From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 309EB25A642; Sat, 9 May 2026 18:41:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778352113; cv=none; b=XwkXRDXLamyE5GDvnqd26dMdJyXnpTeg4EnRVpYJimhC9RSFDEN+Kv8lcucr3V3175PyhzknfuW/zkud7ncsM7eQYm9yryCAGtum9nmu4Bvt6pKIJNqPznuy9jxQ8VO4ENDRm9r7aaU4yyGCSHiTn/6Za9XuCFotVXXN3W9yVwA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778352113; c=relaxed/simple; bh=5x6vMZJIgP2JV5U0sf4/3UHVPYatudGhzTthPLFbE1o=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dsjT+N+pTcUsXzF/1YmrJw4rYLJs1ue3KX95VLlK9OpwU6zlcsTGl9+hArlzQKxPxUwMwrxnoTDhaosoIEjkC9/K42Zd1SWSvtcTfeUek/WlEoJV3b7QUYKnP0Yt5haTkDBbNvXf409tkvuXf5g+g4xtadWf90X5p8yZknxbPKk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AyJ5rWZI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AyJ5rWZI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 626DCC2BCB2; Sat, 9 May 2026 18:41:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778352112; bh=5x6vMZJIgP2JV5U0sf4/3UHVPYatudGhzTthPLFbE1o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=AyJ5rWZIJlvuab7tohPZ8gd7mvCmDxDNq/R998ABZKL2siI3NOIG5fVudgG+OtgJY hNTUVyvIvpVN/IQQdxRB0+xP/TMJRVoi4EUtUA9zmVEOnLlC+vDDBS5mNaY7+I/dwr hznqQ4FgC5RYcm8MWrDvOtf/Pkv/CkE/xcb+X86Cdtdz9lUKt4BxTT5TVtiwSMORdC ICxc/QlGkB2kaXTTOyXicZiiO/mwafgH6knNICANk6kNsvg+SIaNU+HmB0pF1Ii/hd e1njZm9xgEXduDH3ASCwWoCuo+GNQ7ZjjCl57klRJMYkkNb3TMaHVz2azJGCgvPWl9 6IvHRup/FfYXQ== Date: Sat, 9 May 2026 11:41:44 -0700 From: Eric Biggers To: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Ard Biesheuvel , "Jason A . Donenfeld" , Herbert Xu , linuxppc-dev@lists.ozlabs.org, Michael Ellerman , Madhavan Srinivasan , Nicholas Piggin , Christophe Leroy Subject: Re: [PATCH v2] lib/crypto: powerpc/md5: Drop powerpc optimized MD5 code Message-ID: <20260509184144.GB11883@quark> References: <20260506030005.9698-1-ebiggers@kernel.org> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260506030005.9698-1-ebiggers@kernel.org> On Tue, May 05, 2026 at 08:00:05PM -0700, Eric Biggers wrote: > MD5 is obsolete, is vulnerable to collision attacks, and is being > replaced by SHA-256 in new systems. It doesn't make sense to continue > to maintain architecture-optimized implementations of MD5. Effort > should be spent on modern algorithms. > > Indeed, architecture-optimized MD5 code remains only for powerpc. It > was already removed from mips and sparc, and it never existed for any > other architecture (e.g. x86, arm, or arm64) in the first place. > Earlier the decision was made to keep the powerpc MD5 code for a while > anyway because of someone using it via AF_ALG via libkcapi-hasher > (https://lore.kernel.org/r/f0d771d5-ed70-444c-957a-ad4c16f6c115@csgroup.eu/) > > However, with AF_ALG itself now being on its way out due to its > continuous stream of security vulnerabilities > (https://lore.kernel.org/r/20260430011544.31823-1-ebiggers@kernel.org/), > it's also time to be a bit more forceful with nudging people towards > userspace crypto code. It's always been the better solution anyway, and > it's much more efficient if properly optimized code is used. > > Note that the md5-asm.S file contains no privileged instructions and > could be run in userspace just fine. > > Thus, we now have two factors going against keeping the powerpc MD5 > code. Different people might weigh these two factors differently, but I > think the two of them together make the removal the clear choice. > > Let's remove it. > > Acked-by: Christophe Leroy (CS GROUP) > Acked-by: Ard Biesheuvel > Signed-off-by: Eric Biggers > --- > > This patch is intended to be taken via libcrypto-next Applied to https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git/log/?h=libcrypto-next - Eric