| 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 | 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_initialized; |
| 53 | extern int ima_used_chip; |
| 54 | extern int ima_hash_algo; |
| 55 | extern int ima_appraise; |
| 56 | |
| 57 | /* IMA event related data */ |
| 58 | struct ima_event_data { |
| 59 | struct integrity_iint_cache *iint; |
| 60 | struct file *file; |
| 61 | const unsigned char *filename; |
| 62 | struct evm_ima_xattr_data *xattr_value; |
| 63 | int xattr_len; |
| 64 | const char *violation; |
| 65 | }; |
| 66 | |
| 67 | /* IMA template field data definition */ |
| 68 | struct ima_field_data { |
| 69 | u8 *data; |
| 70 | u32 len; |
| 71 | }; |
| 72 | |
| 73 | /* IMA template field definition */ |
| 74 | struct ima_template_field { |
| 75 | const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN]; |
| 76 | int (*field_init)(struct ima_event_data *event_data, |
| 77 | struct ima_field_data *field_data); |
| 78 | void (*field_show)(struct seq_file *m, enum ima_show_type show, |
| 79 | struct ima_field_data *field_data); |
| 80 | }; |
| 81 | |
| 82 | /* IMA template descriptor definition */ |
| 83 | struct ima_template_desc { |
| 84 | char *name; |
| 85 | char *fmt; |
| 86 | int num_fields; |
| 87 | 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 | /* Internal IMA function definitions */ |
| 106 | int ima_init(void); |
| 107 | int ima_fs_init(void); |
| 108 | int ima_add_template_entry(struct ima_template_entry *entry, int violation, |
| 109 | const char *op, struct inode *inode, |
| 110 | const unsigned char *filename); |
| 111 | int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash); |
| 112 | int ima_calc_buffer_hash(const void *buf, loff_t len, |
| 113 | struct ima_digest_data *hash); |
| 114 | int ima_calc_field_array_hash(struct ima_field_data *field_data, |
| 115 | struct ima_template_desc *desc, int num_fields, |
| 116 | struct ima_digest_data *hash); |
| 117 | int __init ima_calc_boot_aggregate(struct ima_digest_data *hash); |
| 118 | void ima_add_violation(struct file *file, const unsigned char *filename, |
| 119 | struct integrity_iint_cache *iint, |
| 120 | const char *op, const char *cause); |
| 121 | int ima_init_crypto(void); |
| 122 | void ima_putc(struct seq_file *m, void *data, int datalen); |
| 123 | void ima_print_digest(struct seq_file *m, u8 *digest, u32 size); |
| 124 | struct ima_template_desc *ima_template_desc_current(void); |
| 125 | int ima_init_template(void); |
| 126 | |
| 127 | /* |
| 128 | * used to protect h_table and sha_table |
| 129 | */ |
| 130 | extern spinlock_t ima_queue_lock; |
| 131 | |
| 132 | struct ima_h_table { |
| 133 | atomic_long_t len; /* number of stored measurements in the list */ |
| 134 | atomic_long_t violations; |
| 135 | struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE]; |
| 136 | }; |
| 137 | extern struct ima_h_table ima_htable; |
| 138 | |
| 139 | static inline unsigned long ima_hash_key(u8 *digest) |
| 140 | { |
| 141 | return hash_long(*digest, IMA_HASH_BITS); |
| 142 | } |
| 143 | |
| 144 | enum ima_hooks { |
| 145 | FILE_CHECK = 1, |
| 146 | MMAP_CHECK, |
| 147 | BPRM_CHECK, |
| 148 | POST_SETATTR, |
| 149 | MODULE_CHECK, |
| 150 | FIRMWARE_CHECK, |
| 151 | KEXEC_KERNEL_CHECK, |
| 152 | KEXEC_INITRAMFS_CHECK, |
| 153 | POLICY_CHECK, |
| 154 | MAX_CHECK |
| 155 | }; |
| 156 | |
| 157 | /* LIM API function definitions */ |
| 158 | int ima_get_action(struct inode *inode, int mask, |
| 159 | enum ima_hooks func, int *pcr); |
| 160 | int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func); |
| 161 | int ima_collect_measurement(struct integrity_iint_cache *iint, |
| 162 | struct file *file, void *buf, loff_t size, |
| 163 | enum hash_algo algo); |
| 164 | void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, |
| 165 | const unsigned char *filename, |
| 166 | struct evm_ima_xattr_data *xattr_value, |
| 167 | int xattr_len, int pcr); |
| 168 | void ima_audit_measurement(struct integrity_iint_cache *iint, |
| 169 | const unsigned char *filename); |
| 170 | int ima_alloc_init_template(struct ima_event_data *event_data, |
| 171 | struct ima_template_entry **entry); |
