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 enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN,
28 IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII };
29 enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8, TPM_PCR10 = 10 };
30
31 /* digest size for IMA, fits SHA1 or MD5 */
32 #define IMA_DIGEST_SIZE SHA1_DIGEST_SIZE
33 #define IMA_EVENT_NAME_LEN_MAX 255
34
35 #define IMA_HASH_BITS 10
36 #define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)
37
38 #define IMA_TEMPLATE_FIELD_ID_MAX_LEN 16
39 #define IMA_TEMPLATE_NUM_FIELDS_MAX 15
40
41 #define IMA_TEMPLATE_IMA_NAME "ima"
42 #define IMA_TEMPLATE_IMA_FMT "d|n"
43
44 #define NR_BANKS(chip) ((chip != NULL) ? chip->nr_allocated_banks : 0)
45
46 /* current content of the policy */
47 extern int ima_policy_flag;
48
49 /* set during initialization */
50 extern int ima_hash_algo;
51 extern int ima_sha1_idx __ro_after_init;
52 extern int ima_hash_algo_idx __ro_after_init;
53 extern int ima_extra_slots __ro_after_init;
54 extern int ima_appraise;
55 extern struct tpm_chip *ima_tpm_chip;
56 extern const char boot_aggregate_name[];
57
58 /* IMA event related data */
59 struct ima_event_data {
60 struct integrity_iint_cache *iint;
61 struct file *file;
62 const unsigned char *filename;
63 struct evm_ima_xattr_data *xattr_value;
64 int xattr_len;
65 const struct modsig *modsig;
66 const char *violation;
67 const void *buf;
68 int buf_len;
69 };
70
71 /* IMA template field data definition */
72 struct ima_field_data {
73 u8 *data;
74 u32 len;
75 };
76
77 /* IMA template field definition */
78 struct ima_template_field {
79 const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
80 int (*field_init)(struct ima_event_data *event_data,
81 struct ima_field_data *field_data);
82 void (*field_show)(struct seq_file *m, enum ima_show_type show,
83 struct ima_field_data *field_data);
84 };
85
86 /* IMA template descriptor definition */
87 struct ima_template_desc {
88 struct list_head list;
89 char *name;
90 char *fmt;
91 int num_fields;
92 const struct ima_template_field **fields;
93 };
94
95 struct ima_template_entry {
96 int pcr;
97 struct tpm_digest *digests;
98 struct ima_template_desc *template_desc; /* template descriptor */
99 u32 template_data_len;
100 struct ima_field_data template_data[]; /* template related data */
101 };
102
103 struct ima_queue_entry {
104 struct hlist_node hnext; /* place in hash collision list */
105 struct list_head later; /* place in ima_measurements list */
106 struct ima_template_entry *entry;
107 };
108 extern struct list_head ima_measurements; /* list of all measurements */
109
110 /* Some details preceding the binary serialized measurement list */
111 struct ima_kexec_hdr {
112 u16 version;
113 u16 _reserved0;
114 u32 _reserved1;
115 u64 buffer_size;
116 u64 count;
117 };
118
119 extern const int read_idmap[];
120
121 #ifdef CONFIG_HAVE_IMA_KEXEC
122 void ima_load_kexec_buffer(void);
123 #else
ima_load_kexec_buffer(void)124 static inline void ima_load_kexec_buffer(void) {}
125 #endif /* CONFIG_HAVE_IMA_KEXEC */
126
127 /*
128 * The default binary_runtime_measurements list format is defined as the
129 * platform native format. The canonical format is defined as little-endian.
