summaryrefslogtreecommitdiff
path: root/security/integrity/ima/ima.h
blob: 38043074ce5e4459d3a71805ca58e0a78062263f (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
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
 *
 * Authors:
 * Reiner Sailer <sailer@watson.ibm.com>
 * Mimi Zohar <zohar@us.ibm.com>
 *
 * 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/fs.h>
#include <linux/security.h>
#include <linux/hash.h>
#include <linux/tpm.h>
#include <linux/audit.h>
#include <crypto/hash_info.h>

#include "../integrity.h"

#ifdef CONFIG_HAVE_IMA_KEXEC
#include <asm/ima.h>
#endif

enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN,
		     IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII };
enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8, TPM_PCR10 = 10 };

/* 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 10
#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"

#define NR_BANKS(chip) ((chip != NULL) ? chip->nr_allocated_banks : 0)

/* current content of the policy */
extern int ima_policy_flag;

/* set during initialization */
extern int ima_hash_algo;
extern int ima_sha1_idx __ro_after_init;
extern int ima_hash_algo_idx __ro_after_init;
extern int ima_extra_slots __ro_after_init;
extern int ima_appraise;
extern struct tpm_chip *ima_tpm_chip;
extern const char boot_aggregate_name[];

/* IMA event related data */
struct ima_event_data {
	struct integrity_iint_cache *iint;
	struct file *file;
	const unsigned char *filename;
	struct evm_ima_xattr_data *xattr_value;
	int xattr_len;
	const struct modsig *modsig;
	const char *violation;
	const void *buf;
	int buf_len;
};

/* 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 ima_event_data *event_data,
			  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 {
	struct list_head list;
	char *name;
	char *fmt;
	int num_fields;
	const struct ima_template_field **fields;
};

struct ima_template_entry {
	int pcr;
	struct tpm_digest *digests;
	struct ima_template_desc *template_desc; /* template descriptor */
	u32 template_data_len;
	struct ima_field_data template_data[0];	/* template related data */
};

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 */

/* Some details preceding the binary serialized measurement list */
struct ima_kexec_hdr {
	u16 version;
	u16 _reserved0;
	u32 _reserved1;
	u64 buffer_size;
	u64 count;
};

extern const int read_idmap[];

#ifdef CONFIG_HAVE_IMA_KEXEC
void ima_load_kexec_buffer(void);
#else
static inline void ima_load_kexec_buffer(void) {}
#endif /* CONFIG_HAVE_IMA_KEXEC */

/*
 * The default binary_runtime_measurements list format is defined as the
 * platform native format.  The canonical format is defined as little-endian.
 */
extern bool ima_canonical_fmt;

/* Internal IMA function definitions */
int ima_init(void);
int ima_fs_init(void);
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 *buf, loff_t len,
			 struct ima_digest_data *hash);
int ima_calc_field_array_hash(struct ima_field_data *field_data,
			      struct ima_template_entry *entry);
int ima_calc_boot_aggregate(struct ima_digest_data *hash);
void ima_add_violation(struct file *file, const unsigned char *filename,
		       struct integrity_iint_cache *iint,
		       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, u32 size);
int template_desc_init_fields(const char *template_fmt,
			      const struct ima_template_field ***fields,
			      int *num_fields);
struct ima_template_desc *ima_template_desc_current(void);
struct ima_template_desc *lookup_template_desc(const char *name);
bool ima_template_has_modsig(const struct ima_template_desc *ima_template);
int ima_restore_measurement_entry(struct ima_template_entry *entry);
int ima_restore_measurement_list(loff_t bufsize, void *buf);
int ima_measurements_show(struct seq_file *m, void *v);
unsigned long ima_get_binary_runtime_size(void);
int ima_init_template(void);
void ima_init_template_list(void);
int __init ima_init_digests(void);
int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
			  void *lsm_data);

/*
 * 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 int ima_hash_key(u8 *digest)
{
	/* there is no point in taking a hash of part of a digest */
	return (digest[0] | digest[1] << 8) % IMA_MEASURE_HTABLE_SIZE;
}

#define __ima_hooks(hook)				\
	hook(NONE, none)				\
	hook(FILE_CHECK, file)				\
	hook(MMAP_CHECK, mmap)				\
	hook(BPRM_CHECK, bprm)				\
	hook(CREDS_CHECK, creds)			\
	hook(POST_SETATTR, post_setattr)		\
	hook(MODULE_CHECK, module)			\
	hook(FIRMWARE_CHECK, firmware)			\
	hook(KEXEC_KERNEL_CHECK, kexec_kernel)		\
	hook(KEXEC_INITRAMFS_CHECK, kexec_initramfs)	\
	hook(POLICY_CHECK, policy)			\
	hook(KEXEC_CMDLINE, kexec_cmdline)		\
	hook(KEY_CHECK, key)				\
	hook(MAX_CHECK, none)

#define __ima_hook_enumify(ENUM, str)	ENUM,
#define __ima_stringify(arg) (#arg)
#define __ima_hook_measuring_stringify(ENUM, str) \
		(__ima_stringify(measuring_ ##str)),

enum ima_hooks {
	__ima_hooks(__ima_hook_enumify)
};

static const char * const ima_hooks_measure_str[] = {
	__ima_hooks(__ima_hook_measuring_stringify)
};

static inline const char *func_measure_str(enum ima_hooks func)
{
	if (func >= MAX_CHECK)
		return ima_hooks_measure_str[NONE];

	return ima_hooks_measure_str[func];
}

extern const char *const func_tokens[];

struct modsig;

#ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS
/*
 * To track keys that need to be measured.
 */
struct ima_key_entry {
	struct list_head list;
	void *payload;
	size_t payload_len;
	char *keyring_name;
};
void ima_init_key_queue(void);
bool ima_should_queue_key(void);
bool ima_queue_key(struct key *keyring, const void *payload,
		   size_t payload_len);
void ima_process_queued_keys(void);
#else
static inline void ima_init_key_queue(void) {}
static inline bool ima_should_queue_key(void) { return false; }
static inline bool ima_queue_key(struct key *keyring,
				 const void *payload,
				 size_t payload_len) { return false; }
static inline void ima_process_queued_keys(void) {}
#endif /* CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS */

/* LIM API function definitions */
int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
		   int mask, enum ima_hooks func, int *pcr,
		   struct ima_template_desc **template_desc,
		   const char *keyring);
int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
int ima_collect_measurement(struct integrity_iint_cache *iint,
			    struct file *file, void *buf, loff_t size,
			    enum hash_algo algo, struct modsig *modsig);
void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
			   const unsigned char *filename,
			   struct evm_ima_xattr_data *xattr_value,
			   int xattr_len, const struct modsig *modsig, int pcr,
			   struct ima_template_desc *template_desc);
void process_buffer_measurement(struct inode *inode, const void *buf, int size,
				const char *eventname, enum ima_hooks func,
				int pcr, const char *keyring);
void ima_audit_measurement(struct integrity_iint_cache *iint,
			   const unsigned char *filename);
int ima_alloc_init_template(struct ima_event_data *event_data,
			    struct ima_template_entry **entry,
			    struct ima_template_desc *template_desc);
int ima_store_template(struct ima_template_entry *entry, int violation,
		       struct inode *inode,
		       const unsigned char *filename, int pcr);
void ima_free_template_entry(struct ima_template_entry *entry);
const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);

/* IMA policy related functions */
int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
		     enum ima_hooks func, int mask, int flags, int *pcr,
		     struct ima_template_desc **template_desc,
		     const char *keyring);
void ima_init_policy(void);
void ima_update_policy(void);
void ima_update_policy_flag(void);
ssize_t ima_parse_add_rule(char *);
void ima_delete_rules(void);
int ima_check_policy(void);
void *ima_policy_start(struct seq_file *m, loff_t *pos);
void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos);
void ima_policy_stop(struct seq_file *m, void *v);
int ima_policy_show(struct seq_file *m, void *v);

/* Appraise integrity measurements */
#define IMA_APPRAISE_ENFORCE	0x01
#define IMA_APPRAISE_FIX	0x02
#define IMA_APPRAISE_LOG	0x04
#define IMA_APPRAISE_MODULES	0x08
#define IMA_APPRAISE_FIRMWARE	0x10
#define IMA_APPRAISE_POLICY	0x20
#define IMA_APPRAISE_KEXEC	0x40

#ifdef CONFIG_IMA_APPRAISE
int ima_check_blacklist(struct integrity_iint_cache *iint,
			const struct modsig *modsig, int pcr);
int ima_appraise_measurement(enum ima_hooks func,
			     struct integrity_iint_cache *iint,
			     struct file *file, const unsigned char *filename,
			     struct evm_ima_xattr_data *xattr_value,
			     int xattr_len, const struct modsig *modsig);
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,
					   enum ima_hooks func);
enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
				 int xattr_len);
int ima_read_xattr(struct dentry *dentry,
		   struct evm_ima_xattr_data **xattr_value);

#else
static inline int ima_check_blacklist(struct integrity_iint_cache *iint,
				      const struct modsig *modsig, int pcr)
{
	return 0;
}

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

static inline enum hash_algo
ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len)
{
	return ima_hash_algo;
}

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

#endif /* CONFIG_IMA_APPRAISE */

#ifdef CONFIG_IMA_APPRAISE_MODSIG
int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
		    struct modsig **modsig);
void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size);
int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo,
			  const u8 **digest, u32 *digest_size);
int ima_get_raw_modsig(const struct modsig *modsig, const void **data,
		       u32 *data_len);
void ima_free_modsig(struct modsig *modsig);
#else
static inline int ima_read_modsig(enum ima_hooks func, const void *buf,
				  loff_t buf_len, struct modsig **modsig)
{
	return -EOPNOTSUPP;
}

static inline void ima_collect_modsig(struct modsig *modsig, const void *buf,
				      loff_t size)
{
}

static inline int ima_get_modsig_digest(const struct modsig *modsig,
					enum hash_algo *algo, const u8 **digest,
					u32 *digest_size)
{
	return -EOPNOTSUPP;
}

static inline int ima_get_raw_modsig(const struct modsig *modsig,
				     const void **data, u32 *data_len)
{
	return -EOPNOTSUPP;
}

static inline void ima_free_modsig(struct modsig *modsig)
{
}
#endif /* CONFIG_IMA_APPRAISE_MODSIG */

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

#define ima_filter_rule_init security_audit_rule_init
#define ima_filter_rule_free security_audit_rule_free
#define ima_filter_rule_match security_audit_rule_match

#else

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

static inline void ima_filter_rule_free(void *lsmrule)
{
}

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

#ifdef	CONFIG_IMA_READ_POLICY
#define	POLICY_FILE_FLAGS	(S_IWUSR | S_IRUSR)
#else
#define	POLICY_FILE_FLAGS	S_IWUSR
#endif /* CONFIG_IMA_READ_POLICY */

#endif /* __LINUX_IMA_H */