From 9b9d4ce592d283fc4c01da746c02a840c499bb7e Mon Sep 17 00:00:00 2001
From: Roberto Sassu <roberto.sassu@polito.it>
Date: Fri, 7 Jun 2013 12:16:35 +0200
Subject: [PATCH] ima: define kernel parameter 'ima_template=' to change
configured default
This patch allows users to specify from the kernel command line the
template descriptor, among those defined, that will be used to generate
and display measurement entries. If an user specifies a wrong template,
IMA reverts to the template descriptor set in the kernel configuration.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
---
Documentation/kernel-parameters.txt | 5 +++++
security/integrity/ima/ima_template.c | 31 +++++++++++++++++++++++++++
2 files changed, 36 insertions(+)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 1a036cd972fb0..2b78cb55ac34e 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1190,6 +1190,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
programs exec'd, files mmap'd for exec, and all files
opened for read by uid=0.
+ ima_template= [IMA]
+ Select one of defined IMA measurements template formats.
+ Formats: { "ima" | "ima-ng" }
+ Default: "ima-ng"
+
init= [KNL]
Format: <full_path>
Run specified binary instead of /sbin/init as init
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index c28ff9bf8f327..000221419f6c9 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -12,6 +12,8 @@
* File: ima_template.c
* Helpers to manage template descriptors.
*/
+#include <crypto/hash_info.h>
+
#include "ima.h"
#include "ima_template_lib.h"
@@ -32,6 +34,35 @@ static struct ima_template_field supported_fields[] = {
};
static struct ima_template_desc *ima_template;
+static struct ima_template_desc *lookup_template_desc(const char *name);
+
+static int __init ima_template_setup(char *str)
+{
+ struct ima_template_desc *template_desc;
+ int template_len = strlen(str);
+
+ /*
+ * Verify that a template with the supplied name exists.
+ * If not, use CONFIG_IMA_DEFAULT_TEMPLATE.
+ */
+ template_desc = lookup_template_desc(str);
+ if (!template_desc)
+ return 1;
+
+ /*
+ * Verify whether the current hash algorithm is supported
+ * by the 'ima' template.
+ */
+ if (template_len == 3 && strcmp(str, IMA_TEMPLATE_IMA_NAME) == 0 &&
+ ima_hash_algo != HASH_ALGO_SHA1 && ima_hash_algo != HASH_ALGO_MD5) {
+ pr_err("IMA: template does not support hash alg\n");
+ return 1;
+ }
+
+ ima_template = template_desc;
+ return 1;
+}
+__setup("ima_template=", ima_template_setup);
static struct ima_template_desc *lookup_template_desc(const char *name)
{
--
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