From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (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 AE11B6BB56; Tue, 21 May 2024 13:26:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716297994; cv=none; b=VzXRVEeDfM1KrpSC4xktzx30u4AG/cbu9/2XmYbp5o2g+GuDJ6a43Tsp9oB/S7Oq1y0qOZVyZee2ue3hPDK9f8Nmf0fTKC1SaDIZCCno8GKKgNz5YAbTIAOc+SK7PgDvs21eq6n5xWBhlimhk3leUGH3ZJMu+IMiueiC6wWy6Sw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716297994; c=relaxed/simple; bh=CDs0kJ+gq9dScn7Lv07LkbmMN9kTpGqps3aarF3aDeY=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=XFyfnWIyFTqsw2KUNI3LLAfXtOd1Gix7iajE4111K3VFoDJfRklakSsCUQ5q4qfTNEO1HiDvuMa0vNvvAWPTEH3vHaba1RLwD7SfKA0WuaBQOe6DuSi7GVQ31BaEy+tteuEkkXCjEaqmJFyX6stqjwlRGb08b8i7uTCjDgo3GDs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=CI+lUcaT; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=CI+lUcaT; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="CI+lUcaT"; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="CI+lUcaT" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1716297991; bh=CDs0kJ+gq9dScn7Lv07LkbmMN9kTpGqps3aarF3aDeY=; h=Message-ID:Subject:From:To:Date:In-Reply-To:References:From; b=CI+lUcaTUAWg4HwCm9yqLZ0TcbYqCn9GHgpo2Mcn1GdPByDs7X1vJf/eorBOX2mk3 k4HUC4OLH9SGrZ3kjKSegc0KafG7pKxZNaD+otEYAdJNboupsdqRlCHuuhn7IGp28H YZDVQrW9hRDyAgRudT+bfSZzQnUO25zje+Ix5MUA= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id E89DB1286DFB; Tue, 21 May 2024 09:26:31 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id EGui8Ex8-1Ii; Tue, 21 May 2024 09:26:31 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1716297991; bh=CDs0kJ+gq9dScn7Lv07LkbmMN9kTpGqps3aarF3aDeY=; h=Message-ID:Subject:From:To:Date:In-Reply-To:References:From; b=CI+lUcaTUAWg4HwCm9yqLZ0TcbYqCn9GHgpo2Mcn1GdPByDs7X1vJf/eorBOX2mk3 k4HUC4OLH9SGrZ3kjKSegc0KafG7pKxZNaD+otEYAdJNboupsdqRlCHuuhn7IGp28H YZDVQrW9hRDyAgRudT+bfSZzQnUO25zje+Ix5MUA= Received: from lingrow.int.hansenpartnership.com (unknown [IPv6:2601:5c4:4302:c21::a774]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id BA3961286DC8; Tue, 21 May 2024 09:26:30 -0400 (EDT) Message-ID: <236606947b691049c650bdf82c37324084662147.camel@HansenPartnership.com> Subject: Re: [PATCH] tpm: enable HMAC encryption for only x86-64 and aarch64 From: James Bottomley To: Jarkko Sakkinen , linux-integrity@vger.kernel.org Cc: keyrings@vger.kernel.org, Peter Huewe , Jason Gunthorpe , Mimi Zohar , David Howells , Paul Moore , James Morris , "Serge E. Hallyn" , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Date: Tue, 21 May 2024 09:26:28 -0400 In-Reply-To: <20240521130921.15028-1-jarkko@kernel.org> References: <20240521130921.15028-1-jarkko@kernel.org> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.4 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Tue, 2024-05-21 at 16:09 +0300, Jarkko Sakkinen wrote: > Let's be more conservative and enable HMAC by default only for the > platforms where it immediately makes sense, i.e. x86-64 and aarch64. > This can be relaxed later on, and obviously the kconfig option can be > set even if not default on a particular arch. > > Cc: James Bottomley > Fixes: d2add27cf2b8 ("tpm: Add NULL primary creation") > Closes: > https://lore.kernel.org/linux-integrity/D1FCAPJSYLTS.R9VC1CXDCIHH@kernel.org/ > Signed-off-by: Jarkko Sakkinen > --- >  drivers/char/tpm/Kconfig | 2 +- >  1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig > index e63a6a17793c..19e61dcfcbbe 100644 > --- a/drivers/char/tpm/Kconfig > +++ b/drivers/char/tpm/Kconfig > @@ -29,7 +29,7 @@ if TCG_TPM >   >  config TCG_TPM2_HMAC >         bool "Use HMAC and encrypted transactions on the TPM bus" > -       default y > +       default X86_64 || ARM64 My first instinct is to say that devices in hostile environments (like IoT) are likely in the most need of this. However, it is an experimental feature, so I would like to debug it first in the environments where it's expected to work, which is desktop and laptop, so I'm happy with this: Acked-by: James Bottomley James