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 };
  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 9
  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
  56 /* IMA event related data */
  57 struct ima_event_data {
  58         struct integrity_iint_cache *iint;
  59         struct file *file;
  60         const unsigned char *filename;
  61         struct evm_ima_xattr_data *xattr_value;
  62         int xattr_len;
  63         const char *violation;
  64 };
  65
  66 /* IMA template field data definition */
  67 struct ima_field_data {
  68         u8 *data;
  69         u32 len;
  70 };
  71
  72 /* IMA template field definition */
  73 struct ima_template_field {
  74         const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
  75         int (*field_init)(struct ima_event_data *event_data,
  76                           struct ima_field_data *field_data);
  77         void (*field_show)(struct seq_file *m, enum ima_show_type show,
  78                            struct ima_field_data *field_data);
  79 };
  80
  81 /* IMA template descriptor definition */
  82 struct ima_template_desc {
  83         struct list_head list;
  84         char *name;
  85         char *fmt;
  86         int num_fields;
  87         const struct ima_template_field **fields;
  88 };
  89
  90 struct ima_template_entry {
  91         int pcr;
  92         u8 digest[TPM_DIGEST_SIZE];     /* sha1 or md5 measurement hash */
  93         struct ima_template_desc *template_desc; /* template descriptor */
  94         u32 template_data_len;
  95         struct ima_field_data template_data[0]; /* template related data */
  96 };
  97
  98 struct ima_queue_entry {
  99         struct hlist_node hnext;        /* place in hash collision list */
 100         struct list_head later;         /* place in ima_measurements list */
 101         struct ima_template_entry *entry;
 102 };
 103 extern struct list_head ima_measurements;       /* list of all measurements */
 104
 105 /* Some details preceding the binary serialized measurement list */
 106 struct ima_kexec_hdr {
 107         u16 version;
 108         u16 _reserved0;
 109         u32 _reserved1;
 110         u64 buffer_size;
 111         u64 count;
 112 };
 113
 114 #ifdef CONFIG_HAVE_IMA_KEXEC
 115 void ima_load_kexec_buffer(void);
 116 #else
 117 static inline void ima_load_kexec_buffer(void) {}
 118 #endif /* CONFIG_HAVE_IMA_KEXEC */
 119
 120 /*
 121  * The default binary_runtime_measurements list format is defined as the
 122  * platform native format.  The canonical format is defined as little-endian.
 123  */
 124 extern bool ima_canonical_fmt;
 125
 126 /* Internal IMA function definitions */
 127 int ima_init(void);
 128 int ima_fs_init(void);
 129 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
 130                            const char *op, struct inode *inode,
 131                            const unsigned char *filename);
 132 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
 133 int ima_calc_buffer_hash(const void *buf, loff_t len,
 134                          struct ima_digest_data *hash);
 135 int ima_calc_field_array_hash(struct ima_field_data *field_data,
 136                               struct ima_template_desc *desc, int num_fields,
 137                               struct ima_digest_data *hash);
 138 int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
 139 void ima_add_violation(struct file *file, const unsigned char *filename,
 140                        struct integrity_iint_cache *iint,
 141                        const char *op, const char *cause);
 142 int ima_init_crypto(void);
 143 void ima_putc(struct seq_file *m, void *data, int datalen);
 144 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size);
 145 struct ima_template_desc *ima_template_desc_current(void);
 146 int ima_restore_measurement_entry(struct ima_template_entry *entry);
 147 int ima_restore_measurement_list(loff_t bufsize, void *buf);
 148 int ima_measurements_show(struct seq_file *m, void *v);
 149 unsigned long ima_get_binary_runtime_size(void);
 150 int ima_init_template(void);
 151 void ima_init_template_list(void);
 152 int __init ima_init_digests(void);
 153
 154 /*
 155  * used to protect h_table and sha_table
 156  */
 157 extern spinlock_t ima_queue_lock;
 158
 159 struct ima_h_table {
 160         atomic_long_t len;      /* number of stored measurements in the list */
 161         atomic_long_t violations;
 162         struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
 163 };
 164 extern struct ima_h_table ima_htable;
 165
 166 static inline unsigned long ima_hash_key(u8 *digest)
 167 {
 168         return hash_long(*digest, IMA_HASH_BITS);
 169 }
 170
 171 #define __ima_hooks(hook)               \
 172         hook(NONE)                      \
 173         hook(FILE_CHECK)                \
 174         hook(MMAP_CHECK)                \
 175         hook(BPRM_CHECK)                \
 176         hook(CREDS_CHECK)               \
 177         hook(POST_SETATTR)              \
 178         hook(MODULE_CHECK)              \
 179         hook(FIRMWARE_CHECK)            \
 180         hook(KEXEC_KERNEL_CHECK)        \
 181         hook(KEXEC_INITRAMFS_CHECK)     \
 182         hook(POLICY_CHECK)              \
 183         hook(MAX_CHECK)
 184 #define __ima_hook_enumify(ENUM)        ENUM,
 185
 186 enum ima_hooks {
 187         __ima_hooks(__ima_hook_enumify)
