From patchwork Thu Nov 14 03:11:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lakshmi Ramasubramanian X-Patchwork-Id: 11242973 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 35080913 for ; Thu, 14 Nov 2019 03:12:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 45C7E206F4 for ; Thu, 14 Nov 2019 03:12:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="sxfYy0ZM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727093AbfKNDMT (ORCPT ); Wed, 13 Nov 2019 22:12:19 -0500 Received: from linux.microsoft.com ([13.77.154.182]:48454 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726528AbfKNDMK (ORCPT ); Wed, 13 Nov 2019 22:12:10 -0500 Received: from nramas-ThinkStation-P520.corp.microsoft.com (unknown [131.107.159.108]) by linux.microsoft.com (Postfix) with ESMTPSA id 5FBDC20B4904; Wed, 13 Nov 2019 19:12:09 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 5FBDC20B4904 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1573701129; bh=DcjuEGpDue6hzcYPER7yA0s/bwWCNqk95yOKVyIqy7s=; h=From:To:Subject:Date:In-Reply-To:References:From; b=sxfYy0ZM+8fA3PgmgbpQ+/pxtjIdIbWB6zXljPg8GkIpFpgv3vsTWz8RWY7cXe8WX K/8A/1JXdEWTEDKkDsqz2eCRQdpTWv6wjI6UNyLdTPTOhjZuQBAGZMFIOJ12XlT1b9 3OR2lpoCCxNYpVP4Tg8+cw7Rhfiqj2z7w2xDAaBo= From: Lakshmi Ramasubramanian To: zohar@linux.ibm.com, dhowells@redhat.com, matthewgarrett@google.com, sashal@kernel.org, jamorris@linux.microsoft.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v7 2/5] IMA: Define an IMA hook to measure keys Date: Wed, 13 Nov 2019 19:11:59 -0800 Message-Id: <20191114031202.18012-3-nramas@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191114031202.18012-1-nramas@linux.microsoft.com> References: <20191114031202.18012-1-nramas@linux.microsoft.com> Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Measure asymmetric keys used for verifying file signatures, certificates, etc. This patch defines a new IMA hook namely ima_post_key_create_or_update() to measure asymmetric keys. The IMA hook is defined in a new file namely ima_asymmetric_keys.c which is built only if CONFIG_KEYS is enabled. Signed-off-by: Lakshmi Ramasubramanian --- security/integrity/ima/Makefile | 1 + security/integrity/ima/ima_asymmetric_keys.c | 51 ++++++++++++++++++++ 2 files changed, 52 insertions(+) create mode 100644 security/integrity/ima/ima_asymmetric_keys.c diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile index 31d57cdf2421..3c796664be8a 100644 --- a/security/integrity/ima/Makefile +++ b/security/integrity/ima/Makefile @@ -12,3 +12,4 @@ ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o ima-$(CONFIG_IMA_APPRAISE_MODSIG) += ima_modsig.o ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o obj-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o +obj-$(CONFIG_KEYS) += ima_asymmetric_keys.o diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c new file mode 100644 index 000000000000..f6884641a622 --- /dev/null +++ b/security/integrity/ima/ima_asymmetric_keys.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * File: ima_asymmetric_keys.c + * Defines an IMA hook to measure asymmetric keys on key + * create or update. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include "ima.h" + +/** + * ima_post_key_create_or_update - measure asymmetric keys + * @keyring: keyring to which the key is linked to + * @key: created or updated key + * @flags: key flags + * @create: flag indicating whether the key was created or updated + * + * Keys can only be measured, not appraised. + */ +void ima_post_key_create_or_update(struct key *keyring, struct key *key, + unsigned long flags, bool create) +{ + const struct public_key *pk; + + /* Only asymmetric keys are handled by this hook. */ + if (key->type != &key_type_asymmetric) + return; + + /* Get the public_key of the given asymmetric key to measure. */ + pk = key->payload.data[asym_crypto]; + + /* + * keyring->description points to the name of the keyring + * (such as ".builtin_trusted_keys", ".ima", etc.) to + * which the given key is linked to. + * + * The name of the keyring is passed in the "eventname" + * parameter to process_buffer_measurement() and is set + * in the "eventname" field in ima_event_data for + * the key measurement IMA event. + */ + process_buffer_measurement(pk->key, pk->keylen, + keyring->description, KEY_CHECK, 0); +}