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 /* 248 * The default binary_runtime_measurements list format is defined as the 249 * platform native format. The canonical format is defined as little-endian. 250 */ 251 extern bool ima_canonical_fmt; 252 253 /* Internal IMA function definitions */ 254 int ima_init(void); 255 int ima_fs_init(void); 256 int ima_add_template_entry(struct ima_template_entry *entry, int violation, 257 const char *op, struct inode *inode, 258 const unsigned char *filename); 259 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash); 260 int ima_calc_buffer_hash(const void *buf, loff_t len, 261 struct ima_digest_data *hash); 262 int ima_calc_field_array_hash(struct ima_field_data *field_data, 263 struct ima_template_entry *entry); 264 int ima_calc_boot_aggregate(struct ima_digest_data *hash); 265 void ima_add_violation(struct file *file, const unsigned char *filename, 266 struct ima_iint_cache *iint, const char *op, 267 const char *cause); 268 int ima_init_crypto(void); 269 void ima_putc(struct seq_file *m, void *data, int datalen); 270 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size); 271 int template_desc_init_fields(const char *template_fmt, 272 const struct ima_template_field ***fields, 273 int *num_fields); 274 struct ima_template_desc *ima_template_desc_current(void); 275 struct ima_template_desc *ima_template_desc_buf(void); 276 struct ima_template_desc *lookup_template_desc(const char *name); 277 bool ima_template_has_modsig(const struct ima_template_desc *ima_template); 278 int ima_restore_measurement_entry(struct ima_template_entry *entry); 279 int ima_restore_measurement_list(loff_t bufsize, void *buf); 280 int ima_measurements_show(struct seq_file *m, void *v); 281 unsigned long ima_get_binary_runtime_size(void); 282 int ima_init_template(void); 283 void ima_init_template_list(void); 284 int __init ima_init_digests(void); 285 void __init ima_init_reboot_notifier(void); 286 int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event, 287 void *lsm_data); 288 289 /* 290 * used to protect h_table and sha_table 291 */ 292 extern spinlock_t ima_queue_lock; 293 294 struct ima_h_table { 295 atomic_long_t len; /* number of stored measurements in the list */ 296 atomic_long_t violations; 297 struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE]; 298 }; 299 extern struct ima_h_table ima_htable; 300 301 static inline unsigned int ima_hash_key(u8 *digest) 302 { 303 /* there is no point in taking a hash of part of a digest */ 304 return (digest[0] | digest[1] << 8) % IMA_MEASURE_HTABLE_SIZE; 305 } 306 307 #define __ima_hooks(hook) \ 308 hook(NONE, none) \ 309 hook(FILE_CHECK, file) \ 310 hook(MMAP_CHECK, mmap) \ 311 hook(MMAP_CHECK_REQPROT, mmap_reqprot) \ 312 hook(BPRM_CHECK, bprm) \ 313 hook(CREDS_CHECK, creds) \ 314 hook(POST_SETATTR, post_setattr) \ 315 hook(MODULE_CHECK, module) \ 316 hook(FIRMWARE_CHECK, firmware) \ 317 hook(KEXEC_KERNEL_CHECK, kexec_kernel) \ 318 hook(KEXEC_INITRAMFS_CHECK, kexec_initramfs) \ 319 hook(POLICY_CHECK, policy) \ 320 hook(KEXEC_CMDLINE, kexec_cmdline) \ 321 hook(KEY_CHECK, key) \ 322 hook(CRITICAL_DATA, critical_data) \ 323 hook(SETXATTR_CHECK, setxattr_check) \ 324 hook(MAX_CHECK, none) 325 326 #define __ima_hook_enumify(ENUM, str) ENUM, 327 #define __ima_stringify(arg) (#arg) 328 #define __ima_hook_measuring_stringify(ENUM, str) \ 329 (__ima_stringify(measuring_ ##str)), 330 331 enum ima_hooks { 332 __ima_hooks(__ima_hook_enumify) 333 }; 334 335 static const char * const ima_hooks_measure_str[] = { 336 __ima_hooks(__ima_hook_measuring_stringify) 337 }; 338 339 static inline const char *func_measure_str(enum ima_hooks func) 340 { 341 if (func >= MAX_CHECK) 342 return ima_hooks_measure_str[NONE]; 343 344 return ima_hooks_measure_str[func]; 345 } 346 347 extern const char *const func_tokens[]; 348 349 struct modsig; 350 351 #ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS 352 /* 353 * To track keys that need to be measured. 