130 */
131 extern bool ima_canonical_fmt;
132
133 /* Internal IMA function definitions */
134 int ima_init(void);
135 int ima_fs_init(void);
136 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
137 const char *op, struct inode *inode,
138 const unsigned char *filename);
139 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
140 int ima_calc_buffer_hash(const void *buf, loff_t len,
141 struct ima_digest_data *hash);
142 int ima_calc_field_array_hash(struct ima_field_data *field_data,
143 struct ima_template_entry *entry);
144 int ima_calc_boot_aggregate(struct ima_digest_data *hash);
145 void ima_add_violation(struct file *file, const unsigned char *filename,
146 struct integrity_iint_cache *iint,
147 const char *op, const char *cause);
148 int ima_init_crypto(void);
149 void ima_putc(struct seq_file *m, void *data, int datalen);
150 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size);
151 int template_desc_init_fields(const char *template_fmt,
152 const struct ima_template_field ***fields,
153 int *num_fields);
154 struct ima_template_desc *ima_template_desc_current(void);
155 struct ima_template_desc *ima_template_desc_buf(void);
156 struct ima_template_desc *lookup_template_desc(const char *name);
157 bool ima_template_has_modsig(const struct ima_template_desc *ima_template);
158 int ima_restore_measurement_entry(struct ima_template_entry *entry);
159 int ima_restore_measurement_list(loff_t bufsize, void *buf);
160 int ima_measurements_show(struct seq_file *m, void *v);
161 unsigned long ima_get_binary_runtime_size(void);
162 int ima_init_template(void);
163 void ima_init_template_list(void);
164 int __init ima_init_digests(void);
165 int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
166 void *lsm_data);
167
168 /*
169 * used to protect h_table and sha_table
170 */
171 extern spinlock_t ima_queue_lock;
172
173 struct ima_h_table {
174 atomic_long_t len; /* number of stored measurements in the list */
175 atomic_long_t violations;
176 struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
177 };
178 extern struct ima_h_table ima_htable;
179
ima_hash_key(u8 * digest)180 static inline unsigned int ima_hash_key(u8 *digest)
181 {
182 /* there is no point in taking a hash of part of a digest */
183 return (digest[0] | digest[1] << 8) % IMA_MEASURE_HTABLE_SIZE;
184 }
185
186 #define __ima_hooks(hook) \
187 hook(NONE, none) \
188 hook(FILE_CHECK, file) \
189 hook(MMAP_CHECK, mmap) \
190 hook(BPRM_CHECK, bprm) \
191 hook(CREDS_CHECK, creds) \
192 hook(POST_SETATTR, post_setattr) \
193 hook(MODULE_CHECK, module) \
194 hook(FIRMWARE_CHECK, firmware) \
195 hook(KEXEC_KERNEL_CHECK, kexec_kernel) \
196 hook(KEXEC_INITRAMFS_CHECK, kexec_initramfs) \
197 hook(POLICY_CHECK, policy) \
198 hook(KEXEC_CMDLINE, kexec_cmdline) \
199 hook(KEY_CHECK, key) \
200 hook(CRITICAL_DATA, critical_data) \
201 hook(MAX_CHECK, none)
202
203 #define __ima_hook_enumify(ENUM, str) ENUM,
204 #define __ima_stringify(arg) (#arg)
205 #define __ima_hook_measuring_stringify(ENUM, str) \
206 (__ima_stringify(measuring_ ##str)),
207
208 enum ima_hooks {
209 __ima_hooks(__ima_hook_enumify)
210 };
211
212 static const char * const ima_hooks_measure_str[] = {
213 __ima_hooks(__ima_hook_measuring_stringify)
214 };
215
func_measure_str(enum ima_hooks func)216 static inline const char *func_measure_str(enum ima_hooks func)
217 {
218 if (func >= MAX_CHECK)
219 return ima_hooks_measure_str[NONE];
220
221 return ima_hooks_measure_str[func];
222 }
223
224 extern const char *const func_tokens[];
225
226 struct modsig;
227
228 #ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS
229 /*
230 * To track keys that need to be measured.
