From patchwork Tue Jan 7 19:43:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lakshmi Ramasubramanian X-Patchwork-Id: 11321697 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 0A34D109A for ; Tue, 7 Jan 2020 19:44:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DBC8E20848 for ; Tue, 7 Jan 2020 19:44:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="b8NkhnkW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728723AbgAGTn7 (ORCPT ); Tue, 7 Jan 2020 14:43:59 -0500 Received: from linux.microsoft.com ([13.77.154.182]:34272 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728660AbgAGTnz (ORCPT ); Tue, 7 Jan 2020 14:43:55 -0500 Received: from nramas-ThinkStation-P520.corp.microsoft.com (unknown [131.107.174.108]) by linux.microsoft.com (Postfix) with ESMTPSA id 08ACF20B479D; Tue, 7 Jan 2020 11:43:55 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 08ACF20B479D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1578426235; bh=vKopEemioZDxxkhIIhSrX9LVxTYuu1tqhtvTwXFOlw8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=b8NkhnkW15jpOvwrsK2vCU2avcMqxoWfj7dFv01AQww+lucA4+JhSNjxL845MgVrt /2zrxEA1T7oS2TqQrLBAyBpYvOXrajBEKhDihs6ARkRhYiUZ4yMHiDU5dS9RZdc8SU ZRF2oHLjWMor95mHprMl9e8tm04ZaFhzcRjr2t2E= From: Lakshmi Ramasubramanian To: zohar@linux.ibm.com, James.Bottomley@HansenPartnership.com, linux-integrity@vger.kernel.org Cc: eric.snowberg@oracle.com, dhowells@redhat.com, mathew.j.martineau@linux.intel.com, matthewgarrett@google.com, sashal@kernel.org, jamorris@linux.microsoft.com, linux-kernel@vger.kernel.org, keyrings@vger.kernel.org Subject: [PATCH 4/4] IMA: Read keyrings= option from the IMA policy Date: Tue, 7 Jan 2020 11:43:50 -0800 Message-Id: <20200107194350.3782-5-nramas@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200107194350.3782-1-nramas@linux.microsoft.com> References: <20200107194350.3782-1-nramas@linux.microsoft.com> Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Read "keyrings=" option, if specified in the IMA policy, and store in the list of IMA rules when the configured IMA policy is read. This patch defines a new policy token enum namely Opt_keyrings and an option flag IMA_KEYRINGS for reading "keyrings=" option from the IMA policy. Updated ima_parse_rule() to parse "keyrings=" option in the policy. Updated ima_policy_show() to display "keyrings=" option. The following example illustrates how key measurement can be verified. Sample "key" measurement rule in the IMA policy: measure func=KEY_CHECK uid=0 keyrings=.ima|.evm template=ima-buf Display "key" measurement in the IMA measurement list: cat /sys/kernel/security/ima/ascii_runtime_measurements 10 faf3...e702 ima-buf sha256:27c915b8ddb9fae7214cf0a8a7043cc3eeeaa7539bcb136f8427067b5f6c3b7b .ima 308202863082...4aee Verify "key" measurement data for a key added to ".ima" keyring: cat /sys/kernel/security/integrity/ima/ascii_runtime_measurements | grep -m 1 "\.ima" | cut -d' ' -f 6 | xxd -r -p |tee ima-cert.der | sha256sum | cut -d' ' -f 1 The output of the above command should match the template hash of the first "key" measurement entry in the IMA measurement list for the key added to ".ima" keyring. The file namely "ima-cert.der" generated by the above command should be a valid x509 certificate (in DER format) and should match the one that was used to import the key to the ".ima" keyring. The certificate file can be verified using openssl tool. Signed-off-by: Lakshmi Ramasubramanian Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy") --- security/integrity/ima/ima_policy.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 7667ca546ce9..8f2ca487753b 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -34,6 +34,7 @@ #define IMA_EUID 0x0080 #define IMA_PCR 0x0100 #define IMA_FSNAME 0x0200 +#define IMA_KEYRINGS 0x0400 #define UNKNOWN 0 #define MEASURE 0x0001 /* same as IMA_MEASURE */ @@ -820,7 +821,8 @@ enum { Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt, Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt, Opt_appraise_type, Opt_appraise_flag, - Opt_permit_directio, Opt_pcr, Opt_template, Opt_err + Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings, + Opt_err }; static const match_table_t policy_tokens = { @@ -856,6 +858,7 @@ static const match_table_t policy_tokens = { {Opt_permit_directio, "permit_directio"}, {Opt_pcr, "pcr=%s"}, {Opt_template, "template=%s"}, + {Opt_keyrings, "keyrings=%s"}, {Opt_err, NULL} }; @@ -1105,6 +1108,23 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) result = 0; entry->flags |= IMA_FSNAME; break; + case Opt_keyrings: + ima_log_string(ab, "keyrings", args[0].from); + + if ((entry->keyrings) || + (entry->action != MEASURE) || + (entry->func != KEY_CHECK)) { + result = -EINVAL; + break; + } + entry->keyrings = kstrdup(args[0].from, GFP_KERNEL); + if (!entry->keyrings) { + result = -ENOMEM; + break; + } + result = 0; + entry->flags |= IMA_KEYRINGS; + break; case Opt_fsuuid: ima_log_string(ab, "fsuuid", args[0].from); @@ -1480,6 +1500,13 @@ int ima_policy_show(struct seq_file *m, void *v) seq_puts(m, " "); } + if (entry->flags & IMA_KEYRINGS) { + if (entry->keyrings != NULL) + snprintf(tbuf, sizeof(tbuf), "%s", entry->keyrings); + seq_printf(m, pt(Opt_keyrings), tbuf); + seq_puts(m, " "); + } + if (entry->flags & IMA_PCR) { snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr); seq_printf(m, pt(Opt_pcr), tbuf);