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, TPM_PCR10 = 10 };
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 10
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 extern const char boot_aggregate_name[];
56
57 /* IMA event related data */
58 struct ima_event_data {
59 struct integrity_iint_cache *iint;
60 struct file *file;
61 const unsigned char *filename;
62 struct evm_ima_xattr_data *xattr_value;
63 int xattr_len;
64 const struct modsig *modsig;
65 const char *violation;
66 const void *buf;
67 int buf_len;
68 };
69
70 /* IMA template field data definition */
71 struct ima_field_data {
72 u8 *data;
73 u32 len;
74 };
75
76 /* IMA template field definition */
77 struct ima_template_field {
78 const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
79 int (*field_init)(struct ima_event_data *event_data,
80 struct ima_field_data *field_data);
81 void (*field_show)(struct seq_file *m, enum ima_show_type show,
82 struct ima_field_data *field_data);
83 };
84
85 /* IMA template descriptor definition */
86 struct ima_template_desc {
87 struct list_head list;
88 char *name;
89 char *fmt;
90 int num_fields;
91 const struct ima_template_field **fields;
92 };
93
94 struct ima_template_entry {
95 int pcr;
96 u8 digest[TPM_DIGEST_SIZE]; /* sha1 or md5 measurement hash */
97 struct ima_template_desc *template_desc; /* template descriptor */
98 u32 template_data_len;
99 struct ima_field_data template_data[0]; /* template related data */
100 };
101
102 struct ima_queue_entry {
103 struct hlist_node hnext; /* place in hash collision list */
104 struct list_head later; /* place in ima_measurements list */
105 struct ima_template_entry *entry;
106 };
107 extern struct list_head ima_measurements; /* list of all measurements */
108
109 /* Some details preceding the binary serialized measurement list */
110 struct ima_kexec_hdr {
111 u16 version;
112 u16 _reserved0;
113 u32 _reserved1;
114 u64 buffer_size;
115 u64 count;
116 };
117
118 extern const int read_idmap[];
119
120 #ifdef CONFIG_HAVE_IMA_KEXEC
121 void ima_load_kexec_buffer(void);
122 #else
ima_load_kexec_buffer(void)123 static inline void ima_load_kexec_buffer(void) {}
124 #endif /* CONFIG_HAVE_IMA_KEXEC */
125
126 /*
127 * The default binary_runtime_measurements list format is defined as the
128 * platform native format. The canonical format is defined as little-endian.
129 */
130 extern bool ima_canonical_fmt;
131
132 /* Internal IMA function definitions */
133 int ima_init(void);
134 int ima_fs_init(void);
135 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
136 const char *op, struct inode *inode,
137 const unsigned char *filename);
138 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
139 int ima_calc_buffer_hash(const void *buf, loff_t len,
140 struct ima_digest_data *hash);
141 int ima_calc_field_array_hash(struct ima_field_data *field_data,
142 struct ima_template_desc *desc, int num_fields,
143 struct ima_digest_data *hash);
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 *lookup_template_desc(const char *name);
156 bool ima_template_has_modsig(const struct ima_template_desc *ima_template);
157 int ima_restore_measurement_entry(struct ima_template_entry *entry);
158 int ima_restore_measurement_list(loff_t bufsize, void *buf);
159 int ima_measurements_show(struct seq_file *m, void *v);
160 unsigned long ima_get_binary_runtime_size(void);
161 int ima_init_template(void);
162 void ima_init_template_list(void);
163 int __init ima_init_digests(void);
164 int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
165 void *lsm_data);
166
167 /*
168 * used to protect h_table and sha_table
169 */
170 extern spinlock_t ima_queue_lock;
171
172 struct ima_h_table {
173 atomic_long_t len; /* number of stored measurements in the list */
174 atomic_long_t violations;
175 struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
176 };
177 extern struct ima_h_table ima_htable;
