From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E246C11D3D for ; Thu, 27 Feb 2020 16:19:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7F66E2469F for ; Thu, 27 Feb 2020 16:19:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729676AbgB0QTx (ORCPT ); Thu, 27 Feb 2020 11:19:53 -0500 Received: from mga05.intel.com ([192.55.52.43]:18983 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728993AbgB0QTx (ORCPT ); Thu, 27 Feb 2020 11:19:53 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Feb 2020 08:19:51 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,492,1574150400"; d="scan'208";a="385205579" Received: from asliwa-mobl.ger.corp.intel.com (HELO localhost) ([10.252.26.84]) by orsmga004.jf.intel.com with ESMTP; 27 Feb 2020 08:19:50 -0800 Date: Thu, 27 Feb 2020 18:19:49 +0200 From: Jarkko Sakkinen To: James Bottomley Cc: linux-integrity@vger.kernel.org, Mimi Zohar , David Woodhouse , keyrings@vger.kernel.org Subject: Re: [PATCH v5 3/6] security: keys: trusted fix tpm2 authorizations Message-ID: <20200227161949.GD5140@linux.intel.com> References: <20200130101812.6271-1-James.Bottomley@HansenPartnership.com> <20200130101812.6271-4-James.Bottomley@HansenPartnership.com> <20200225164850.GB15662@linux.intel.com> <1582765091.4245.33.camel@HansenPartnership.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1582765091.4245.33.camel@HansenPartnership.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Wed, Feb 26, 2020 at 04:58:11PM -0800, James Bottomley wrote: > On Tue, 2020-02-25 at 18:48 +0200, Jarkko Sakkinen wrote: > > On Thu, Jan 30, 2020 at 11:18:09AM +0100, James Bottomley wrote: > > > In TPM 1.2 an authorization was a 20 byte number. The spec > > > actually recommended you to hash variable length passwords and use > > > the sha1 hash as the authorization. Because the spec doesn't > > > require this hashing, the current authorization for trusted keys is > > > a 40 digit hex number. For TPM 2.0 the spec allows the passing in > > > of variable length passwords and passphrases directly, so we should > > > allow that in trusted keys for ease of use. Update the 'blobauth' > > > parameter to take this into account, so we can now use plain text > > > passwords for the keys. > > > > > > so before > > > > > > keyctl add trusted kmk "new 32 > > > blobauth=f572d396fae9206628714fb2ce00f72e94f2258f" > > > > > > after we will accept both the old hex sha1 form as well as a new > > > directly supplied password: > > > > > > keyctl add trusted kmk "new 32 blobauth=hello keyhandle=81000001" > > > > > > Since a sha1 hex code must be exactly 40 bytes long and a direct > > > password must be 20 or less, we use the length as the discriminator > > > for which form is input. > > > > > > Note this is both and enhancement and a potential bug fix. The TPM > > > 2.0 spec requires us to strip leading zeros, meaning empyty > > > authorization is a zero length HMAC whereas we're currently passing > > > in > > > 20 bytes of zeros. A lot of TPMs simply accept this as OK, but the > > > Microsoft TPM emulator rejects it with TPM_RC_BAD_AUTH, so this > > > patch > > > makes the Microsoft TPM emulator work with trusted keys. > > > > > > Signed-off-by: James Bottomley > > om> > > > > Should have a fixes tag. > > I made all the other changes, but I'm not sure what to identify in the > fixes tag. The problem is the code I updated was simply carried over > unaltered from TPM 1.2 > > You could certainly argue that commit > > commit 0fe5480303a1657b328a0a389f8d99249d9961f5 > Author: Jarkko Sakkinen > Date: Fri Jun 26 22:28:26 2015 +0300 > > keys, trusted: seal/unseal with TPM 2.0 chips > > Should have updated the blobauth handling ... is that the one you'd > like fixes: to identify? What I'm thinking is to have fixes tag w/o cc to stable. I'm not sure at this point whether we want to backport this but it still makes sense to tag it. /Jarkko