From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.secunet.com (mx1.secunet.com [62.96.220.36]) (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 7F0E4224B04; Wed, 8 Apr 2026 09:34:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.96.220.36 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775640889; cv=none; b=aaGLJzr91Y9N6AtAGwHCD1fZDIdWiiW87ge6+qAkM9a4805vx7/aPlFSHiJ1opC7K2aV2eAhTHFH0xvBQhWbq12MaBPbYe6YxBAaKE0eagh+FxcvpRp5f+r10JPdyZUP9b0yQ3W5vEGzghgmMwgqUBpiiVRxbIn5lLG2fIFevO0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775640889; c=relaxed/simple; bh=R/b1bc5OVvwE31LlF+wFK+5d+Ru91KTenrJH4/xCRr4=; h=Date:From:To:CC:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jgaWfyFmY+wmBiYr8Rc8e8nhg2TO7Cl1MILyMTmRjovHRtpL760NuGuIUV4Z1Yt1gePOBrtM0SBysUKcMkOlA1ulUdFRxendN6mNdFJkFu1ghyds5Xteib+JBmJKSvlFHlw6jq1SNqgKmdyQbWqyohEsBOQ+WkIzl0PmInHt9do= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=secunet.com; spf=pass smtp.mailfrom=secunet.com; dkim=pass (2048-bit key) header.d=secunet.com header.i=@secunet.com header.b=ymtEqxe6; arc=none smtp.client-ip=62.96.220.36 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=secunet.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=secunet.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=secunet.com header.i=@secunet.com header.b="ymtEqxe6" Received: from localhost (localhost [127.0.0.1]) by mx1.secunet.com (Postfix) with ESMTP id F2BF020728; Wed, 8 Apr 2026 11:34:46 +0200 (CEST) X-Virus-Scanned: by secunet Received: from mx1.secunet.com ([127.0.0.1]) by localhost (mx1.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id AbnceWvLlMfr; Wed, 8 Apr 2026 11:34:46 +0200 (CEST) Received: from EXCH-01.secunet.de (rl1.secunet.de [10.32.0.231]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.secunet.com (Postfix) with ESMTPS id 21BA2201D5; Wed, 8 Apr 2026 11:34:46 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.secunet.com 21BA2201D5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=secunet.com; s=202301; t=1775640886; bh=zS79HN+MwePvO/pYvOblADFlSrM4jAhkaN0vzpnyOS8=; h=Date:From:To:CC:Subject:References:In-Reply-To:From; b=ymtEqxe69DCmzevK5Ljizo2/qDSyJgxcb9M4EGhl2jM5po49jngpcItxeADk2mAd1 GPdwysYdHLIeXsgjl8OVk8Rlf7zrZlmHwapuUKWRoEeoe2mJeTe0k7u8YnFG+PlpEn PrbZslM/YrlOghjS1u3Om/dtKhFA03FUG4pM8vnb7IO7foyQkZH1hC8AWH+hLdqYW+ nkkKGCuoa2dVWzUMn7+TohzR+xZxFpMwRYHxn22bq7SK6Zv2yBeQAIYwWKS/7Noo+j Q5OTu6x0TUsGOgoei9FG2DlP5UM9RwLpsqg3RPcBO/JkpPShGtV/suoh+qE4ku+mcx 5Ojrkn30wNGEg== Received: from secunet.com (10.182.7.193) by EXCH-01.secunet.de (10.32.0.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.17; Wed, 8 Apr 2026 11:34:45 +0200 Received: (nullmailer pid 95933 invoked by uid 1000); Wed, 08 Apr 2026 09:34:44 -0000 Date: Wed, 8 Apr 2026 11:34:44 +0200 From: Steffen Klassert To: Eric Biggers CC: , Herbert Xu , "David S. Miller" , , Subject: Re: [PATCH ipsec-next] xfrm: Drop support for HMAC-RIPEMD-160 Message-ID: References: <20260405011513.64909-1-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: <20260405011513.64909-1-ebiggers@kernel.org> X-ClientProxiedBy: EXCH-01.secunet.de (10.32.0.171) To EXCH-01.secunet.de (10.32.0.171) On Sat, Apr 04, 2026 at 06:15:13PM -0700, Eric Biggers wrote: > Drop support for HMAC-RIPEMD-160 from IPsec to reduce the UAPI surface > and simplify future maintenance. It's almost certainly unused. > > RIPEMD-160 received some attention in the early 2000s when SHA-* weren't > quite as well established. But it never received much adoption outside > of certain niches such as Bitcoin. > > It's actually unclear that Linux + IPsec + HMAC-RIPEMD-160 has *ever* > been used, even historically. When support for it was added in 2003, it > was done so in a "cleanup" commit without any justification [1]. It > didn't actually work until someone happened to fix it 5 years later [2]. > That person didn't use or test it either [3]. Finally, also note that > "hmac(rmd160)" is by far the slowest of the algorithms in aalg_list[]. > > Of course, today IPsec is usually used with an AEAD, such as AES-GCM. > But even for IPsec users still using a dedicated auth algorithm, they > almost certainly aren't using, and shouldn't use, HMAC-RIPEMD-160. > > Thus, let's just drop support for it. Note: no kconfig update is > needed, since CRYPTO_RMD160 wasn't actually being selected anyway. > > References: > [1] linux-history commit d462985fc1941a47 > ("[IPSEC]: Clean up key manager algorithm handling.") > [2] linux commit a13366c632132bb9 > ("xfrm: xfrm_algo: correct usage of RIPEMD-160") > [3] https://lore.kernel.org/all/1212340578-15574-1-git-send-email-rueegsegger@swiss-it.ch > > Signed-off-by: Eric Biggers Applied, thanks a lot Eric!