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 /* bitset of digests algorithms allowed in the setxattr hook */ 50 extern atomic_t ima_setxattr_allowed_hash_algorithms; 51 52 /* IMA hash algorithm description */ 53 struct ima_algo_desc { 54 struct crypto_shash *tfm; 55 enum hash_algo algo; 56 }; 57 58 /* set during initialization */ 59 extern int ima_hash_algo __ro_after_init; 60 extern int ima_sha1_idx __ro_after_init; 61 extern int ima_hash_algo_idx __ro_after_init; 62 extern int ima_extra_slots __ro_after_init; 63 extern struct ima_algo_desc *ima_algo_array __ro_after_init; 64 65 extern int ima_appraise; 66 extern struct tpm_chip *ima_tpm_chip; 67 extern const char boot_aggregate_name[]; 68 69 /* IMA event related data */ 70 struct ima_event_data { 71 struct ima_iint_cache *iint; 72 struct file *file; 73 const unsigned char *filename; 74 struct evm_ima_xattr_data *xattr_value; 75 int xattr_len; 76 const struct modsig *modsig; 77 const char *violation; 78 const void *buf; 79 int buf_len; 80 }; 81 82 /* IMA template field data definition */ 83 struct ima_field_data { 84 u8 *data; 85 u32 len; 86 }; 87 88 /* IMA template field definition */ 89 struct ima_template_field { 90 const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN]; 91 int (*field_init)(struct ima_event_data *event_data, 92 struct ima_field_data *field_data); 93 void (*field_show)(struct seq_file *m, enum ima_show_type show, 94 struct ima_field_data *field_data); 95 }; 96 97 /* IMA template descriptor definition */ 98 struct ima_template_desc { 99 struct list_head list; 100 char *name; 101 char *fmt; 102 int num_fields; 103 const struct ima_template_field **fields; 104 }; 105 106 struct ima_template_entry { 107 int pcr; 108 struct tpm_digest *digests; 109 struct ima_template_desc *template_desc; /* template descriptor */ 110 u32 template_data_len; 111 struct ima_field_data template_data[]; /* template related data */ 112 }; 113 114 struct ima_queue_entry { 115 struct hlist_node hnext; /* place in hash collision list */ 116 struct list_head later; /* place in ima_measurements list */ 117 struct ima_template_entry *entry; 118 }; 119 extern struct list_head ima_measurements; /* list of all measurements */ 120 121 /* Some details preceding the binary serialized measurement list */ 122 struct ima_kexec_hdr { 123 u16 version; 124 u16 _reserved0; 125 u32 _reserved1; 126 u64 buffer_size; 127 u64 count; 128 }; 129 130 /* IMA iint action cache flags */ 131 #define IMA_MEASURE 0x00000001 132 #define IMA_MEASURED 0x00000002 133 #define IMA_APPRAISE 0x00000004 134 #define IMA_APPRAISED 0x00000008 135 /*#define IMA_COLLECT 0x00000010 do not use this flag */ 136 #define IMA_COLLECTED 0x00000020 137 #define IMA_AUDIT 0x00000040 138 #define IMA_AUDITED 0x00000080 139 #define IMA_HASH 0x00000100 140 #define IMA_HASHED 0x00000200 141 142 /* IMA iint policy rule cache flags */ 143 #define IMA_NONACTION_FLAGS 0xff000000 144 #define IMA_DIGSIG_REQUIRED 0x01000000 145 #define IMA_PERMIT_DIRECTIO 0x02000000 146 #define IMA_NEW_FILE 0x04000000 147 #define IMA_FAIL_UNVERIFIABLE_SIGS 0x10000000 148 #define IMA_MODSIG_ALLOWED 0x20000000 149 #define IMA_CHECK_BLACKLIST 0x40000000 150 #define IMA_VERITY_REQUIRED 0x80000000 151 152 /* Exclude non-action flags which are not rule-specific. */ 153 #define IMA_NONACTION_RULE_FLAGS (IMA_NONACTION_FLAGS & ~IMA_NEW_FILE) 154 155 #define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \ 156 IMA_HASH | IMA_APPRAISE_SUBMASK) 157 #define IMA_DONE_MASK (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \ 158 IMA_HASHED | IMA_COLLECTED | \ 159 IMA_APPRAISED_SUBMASK) 160 161 /* IMA iint subaction appraise cache