 188 };
 189
 190 /* LIM API function definitions */
 191 int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
 192                    int mask, enum ima_hooks func, int *pcr);
 193 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
 194 int ima_collect_measurement(struct integrity_iint_cache *iint,
 195                             struct file *file, void *buf, loff_t size,
 196                             enum hash_algo algo);
 197 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
 198                            const unsigned char *filename,
 199                            struct evm_ima_xattr_data *xattr_value,
 200                            int xattr_len, int pcr);
 201 void ima_audit_measurement(struct integrity_iint_cache *iint,
 202                            const unsigned char *filename);
 203 int ima_alloc_init_template(struct ima_event_data *event_data,
 204                             struct ima_template_entry **entry);
 205 int ima_store_template(struct ima_template_entry *entry, int violation,
 206                        struct inode *inode,
 207                        const unsigned char *filename, int pcr);
 208 void ima_free_template_entry(struct ima_template_entry *entry);
 209 const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
 210
 211 /* IMA policy related functions */
 212 int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
 213                      enum ima_hooks func, int mask, int flags, int *pcr);
 214 void ima_init_policy(void);
 215 void ima_update_policy(void);
 216 void ima_update_policy_flag(void);
 217 ssize_t ima_parse_add_rule(char *);
 218 void ima_delete_rules(void);
 219 int ima_check_policy(void);
 220 void *ima_policy_start(struct seq_file *m, loff_t *pos);
 221 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos);
 222 void ima_policy_stop(struct seq_file *m, void *v);
 223 int ima_policy_show(struct seq_file *m, void *v);
 224
 225 /* Appraise integrity measurements */
 226 #define IMA_APPRAISE_ENFORCE    0x01
 227 #define IMA_APPRAISE_FIX        0x02
 228 #define IMA_APPRAISE_LOG        0x04
 229 #define IMA_APPRAISE_MODULES    0x08
 230 #define IMA_APPRAISE_FIRMWARE   0x10
 231 #define IMA_APPRAISE_POLICY     0x20
 232 #define IMA_APPRAISE_KEXEC      0x40
 233
 234 #ifdef CONFIG_IMA_APPRAISE
 235 int ima_appraise_measurement(enum ima_hooks func,
 236                              struct integrity_iint_cache *iint,
 237                              struct file *file, const unsigned char *filename,
 238                              struct evm_ima_xattr_data *xattr_value,
 239                              int xattr_len);
 240 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
 241 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
 242 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
 243                                            enum ima_hooks func);
 244 enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
 245                                  int xattr_len);
 246 int ima_read_xattr(struct dentry *dentry,
 247                    struct evm_ima_xattr_data **xattr_value);
 248
 249 #else
 250 static inline int ima_appraise_measurement(enum ima_hooks func,
 251                                            struct integrity_iint_cache *iint,
 252                                            struct file *file,
 253                                            const unsigned char *filename,
 254                                            struct evm_ima_xattr_data *xattr_value,
 255                                            int xattr_len)
 256 {
 257         return INTEGRITY_UNKNOWN;
 258 }
 259
 260 static inline int ima_must_appraise(struct inode *inode, int mask,
 261                                     enum ima_hooks func)
 262 {
 263         return 0;
 264 }
 265
 266 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
 267                                     struct file *file)
 268 {
 269 }
 270
 271 static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
 272                                                          *iint,
 273                                                          enum ima_hooks func)
 274 {
 275         return INTEGRITY_UNKNOWN;
 276 }
 277
 278 static inline enum hash_algo
 279 ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len)
 280 {
 281         return ima_hash_algo;
 282 }
 283
 284 static inline int ima_read_xattr(struct dentry *dentry,
 285                                  struct evm_ima_xattr_data **xattr_value)
 286 {
 287         return 0;
 288 }
 289
 290 #endif /* CONFIG_IMA_APPRAISE */
 291
 292 /* LSM based policy rules require audit */
 293 #ifdef CONFIG_IMA_LSM_RULES
 294
 295 #define security_filter_rule_init security_audit_rule_init
 296 #define security_filter_rule_match security_audit_rule_match
 297
 298 #else
 299
 300 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
 301                                             void **lsmrule)
 302 {
 303         return -EINVAL;
 304 }
 305
 306 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
 307                                              void *lsmrule)
 308 {
 309         return -EINVAL;
 310 }
 311 #endif /* CONFIG_IMA_LSM_RULES */
 312
 313 #ifdef  CONFIG_IMA_READ_POLICY
 314 #define POLICY_FILE_FLAGS       (S_IWUSR | S_IRUSR)
 315 #else
 316 #define POLICY_FILE_FLAGS       S_IWUSR
 317 #endif /* CONFIG_IMA_READ_POLICY */
 318
 319 #endif /* __LINUX_IMA_H */