231 */
232 struct ima_key_entry {
233 struct list_head list;
234 void *payload;
235 size_t payload_len;
236 char *keyring_name;
237 };
238 void ima_init_key_queue(void);
239 bool ima_should_queue_key(void);
240 bool ima_queue_key(struct key *keyring, const void *payload,
241 size_t payload_len);
242 void ima_process_queued_keys(void);
243 #else
ima_init_key_queue(void)244 static inline void ima_init_key_queue(void) {}
ima_should_queue_key(void)245 static inline bool ima_should_queue_key(void) { return false; }
ima_queue_key(struct key * keyring,const void * payload,size_t payload_len)246 static inline bool ima_queue_key(struct key *keyring,
247 const void *payload,
248 size_t payload_len) { return false; }
ima_process_queued_keys(void)249 static inline void ima_process_queued_keys(void) {}
250 #endif /* CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS */
251
252 /* LIM API function definitions */
253 int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
254 const struct cred *cred, u32 secid, int mask,
255 enum ima_hooks func, int *pcr,
256 struct ima_template_desc **template_desc,
257 const char *func_data);
258 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
259 int ima_collect_measurement(struct integrity_iint_cache *iint,
260 struct file *file, void *buf, loff_t size,
261 enum hash_algo algo, struct modsig *modsig);
262 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
263 const unsigned char *filename,
264 struct evm_ima_xattr_data *xattr_value,
265 int xattr_len, const struct modsig *modsig, int pcr,
266 struct ima_template_desc *template_desc);
267 void process_buffer_measurement(struct user_namespace *mnt_userns,
268 struct inode *inode, const void *buf, int size,
269 const char *eventname, enum ima_hooks func,
270 int pcr, const char *func_data,
271 bool buf_hash);
272 void ima_audit_measurement(struct integrity_iint_cache *iint,
273 const unsigned char *filename);
274 int ima_alloc_init_template(struct ima_event_data *event_data,
275 struct ima_template_entry **entry,
276 struct ima_template_desc *template_desc);
277 int ima_store_template(struct ima_template_entry *entry, int violation,
278 struct inode *inode,
279 const unsigned char *filename, int pcr);
280 void ima_free_template_entry(struct ima_template_entry *entry);
281 const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
282
283 /* IMA policy related functions */
284 int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
285 const struct cred *cred, u32 secid, enum ima_hooks func,
286 int mask, int flags, int *pcr,
287 struct ima_template_desc **template_desc,
288 const char *func_data);
289 void ima_init_policy(void);
290 void ima_update_policy(void);
291 void ima_update_policy_flag(void);
292 ssize_t ima_parse_add_rule(char *);
293 void ima_delete_rules(void);
294 int ima_check_policy(void);
295 void *ima_policy_start(struct seq_file *m, loff_t *pos);
296 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos);
297 void ima_policy_stop(struct seq_file *m, void *v);
298 int ima_policy_show(struct seq_file *m, void *v);
299
300 /* Appraise integrity measurements */
301 #define IMA_APPRAISE_ENFORCE 0x01
302 #define IMA_APPRAISE_FIX 0x02
303 #define IMA_APPRAISE_LOG 0x04
304 #define IMA_APPRAISE_MODULES 0x08
305 #define IMA_APPRAISE_FIRMWARE 0x10
306 #define IMA_APPRAISE_POLICY 0x20
307 #define IMA_APPRAISE_KEXEC 0x40
308
309 #ifdef CONFIG_IMA_APPRAISE
310 int ima_check_blacklist(struct integrity_iint_cache *iint,
311 const struct modsig *modsig, int pcr);
312 int ima_appraise_measurement(enum ima_hooks func,
313 struct integrity_iint_cache *iint,
314 struct file *file, const unsigned char *filename,
315 struct evm_ima_xattr_data *xattr_value,
316 int xattr_len, const struct modsig *modsig);
317 int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode,
318 int mask, enum ima_hooks func);
319 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
320 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
321 enum ima_hooks func);
322 enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
323 int xattr_len);
324 int ima_read_xattr(struct dentry *dentry,
325 struct evm_ima_xattr_data **xattr_value);
326
327 #else
