From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Date: Thu, 14 May 2020 01:41:09 +0000 Subject: Re: [PATCH v9 3/8] security: keys: trusted: fix TPM2 authorizations Message-Id: <1589420469.9117.12.camel@HansenPartnership.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable List-Id: References: <20200507231147.27025-1-James.Bottomley@HansenPartnership.com> <20200507231147.27025-4-James.Bottomley@HansenPartnership.com> <00325dff8292a18212bbdaa3fd81cebee2a60bc2.camel@linux.intel.com> <664f00cf18c68e3f6316b50679b2fd56919d5aeb.camel@linux.intel.com> In-Reply-To: <664f00cf18c68e3f6316b50679b2fd56919d5aeb.camel@linux.intel.com> To: Jarkko Sakkinen , linux-integrity@vger.kernel.org Cc: Mimi Zohar , David Woodhouse , keyrings@vger.kernel.org, David Howells On Thu, 2020-05-14 at 04:12 +0300, Jarkko Sakkinen wrote: > On Thu, 2020-05-14 at 04:11 +0300, Jarkko Sakkinen wrote: > > 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. > > >=20 > > > so before > > >=20 > > > keyctl add trusted kmk "new 32 > > > blobauth=F572d396fae9206628714fb2ce00f72e94f2258f" > > >=20 > > > after we will accept both the old hex sha1 form as well as a new > > > directly supplied password: > > >=20 > > > keyctl add trusted kmk "new 32 blobauth=3Dhello keyhandle=81000001" > > >=20 > > > 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. > > >=20 > > > 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. > > >=20 > > > Fixes: 0fe5480303a1 ("keys, trusted: seal/unseal with TPM 2.0 > > > chips") > > > Signed-off-by: James Bottomley > > .com> > > > Reviewed-by: Jarkko Sakkinen > >=20 > > Have not checked yet the tail. Probably won't check before PR for > > v5.8 is out. > >=20 > > Just wondering would it hurt to merge everything up until this > > patch? Everything would be OK if you applied 1, 2 and 3. Except we'd have an ASN.1 API in the tree with no consumers, which excites some people. > I.e. could land it also to the release. That would likely be fine and should satisfy the API with no consumers issue. James 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=-5.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_2 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 36185C433DF for ; Thu, 14 May 2020 01:41:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1BD6A2065F for ; Thu, 14 May 2020 01:41:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="khU5xKIQ"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="khU5xKIQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725952AbgENBlM (ORCPT ); Wed, 13 May 2020 21:41:12 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:55924 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725943AbgENBlM (ORCPT ); Wed, 13 May 2020 21:41:12 -0400 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id DB5178EE268; Wed, 13 May 2020 18:41:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1589420471; bh=A1nXPApd7wcueNVD8U+KyxA88Q0w9bBsMwIvb9bzOW0=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=khU5xKIQkgyJg0umnQ9QSPgFBgcIXCiVuNuXbDKdDQFhrX/qq9Rh3jKekxBhoYSDy QeDj9bCJV2GleaC1MQWmHTDgLYT8uz7MtzzlEnNqQO6fi4WfEsxviA1bKk1byazRnB NU/JYZSltrWHigfDEI2aHFug/9tZz+98Eh8yRrRY= Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id wB0GkTSLQdKd; Wed, 13 May 2020 18:41:11 -0700 (PDT) Received: from [153.66.254.194] (unknown [50.35.76.230]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id 5D07A8EE173; Wed, 13 May 2020 18:41:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1589420471; bh=A1nXPApd7wcueNVD8U+KyxA88Q0w9bBsMwIvb9bzOW0=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=khU5xKIQkgyJg0umnQ9QSPgFBgcIXCiVuNuXbDKdDQFhrX/qq9Rh3jKekxBhoYSDy QeDj9bCJV2GleaC1MQWmHTDgLYT8uz7MtzzlEnNqQO6fi4WfEsxviA1bKk1byazRnB NU/JYZSltrWHigfDEI2aHFug/9tZz+98Eh8yRrRY= Message-ID: <1589420469.9117.12.camel@HansenPartnership.com> Subject: Re: [PATCH v9 3/8] security: keys: trusted: fix TPM2 authorizations From: James Bottomley To: Jarkko Sakkinen , linux-integrity@vger.kernel.org Cc: Mimi Zohar , David Woodhouse , keyrings@vger.kernel.org, David Howells Date: Wed, 13 May 2020 18:41:09 -0700 In-Reply-To: <664f00cf18c68e3f6316b50679b2fd56919d5aeb.camel@linux.intel.com> References: <20200507231147.27025-1-James.Bottomley@HansenPartnership.com> <20200507231147.27025-4-James.Bottomley@HansenPartnership.com> <00325dff8292a18212bbdaa3fd81cebee2a60bc2.camel@linux.intel.com> <664f00cf18c68e3f6316b50679b2fd56919d5aeb.camel@linux.intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 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, 2020-05-14 at 04:12 +0300, Jarkko Sakkinen wrote: > On Thu, 2020-05-14 at 04:11 +0300, Jarkko Sakkinen wrote: > > 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 > > .com> > > > 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? Everything would be OK if you applied 1, 2 and 3. Except we'd have an ASN.1 API in the tree with no consumers, which excites some people. > I.e. could land it also to the release. That would likely be fine and should satisfy the API with no consumers issue. James