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=-6.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 A38A7C433E2 for ; Thu, 17 Sep 2020 15:31:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 60D97222C2 for ; Thu, 17 Sep 2020 15:31:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728140AbgIQPbs (ORCPT ); Thu, 17 Sep 2020 11:31:48 -0400 Received: from mga04.intel.com ([192.55.52.120]:9074 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728203AbgIQPbn (ORCPT ); Thu, 17 Sep 2020 11:31:43 -0400 X-Greylist: delayed 569 seconds by postgrey-1.27 at vger.kernel.org; Thu, 17 Sep 2020 11:31:40 EDT IronPort-SDR: 94aBwliQ1C1nBmcFdKM7vA/ghA2xH8LcmLcemg0i6/oPGcLBnCZrj//J47eECPN0KNgmVt5e++ VsmjlZklZgEA== X-IronPort-AV: E=McAfee;i="6000,8403,9747"; a="157107484" X-IronPort-AV: E=Sophos;i="5.77,271,1596524400"; d="scan'208";a="157107484" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Sep 2020 08:22:03 -0700 IronPort-SDR: IZG7WXN5+7oWENMzB31OtquHbg4t/UtDS3zCpMfH4swni9wlGWlHMzV7i68kPPT2zj1//CaOs5 B3WEN0hczsow== X-IronPort-AV: E=Sophos;i="5.77,271,1596524400"; d="scan'208";a="483787229" Received: from sdompke-mobl.ger.corp.intel.com (HELO localhost) ([10.249.45.123]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Sep 2020 08:22:01 -0700 Date: Thu, 17 Sep 2020 18:21:59 +0300 From: Jarkko Sakkinen To: James Bottomley Cc: linux-integrity@vger.kernel.org, Mimi Zohar , David Woodhouse , keyrings@vger.kernel.org, David Howells Subject: Re: [PATCH v11 3/5] security: keys: trusted: fix TPM2 authorizations Message-ID: <20200917152159.GB7389@linux.intel.com> References: <20200912172643.9063-1-James.Bottomley@HansenPartnership.com> <20200912172643.9063-4-James.Bottomley@HansenPartnership.com> <20200915090950.GB3612@linux.intel.com> <1600285934.7475.19.camel@HansenPartnership.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1600285934.7475.19.camel@HansenPartnership.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Wed, Sep 16, 2020 at 12:52:14PM -0700, James Bottomley wrote: > On Tue, 2020-09-15 at 12:09 +0300, Jarkko Sakkinen wrote: > > On Sat, Sep 12, 2020 at 10:26:41AM -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 > > > > I created a key: > > > > $ sudo ./tpm2-root-key > > 0x80000000 > > $ sudo ./tpm2-list-handles > > 0x80000000 > > $ keyctl add trusted kmk "new 32 blobauth=hello keyhandle=0x80000000" > > > > Well, you're getting that because the command isn't complete ... you > need a keyring specifier at the end, like @u. However, even with that > there's a bug in the code that would cause this to return EINVAL: the > blobauth handler has a return 0 where it should have a break ... I > think that happened as a result of the v6 rework which split up the if > ... else if ... else chain. The result is the processing of options > terminates at blobauth, so if it's last, as I've been testing with, > everything is fine. If it's first as you specify, none of the options > following the blobauth get processed. I'll fix this up and add an @u > to the commit message. Ugh, it's true, missing @u from the tail :-) And I was looking for a long time old test script and this and wondering where is the difference... Fix those so that we can finally merge this :-) > > James > /Jarkko