2 * Copyright (C) 2013 Politecnico di Torino, Italy
3 * TORSEC group -- http://security.polito.it
5 * Author: Roberto Sassu <roberto.sassu@polito.it>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation, version 2 of the
12 * File: ima_template.c
13 * Helpers to manage template descriptors.
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <crypto/hash_info.h>
21 #include "ima_template_lib.h"
23 static struct ima_template_desc defined_templates[] = {
24 {.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT},
25 {.name = "ima-ng",.fmt = "d-ng|n-ng"},
26 {.name = "ima-sig",.fmt = "d-ng|n-ng|sig"},
29 static struct ima_template_field supported_fields[] = {
30 {.field_id = "d",.field_init = ima_eventdigest_init,
31 .field_show = ima_show_template_digest},
32 {.field_id = "n",.field_init = ima_eventname_init,
33 .field_show = ima_show_template_string},
34 {.field_id = "d-ng",.field_init = ima_eventdigest_ng_init,
35 .field_show = ima_show_template_digest_ng},
36 {.field_id = "n-ng",.field_init = ima_eventname_ng_init,
37 .field_show = ima_show_template_string},
38 {.field_id = "sig",.field_init = ima_eventsig_init,
39 .field_show = ima_show_template_sig},
42 static struct ima_template_desc *ima_template;
43 static struct ima_template_desc *lookup_template_desc(const char *name);
45 static int __init ima_template_setup(char *str)
47 struct ima_template_desc *template_desc;
48 int template_len = strlen(str);
51 * Verify that a template with the supplied name exists.
52 * If not, use CONFIG_IMA_DEFAULT_TEMPLATE.
54 template_desc = lookup_template_desc(str);
59 * Verify whether the current hash algorithm is supported
60 * by the 'ima' template.
62 if (template_len == 3 && strcmp(str, IMA_TEMPLATE_IMA_NAME) == 0 &&
63 ima_hash_algo != HASH_ALGO_SHA1 && ima_hash_algo != HASH_ALGO_MD5) {
64 pr_err("template does not support hash alg\n");
68 ima_template = template_desc;
71 __setup("ima_template=", ima_template_setup);
73 static struct ima_template_desc *lookup_template_desc(const char *name)
77 for (i = 0; i < ARRAY_SIZE(defined_templates); i++) {
78 if (strcmp(defined_templates[i].name, name) == 0)
79 return defined_templates + i;
85 static struct ima_template_field *lookup_template_field(const char *field_id)
89 for (i = 0; i < ARRAY_SIZE(supported_fields); i++)
90 if (strncmp(supported_fields[i].field_id, field_id,
91 IMA_TEMPLATE_FIELD_ID_MAX_LEN) == 0)
92 return &supported_fields[i];
96 static int template_fmt_size(const char *template_fmt)
99 int template_fmt_len = strlen(template_fmt);
102 while (i < template_fmt_len) {
112 static int template_desc_init_fields(const char *template_fmt,
113 struct ima_template_field ***fields,
116 char *c, *template_fmt_copy, *template_fmt_ptr;
117 int template_num_fields = template_fmt_size(template_fmt);
120 if (template_num_fields > IMA_TEMPLATE_NUM_FIELDS_MAX)
123 /* copying is needed as strsep() modifies the original buffer */
124 template_fmt_copy = kstrdup(template_fmt, GFP_KERNEL);
125 if (template_fmt_copy == NULL)
128 *fields = kzalloc(template_num_fields * sizeof(*fields), GFP_KERNEL);
129 if (*fields == NULL) {
134 template_fmt_ptr = template_fmt_copy;
135 for (i = 0; (c = strsep(&template_fmt_ptr, "|")) != NULL &&
136 i < template_num_fields; i++) {
137 struct ima_template_field *f = lookup_template_field(c);
151 kfree(template_fmt_copy);
155 static int init_defined_templates(void)
160 /* Init defined templates. */
161 for (i = 0; i < ARRAY_SIZE(defined_templates); i++) {
162 struct ima_template_desc *template = &defined_templates[i];
164 result = template_desc_init_fields(template->fmt,
166 &(template->num_fields));
173 struct ima_template_desc *ima_template_desc_current(void)
177 lookup_template_desc(CONFIG_IMA_DEFAULT_TEMPLATE);
181 int ima_init_template(void)
185 result = init_defined_templates();