From patchwork Fri Nov 16 20:07:01 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thiago Jung Bauermann X-Patchwork-Id: 10686935 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 23EC513B5 for ; Fri, 16 Nov 2018 20:08:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1850F2CD3E for ; Fri, 16 Nov 2018 20:08:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0CBFE2CD43; Fri, 16 Nov 2018 20:08:36 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A13BC2CD43 for ; Fri, 16 Nov 2018 20:08:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727585AbeKQGWW (ORCPT ); Sat, 17 Nov 2018 01:22:22 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:57922 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727606AbeKQGWV (ORCPT ); Sat, 17 Nov 2018 01:22:21 -0500 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wAGK4Cfb042457 for ; Fri, 16 Nov 2018 15:08:32 -0500 Received: from e17.ny.us.ibm.com (e17.ny.us.ibm.com [129.33.205.207]) by mx0a-001b2d01.pphosted.com with ESMTP id 2nt358kdfq-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 16 Nov 2018 15:08:32 -0500 Received: from localhost by e17.ny.us.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) Fri, 16 Nov 2018 20:08:26 -0000 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wAGK8P6v29229292 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 16 Nov 2018 20:08:25 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 14AFFAC062; Fri, 16 Nov 2018 20:08:25 +0000 (GMT) Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F088EAC059; Fri, 16 Nov 2018 20:08:20 +0000 (GMT) Received: from morokweng.localdomain.com (unknown [9.80.224.199]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP; Fri, 16 Nov 2018 20:08:20 +0000 (GMT) From: Thiago Jung Bauermann To: linux-integrity@vger.kernel.org Cc: linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Mimi Zohar , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , David Howells , David Woodhouse , Jessica Yu , Herbert Xu , "David S. Miller" , Jonathan Corbet , "AKASHI, Takahiro" , Thiago Jung Bauermann Subject: [PATCH v8 03/14] PKCS#7: Introduce pkcs7_get_digest() Date: Fri, 16 Nov 2018 18:07:01 -0200 X-Mailer: git-send-email 2.17.2 In-Reply-To: <20181116200712.14154-1-bauerman@linux.ibm.com> References: <20181116200712.14154-1-bauerman@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18111620-0040-0000-0000-00000493BC29 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010063; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000270; SDB=6.01118417; UDB=6.00577119; IPR=6.00898525; MB=3.00024197; MTD=3.00000008; XFM=3.00000015; UTC=2018-11-16 20:08:30 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18111620-0041-0000-0000-0000089CC8B6 Message-Id: <20181116200712.14154-4-bauerman@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-11-16_11:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1811160178 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP IMA will need to access the digest of the PKCS7 message (as calculated by the kernel) before the signature is verified, so introduce pkcs7_get_digest() for that purpose. Also, modify pkcs7_digest() to detect when the digest was already calculated so that it doesn't have to do redundant work. Verifying that sinfo->sig->digest isn't NULL is sufficient because both places which allocate sinfo->sig (pkcs7_parse_message() and pkcs7_note_signed_info()) use kzalloc() so sig->digest is always initialized to zero. Signed-off-by: Thiago Jung Bauermann Reviewed-by: Mimi Zohar Cc: David Howells Cc: Herbert Xu Cc: "David S. Miller" --- crypto/asymmetric_keys/pkcs7_verify.c | 25 +++++++++++++++++++++++++ include/crypto/pkcs7.h | 3 +++ 2 files changed, 28 insertions(+) diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c index 97c77f66b20d..e61f121bfc87 100644 --- a/crypto/asymmetric_keys/pkcs7_verify.c +++ b/crypto/asymmetric_keys/pkcs7_verify.c @@ -33,6 +33,10 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7, kenter(",%u,%s", sinfo->index, sinfo->sig->hash_algo); + /* The digest was calculated already. */ + if (sig->digest) + return 0; + if (!sinfo->sig->hash_algo) return -ENOPKG; @@ -122,6 +126,27 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7, return ret; } +int pkcs7_get_digest(struct pkcs7_message *pkcs7, const u8 **buf, u8 *len) +{ + struct pkcs7_signed_info *sinfo = pkcs7->signed_infos; + int ret; + + /* + * This function doesn't support messages with more than one signature. + */ + if (sinfo == NULL || sinfo->next != NULL) + return -EBADMSG; + + ret = pkcs7_digest(pkcs7, sinfo); + if (ret) + return ret; + + *buf = sinfo->sig->digest; + *len = sinfo->sig->digest_size; + + return 0; +} + /* * Find the key (X.509 certificate) to use to verify a PKCS#7 message. PKCS#7 * uses the issuer's name and the issuing certificate serial number for diff --git a/include/crypto/pkcs7.h b/include/crypto/pkcs7.h index 6f51d0cb6d12..cfaea9c37f4a 100644 --- a/include/crypto/pkcs7.h +++ b/include/crypto/pkcs7.h @@ -46,4 +46,7 @@ extern int pkcs7_verify(struct pkcs7_message *pkcs7, extern int pkcs7_supply_detached_data(struct pkcs7_message *pkcs7, const void *data, size_t datalen); +extern int pkcs7_get_digest(struct pkcs7_message *pkcs7, const u8 **buf, + u8 *len); + #endif /* _CRYPTO_PKCS7_H */