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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 1B901C433E0 for ; Thu, 14 May 2020 01:11:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 30E06205ED for ; Thu, 14 May 2020 01:11:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725977AbgENBLr (ORCPT ); Wed, 13 May 2020 21:11:47 -0400 Received: from mga04.intel.com ([192.55.52.120]:3479 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725943AbgENBLr (ORCPT ); Wed, 13 May 2020 21:11:47 -0400 IronPort-SDR: zVy8JUGXZYoiPcRIFbu8aRR8tBUy5E8srdppMWIrN9bn9U6ebbxL4AJjZv3pR+cZdufJk7QYzM Izg4BcMfq6GA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 May 2020 18:11:46 -0700 IronPort-SDR: 2riP92HJXoTs4+2KeUluddBFfW61upoGPGWR2c4ITbdKxk75kqOiJ3x8aPmJfq455a6+2/3/8n x/LY9S2DSFHw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,389,1583222400"; d="scan'208";a="372079754" Received: from gliber-mobl1.ger.corp.intel.com ([10.249.38.41]) by fmsmga001.fm.intel.com with ESMTP; 13 May 2020 18:11:44 -0700 Message-ID: <00325dff8292a18212bbdaa3fd81cebee2a60bc2.camel@linux.intel.com> Subject: Re: [PATCH v9 3/8] security: keys: trusted: fix TPM2 authorizations From: Jarkko Sakkinen To: James Bottomley , linux-integrity@vger.kernel.org Cc: Mimi Zohar , David Woodhouse , keyrings@vger.kernel.org, David Howells Date: Thu, 14 May 2020 04:11:43 +0300 In-Reply-To: <20200507231147.27025-4-James.Bottomley@HansenPartnership.com> References: <20200507231147.27025-1-James.Bottomley@HansenPartnership.com> <20200507231147.27025-4-James.Bottomley@HansenPartnership.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.1-2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Thu, 2020-05-07 at 16:11 -0700, 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. > > Fixes: 0fe5480303a1 ("keys, trusted: seal/unseal with TPM 2.0 chips") > Signed-off-by: James Bottomley > Reviewed-by: Jarkko Sakkinen Have not checked yet the tail. Probably won't check before PR for v5.8 is out. Just wondering would it hurt to merge everything up until this patch? /Jarkko