flags */ 162 #define IMA_FILE_APPRAISE 0x00001000 163 #define IMA_FILE_APPRAISED 0x00002000 164 #define IMA_MMAP_APPRAISE 0x00004000 165 #define IMA_MMAP_APPRAISED 0x00008000 166 #define IMA_BPRM_APPRAISE 0x00010000 167 #define IMA_BPRM_APPRAISED 0x00020000 168 #define IMA_READ_APPRAISE 0x00040000 169 #define IMA_READ_APPRAISED 0x00080000 170 #define IMA_CREDS_APPRAISE 0x00100000 171 #define IMA_CREDS_APPRAISED 0x00200000 172 #define IMA_APPRAISE_SUBMASK (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \ 173 IMA_BPRM_APPRAISE | IMA_READ_APPRAISE | \ 174 IMA_CREDS_APPRAISE) 175 #define IMA_APPRAISED_SUBMASK (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \ 176 IMA_BPRM_APPRAISED | IMA_READ_APPRAISED | \ 177 IMA_CREDS_APPRAISED) 178 179 /* IMA iint cache atomic_flags */ 180 #define IMA_CHANGE_XATTR 0 181 #define IMA_UPDATE_XATTR 1 182 #define IMA_CHANGE_ATTR 2 183 #define IMA_DIGSIG 3 184 #define IMA_MAY_EMIT_TOMTOU 4 185 #define IMA_EMITTED_OPENWRITERS 5 186 187 /* IMA integrity metadata associated with an inode */ 188 struct ima_iint_cache { 189 struct mutex mutex; /* protects: version, flags, digest */ 190 struct integrity_inode_attributes real_inode; 191 unsigned long flags; 192 unsigned long measured_pcrs; 193 unsigned long atomic_flags; 194 enum integrity_status ima_file_status:4; 195 enum integrity_status ima_mmap_status:4; 196 enum integrity_status ima_bprm_status:4; 197 enum integrity_status ima_read_status:4; 198 enum integrity_status ima_creds_status:4; 199 struct ima_digest_data *ima_hash; 200 }; 201 202 extern struct lsm_blob_sizes ima_blob_sizes; 203 204 static inline struct ima_iint_cache * 205 ima_inode_get_iint(const struct inode *inode) 206 { 207 struct ima_iint_cache **iint_sec; 208 209 if (unlikely(!inode->i_security)) 210 return NULL; 211 212 iint_sec = inode->i_security + ima_blob_sizes.lbs_inode; 213 return *iint_sec; 214 } 215 216 static inline void ima_inode_set_iint(const struct inode *inode, 217 struct ima_iint_cache *iint) 218 { 219 struct ima_iint_cache **iint_sec; 220 221 if (unlikely(!inode->i_security)) 222 return; 223 224 iint_sec = inode->i_security + ima_blob_sizes.lbs_inode; 225 *iint_sec = iint; 226 } 227 228 struct ima_iint_cache *ima_iint_find(struct inode *inode); 229 struct ima_iint_cache *ima_inode_get(struct inode *inode); 230 void ima_inode_free_rcu(void *inode_security); 231 void __init ima_iintcache_init(void); 232 233 extern const int read_idmap[]; 234 235 #ifdef CONFIG_HAVE_IMA_KEXEC 236 void ima_load_kexec_buffer(void); 237 #else 238 static inline void ima_load_kexec_buffer(void) {} 239 #endif /* CONFIG_HAVE_IMA_KEXEC */ 240 241 #ifdef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS 242 void ima_post_key_create_or_update(struct key *keyring, struct key *key, 243 const void *payload, size_t plen, 244 unsigned long flags, bool create); 245 #endif 246 247 #ifdef CONFIG_IMA_KEXEC 248 void ima_measure_kexec_event(const char *event_name); 249 #else 250 static inline void ima_measure_kexec_event(const char *event_name) {} 251 #endif 252 253 /* 254 * The default binary_runtime_measurements list format is defined as the 255 * platform native format. The canonical format is defined as little-endian. 