From patchwork Wed May 8 14:43:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A . Shutemov" X-Patchwork-Id: 10936007 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 2FDD21515 for ; Wed, 8 May 2019 14:50:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 22D0928A85 for ; Wed, 8 May 2019 14:50:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 16AF928A7A; Wed, 8 May 2019 14:50:55 +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 B6C1328A74 for ; Wed, 8 May 2019 14:50:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728637AbfEHOuk (ORCPT ); Wed, 8 May 2019 10:50:40 -0400 Received: from mga02.intel.com ([134.134.136.20]:19899 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728274AbfEHOoo (ORCPT ); Wed, 8 May 2019 10:44:44 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 May 2019 07:44:44 -0700 X-ExtLoop1: 1 Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga005.fm.intel.com with ESMTP; 08 May 2019 07:44:40 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 06098AD9; Wed, 8 May 2019 17:44:30 +0300 (EEST) From: "Kirill A. Shutemov" To: Andrew Morton , x86@kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Borislav Petkov , Peter Zijlstra , Andy Lutomirski , David Howells Cc: Kees Cook , Dave Hansen , Kai Huang , Jacob Pan , Alison Schofield , linux-mm@kvack.org, kvm@vger.kernel.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A . Shutemov" Subject: [PATCH, RFC 27/62] keys/mktme: Strengthen the entropy of CPU generated MKTME keys Date: Wed, 8 May 2019 17:43:47 +0300 Message-Id: <20190508144422.13171-28-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190508144422.13171-1-kirill.shutemov@linux.intel.com> References: <20190508144422.13171-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Alison Schofield If users request CPU generated keys, mix additional entropy bits from the kernel into the key programming fields used by the hardware. This additional entropy may compensate for weak user supplied, or CPU generated, entropy. Signed-off-by: Alison Schofield Signed-off-by: Kirill A. Shutemov --- security/keys/mktme_keys.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/security/keys/mktme_keys.c b/security/keys/mktme_keys.c index a7ca32865a1c..9fdf482ea3e6 100644 --- a/security/keys/mktme_keys.c +++ b/security/keys/mktme_keys.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -102,7 +103,8 @@ struct mktme_payload { static int mktme_program_keyid(int keyid, struct mktme_payload *payload) { struct mktme_key_program *kprog = NULL; - int ret; + u8 kern_entropy[MKTME_AES_XTS_SIZE]; + int ret, i; kprog = kmem_cache_zalloc(mktme_prog_cache, GFP_ATOMIC); if (!kprog) @@ -114,6 +116,14 @@ static int mktme_program_keyid(int keyid, struct mktme_payload *payload) memcpy(kprog->key_field_1, payload->data_key, MKTME_AES_XTS_SIZE); memcpy(kprog->key_field_2, payload->tweak_key, MKTME_AES_XTS_SIZE); + /* Strengthen the entropy fields for CPU generated keys */ + if ((payload->keyid_ctrl & 0xff) == MKTME_KEYID_SET_KEY_RANDOM) { + get_random_bytes(&kern_entropy, sizeof(kern_entropy)); + for (i = 0; i < (MKTME_AES_XTS_SIZE); i++) { + kprog->key_field_1[i] ^= kern_entropy[i]; + kprog->key_field_2[i] ^= kern_entropy[i]; + } + } ret = MKTME_PROG_SUCCESS; /* Future programming call */ kmem_cache_free(mktme_prog_cache, kprog); return ret;