xref: /openbmc/linux/security/integrity/ima/ima.h (revision dc6a81c3)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2005,2006,2007,2008 IBM Corporation
4  *
5  * Authors:
6  * Reiner Sailer <sailer@watson.ibm.com>
7  * Mimi Zohar <zohar@us.ibm.com>
8  *
9  * File: ima.h
10  *	internal Integrity Measurement Architecture (IMA) definitions
11  */
12 
13 #ifndef __LINUX_IMA_H
14 #define __LINUX_IMA_H
15 
16 #include <linux/types.h>
17 #include <linux/crypto.h>
18 #include <linux/fs.h>
19 #include <linux/security.h>
20 #include <linux/hash.h>
21 #include <linux/tpm.h>
22 #include <linux/audit.h>
23 #include <crypto/hash_info.h>
24 
25 #include "../integrity.h"
26 
27 #ifdef CONFIG_HAVE_IMA_KEXEC
28 #include <asm/ima.h>
29 #endif
30 
31 enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN,
32 		     IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII };
33 enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
34 
35 /* digest size for IMA, fits SHA1 or MD5 */
36 #define IMA_DIGEST_SIZE		SHA1_DIGEST_SIZE
37 #define IMA_EVENT_NAME_LEN_MAX	255
38 
39 #define IMA_HASH_BITS 9
40 #define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)
41 
42 #define IMA_TEMPLATE_FIELD_ID_MAX_LEN	16
43 #define IMA_TEMPLATE_NUM_FIELDS_MAX	15
44 
45 #define IMA_TEMPLATE_IMA_NAME "ima"
46 #define IMA_TEMPLATE_IMA_FMT "d|n"
47 
48 /* current content of the policy */
49 extern int ima_policy_flag;
50 
51 /* set during initialization */
52 extern int ima_hash_algo;
53 extern int ima_appraise;
54 extern struct tpm_chip *ima_tpm_chip;
55 
56 /* IMA event related data */
57 struct ima_event_data {
58 	struct integrity_iint_cache *iint;
59 	struct file *file;
60 	const unsigned char *filename;
61 	struct evm_ima_xattr_data *xattr_value;
62 	int xattr_len;
63 	const struct modsig *modsig;
64 	const char *violation;
65 	const void *buf;
66 	int buf_len;
67 };
68 
69 /* IMA template field data definition */
70 struct ima_field_data {
71 	u8 *data;
72 	u32 len;
73 };
74 
75 /* IMA template field definition */
76 struct ima_template_field {
77 	const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
78 	int (*field_init)(struct ima_event_data *event_data,
79 			  struct ima_field_data *field_data);
80 	void (*field_show)(struct seq_file *m, enum ima_show_type show,
81 			   struct ima_field_data *field_data);
82 };
83 
84 /* IMA template descriptor definition */
85 struct ima_template_desc {
86 	struct list_head list;
87 	char *name;
88 	char *fmt;
89 	int num_fields;
90 	const struct ima_template_field **fields;
91 };
92 
93 struct ima_template_entry {
94 	int pcr;
95 	u8 digest[TPM_DIGEST_SIZE];	/* sha1 or md5 measurement hash */
96 	struct ima_template_desc *template_desc; /* template descriptor */
97 	u32 template_data_len;
98 	struct ima_field_data template_data[0];	/* template related data */
99 };
100 
101 struct ima_queue_entry {
102 	struct hlist_node hnext;	/* place in hash collision list */
103 	struct list_head later;		/* place in ima_measurements list */
104 	struct ima_template_entry *entry;
105 };
106 extern struct list_head ima_measurements;	/* list of all measurements */
107 
108 /* Some details preceding the binary serialized measurement list */
109 struct ima_kexec_hdr {
110 	u16 version;
111 	u16 _reserved0;
112 	u32 _reserved1;
113 	u64 buffer_size;
114 	u64 count;
115 };
116 
117 extern const int read_idmap[];
118 
119 #ifdef CONFIG_HAVE_IMA_KEXEC
120 void ima_load_kexec_buffer(void);
121 #else
122 static inline void ima_load_kexec_buffer(void) {}
123 #endif /* CONFIG_HAVE_IMA_KEXEC */
124 
125 /*
126  * The default binary_runtime_measurements list format is defined as the
127  * platform native format.  The canonical format is defined as little-endian.