354 */ 355 struct ima_key_entry { 356 struct list_head list; 357 void *payload; 358 size_t payload_len; 359 char *keyring_name; 360 }; 361 void ima_init_key_queue(void); 362 bool ima_should_queue_key(void); 363 bool ima_queue_key(struct key *keyring, const void *payload, 364 size_t payload_len); 365 void ima_process_queued_keys(void); 366 #else 367 static inline void ima_init_key_queue(void) {} 368 static inline bool ima_should_queue_key(void) { return false; } 369 static inline bool ima_queue_key(struct key *keyring, 370 const void *payload, 371 size_t payload_len) { return false; } 372 static inline void ima_process_queued_keys(void) {} 373 #endif /* CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS */ 374 375 /* LIM API function definitions */ 376 int ima_get_action(struct mnt_idmap *idmap, struct inode *inode, 377 const struct cred *cred, struct lsm_prop *prop, int mask, 378 enum ima_hooks func, int *pcr, 379 struct ima_template_desc **template_desc, 380 const char *func_data, unsigned int *allowed_algos); 381 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func); 382 int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file, 383 void *buf, loff_t size, enum hash_algo algo, 384 struct modsig *modsig); 385 void ima_store_measurement(struct ima_iint_cache *iint, struct file *file, 386 const unsigned char *filename, 387 struct evm_ima_xattr_data *xattr_value, 388 int xattr_len, const struct modsig *modsig, int pcr, 389 struct ima_template_desc *template_desc); 390 int process_buffer_measurement(struct mnt_idmap *idmap, 391 struct inode *inode, const void *buf, int size, 392 const char *eventname, enum ima_hooks func, 393 int pcr, const char *func_data, 394 bool buf_hash, u8 *digest, size_t digest_len); 395 void ima_audit_measurement(struct ima_iint_cache *iint, 396 const unsigned char *filename); 397 int ima_alloc_init_template(struct ima_event_data *event_data, 398 struct ima_template_entry **entry, 399 struct ima_template_desc *template_desc); 400 int ima_store_template(struct ima_template_entry *entry, int violation, 401 struct inode *inode, 402 const unsigned char *filename, int pcr); 403 void ima_free_template_entry(struct ima_template_entry *entry); 404 const char *ima_d_path(const struct path *path, char **pathbuf, char *filename); 405 406 /* IMA policy related functions */ 407 int ima_match_policy(struct mnt_idmap *idmap, struct inode *inode, 408 const struct cred *cred, struct lsm_prop *prop, 409 enum ima_hooks func, int mask, int flags, int *pcr, 410 struct ima_template_desc **template_desc, 411 const char *func_data, unsigned int *allowed_algos); 412 void ima_init_policy(void); 413 void ima_update_policy(void); 414 void ima_update_policy_flags(void); 415 ssize_t ima_parse_add_rule(char *); 416 void ima_delete_rules(void); 417 int ima_check_policy(void); 418 void *ima_policy_start(struct seq_file *m, loff_t *pos); 419 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos); 420 void ima_policy_stop(struct seq_file *m, void *v); 421 int ima_policy_show(struct seq_file *m, void *v); 422 423 /* Appraise integrity measurements */ 424 #define IMA_APPRAISE_ENFORCE 0x01 425 #define IMA_APPRAISE_FIX 0x02 426 #define IMA_APPRAISE_LOG 0x04 427 #define IMA_APPRAISE_MODULES 0x08 428 #define IMA_APPRAISE_FIRMWARE 0x10 429 #define IMA_APPRAISE_POLICY 0x20 430 #define IMA_APPRAISE_KEXEC 0x40 431 432 #ifdef CONFIG_IMA_APPRAISE 433 int ima_check_blacklist(struct ima_iint_cache *iint, 434 const struct modsig *modsig, int pcr); 435 int ima_appraise_measurement(enum ima_hooks func, struct ima_iint_cache *iint, 436 struct file *file, const unsigned char *filename, 437 struct evm_ima_xattr_data *xattr_value, 438 int xattr_len, const struct modsig *modsig); 439 int ima_must_appraise(struct mnt_idmap *idmap, struct