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_hash_algo;
57 extern int ima_appraise;
58 extern struct tpm_chip *ima_tpm_chip;
59
60 /* IMA event related data */
61 struct ima_event_data {
62 struct integrity_iint_cache *iint;
63 struct file *file;
64 const unsigned char *filename;
65 struct evm_ima_xattr_data *xattr_value;
66 int xattr_len;
67 const char *violation;
68 };
69
70 /* IMA template field data definition */
71 struct ima_field_data {
72 u8 *data;
73 u32 len;
74 };
75
76 /* IMA template field definition */
77 struct ima_template_field {
78 const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
79 int (*field_init)(struct ima_event_data *event_data,
80 struct ima_field_data *field_data);
81 void (*field_show)(struct seq_file *m, enum ima_show_type show,
82 struct ima_field_data *field_data);
83 };
84
85 /* IMA template descriptor definition */
86 struct ima_template_desc {
87 struct list_head list;
88 char *name;
89 char *fmt;
90 int num_fields;
91 struct ima_template_field **fields;
92 };
93
94 struct ima_template_entry {
95 int pcr;
96 u8 digest[TPM_DIGEST_SIZE]; /* sha1 or md5 measurement hash */
97 struct ima_template_desc *template_desc; /* template descriptor */
98 u32 template_data_len;
99 struct ima_field_data template_data[0]; /* template related data */
100 };
101
102 struct ima_queue_entry {
103 struct hlist_node hnext; /* place in hash collision list */
104 struct list_head later; /* place in ima_measurements list */
105 struct ima_template_entry *entry;
106 };
107 extern struct list_head ima_measurements; /* list of all measurements */
108
109 /* Some details preceding the binary serialized measurement list */
110 struct ima_kexec_hdr {
111 u16 version;
112 u16 _reserved0;
113 u32 _reserved1;
114 u64 buffer_size;
115 u64 count;
116 };
117
118 #ifdef CONFIG_HAVE_IMA_KEXEC
119 void ima_load_kexec_buffer(void);
120 #else
ima_load_kexec_buffer(void)121 static inline void ima_load_kexec_buffer(void) {}
122 #endif /* CONFIG_HAVE_IMA_KEXEC */
123
124 /*
125 * The default binary_runtime_measurements list format is defined as the
126 * platform native format. The canonical format is defined as little-endian.
127 */
128 extern bool ima_canonical_fmt;
129
130 /* Internal IMA function definitions */
131 int ima_init(void);
132 int ima_fs_init(void);
133 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
134 const char *op, struct inode *inode,
135 const unsigned char *filename);
136 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
137 int ima_calc_buffer_hash(const void *buf, loff_t len,
138 struct ima_digest_data *hash);
139 int ima_calc_field_array_hash(struct ima_field_data *field_data,
140 struct ima_template_desc *desc, int num_fields,
141 struct ima_digest_data *hash);
142 int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
143 void ima_add_violation(struct file *file, const unsigned char *filename,
144 struct integrity_iint_cache *iint,
145 const char *op, const char *cause);
146 int ima_init_crypto(void);
147 void ima_putc(struct seq_file *m, void *data, int datalen);
148 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size);
149 struct ima_template_desc *ima_template_desc_current(void);
150 int ima_restore_measurement_entry(struct ima_template_entry *entry);
151 int ima_restore_measurement_list(loff_t bufsize, void *buf);
152 int ima_measurements_show(struct seq_file *m, void *v);
153 unsigned long ima_get_binary_runtime_size(void);
154 int ima_init_template(void);
155 void ima_init_template_list(void);
156
157 /*
158 * used to protect h_table and sha_table
159 */
160 extern spinlock_t ima_queue_lock;
161
162 struct ima_h_table {
163 atomic_long_t len; /* number of stored measurements in the list */
164 atomic_long_t violations;
165 struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
166 };
167 extern struct ima_h_table ima_htable;
168
ima_hash_key(u8 * digest)169 static inline unsigned long ima_hash_key(u8 *digest)
170 {
171 return hash_long(*digest, IMA_HASH_BITS);
172 }
173
174 #define __ima_hooks(hook) \
175 hook(NONE) \
176 hook(FILE_CHECK) \
177 hook(MMAP_CHECK) \
178 hook(BPRM_CHECK) \
179 hook(CREDS_CHECK) \
180 hook(POST_SETATTR) \
181 hook(MODULE_CHECK) \
182 hook(FIRMWARE_CHECK) \
183 hook(KEXEC_KERNEL_CHECK) \
184 hook(KEXEC_INITRAMFS_CHECK) \
185 hook(POLICY_CHECK) \
186 hook(MAX_CHECK)
187 #define __ima_hook_enumify(ENUM) ENUM,
188
189 enum ima_hooks {
190 __ima_hooks(__ima_hook_enumify)
191 };
192
193 /* LIM API function definitions */
194 int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
195 int mask, enum ima_hooks func, int *pcr);
196 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