128  */
129 extern bool ima_canonical_fmt;
130 
131 /* Internal IMA function definitions */
132 int ima_init(void);
133 int ima_fs_init(void);
134 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
135 			   const char *op, struct inode *inode,
136 			   const unsigned char *filename);
137 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
138 int ima_calc_buffer_hash(const void *buf, loff_t len,
139 			 struct ima_digest_data *hash);
140 int ima_calc_field_array_hash(struct ima_field_data *field_data,
141 			      struct ima_template_desc *desc, int num_fields,
142 			      struct ima_digest_data *hash);
143 int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
144 void ima_add_violation(struct file *file, const unsigned char *filename,
145 		       struct integrity_iint_cache *iint,
146 		       const char *op, const char *cause);
147 int ima_init_crypto(void);
148 void ima_putc(struct seq_file *m, void *data, int datalen);
149 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size);
150 int template_desc_init_fields(const char *template_fmt,
151 			      const struct ima_template_field ***fields,
152 			      int *num_fields);
153 struct ima_template_desc *ima_template_desc_current(void);
154 struct ima_template_desc *lookup_template_desc(const char *name);
155 bool ima_template_has_modsig(const struct ima_template_desc *ima_template);
156 int ima_restore_measurement_entry(struct ima_template_entry *entry);
157 int ima_restore_measurement_list(loff_t bufsize, void *buf);
158 int ima_measurements_show(struct seq_file *m, void *v);
159 unsigned long ima_get_binary_runtime_size(void);
160 int ima_init_template(void);
161 void ima_init_template_list(void);
162 int __init ima_init_digests(void);
163 int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
164 			  void *lsm_data);
165 
166 /*
167  * used to protect h_table and sha_table
168  */
169 extern spinlock_t ima_queue_lock;
170 
171 struct ima_h_table {
172 	atomic_long_t len;	/* number of stored measurements in the list */
173 	atomic_long_t violations;
174 	struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
175 };
176 extern struct ima_h_table ima_htable;
177 
178 static inline unsigned long ima_hash_key(u8 *digest)
179 {
180 	return hash_long(*digest, IMA_HASH_BITS);
181 }
182 
183 #define __ima_hooks(hook)		\
184 	hook(NONE)			\
185 	hook(FILE_CHECK)		\
186 	hook(MMAP_CHECK)		\
187 	hook(BPRM_CHECK)		\
188 	hook(CREDS_CHECK)		\
189 	hook(POST_SETATTR)		\
190 	hook(MODULE_CHECK)		\
191 	hook(FIRMWARE_CHECK)		\
192 	hook(KEXEC_KERNEL_CHECK)	\
193 	hook(KEXEC_INITRAMFS_CHECK)	\
194 	hook(POLICY_CHECK)		\
195 	hook(KEXEC_CMDLINE)		\
196 	hook(KEY_CHECK)			\
197 	hook(MAX_CHECK)
198 #define __ima_hook_enumify(ENUM)	ENUM,
199 
200 enum ima_hooks {
201 	__ima_hooks(__ima_hook_enumify)
202 };
203 
204 extern const char *const func_tokens[];
205 
206 struct modsig;
207 
208 #ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS
209 /*
210  * To track keys that need to be measured.
211  */
212 struct ima_key_entry {
213 	struct list_head list;
214 	void *payload;
215 	size_t payload_len;
216 	char *keyring_name;
217 };
218 void ima_init_key_queue(void);
219 bool ima_should_queue_key(void);
220 bool ima_queue_key(struct key *keyring, const void *payload,
221 		   size_t payload_len);
222 void ima_process_queued_keys(void);
223 #else
224 static inline void ima_init_key_queue(void) {}
225 static inline bool ima_should_queue_key(void) { return false; }
226 static inline bool ima_queue_key(struct key *keyring,
227 				 const void *payload,
228 				 size_t payload_len) { return false; }
229 static inline void ima_process_queued_keys(void) {}
230 #endif /* CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS */
231 
232 /* LIM API function definitions */
233 int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
234 		   int mask, enum ima_hooks func, int *pcr,
235 		   struct ima_template_desc **template_desc,
236 		   const char *keyring);
237 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
238 int ima_collect_measurement(struct integrity_iint_cache *iint,
239 			    struct file *file, void *buf, loff_t size,
240 			    enum hash_algo algo, struct modsig *modsig);
241 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
242 			   const unsigned char *filename,
243 			   struct evm_ima_xattr_data *xattr_value,
244 			   int xattr_len, const struct modsig *modsig, int pcr,
245 			   struct ima_template_desc *template_desc);
246 void process_buffer_measurement(const void *buf, int size,
247 				const char *eventname, enum ima_hooks func,
248 				int pcr, const char *keyring);
249 void ima_audit_measurement(struct integrity_iint_cache *iint,
250 			   const unsigned char *filename);
251 int ima_alloc_init_template(struct ima_event_data *event_data,
252 			    struct ima_template_entry **entry,
253 			    struct ima_template_desc *template_desc);
254 int ima_store_template(struct ima_template_entry *entry, int violation,
255 		       struct inode *inode,
256 		       const unsigned char *filename, int pcr);
257 void ima_free_template_entry(struct ima_template_entry *entry);
258 const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