178
ima_hash_key(u8 * digest)179 static inline unsigned int ima_hash_key(u8 *digest)
180 {
181 /* there is no point in taking a hash of part of a digest */
182 return (digest[0] | digest[1] << 8) % IMA_MEASURE_HTABLE_SIZE;
183 }
184
185 #define __ima_hooks(hook) \
186 hook(NONE) \
187 hook(FILE_CHECK) \
188 hook(MMAP_CHECK) \
189 hook(BPRM_CHECK) \
190 hook(CREDS_CHECK) \
191 hook(POST_SETATTR) \
192 hook(MODULE_CHECK) \
193 hook(FIRMWARE_CHECK) \
194 hook(KEXEC_KERNEL_CHECK) \
195 hook(KEXEC_INITRAMFS_CHECK) \
196 hook(POLICY_CHECK) \
197 hook(KEXEC_CMDLINE) \
198 hook(MAX_CHECK)
199 #define __ima_hook_enumify(ENUM) ENUM,
200
201 enum ima_hooks {
202 __ima_hooks(__ima_hook_enumify)
203 };
204
205 extern const char *const func_tokens[];
206
207 struct modsig;
208
209 /* LIM API function definitions */
210 int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
211 int mask, enum ima_hooks func, int *pcr,
212 struct ima_template_desc **template_desc);
213 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
214 int ima_collect_measurement(struct integrity_iint_cache *iint,
215 struct file *file, void *buf, loff_t size,
216 enum hash_algo algo, struct modsig *modsig);
217 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
218 const unsigned char *filename,
219 struct evm_ima_xattr_data *xattr_value,
220 int xattr_len, const struct modsig *modsig, int pcr,
221 struct ima_template_desc *template_desc);
222 void ima_audit_measurement(struct integrity_iint_cache *iint,
223 const unsigned char *filename);
224 int ima_alloc_init_template(struct ima_event_data *event_data,
225 struct ima_template_entry **entry,
226 struct ima_template_desc *template_desc);
227 int ima_store_template(struct ima_template_entry *entry, int violation,
228 struct inode *inode,
229 const unsigned char *filename, int pcr);
230 void ima_free_template_entry(struct ima_template_entry *entry);
231 const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
232
233 /* IMA policy related functions */
234 int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
235 enum ima_hooks func, int mask, int flags, int *pcr,
236 struct ima_template_desc **template_desc);
237 void ima_init_policy(void);
238 void ima_update_policy(void);
239 void ima_update_policy_flag(void);
240 ssize_t ima_parse_add_rule(char *);
241 void ima_delete_rules(void);
242 int ima_check_policy(void);
243 void *ima_policy_start(struct seq_file *m, loff_t *pos);
244 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos);
245 void ima_policy_stop(struct seq_file *m, void *v);
246 int ima_policy_show(struct seq_file *m, void *v);
247
248 /* Appraise integrity measurements */
249 #define IMA_APPRAISE_ENFORCE 0x01
250 #define IMA_APPRAISE_FIX 0x02
251 #define IMA_APPRAISE_LOG 0x04
252 #define IMA_APPRAISE_MODULES 0x08
253 #define IMA_APPRAISE_FIRMWARE 0x10
254 #define IMA_APPRAISE_POLICY 0x20
255 #define IMA_APPRAISE_KEXEC 0x40
256
257 #ifdef CONFIG_IMA_APPRAISE
258 int ima_appraise_measurement(enum ima_hooks func,
259 struct integrity_iint_cache *iint,
260 struct file *file, const unsigned char *filename,
261 struct evm_ima_xattr_data *xattr_value,
262 int xattr_len, const struct modsig *modsig);
263 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
264 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
265 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
266 enum ima_hooks func);
267 enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
268 int xattr_len);
269 int ima_read_xattr(struct dentry *dentry,
270 struct evm_ima_xattr_data **xattr_value);
271
272 #else
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)273 static inline int ima_appraise_measurement(enum ima_hooks func,
274 struct integrity_iint_cache *iint,
275 struct file *file,
276 const unsigned char *filename,
277 struct evm_ima_xattr_data *xattr_value,
278 int xattr_len,
279 const struct modsig *modsig)