| 172 | int ima_store_template(struct ima_template_entry *entry, int violation, |
| 173 | struct inode *inode, |
| 174 | const unsigned char *filename, int pcr); |
| 175 | void ima_free_template_entry(struct ima_template_entry *entry); |
| 176 | const char *ima_d_path(const struct path *path, char **pathbuf); |
| 177 | |
| 178 | /* IMA policy related functions */ |
| 179 | int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask, |
| 180 | int flags, int *pcr); |
| 181 | void ima_init_policy(void); |
| 182 | void ima_update_policy(void); |
| 183 | void ima_update_policy_flag(void); |
| 184 | ssize_t ima_parse_add_rule(char *); |
| 185 | void ima_delete_rules(void); |
| 186 | int ima_check_policy(void); |
| 187 | void *ima_policy_start(struct seq_file *m, loff_t *pos); |
| 188 | void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos); |
| 189 | void ima_policy_stop(struct seq_file *m, void *v); |
| 190 | int ima_policy_show(struct seq_file *m, void *v); |
| 191 | |
| 192 | /* Appraise integrity measurements */ |
| 193 | #define IMA_APPRAISE_ENFORCE 0x01 |
| 194 | #define IMA_APPRAISE_FIX 0x02 |
| 195 | #define IMA_APPRAISE_LOG 0x04 |
| 196 | #define IMA_APPRAISE_MODULES 0x08 |
| 197 | #define IMA_APPRAISE_FIRMWARE 0x10 |
| 198 | #define IMA_APPRAISE_POLICY 0x20 |
| 199 | |
| 200 | #ifdef CONFIG_IMA_APPRAISE |
| 201 | int ima_appraise_measurement(enum ima_hooks func, |
| 202 | struct integrity_iint_cache *iint, |
| 203 | struct file *file, const unsigned char *filename, |
| 204 | struct evm_ima_xattr_data *xattr_value, |
| 205 | int xattr_len, int opened); |
| 206 | int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func); |
| 207 | void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file); |
| 208 | enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint, |
| 209 | enum ima_hooks func); |
| 210 | enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, |
| 211 | int xattr_len); |
| 212 | int ima_read_xattr(struct dentry *dentry, |
| 213 | struct evm_ima_xattr_data **xattr_value); |
| 214 | |
| 215 | #else |
| 216 | static inline int ima_appraise_measurement(enum ima_hooks func, |
| 217 | struct integrity_iint_cache *iint, |
| 218 | struct file *file, |
| 219 | const unsigned char *filename, |
| 220 | struct evm_ima_xattr_data *xattr_value, |
| 221 | int xattr_len, int opened) |
| 222 | { |
| 223 | return INTEGRITY_UNKNOWN; |
| 224 | } |
| 225 | |
| 226 | static inline int ima_must_appraise(struct inode *inode, int mask, |
| 227 | enum ima_hooks func) |
| 228 | { |
| 229 | return 0; |
| 230 | } |
| 231 | |
| 232 | static inline void ima_update_xattr(struct integrity_iint_cache *iint, |
| 233 | struct file *file) |
| 234 | { |
| 235 | } |
| 236 | |
| 237 | static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache |
| 238 | *iint, |
| 239 | enum ima_hooks func) |
| 240 | { |
| 241 | return INTEGRITY_UNKNOWN; |
| 242 | } |
| 243 | |
| 244 | static inline enum hash_algo |
| 245 | ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len) |
| 246 | { |
| 247 | return ima_hash_algo; |
| 248 | } |
| 249 | |
| 250 | static inline int ima_read_xattr(struct dentry *dentry, |
| 251 | struct evm_ima_xattr_data **xattr_value) |
| 252 | { |
| 253 | return 0; |
| 254 | } |
| 255 | |
| 256 | #endif |
| 257 | |
| 258 | /* LSM based policy rules require audit */ |
| 259 | #ifdef CONFIG_IMA_LSM_RULES |
| 260 | |
| 261 | #define security_filter_rule_init security_audit_rule_init |
| 262 | #define security_filter_rule_match security_audit_rule_match |
| 263 | |
| 264 | #else |
| 265 | |
| 266 | static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr, |
| 267 | void **lsmrule) |
| 268 | { |
| 269 | return -EINVAL; |
| 270 | } |
| 271 | |
| 272 | static inline int security_filter_rule_match(u32 secid, u32 field, u32 op, |
| 273 | void *lsmrule, |
| 274 | struct audit_context *actx) |
| 275 | { |
| 276 | return -EINVAL; |
| 277 | } |
| 278 | #endif /* CONFIG_IMA_TRUSTED_KEYRING */ |
| 279 | |
| 280 | #ifdef CONFIG_IMA_READ_POLICY |
| 281 | #define POLICY_FILE_FLAGS (S_IWUSR | S_IRUSR) |
| 282 | #else |
| 283 | #define POLICY_FILE_FLAGS S_IWUSR |
| 284 | #endif /* CONFIG_IMA_WRITE_POLICY */ |
| 285 | |
| 286 | #endif /* __LINUX_IMA_H */ |