ima_check_blacklist(struct integrity_iint_cache * iint,const struct modsig * modsig,int pcr)328 static inline int ima_check_blacklist(struct integrity_iint_cache *iint,
329 const struct modsig *modsig, int pcr)
330 {
331 return 0;
332 }
333
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)334 static inline int ima_appraise_measurement(enum ima_hooks func,
335 struct integrity_iint_cache *iint,
336 struct file *file,
337 const unsigned char *filename,
338 struct evm_ima_xattr_data *xattr_value,
339 int xattr_len,
340 const struct modsig *modsig)
341 {
342 return INTEGRITY_UNKNOWN;
343 }
344
ima_must_appraise(struct user_namespace * mnt_userns,struct inode * inode,int mask,enum ima_hooks func)345 static inline int ima_must_appraise(struct user_namespace *mnt_userns,
346 struct inode *inode, int mask,
347 enum ima_hooks func)
348 {
349 return 0;
350 }
351
ima_update_xattr(struct integrity_iint_cache * iint,struct file * file)352 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
353 struct file *file)
354 {
355 }
356
ima_get_cache_status(struct integrity_iint_cache * iint,enum ima_hooks func)357 static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
358 *iint,
359 enum ima_hooks func)
360 {
361 return INTEGRITY_UNKNOWN;
362 }
363
364 static inline enum hash_algo
ima_get_hash_algo(struct evm_ima_xattr_data * xattr_value,int xattr_len)365 ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len)
366 {
367 return ima_hash_algo;
368 }
369
ima_read_xattr(struct dentry * dentry,struct evm_ima_xattr_data ** xattr_value)370 static inline int ima_read_xattr(struct dentry *dentry,
371 struct evm_ima_xattr_data **xattr_value)
372 {
373 return 0;
374 }
375
376 #endif /* CONFIG_IMA_APPRAISE */
377
378 #ifdef CONFIG_IMA_APPRAISE_MODSIG
379 int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
380 struct modsig **modsig);
381 void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size);
382 int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo,
383 const u8 **digest, u32 *digest_size);
384 int ima_get_raw_modsig(const struct modsig *modsig, const void **data,
385 u32 *data_len);
386 void ima_free_modsig(struct modsig *modsig);
387 #else
ima_read_modsig(enum ima_hooks func,const void * buf,loff_t buf_len,struct modsig ** modsig)388 static inline int ima_read_modsig(enum ima_hooks func, const void *buf,
389 loff_t buf_len, struct modsig **modsig)
390 {
391 return -EOPNOTSUPP;
392 }
393
ima_collect_modsig(struct modsig * modsig,const void * buf,loff_t size)394 static inline void ima_collect_modsig(struct modsig *modsig, const void *buf,
395 loff_t size)
396 {
397 }
398
ima_get_modsig_digest(const struct modsig * modsig,enum hash_algo * algo,const u8 ** digest,u32 * digest_size)399 static inline int ima_get_modsig_digest(const struct modsig *modsig,
400 enum hash_algo *algo, const u8 **digest,
401 u32 *digest_size)
402 {
403 return -EOPNOTSUPP;
404 }
405
ima_get_raw_modsig(const struct modsig * modsig,const void ** data,u32 * data_len)406 static inline int ima_get_raw_modsig(const struct modsig *modsig,
407 const void **data, u32 *data_len)
408 {
409 return -EOPNOTSUPP;
410 }
411
ima_free_modsig(struct modsig * modsig)412 static inline void ima_free_modsig(struct modsig *modsig)
413 {
414 }
415 #endif /* CONFIG_IMA_APPRAISE_MODSIG */
416
417 /* LSM based policy rules require audit */
418 #ifdef CONFIG_IMA_LSM_RULES
419
420 #define ima_filter_rule_init security_audit_rule_init
421 #define ima_filter_rule_free security_audit_rule_free
422 #define ima_filter_rule_match security_audit_rule_match
423
424 #else
425
ima_filter_rule_init(u32 field,u32 op,char * rulestr,void ** lsmrule)426 static inline int ima_filter_rule_init(u32 field, u32 op, char *rulestr,
427 void **lsmrule)
428 {
429 return -EINVAL;
430 }
431
ima_filter_rule_free(void * lsmrule)432 static inline void ima_filter_rule_free(void *lsmrule)
433 {
434 }
435
ima_filter_rule_match(u32 secid,u32 field,u32 op,void * lsmrule)436 static inline int ima_filter_rule_match(u32 secid, u32 field, u32 op,
437 void *lsmrule)
438 {
439 return -EINVAL;
440 }
441 #endif /* CONFIG_IMA_LSM_RULES */
442
443 #ifdef CONFIG_IMA_READ_POLICY
444 #define POLICY_FILE_FLAGS (S_IWUSR | S_IRUSR)
445 #else
446 #define POLICY_FILE_FLAGS S_IWUSR
447 #endif /* CONFIG_IMA_READ_POLICY */
448
449 #endif /* __LINUX_IMA_H */
450