280 {
281 return INTEGRITY_UNKNOWN;
282 }
283
ima_must_appraise(struct inode * inode,int mask,enum ima_hooks func)284 static inline int ima_must_appraise(struct inode *inode, int mask,
285 enum ima_hooks func)
286 {
287 return 0;
288 }
289
ima_update_xattr(struct integrity_iint_cache * iint,struct file * file)290 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
291 struct file *file)
292 {
293 }
294
ima_get_cache_status(struct integrity_iint_cache * iint,enum ima_hooks func)295 static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
296 *iint,
297 enum ima_hooks func)
298 {
299 return INTEGRITY_UNKNOWN;
300 }
301
302 static inline enum hash_algo
ima_get_hash_algo(struct evm_ima_xattr_data * xattr_value,int xattr_len)303 ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len)
304 {
305 return ima_hash_algo;
306 }
307
ima_read_xattr(struct dentry * dentry,struct evm_ima_xattr_data ** xattr_value)308 static inline int ima_read_xattr(struct dentry *dentry,
309 struct evm_ima_xattr_data **xattr_value)
310 {
311 return 0;
312 }
313
314 #endif /* CONFIG_IMA_APPRAISE */
315
316 #ifdef CONFIG_IMA_APPRAISE_MODSIG
317 bool ima_hook_supports_modsig(enum ima_hooks func);
318 int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
319 struct modsig **modsig);
320 void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size);
321 int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo,
322 const u8 **digest, u32 *digest_size);
323 int ima_get_raw_modsig(const struct modsig *modsig, const void **data,
324 u32 *data_len);
325 void ima_free_modsig(struct modsig *modsig);
326 #else
ima_hook_supports_modsig(enum ima_hooks func)327 static inline bool ima_hook_supports_modsig(enum ima_hooks func)
328 {
329 return false;
330 }
331
ima_read_modsig(enum ima_hooks func,const void * buf,loff_t buf_len,struct modsig ** modsig)332 static inline int ima_read_modsig(enum ima_hooks func, const void *buf,
333 loff_t buf_len, struct modsig **modsig)
334 {
335 return -EOPNOTSUPP;
336 }
337
ima_collect_modsig(struct modsig * modsig,const void * buf,loff_t size)338 static inline void ima_collect_modsig(struct modsig *modsig, const void *buf,
339 loff_t size)
340 {
341 }
342
ima_get_modsig_digest(const struct modsig * modsig,enum hash_algo * algo,const u8 ** digest,u32 * digest_size)343 static inline int ima_get_modsig_digest(const struct modsig *modsig,
344 enum hash_algo *algo, const u8 **digest,
345 u32 *digest_size)
346 {
347 return -EOPNOTSUPP;
348 }
349
ima_get_raw_modsig(const struct modsig * modsig,const void ** data,u32 * data_len)350 static inline int ima_get_raw_modsig(const struct modsig *modsig,
351 const void **data, u32 *data_len)
352 {
353 return -EOPNOTSUPP;
354 }
355
ima_free_modsig(struct modsig * modsig)356 static inline void ima_free_modsig(struct modsig *modsig)
357 {
358 }
359 #endif /* CONFIG_IMA_APPRAISE_MODSIG */
360
361 /* LSM based policy rules require audit */
362 #ifdef CONFIG_IMA_LSM_RULES
363
364 #define ima_filter_rule_init security_audit_rule_init
365 #define ima_filter_rule_free security_audit_rule_free
366 #define ima_filter_rule_match security_audit_rule_match
367
368 #else
369
ima_filter_rule_init(u32 field,u32 op,char * rulestr,void ** lsmrule)370 static inline int ima_filter_rule_init(u32 field, u32 op, char *rulestr,
371 void **lsmrule)
372 {
373 return -EINVAL;
374 }
375
ima_filter_rule_free(void * lsmrule)376 static inline void ima_filter_rule_free(void *lsmrule)
377 {
378 }
379
ima_filter_rule_match(u32 secid,u32 field,u32 op,void * lsmrule)380 static inline int ima_filter_rule_match(u32 secid, u32 field, u32 op,
381 void *lsmrule)
382 {
383 return -EINVAL;
384 }
385 #endif /* CONFIG_IMA_LSM_RULES */
386
387 #ifdef CONFIG_IMA_READ_POLICY
388 #define POLICY_FILE_FLAGS (S_IWUSR | S_IRUSR)
389 #else
390 #define POLICY_FILE_FLAGS S_IWUSR
391 #endif /* CONFIG_IMA_READ_POLICY */
392
393 #endif /* __LINUX_IMA_H */
394