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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 A2516C2D0DB for ; Thu, 30 Jan 2020 17:32:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 814DA2083E for ; Thu, 30 Jan 2020 17:32:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727267AbgA3Rcx (ORCPT ); Thu, 30 Jan 2020 12:32:53 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:48216 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727158AbgA3Rcw (ORCPT ); Thu, 30 Jan 2020 12:32:52 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 00UHWZVs094547 for ; Thu, 30 Jan 2020 12:32:51 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2xubctmk6h-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 30 Jan 2020 12:32:51 -0500 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 30 Jan 2020 17:32:47 -0000 Received: from d06av24.portsmouth.uk.ibm.com (mk.ibm.com [9.149.105.60]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 00UHVs6333292588 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 30 Jan 2020 17:31:54 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3250842047; Thu, 30 Jan 2020 17:32:46 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 43FDB4203F; Thu, 30 Jan 2020 17:32:45 +0000 (GMT) Received: from localhost.localdomain (unknown [9.80.199.205]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 30 Jan 2020 17:32:45 +0000 (GMT) Subject: Re: [PATCH v3 2/2] ima: support calculating the boot_aggregate based on different TPM banks From: Mimi Zohar To: Roberto Sassu , "linux-integrity@vger.kernel.org" Cc: Jerry Snitselaar , James Bottomley , "linux-kernel@vger.kernel.org" , Silviu Vlasceanu , Lakshmi Ramasubramanian Date: Thu, 30 Jan 2020 12:32:44 -0500 In-Reply-To: <1065c502840c4f66baed9a771f3f2409@huawei.com> References: <1580401363-5593-1-git-send-email-zohar@linux.ibm.com> <1580401363-5593-2-git-send-email-zohar@linux.ibm.com> <1065c502840c4f66baed9a771f3f2409@huawei.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.20.5 (3.20.5-1.fc24) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 20013017-0020-0000-0000-000003A592C0 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20013017-0021-0000-0000-000021FD494D Message-Id: <1580405564.5228.6.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.572 definitions=2020-01-30_05:2020-01-28,2020-01-30 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 mlxlogscore=999 clxscore=1015 adultscore=0 phishscore=0 suspectscore=0 malwarescore=0 priorityscore=1501 spamscore=0 mlxscore=0 lowpriorityscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1911200001 definitions=main-2001300122 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Thu, 2020-01-30 at 16:54 +0000, Roberto Sassu wrote: > > -----Original Message----- > > From: linux-integrity-owner@vger.kernel.org [mailto:linux-integrity- > > owner@vger.kernel.org] On Behalf Of Mimi Zohar > > Sent: Thursday, January 30, 2020 5:23 PM > > To: linux-integrity@vger.kernel.org > > Cc: Jerry Snitselaar ; James Bottomley > > ; linux- > > kernel@vger.kernel.org; Mimi Zohar > > Subject: [PATCH v3 2/2] ima: support calculating the boot_aggregate based > > on different TPM banks > > > > Calculating the boot_aggregate attempts to read the TPM SHA1 bank, > > assuming it is always enabled. With TPM 2.0 hash agility, TPM chips > > could support multiple TPM PCR banks, allowing firmware to configure and > > enable different banks. > > > > Instead of hard coding the TPM 2.0 bank hash algorithm used for calculating > > the boot-aggregate, use the same hash algorithm for reading the TPM PCRs > > as > > for calculating the boot aggregate digest. Preference is given to the > > configured IMA default hash algorithm. > > > > For TPM 1.2 SHA1 is the only supported hash algorithm. > > > > Reported-by: Jerry Snitselaar > > Suggested-by: Roberto Sassu > > Signed-off-by: Mimi Zohar > > --- > > security/integrity/ima/ima_crypto.c | 45 > > ++++++++++++++++++++++++++++++++++++- > > 1 file changed, 44 insertions(+), 1 deletion(-) > > > > diff --git a/security/integrity/ima/ima_crypto.c > > b/security/integrity/ima/ima_crypto.c > > index 7967a6904851..a020aaefdea8 100644 > > --- a/security/integrity/ima/ima_crypto.c > > +++ b/security/integrity/ima/ima_crypto.c > > @@ -656,13 +656,34 @@ static void __init ima_pcrread(u32 idx, struct > > tpm_digest *d) > > pr_err("Error Communicating to TPM chip\n"); > > } > > > > +static enum hash_algo get_hash_algo(const char *algname) > > +{ > > + int i; > > + > > + for (i = 0; i < HASH_ALGO__LAST; i++) { > > + if (strcmp(algname, hash_algo_name[i]) == 0) > > + break; > > + } > > + > > + return i; > > +} > > + > > /* > > - * Calculate the boot aggregate hash > > + * The boot_aggregate is a cumulative hash over TPM registers 0 - 7. With > > + * TPM 1.2 the boot_aggregate was based on reading the SHA1 PCRs, but > > with > > + * TPM 2.0 hash agility, TPM chips could support multiple TPM PCR banks, > > + * allowing firmware to configure and enable different banks. > > + * > > + * Knowing which TPM bank is read to calculate the boot_aggregate digest > > + * needs to be conveyed to a verifier. For this reason, use the same > > + * hash algorithm for reading the TPM PCRs as for calculating the boot > > + * aggregate digest as stored in the measurement list. > > */ > > static int __init ima_calc_boot_aggregate_tfm(char *digest, > > struct crypto_shash *tfm) > > { > > struct tpm_digest d = { .alg_id = TPM_ALG_SHA1, .digest = {0} }; > > + enum hash_algo crypto_id; > > int rc; > > u32 i; > > SHASH_DESC_ON_STACK(shash, tfm); > > @@ -673,6 +694,28 @@ static int __init ima_calc_boot_aggregate_tfm(char > > *digest, > > if (rc != 0) > > return rc; > > > > + crypto_id = get_hash_algo(crypto_shash_alg_name(tfm)); > > Wouldn't be better to determine the index of ima_tpm_chip->allocated_banks > in patch 1/2 and pass that index here, to avoid another search? Both your suggestion and Lakshmi's suggestion change the parameters to ima_calc_boot_aggregate_tfm(), which I was trying to avoid for now.  I want it to be as easy as possible to backport. Going forward, you might be correct. Mimi