256 */ 257 extern bool ima_canonical_fmt; 258 259 /* Internal IMA function definitions */ 260 int ima_init(void); 261 int ima_fs_init(void); 262 int ima_add_template_entry(struct ima_template_entry *entry, int violation, 263 const char *op, struct inode *inode, 264 const unsigned char *filename); 265 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash); 266 int ima_calc_buffer_hash(const void *buf, loff_t len, 267 struct ima_digest_data *hash); 268 int ima_calc_field_array_hash(struct ima_field_data *field_data, 269 struct ima_template_entry *entry); 270 int ima_calc_boot_aggregate(struct ima_digest_data *hash); 271 void ima_add_violation(struct file *file, const unsigned char *filename, 272 struct ima_iint_cache *iint, const char *op, 273 const char *cause); 274 int ima_init_crypto(void); 275 void ima_putc(struct seq_file *m, void *data, int datalen); 276 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size); 277 int template_desc_init_fields(const char *template_fmt, 278 const struct ima_template_field ***fields, 279 int *num_fields); 280 struct ima_template_desc *ima_template_desc_current(void); 281 struct ima_template_desc *ima_template_desc_buf(void); 282 struct ima_template_desc *lookup_template_desc(const char *name); 283 bool ima_template_has_modsig(const struct ima_template_desc *ima_template); 284 int ima_restore_measurement_entry(struct ima_template_entry *entry); 285 int ima_restore_measurement_list(loff_t bufsize, void *buf); 286 int ima_measurements_show(struct seq_file *m, void *v); 287 unsigned long ima_get_binary_runtime_size(void); 288 int ima_init_template(void); 289 void ima_init_template_list(void); 290 int __init ima_init_digests(void); 291 void __init ima_init_reboot_notifier(void); 292 int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event, 293 void *lsm_data); 294 295 /* 296 * used to protect h_table and sha_table 297 */ 298 extern spinlock_t ima_queue_lock; 299 300 struct ima_h_table { 301 atomic_long_t len; /* number of stored measurements in the list */ 302 atomic_long_t violations; 303 struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE]; 304 }; 305 extern struct ima_h_table ima_htable; 306 307 static inline unsigned int ima_hash_key(u8 *digest) 308 { 309 /* there is no point in taking a hash of part of a digest */ 310 return (digest[0] | digest[1] << 8) % IMA_MEASURE_HTABLE_SIZE; 311 } 312 313 #define __ima_hooks(hook) \ 314 hook(NONE, none) \ 315 hook(FILE_CHECK, file) \ 316 hook(MMAP_CHECK, mmap) \ 317 hook(MMAP_CHECK_REQPROT, mmap_reqprot) \ 318 hook(BPRM_CHECK, bprm) \ 319 hook(CREDS_CHECK, creds) \ 320 hook(POST_SETATTR, post_setattr) \ 321 hook(MODULE_CHECK, module) \ 322 hook(FIRMWARE_CHECK, firmware) \ 323 hook(KEXEC_KERNEL_CHECK, kexec_kernel) \ 324 hook(KEXEC_INITRAMFS_CHECK, kexec_initramfs) \ 325 hook(POLICY_CHECK, policy) \ 326 hook(KEXEC_CMDLINE, kexec_cmdline) \ 327 hook(KEY_CHECK, key) \ 328 hook(CRITICAL_DATA, critical_data) \ 329 hook(SETXATTR_CHECK, setxattr_check) \ 330 hook(MAX_CHECK, none) 331 332 #define __ima_hook_enumify(ENUM, str) ENUM, 333 #define __ima_stringify(arg) (#arg) 334 #define __ima_hook_measuring_stringify(ENUM, str) \ 335 (__ima_stringify(measuring_ ##str)), 336 337 enum ima_hooks { 338 __ima_hooks(__ima_hook_enumify) 339 }; 340 341 static const char * const ima_hooks_measure_str[] = { 342 __ima_hooks(__ima_hook_measuring_stringify) 343 }; 344 345 static inline const char *func_measure_str(enum ima_hooks func) 346 { 347 if (func >= MAX_CHECK) 348 return ima_hooks_measure_str[NONE]; 349 350 return ima_hooks_measure_str[func]; 351 } 352 353 extern const char *const func_tokens[]; 354 355 struct modsig; 356 357 #ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS 358 /* 359 * To track keys that need to be measured. 