259 
260 /* IMA policy related functions */
261 int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
262 		     enum ima_hooks func, int mask, int flags, int *pcr,
263 		     struct ima_template_desc **template_desc,
264 		     const char *keyring);
265 void ima_init_policy(void);
266 void ima_update_policy(void);
267 void ima_update_policy_flag(void);
268 ssize_t ima_parse_add_rule(char *);
269 void ima_delete_rules(void);
270 int ima_check_policy(void);
271 void *ima_policy_start(struct seq_file *m, loff_t *pos);
272 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos);
273 void ima_policy_stop(struct seq_file *m, void *v);
274 int ima_policy_show(struct seq_file *m, void *v);
275 
276 /* Appraise integrity measurements */
277 #define IMA_APPRAISE_ENFORCE	0x01
278 #define IMA_APPRAISE_FIX	0x02
279 #define IMA_APPRAISE_LOG	0x04
280 #define IMA_APPRAISE_MODULES	0x08
281 #define IMA_APPRAISE_FIRMWARE	0x10
282 #define IMA_APPRAISE_POLICY	0x20
283 #define IMA_APPRAISE_KEXEC	0x40
284 
285 #ifdef CONFIG_IMA_APPRAISE
286 int ima_check_blacklist(struct integrity_iint_cache *iint,
287 			const struct modsig *modsig, int pcr);
288 int ima_appraise_measurement(enum ima_hooks func,
289 			     struct integrity_iint_cache *iint,
290 			     struct file *file, const unsigned char *filename,
291 			     struct evm_ima_xattr_data *xattr_value,
292 			     int xattr_len, const struct modsig *modsig);
293 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
294 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
295 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
296 					   enum ima_hooks func);
297 enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
298 				 int xattr_len);
299 int ima_read_xattr(struct dentry *dentry,
300 		   struct evm_ima_xattr_data **xattr_value);
301 
302 #else
303 static inline int ima_check_blacklist(struct integrity_iint_cache *iint,
304 				      const struct modsig *modsig, int pcr)
305 {
306 	return 0;
307 }
308 
309 static inline int ima_appraise_measurement(enum ima_hooks func,
310 					   struct integrity_iint_cache *iint,
311 					   struct file *file,
312 					   const unsigned char *filename,
313 					   struct evm_ima_xattr_data *xattr_value,
314 					   int xattr_len,
315 					   const struct modsig *modsig)
316 {
317 	return INTEGRITY_UNKNOWN;
318 }
319 
320 static inline int ima_must_appraise(struct inode *inode, int mask,
321 				    enum ima_hooks func)
322 {
323 	return 0;
324 }
325 
326 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
327 				    struct file *file)
328 {
329 }
330 
331 static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
332 							 *iint,
333 							 enum ima_hooks func)
334 {
335 	return INTEGRITY_UNKNOWN;
336 }
337 
338 static inline enum hash_algo
339 ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len)
340 {
341 	return ima_hash_algo;
342 }
343 
344 static inline int ima_read_xattr(struct dentry *dentry,
345 				 struct evm_ima_xattr_data **xattr_value)
346 {
347 	return 0;
348 }
349 
350 #endif /* CONFIG_IMA_APPRAISE */
351 
352 #ifdef CONFIG_IMA_APPRAISE_MODSIG
353 bool ima_hook_supports_modsig(enum ima_hooks func);
354 int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
355 		    struct modsig **modsig);
356 void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size);
357 int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo,
358 			  const u8 **digest, u32 *digest_size);
359 int ima_get_raw_modsig(const struct modsig *modsig, const void **data,
360 		       u32 *data_len);
361 void ima_free_modsig(struct modsig *modsig);
362 #else
363 static inline bool ima_hook_supports_modsig(enum ima_hooks func)
364 {
365 	return false;
366 }
367 
368 static inline int ima_read_modsig(enum ima_hooks func, const void *buf,
369 				  loff_t buf_len, struct modsig **modsig)
370 {
371 	return -EOPNOTSUPP;
372 }
373 
374 static inline void ima_collect_modsig(struct modsig *modsig, const void *buf,
375 				      loff_t size)
376 {
377 }
378 
379 static inline int ima_get_modsig_digest(const struct modsig *modsig,
380 					enum hash_algo *algo, const u8 **digest,
381 					u32 *digest_size)
382 {
383 	return -EOPNOTSUPP;
384 }
385 
386 static inline int ima_get_raw_modsig(const struct modsig *modsig,
387 				     const void **data, u32 *data_len)
388 {
389 	return -EOPNOTSUPP;
390 }
391 
392 static inline void ima_free_modsig(struct modsig *modsig)
393 {
394 }
395 #endif /* CONFIG_IMA_APPRAISE_MODSIG */
396 
397 /* LSM based policy rules require audit */
398 #ifdef CONFIG_IMA_LSM_RULES
399 
400 #define security_filter_rule_init security_audit_rule_init
401 #define security_filter_rule_match security_audit_rule_match
402 
403 #else
404 
405 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
406 					    void **lsmrule)
407 {
408 	return -EINVAL;
409 }
410 
411 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
412 					     void *lsmrule)
413 {
414 	return -EINVAL;
415 }
416 #endif /* CONFIG_IMA_LSM_RULES */
417 
418 #ifdef	CONFIG_IMA_READ_POLICY
419 #define	POLICY_FILE_FLAGS	(S_IWUSR | S_IRUSR)
420 #else
421 #define	POLICY_FILE_FLAGS	S_IWUSR
422 #endif /* CONFIG_IMA_READ_POLICY */
423 
424 #endif /* __LINUX_IMA_H */
425