security/integrity/ima/ima.h

   1 /*
   2  * Copyright (C) 2005,2006,2007,2008 IBM Corporation
   3  *
   4  * Authors:
   5  * Reiner Sailer <sailer@watson.ibm.com>
   6  * Mimi Zohar <zohar@us.ibm.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation, version 2 of the
  11  * License.
  12  *
  13  * File: ima.h
  14  *      internal Integrity Measurement Architecture (IMA) definitions
  15  */
  16
  17 #ifndef __LINUX_IMA_H
  18 #define __LINUX_IMA_H
  19
  20 #include <linux/types.h>
  21 #include <linux/crypto.h>
  22 #include <linux/fs.h>
  23 #include <linux/security.h>
  24 #include <linux/hash.h>
  25 #include <linux/tpm.h>
  26 #include <linux/audit.h>
  27 #include <crypto/hash_info.h>
  28
  29 #include "../integrity.h"
  30
  31 #ifdef CONFIG_HAVE_IMA_KEXEC
  32 #include <asm/ima.h>
  33 #endif
  34
  35 enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN,
  36                      IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII };
  37 enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
  38
  39 /* digest size for IMA, fits SHA1 or MD5 */
  40 #define IMA_DIGEST_SIZE         SHA1_DIGEST_SIZE
  41 #define IMA_EVENT_NAME_LEN_MAX  255
  42
  43 #define IMA_HASH_BITS 9
  44 #define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)
  45
  46 #define IMA_TEMPLATE_FIELD_ID_MAX_LEN   16
  47 #define IMA_TEMPLATE_NUM_FIELDS_MAX     15
  48
  49 #define IMA_TEMPLATE_IMA_NAME "ima"
  50 #define IMA_TEMPLATE_IMA_FMT "d|n"
  51
  52 /* current content of the policy */
  53 extern int ima_policy_flag;
  54
  55 /* set during initialization */
  56 extern int ima_initialized;
  57 extern int ima_used_chip;
  58 extern int ima_hash_algo;
  59 extern int ima_appraise;
  60
  61 /* IMA event related data */
  62 struct ima_event_data {
  63         struct integrity_iint_cache *iint;
  64         struct file *file;
  65         const unsigned char *filename;
  66         struct evm_ima_xattr_data *xattr_value;
  67         int xattr_len;
  68         const char *violation;
  69 };
  70
  71 /* IMA template field data definition */
  72 struct ima_field_data {
  73         u8 *data;
  74         u32 len;
  75 };
  76
  77 /* IMA template field definition */
  78 struct ima_template_field {
  79         const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
  80         int (*field_init)(struct ima_event_data *event_data,
  81                           struct ima_field_data *field_data);
  82         void (*field_show)(struct seq_file *m, enum ima_show_type show,
  83                            struct ima_field_data *field_data);
  84 };
  85
  86 /* IMA template descriptor definition */
  87 struct ima_template_desc {
  88         struct list_head list;
  89         char *name;
  90         char *fmt;
  91         int num_fields;
  92         struct ima_template_field **fields;
  93 };
  94
  95 struct ima_template_entry {
  96         int pcr;
  97         u8 digest[TPM_DIGEST_SIZE];     /* sha1 or md5 measurement hash */
  98         struct ima_template_desc *template_desc; /* template descriptor */
  99         u32 template_data_len;
 100         struct ima_field_data template_data[0]; /* template related data */
 101 };
 102
 103 struct ima_queue_entry {
 104         struct hlist_node hnext;        /* place in hash collision list */
 105         struct list_head later;         /* place in ima_measurements list */
 106         struct ima_template_entry *entry;
 107 };
 108 extern struct list_head ima_measurements;       /* list of all measurements */
 109
 110 /* Some details preceding the binary serialized measurement list */
 111 struct ima_kexec_hdr {
 112         u16 version;
 113         u16 _reserved0;
 114         u32 _reserved1;
 115         u64 buffer_size;
 116         u64 count;
 117 };
 118
 119 #ifdef CONFIG_HAVE_IMA_KEXEC
 120 void ima_load_kexec_buffer(void);
 121 #else
 122 static inline void ima_load_kexec_buffer(void) {}
 123 #endif /* CONFIG_HAVE_IMA_KEXEC */
 124
 125 /*
 126  * The default binary_runtime_measurements list format is defined as the
 127  * platform native format.  The canonical format is defined as little-endian.