360 */ 361 struct ima_key_entry { 362 struct list_head list; 363 void *payload; 364 size_t payload_len; 365 char *keyring_name; 366 }; 367 void ima_init_key_queue(void); 368 bool ima_should_queue_key(void); 369 bool ima_queue_key(struct key *keyring, const void *payload, 370 size_t payload_len); 371 void ima_process_queued_keys(void); 372 #else 373 static inline void ima_init_key_queue(void) {} 374 static inline bool ima_should_queue_key(void) { return false; } 375 static inline bool ima_queue_key(struct key *keyring, 376 const void *payload, 377 size_t payload_len) { return false; } 378 static inline void ima_process_queued_keys(void) {} 379 #endif /* CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS */ 380 381 /* LIM API function definitions */ 382 int ima_get_action(struct mnt_idmap *idmap, struct inode *inode, 383 const struct cred *cred, struct lsm_prop *prop, int mask, 384 enum ima_hooks func, int *pcr, 385 struct ima_template_desc **template_desc, 386 const char *func_data, unsigned int *allowed_algos); 387 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func); 388 int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file, 389 void *buf, loff_t size, enum hash_algo algo, 390 struct modsig *modsig); 391 void ima_store_measurement(struct ima_iint_cache *iint, struct file *file, 392 const unsigned char *filename, 393 struct evm_ima_xattr_data *xattr_value, 394 int xattr_len, const struct modsig *modsig, int pcr, 395 struct ima_template_desc *template_desc); 396 int process_buffer_measurement(struct mnt_idmap *idmap, 397 struct inode *inode, const void *buf, int size, 398 const char *eventname, enum ima_hooks func, 399 int pcr, const char *func_data, 400 bool buf_hash, u8 *digest, size_t digest_len); 401 void ima_audit_measurement(struct ima_iint_cache *iint, 402 const unsigned char *filename); 403 int ima_alloc_init_template(struct ima_event_data *event_data, 404 struct ima_template_entry **entry, 405 struct ima_template_desc *template_desc); 406 int ima_store_template(struct ima_template_entry *entry, int violation, 407 struct inode *inode, 408 const unsigned char *filename, int pcr); 409 void ima_free_template_entry(struct ima_template_entry *entry); 410 const char *ima_d_path(const struct path *path, char **pathbuf, char *filename); 411 412 /* IMA policy related functions */ 413 int ima_match_policy(struct mnt_idmap *idmap, struct inode *inode, 414 const struct cred *cred, struct lsm_prop *prop, 415 enum ima_hooks func, int mask, int flags, int *pcr, 416 struct ima_template_desc **template_desc, 417 const char *func_data, unsigned int *allowed_algos); 418 void ima_init_policy(void); 419 void ima_update_policy(void); 420 void ima_update_policy_flags(void); 421 ssize_t ima_parse_add_rule(char *); 422 void ima_delete_rules(void); 423 int ima_check_policy(void); 424 void *ima_policy_start(struct seq_file *m, loff_t *pos); 425 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos); 426 void ima_policy_stop(struct seq_file *m, void *v); 427 int ima_policy_show(struct seq_file *m, void *v); 428 429 /* Appraise integrity measurements */ 430 #define IMA_APPRAISE_ENFORCE 0x01 431 #define IMA_APPRAISE_FIX 0x02 432 #define IMA_APPRAISE_LOG 0x04 433 #define IMA_APPRAISE_MODULES 0x08 434 #define IMA_APPRAISE_FIRMWARE 0x10 435 #define IMA_APPRAISE_POLICY 0x20 436 #define IMA_APPRAISE_KEXEC 0x40 437 438 #ifdef CONFIG_IMA_APPRAISE 439 int ima_check_blacklist(struct ima_iint_cache *iint, 440 const struct modsig *modsig, int pcr); 441 int ima_appraise_measurement(enum ima_hooks func, struct ima_iint_cache *iint, 442 struct file *file, const unsigned char *filename, 443 struct evm_ima_xattr_data *xattr_value, 444 int xattr_len, const struct modsig *modsig); 445 int ima_must_appraise(struct mnt_idmap *idmap, struct inode *inode, 446 int mask, enum ima_hooks func); 447 void ima_update_xattr(struct ima_iint_cache *iint, struct file *file); 448 enum integrity_status ima_get_cache_status(struct ima_iint_cache *iint, 449 enum ima_hooks