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-rw-r--r--security/integrity/ima/ima_template.c187
1 files changed, 187 insertions, 0 deletions
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
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--- /dev/null
+++ b/security/integrity/ima/ima_template.c
@@ -0,0 +1,187 @@
+/*
+ * 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.
+ */
+#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"},
+};
+
+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 __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)
+{
+ 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)
+{
+ char *c, *template_fmt_copy, *template_fmt_ptr;
+ int template_num_fields = template_fmt_size(template_fmt);
+ int i, result = 0;
+
+ if (template_num_fields > IMA_TEMPLATE_NUM_FIELDS_MAX)
+ return -EINVAL;
+
+ /* copying is needed as strsep() modifies the original buffer */
+ template_fmt_copy = kstrdup(template_fmt, GFP_KERNEL);
+ if (template_fmt_copy == NULL)
+ return -ENOMEM;
+
+ *fields = kzalloc(template_num_fields * sizeof(*fields), GFP_KERNEL);
+ if (*fields == NULL) {
+ result = -ENOMEM;
+ goto out;
+ }
+
+ template_fmt_ptr = template_fmt_copy;
+ for (i = 0; (c = strsep(&template_fmt_ptr, "|")) != NULL &&
+ i < template_num_fields; i++) {
+ struct ima_template_field *f = lookup_template_field(c);
+
+ if (!f) {
+ result = -ENOENT;
+ goto out;
+ }
+ (*fields)[i] = f;
+ }
+ *num_fields = i;
+out:
+ if (result < 0) {
+ kfree(*fields);
+ *fields = NULL;
+ }
+ kfree(template_fmt_copy);
+ return result;
+}
+
+static int init_defined_templates(void)
+{
+ int i = 0;
+ int result = 0;
+
+ /* Init defined templates. */
+ for (i = 0; i < ARRAY_SIZE(defined_templates); i++) {
+ struct ima_template_desc *template = &defined_templates[i];
+
+ result = template_desc_init_fields(template->fmt,
+ &(template->fields),
+ &(template->num_fields));
+ if (result < 0)
+ return result;
+ }
+ return result;
+}
+
+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 ima_init_template(void)
+{
+ int result;
+
+ result = init_defined_templates();
+ if (result < 0)
+ return result;
+
+ return 0;
+}
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