aboutsummaryrefslogtreecommitdiff
path: root/security/integrity/ima/ima.h
blob: e1f081d65dbf9c9ca7954626ebe286e454f8bb05 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
/*
 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
 *
 * Authors:
 * Reiner Sailer <sailer@watson.ibm.com>
 * Mimi Zohar <zohar@us.ibm.com>
 *
 * 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.h
 *	internal Integrity Measurement Architecture (IMA) definitions
 */

#ifndef __LINUX_IMA_H
#define __LINUX_IMA_H

#include <linux/types.h>
#include <linux/crypto.h>
#include <linux/security.h>
#include <linux/hash.h>
#include <linux/tpm.h>
#include <linux/audit.h>

#include "../integrity.h"

enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_ASCII };
enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };

/* digest size for IMA, fits SHA1 or MD5 */
#define IMA_DIGEST_SIZE		SHA1_DIGEST_SIZE
#define IMA_EVENT_NAME_LEN_MAX	255

#define IMA_HASH_BITS 9
#define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)

#define IMA_TEMPLATE_FIELD_ID_MAX_LEN	16
#define IMA_TEMPLATE_NUM_FIELDS_MAX	15

#define IMA_TEMPLATE_IMA_NAME "ima"
#define IMA_TEMPLATE_IMA_FMT "d|n"

/* set during initialization */
extern int ima_initialized;
extern int ima_used_chip;
extern int ima_hash_algo;
extern int ima_appraise;

/* IMA template field data definition */
struct ima_field_data {
	u8 *data;
	u32 len;
};

/* IMA template field definition */
struct ima_template_field {
	const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
	int (*field_init) (struct integrity_iint_cache *iint, struct file *file,
			   const unsigned char *filename,
			   struct ima_field_data *field_data);
	void (*field_show) (struct seq_file *m, enum ima_show_type show,
			    struct ima_field_data *field_data);
};

/* IMA template descriptor definition */
struct ima_template_desc {
	char *name;
	char *fmt;
	int num_fields;
	struct ima_template_field **fields;
};

/* IMA inode template definition */
struct ima_template_data {
	u8 digest[IMA_DIGEST_SIZE];	/* sha1/md5 measurement hash */
	char file_name[IMA_EVENT_NAME_LEN_MAX + 1];	/* name + \0 */
};

struct ima_template_entry {
	u8 digest[TPM_DIGEST_SIZE];	/* sha1 or md5 measurement hash */
	const char *template_name;
	int template_len;
	struct ima_template_data template;
};

struct ima_queue_entry {
	struct hlist_node hnext;	/* place in hash collision list */
	struct list_head later;		/* place in ima_measurements list */
	struct ima_template_entry *entry;
};
extern struct list_head ima_measurements;	/* list of all measurements */

/* Internal IMA function definitions */
int ima_init(void);
void ima_cleanup(void);
int ima_fs_init(void);
void ima_fs_cleanup(void);
int ima_inode_alloc(struct inode *inode);
int ima_add_template_entry(struct ima_template_entry *entry, int violation,
			   const char *op, struct inode *inode,
			   const unsigned char *filename);
int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
int ima_calc_buffer_hash(const void *data, int len,
			 struct ima_digest_data *hash);
int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
void ima_add_violation(struct file *file, const unsigned char *filename,
		       const char *op, const char *cause);
int ima_init_crypto(void);
void ima_putc(struct seq_file *m, void *data, int datalen);
void ima_print_digest(struct seq_file *m, u8 *digest, int size);

int ima_init_template(void);

/*
 * used to protect h_table and sha_table
 */
extern spinlock_t ima_queue_lock;

struct ima_h_table {
	atomic_long_t len;	/* number of stored measurements in the list */
	atomic_long_t violations;
	struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
};
extern struct ima_h_table ima_htable;

static inline unsigned long ima_hash_key(u8 *digest)
{
	return hash_long(*digest, IMA_HASH_BITS);
}

/* LIM API function definitions */
int ima_get_action(struct inode *inode, int mask, int function);
int ima_must_measure(struct inode *inode, int mask, int function);
int ima_collect_measurement(struct integrity_iint_cache *iint,
			    struct file *file,
			    struct evm_ima_xattr_data **xattr_value,
			    int *xattr_len);
void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
			   const unsigned char *filename);
void ima_audit_measurement(struct integrity_iint_cache *iint,
			   const unsigned char *filename);
int ima_alloc_init_template(struct integrity_iint_cache *iint,
			    struct file *file, const unsigned char *filename,
			    struct ima_template_entry **entry);
int ima_store_template(struct ima_template_entry *entry, int violation,
		       struct inode *inode, const unsigned char *filename);
void ima_template_show(struct seq_file *m, void *e, enum ima_show_type show);
const char *ima_d_path(struct path *path, char **pathbuf);

/* rbtree tree calls to lookup, insert, delete
 * integrity data associated with an inode.
 */
struct integrity_iint_cache *integrity_iint_insert(struct inode *inode);
struct integrity_iint_cache *integrity_iint_find(struct inode *inode);

/* IMA policy related functions */
enum ima_hooks { FILE_CHECK = 1, MMAP_CHECK, BPRM_CHECK, MODULE_CHECK, POST_SETATTR };

int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
		     int flags);
void ima_init_policy(void);
void ima_update_policy(void);
ssize_t ima_parse_add_rule(char *);
void ima_delete_rules(void);

/* Appraise integrity measurements */
#define IMA_APPRAISE_ENFORCE	0x01
#define IMA_APPRAISE_FIX	0x02
#define IMA_APPRAISE_MODULES	0x04

#ifdef CONFIG_IMA_APPRAISE
int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
			     struct file *file, const unsigned char *filename,
			     struct evm_ima_xattr_data *xattr_value,
			     int xattr_len);
int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
					   int func);
void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len,
		       struct ima_digest_data *hash);
int ima_read_xattr(struct dentry *dentry,
		   struct evm_ima_xattr_data **xattr_value);

#else
static inline int ima_appraise_measurement(int func,
					   struct integrity_iint_cache *iint,
					   struct file *file,
					   const unsigned char *filename,
					   struct evm_ima_xattr_data *xattr_value,
					   int xattr_len)
{
	return INTEGRITY_UNKNOWN;
}

static inline int ima_must_appraise(struct inode *inode, int mask,
				    enum ima_hooks func)
{
	return 0;
}

static inline void ima_update_xattr(struct integrity_iint_cache *iint,
				    struct file *file)
{
}

static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
							 *iint, int func)
{
	return INTEGRITY_UNKNOWN;
}

static inline void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
				     int xattr_len,
				     struct ima_digest_data *hash)
{
}

static inline int ima_read_xattr(struct dentry *dentry,
				 struct evm_ima_xattr_data **xattr_value)
{
	return 0;
}

#endif

/* LSM based policy rules require audit */
#ifdef CONFIG_IMA_LSM_RULES

#define security_filter_rule_init security_audit_rule_init
#define security_filter_rule_match security_audit_rule_match

#else

static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
					    void **lsmrule)
{
	return -EINVAL;
}

static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
					     void *lsmrule,
					     struct audit_context *actx)
{
	return -EINVAL;
}
#endif /* CONFIG_IMA_LSM_RULES */
#endif