security/integrity/ima/ima.h

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