Initial import

1 files changed, 209 insertions, 0 deletions

diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
new file mode 100644
index 000000000..0b7404ebf
--- /dev/null
+++ b/security/integrity/ima/ima_template.c
@@ -0,0 +1,209 @@
+/*
+ * Copyright (C) 2013 Politecnico di Torino, Italy
+ *                    TORSEC group -- http://security.polito.it
+ *
+ * Author: Roberto Sassu <roberto.sassu@polito.it>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ * File: ima_template.c
+ *      Helpers to manage template descriptors.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <crypto/hash_info.h>
+
+#include "ima.h"
+#include "ima_template_lib.h"
+
+static struct ima_template_desc defined_templates[] = {
+	{.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT},
+	{.name = "ima-ng", .fmt = "d-ng|n-ng"},
+	{.name = "ima-sig", .fmt = "d-ng|n-ng|sig"},
+	{.name = "", .fmt = ""},	/* placeholder for a custom format */
+};
+
+static struct ima_template_field supported_fields[] = {
+	{.field_id = "d", .field_init = ima_eventdigest_init,
+	 .field_show = ima_show_template_digest},
+	{.field_id = "n", .field_init = ima_eventname_init,
+	 .field_show = ima_show_template_string},
+	{.field_id = "d-ng", .field_init = ima_eventdigest_ng_init,
+	 .field_show = ima_show_template_digest_ng},
+	{.field_id = "n-ng", .field_init = ima_eventname_ng_init,
+	 .field_show = ima_show_template_string},
+	{.field_id = "sig", .field_init = ima_eventsig_init,
+	 .field_show = ima_show_template_sig},
+};
+
+static struct ima_template_desc *ima_template;
+static struct ima_template_desc *lookup_template_desc(const char *name);
+static int template_desc_init_fields(const char *template_fmt,
+				     struct ima_template_field ***fields,
+				     int *num_fields);
+
+static int __init ima_template_setup(char *str)
+{
+	struct ima_template_desc *template_desc;
+	int template_len = strlen(str);
+
+	if (ima_template)
+		return 1;
+
+	/*
+	 * 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) {
+		pr_err("template %s not found, using %s\n",
+		       str, CONFIG_IMA_DEFAULT_TEMPLATE);
+		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("template does not support hash alg\n");
+		return 1;
+	}
+
+	ima_template = template_desc;
+	return 1;
+}
+__setup("ima_template=", ima_template_setup);
+
+static int __init ima_template_fmt_setup(char *str)
+{
+	int num_templates = ARRAY_SIZE(defined_templates);
+
+	if (ima_template)
+		return 1;
+
+	if (template_desc_init_fields(str, NULL, NULL) < 0) {
+		pr_err("format string '%s' not valid, using template %s\n",
+		       str, CONFIG_IMA_DEFAULT_TEMPLATE);
+		return 1;
+	}
+
+	defined_templates[num_templates - 1].fmt = str;
+	ima_template = defined_templates + num_templates - 1;
+	return 1;
+}
+__setup("ima_template_fmt=", ima_template_fmt_setup);
+
+static struct ima_template_desc *lookup_template_desc(const char *name)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(defined_templates); i++) {
+		if (strcmp(defined_templates[i].name, name) == 0)
+			return defined_templates + i;
+	}
+
+	return NULL;
+}
+
+static struct ima_template_field *lookup_template_field(const char *field_id)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(supported_fields); i++)
+		if (strncmp(supported_fields[i].field_id, field_id,
+			    IMA_TEMPLATE_FIELD_ID_MAX_LEN) == 0)
+			return &supported_fields[i];
+	return NULL;
+}
+
+static int template_fmt_size(const char *template_fmt)
+{
+	char c;
+	int template_fmt_len = strlen(template_fmt);
+	int i = 0, j = 0;
+
+	while (i < template_fmt_len) {
+		c = template_fmt[i];
+		if (c == '|')
+			j++;
+		i++;
+	}
+
+	return j + 1;
+}
+
+static int template_desc_init_fields(const char *template_fmt,
+				     struct ima_template_field ***fields,
+				     int *num_fields)
+{
+	const char *template_fmt_ptr;
+	struct ima_template_field *found_fields[IMA_TEMPLATE_NUM_FIELDS_MAX];
+	int template_num_fields = template_fmt_size(template_fmt);
+	int i, len;
+
+	if (template_num_fields > IMA_TEMPLATE_NUM_FIELDS_MAX) {
+		pr_err("format string '%s' contains too many fields\n",
+		       template_fmt);
+		return -EINVAL;
+	}
+
+	for (i = 0, template_fmt_ptr = template_fmt; i < template_num_fields;
+	     i++, template_fmt_ptr += len + 1) {
+		char tmp_field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN + 1];
+
+		len = strchrnul(template_fmt_ptr, '|') - template_fmt_ptr;
+		if (len == 0 || len > IMA_TEMPLATE_FIELD_ID_MAX_LEN) {
+			pr_err("Invalid field with length %d\n", len);
+			return -EINVAL;
+		}
+
+		memcpy(tmp_field_id, template_fmt_ptr, len);
+		tmp_field_id[len] = '\0';
+		found_fields[i] = lookup_template_field(tmp_field_id);
+		if (!found_fields[i]) {
+			pr_err("field '%s' not found\n", tmp_field_id);
+			return -ENOENT;
+		}
+	}
+
+	if (fields && num_fields) {
+		*fields = kmalloc_array(i, sizeof(*fields), GFP_KERNEL);
+		if (*fields == NULL)
+			return -ENOMEM;
+
+		memcpy(*fields, found_fields, i * sizeof(*fields));
+		*num_fields = i;
+	}
+
+	return 0;
+}
+
+struct ima_template_desc *ima_template_desc_current(void)
+{
+	if (!ima_template)
+		ima_template =
+		    lookup_template_desc(CONFIG_IMA_DEFAULT_TEMPLATE);
+	return ima_template;
+}
+
+int __init ima_init_template(void)
+{
+	struct ima_template_desc *template = ima_template_desc_current();
+	int result;
+
+	result = template_desc_init_fields(template->fmt,
+					   &(template->fields),
+					   &(template->num_fields));
+	if (result < 0)
+		pr_err("template %s init failed, result: %d\n",
+		       (strlen(template->name) ?
+		       template->name : template->fmt), result);
+
+	return result;
+}