 128  */
 129 extern bool ima_canonical_fmt;
 130
 131 /* Internal IMA function definitions */
 132 int ima_init(void);
 133 int ima_fs_init(void);
 134 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
 135                            const char *op, struct inode *inode,
 136                            const unsigned char *filename);
 137 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
 138 int ima_calc_buffer_hash(const void *buf, loff_t len,
 139                          struct ima_digest_data *hash);
 140 int ima_calc_field_array_hash(struct ima_field_data *field_data,
 141                               struct ima_template_desc *desc, int num_fields,
 142                               struct ima_digest_data *hash);
 143 int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
 144 void ima_add_violation(struct file *file, const unsigned char *filename,
 145                        struct integrity_iint_cache *iint,
 146                        const char *op, const char *cause);
 147 int ima_init_crypto(void);
 148 void ima_putc(struct seq_file *m, void *data, int datalen);
 149 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size);
 150 struct ima_template_desc *ima_template_desc_current(void);
 151 int ima_restore_measurement_entry(struct ima_template_entry *entry);
 152 int ima_restore_measurement_list(loff_t bufsize, void *buf);
 153 int ima_measurements_show(struct seq_file *m, void *v);
 154 unsigned long ima_get_binary_runtime_size(void);
 155 int ima_init_template(void);
 156 void ima_init_template_list(void);
 157
 158 /*
 159  * used to protect h_table and sha_table
 160  */
 161 extern spinlock_t ima_queue_lock;
 162
 163 struct ima_h_table {
 164         atomic_long_t len;      /* number of stored measurements in the list */
 165         atomic_long_t violations;
 166         struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
 167 };
 168 extern struct ima_h_table ima_htable;
 169
 170 static inline unsigned long ima_hash_key(u8 *digest)
 171 {
 172         return hash_long(*digest, IMA_HASH_BITS);
 173 }
 174
 175 enum ima_hooks {
 176         FILE_CHECK = 1,
 177         MMAP_CHECK,
 178         BPRM_CHECK,
 179         POST_SETATTR,
 180         MODULE_CHECK,
 181         FIRMWARE_CHECK,
 182         KEXEC_KERNEL_CHECK,
 183         KEXEC_INITRAMFS_CHECK,
 184         POLICY_CHECK,
 185         MAX_CHECK
 186 };
 187
 188 /* LIM API function definitions */
 189 int ima_get_action(struct inode *inode, int mask,
 190                    enum ima_hooks func, int *pcr);
 191 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
 192 int ima_collect_measurement(struct integrity_iint_cache *iint,
 193                             struct file *file, void *buf, loff_t size,
 194                             enum hash_algo algo);
 195 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
 196                            const unsigned char *filename,
 197                            struct evm_ima_xattr_data *xattr_value,
 198                            int xattr_len, int pcr);
 199 void ima_audit_measurement(struct integrity_iint_cache *iint,
 200                            const unsigned char *filename);
 201 int ima_alloc_init_template(struct ima_event_data *event_data,
 202                             struct ima_template_entry **entry);
 203 int ima_store_template(struct ima_template_entry *entry, int violation,
 204                        struct inode *inode,
 205                        const unsigned char *filename, int pcr);
 206 void ima_free_template_entry(struct ima_template_entry *entry);
 207 const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
 208
 209 /* IMA policy related functions */
 210 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
 211                      int flags, int *pcr);
 212 void ima_init_policy(void);
 213 void ima_update_policy(void);
 214 void ima_update_policy_flag(void);
 215 ssize_t ima_parse_add_rule(char *);
 216 void ima_delete_rules(void);
 217 int ima_check_policy(void);
 218 void *ima_policy_start(struct seq_file *m, loff_t *pos);
 219 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos);
 220 void ima_policy_stop(struct seq_file *m, void *v);
 221 int ima_policy_show(struct seq_file *m, void *v);
 222
 223 /* Appraise integrity measurements */
 224 #define IMA_APPRAISE_ENFORCE    0x01
 225 #define IMA_APPRAISE_FIX        0x02
 226 #define IMA_APPRAISE_LOG        0x04
 227 #define IMA_APPRAISE_MODULES    0x08
 228 #define IMA_APPRAISE_FIRMWARE   0x10
 229 #define IMA_APPRAISE_POLICY     0x20
 230
 231 #ifdef CONFIG_IMA_APPRAISE
 232 int ima_appraise_measurement(enum ima_hooks func,
 233                              struct integrity_iint_cache *iint,
 234                              struct file *file, const unsigned char *filename,
 235                              struct evm_ima_xattr_data *xattr_value,
 236                              int xattr_len, int opened);
 237 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
 238 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
 239 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
 240                                            enum ima_hooks func);
 241 enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
 242                                  int xattr_len);
 243 int ima_read_xattr(struct dentry *dentry,
 244                    struct evm_ima_xattr_data **xattr_value);
 245
 246 #else
 247 static inline int ima_appraise_measurement(enum ima_hooks func,
 248                                            struct integrity_iint_cache *iint,
 249                                            struct file *file,
 250                                            const unsigned char *filename,
 251                                            struct evm_ima_xattr_data *xattr_value,
 252                                            int xattr_len, int opened)
 253 {
 254         return INTEGRITY_UNKNOWN;
 255 }
 256
 257 static inline int ima_must_appraise(struct inode *inode, int mask,
 258                                     enum ima_hooks func)
 259 {
 260         return 0;
 261 }
 262
 263 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
 264                                     struct file *file)
 265 {
 266 }
 267
 268 static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
 269                                                          *iint,
 270                                                          enum ima_hooks func)
 271 {
 272         return INTEGRITY_UNKNOWN;
 273 }
 274
 275 static inline enum hash_algo
 276 ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len)
 277 {
 278         return ima_hash_algo;
 279 }
 280
 281 static inline int ima_read_xattr(struct dentry *dentry,
 282                                  struct evm_ima_xattr_data **xattr_value)
 283 {
 284         return 0;
 285 }
 286
 287 #endif
 288
 289 /* LSM based policy rules require audit */
 290 #ifdef CONFIG_IMA_LSM_RULES
 291
 292 #define security_filter_rule_init security_audit_rule_init
 293 #define security_filter_rule_match security_audit_rule_match
 294
 295 #else
 296
 297 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
 298                                             void **lsmrule)
 299 {
 300         return -EINVAL;
 301 }
 302
 303 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
 304                                              void *lsmrule,
 305                                              struct audit_context *actx)
 306 {
 307         return -EINVAL;
 308 }
 309 #endif /* CONFIG_IMA_TRUSTED_KEYRING */
 310
 311 #ifdef  CONFIG_IMA_READ_POLICY
 312 #define POLICY_FILE_FLAGS       (S_IWUSR | S_IRUSR)
 313 #else
 314 #define POLICY_FILE_FLAGS       S_IWUSR
 315 #endif /* CONFIG_IMA_WRITE_POLICY */
 316
 317 #endif /* __LINUX_IMA_H */