inode *inode, 440 int mask, enum ima_hooks func); 441 void ima_update_xattr(struct ima_iint_cache *iint, struct file *file); 442 enum integrity_status ima_get_cache_status(struct ima_iint_cache *iint, 443 enum ima_hooks func); 444 enum hash_algo ima_get_hash_algo(const struct evm_ima_xattr_data *xattr_value, 445 int xattr_len); 446 int ima_read_xattr(struct dentry *dentry, 447 struct evm_ima_xattr_data **xattr_value, int xattr_len); 448 void __init init_ima_appraise_lsm(const struct lsm_id *lsmid); 449 450 #else 451 static inline int ima_check_blacklist(struct ima_iint_cache *iint, 452 const struct modsig *modsig, int pcr) 453 { 454 return 0; 455 } 456 457 static inline int ima_appraise_measurement(enum ima_hooks func, 458 struct ima_iint_cache *iint, 459 struct file *file, 460 const unsigned char *filename, 461 struct evm_ima_xattr_data *xattr_value, 462 int xattr_len, 463 const struct modsig *modsig) 464 { 465 return INTEGRITY_UNKNOWN; 466 } 467 468 static inline int ima_must_appraise(struct mnt_idmap *idmap, 469 struct inode *inode, int mask, 470 enum ima_hooks func) 471 { 472 return 0; 473 } 474 475 static inline void ima_update_xattr(struct ima_iint_cache *iint, 476 struct file *file) 477 { 478 } 479 480 static inline enum integrity_status 481 ima_get_cache_status(struct ima_iint_cache *iint, enum ima_hooks func) 482 { 483 return INTEGRITY_UNKNOWN; 484 } 485 486 static inline enum hash_algo 487 ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len) 488 { 489 return ima_hash_algo; 490 } 491 492 static inline int ima_read_xattr(struct dentry *dentry, 493 struct evm_ima_xattr_data **xattr_value, 494 int xattr_len) 495 { 496 return 0; 497 } 498 499 static inline void __init init_ima_appraise_lsm(const struct lsm_id *lsmid) 500 { 501 } 502 503 #endif /* CONFIG_IMA_APPRAISE */ 504 505 #ifdef CONFIG_IMA_APPRAISE_MODSIG 506 int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, 507 struct modsig **modsig); 508 void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size); 509 int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo, 510 const u8 **digest, u32 *digest_size); 511 int ima_get_raw_modsig(const struct modsig *modsig, const void **data, 512 u32 *data_len); 513 void ima_free_modsig(struct modsig *modsig); 514 #else 515 static inline int ima_read_modsig(enum ima_hooks func, const void *buf, 516 loff_t buf_len, struct modsig **modsig) 517 { 518 return -EOPNOTSUPP; 519 } 520 521 static inline void ima_collect_modsig(struct modsig *modsig, const void *buf, 522 loff_t size) 523 { 524 } 525 526 static inline int ima_get_modsig_digest(const struct modsig *modsig, 527 enum hash_algo *algo, const u8 **digest, 528 u32 *digest_size) 529 { 530 return -EOPNOTSUPP; 531 } 532 533 static inline int ima_get_raw_modsig(const struct modsig *modsig, 534 const void **data, u32 *data_len) 535 { 536 return -EOPNOTSUPP; 537 } 538 539 static inline void ima_free_modsig(struct modsig *modsig) 540 { 541 } 542 #endif /* CONFIG_IMA_APPRAISE_MODSIG */ 543 544 /* LSM based policy rules require audit */ 545 #ifdef CONFIG_IMA_LSM_RULES 546 547 #define ima_filter_rule_init security_audit_rule_init 548 #define ima_filter_rule_free security_audit_rule_free 549 #define ima_filter_rule_match security_audit_rule_match 550 551 #else 552 553 static inline int ima_filter_rule_init(u32 field, u32 op, char *rulestr, 554 void **lsmrule, gfp_t gfp) 555 { 556 return -EINVAL; 557 } 558 559 static inline void ima_filter_rule_free(void *lsmrule) 560 { 561 } 562 563 static inline int ima_filter_rule_match(struct lsm_prop *prop, u32 field, u32 op, 564 void *lsmrule) 565 { 566 return -EINVAL; 567 } 568 #endif /* CONFIG_IMA_LSM_RULES */ 569 570 #ifdef CONFIG_IMA_READ_POLICY 571 #define POLICY_FILE_FLAGS (S_IWUSR | S_IRUSR) 572 #else 573 #define POLICY_FILE_FLAGS S_IWUSR 574 #endif /* CONFIG_IMA_READ_POLICY */ 575 576 #endif /* __LINUX_IMA_H */ 577