func); 450 enum hash_algo ima_get_hash_algo(const struct evm_ima_xattr_data *xattr_value, 451 int xattr_len); 452 int ima_read_xattr(struct dentry *dentry, 453 struct evm_ima_xattr_data **xattr_value, int xattr_len); 454 void __init init_ima_appraise_lsm(const struct lsm_id *lsmid); 455 456 #else 457 static inline int ima_check_blacklist(struct ima_iint_cache *iint, 458 const struct modsig *modsig, int pcr) 459 { 460 return 0; 461 } 462 463 static inline int ima_appraise_measurement(enum ima_hooks func, 464 struct ima_iint_cache *iint, 465 struct file *file, 466 const unsigned char *filename, 467 struct evm_ima_xattr_data *xattr_value, 468 int xattr_len, 469 const struct modsig *modsig) 470 { 471 return INTEGRITY_UNKNOWN; 472 } 473 474 static inline int ima_must_appraise(struct mnt_idmap *idmap, 475 struct inode *inode, int mask, 476 enum ima_hooks func) 477 { 478 return 0; 479 } 480 481 static inline void ima_update_xattr(struct ima_iint_cache *iint, 482 struct file *file) 483 { 484 } 485 486 static inline enum integrity_status 487 ima_get_cache_status(struct ima_iint_cache *iint, enum ima_hooks func) 488 { 489 return INTEGRITY_UNKNOWN; 490 } 491 492 static inline enum hash_algo 493 ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len) 494 { 495 return ima_hash_algo; 496 } 497 498 static inline int ima_read_xattr(struct dentry *dentry, 499 struct evm_ima_xattr_data **xattr_value, 500 int xattr_len) 501 { 502 return 0; 503 } 504 505 static inline void __init init_ima_appraise_lsm(const struct lsm_id *lsmid) 506 { 507 } 508 509 #endif /* CONFIG_IMA_APPRAISE */ 510 511 #ifdef CONFIG_IMA_APPRAISE_MODSIG 512 int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, 513 struct modsig **modsig); 514 void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size); 515 int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo, 516 const u8 **digest, u32 *digest_size); 517 int ima_get_raw_modsig(const struct modsig *modsig, const void **data, 518 u32 *data_len); 519 void ima_free_modsig(struct modsig *modsig); 520 #else 521 static inline int ima_read_modsig(enum ima_hooks func, const void *buf, 522 loff_t buf_len, struct modsig **modsig) 523 { 524 return -EOPNOTSUPP; 525 } 526 527 static inline void ima_collect_modsig(struct modsig *modsig, const void *buf, 528 loff_t size) 529 { 530 } 531 532 static inline int ima_get_modsig_digest(const struct modsig *modsig, 533 enum hash_algo *algo, const u8 **digest, 534 u32 *digest_size) 535 { 536 return -EOPNOTSUPP; 537 } 538 539 static inline int ima_get_raw_modsig(const struct modsig *modsig, 540 const void **data, u32 *data_len) 541 { 542 return -EOPNOTSUPP; 543 } 544 545 static inline void ima_free_modsig(struct modsig *modsig) 546 { 547 } 548 #endif /* CONFIG_IMA_APPRAISE_MODSIG */ 549 550 /* LSM based policy rules require audit */ 551 #ifdef CONFIG_IMA_LSM_RULES 552 553 #define ima_filter_rule_init security_audit_rule_init 554 #define ima_filter_rule_free security_audit_rule_free 555 #define ima_filter_rule_match security_audit_rule_match 556 557 #else 558 559 static inline int ima_filter_rule_init(u32 field, u32 op, char *rulestr, 560 void **lsmrule, gfp_t gfp) 561 { 562 return -EINVAL; 563 } 564 565 static inline void ima_filter_rule_free(void *lsmrule) 566 { 567 } 568 569 static inline int ima_filter_rule_match(struct lsm_prop *prop, u32 field, u32 op, 570 void *lsmrule) 571 { 572 return -EINVAL; 573 } 574 #endif /* CONFIG_IMA_LSM_RULES */ 575 576 #ifdef CONFIG_IMA_READ_POLICY 577 #define POLICY_FILE_FLAGS (S_IWUSR | S_IRUSR) 578 #else 579 #define POLICY_FILE_FLAGS S_IWUSR 580 #endif /* CONFIG_IMA_READ_POLICY */ 581 582 #endif /* __LINUX_IMA_H */ 583