5zRNbaS8t3A== Message-ID: <83d09aa1-729a-47a2-a8e9-381c74e92f42@jvdsn.com> Date: Wed, 9 Sep 2026 22:24:42 -0500 Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH] crypto: testmgr - block Crypto API xxhash64 in FIPS mode To: Thomas Huth Cc: "David S. Miller" , Maxime Coquelin , Alexandre Torgue , linux-crypto@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Herbert Xu References: <20260303060509.246038-1-git@jvdsn.com> <64592fee-1956-4a70-a751-9ac3335cfc27@jvdsn.com> <9926908a-5f08-43ba-99dd-b83c7067d52b@redhat.com> From: Joachim Vandersmissen Content-Language: en-US In-Reply-To: <9926908a-5f08-43ba-99dd-b83c7067d52b@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi Thomas, On 9/9/26 9:36 AM, Thomas Huth wrote: > On 15/03/2026 01.43, Joachim Vandersmissen wrote: >> Hi Herbert, >> >> I don't think this one can be applied yet since dm-integrity still >> uses xxhash64 through the crypto API. This would break fips=1 systems >> that use it. > > Out of curiosity: Wouldn't such a system be FIPS-incompliant anyway? > If xxhash64 isn't FIPS-compliant, nobody should use it for > dm-integrity there, right? So I doubt that there are any systems out > there that use fips=1 and use xxhash64 at the same time? There is a risk that users may not know that xxhash64 is not FIPS compliant and would still use it. Especially considering it was marked as "fips_allowed = 1" for a while. Distributions that actually need FIPS validation will probably apply this patch anyway and deal with the breakage if it happens. > >  Thomas > >> >> On 3/14/26 12:11 AM, Herbert Xu wrote: >>> On Tue, Mar 03, 2026 at 12:05:09AM -0600, Joachim Vandersmissen wrote: >>>> xxhash64 is not a cryptographic hash algorithm, but is offered in the >>>> same API (shash) as actual cryptographic hash algorithms such as >>>> SHA-256. The Cryptographic Module Validation Program (CMVP), managing >>>> FIPS certification, believes that this could cause confusion. xxhash64 >>>> must therefore be blocked in FIPS mode. >>>> >>>> The only usage of xxhash64 in the kernel is btrfs. Commit fe11ac191ce0 >>>> ("btrfs: switch to library APIs for checksums") recently modified the >>>> btrfs code to use the lib/crypto API, avoiding the Kernel >>>> Cryptographic >>>> API. Consequently, the removal of xxhash64 from the Crypto API in FIPS >>>> mode should now have no impact on btrfs usage. >>>> >>>> Signed-off-by: Joachim Vandersmissen >>>> --- >>>>   crypto/testmgr.c | 1 - >>>>   1 file changed, 1 deletion(-) >>> Patch applied.  Thanks. >> >