197 int ima_collect_measurement(struct integrity_iint_cache *iint,
198 struct file *file, void *buf, loff_t size,
199 enum hash_algo algo);
200 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
201 const unsigned char *filename,
202 struct evm_ima_xattr_data *xattr_value,
203 int xattr_len, int pcr);
204 void ima_audit_measurement(struct integrity_iint_cache *iint,
205 const unsigned char *filename);
206 int ima_alloc_init_template(struct ima_event_data *event_data,
207 struct ima_template_entry **entry);
208 int ima_store_template(struct ima_template_entry *entry, int violation,
209 struct inode *inode,
210 const unsigned char *filename, int pcr);
211 void ima_free_template_entry(struct ima_template_entry *entry);
212 const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
213
214 /* IMA policy related functions */
215 int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
216 enum ima_hooks func, int mask, int flags, int *pcr);
217 void ima_init_policy(void);
218 void ima_update_policy(void);
219 void ima_update_policy_flag(void);
220 ssize_t ima_parse_add_rule(char *);
221 void ima_delete_rules(void);
222 int ima_check_policy(void);
223 void *ima_policy_start(struct seq_file *m, loff_t *pos);
224 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos);
225 void ima_policy_stop(struct seq_file *m, void *v);
226 int ima_policy_show(struct seq_file *m, void *v);
227
228 /* Appraise integrity measurements */
229 #define IMA_APPRAISE_ENFORCE 0x01
230 #define IMA_APPRAISE_FIX 0x02
231 #define IMA_APPRAISE_LOG 0x04
232 #define IMA_APPRAISE_MODULES 0x08
233 #define IMA_APPRAISE_FIRMWARE 0x10
234 #define IMA_APPRAISE_POLICY 0x20
235 #define IMA_APPRAISE_KEXEC 0x40
236
237 #ifdef CONFIG_IMA_APPRAISE
238 int ima_appraise_measurement(enum ima_hooks func,
239 struct integrity_iint_cache *iint,
240 struct file *file, const unsigned char *filename,
241 struct evm_ima_xattr_data *xattr_value,
242 int xattr_len);
243 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
244 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
245 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
246 enum ima_hooks func);
247 enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
248 int xattr_len);
249 int ima_read_xattr(struct dentry *dentry,
250 struct evm_ima_xattr_data **xattr_value);
251
252 #else
ima_appraise_measurement(enum ima_hooks func,struct integrity_iint_cache * iint,struct file * file,const unsigned char * filename,struct evm_ima_xattr_data * xattr_value,int xattr_len)253 static inline int ima_appraise_measurement(enum ima_hooks func,
254 struct integrity_iint_cache *iint,
255 struct file *file,
256 const unsigned char *filename,
257 struct evm_ima_xattr_data *xattr_value,
258 int xattr_len)
259 {
260 return INTEGRITY_UNKNOWN;
261 }
262
ima_must_appraise(struct inode * inode,int mask,enum ima_hooks func)263 static inline int ima_must_appraise(struct inode *inode, int mask,
264 enum ima_hooks func)
265 {
266 return 0;
267 }
268
ima_update_xattr(struct integrity_iint_cache * iint,struct file * file)269 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
270 struct file *file)
271 {
272 }
273
ima_get_cache_status(struct integrity_iint_cache * iint,enum ima_hooks func)274 static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
275 *iint,
276 enum ima_hooks func)
277 {
278 return INTEGRITY_UNKNOWN;
279 }
280
281 static inline enum hash_algo
ima_get_hash_algo(struct evm_ima_xattr_data * xattr_value,int xattr_len)282 ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len)
283 {
284 return ima_hash_algo;
285 }
286
ima_read_xattr(struct dentry * dentry,struct evm_ima_xattr_data ** xattr_value)287 static inline int ima_read_xattr(struct dentry *dentry,
288 struct evm_ima_xattr_data **xattr_value)
289 {
290 return 0;
291 }
292
293 #endif /* CONFIG_IMA_APPRAISE */
294
295 /* LSM based policy rules require audit */
296 #ifdef CONFIG_IMA_LSM_RULES
297
298 #define security_filter_rule_init security_audit_rule_init
299 #define security_filter_rule_match security_audit_rule_match
300
301 #else
302
security_filter_rule_init(u32 field,u32 op,char * rulestr,void ** lsmrule)303 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
304 void **lsmrule)
305 {
306 return -EINVAL;
307 }
308
security_filter_rule_match(u32 secid,u32 field,u32 op,void * lsmrule,struct audit_context * actx)309 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
310 void *lsmrule,
311 struct audit_context *actx)
312 {
313 return -EINVAL;
314 }
315 #endif /* CONFIG_IMA_LSM_RULES */
316
317 #ifdef CONFIG_IMA_READ_POLICY
318 #define POLICY_FILE_FLAGS (S_IWUSR | S_IRUSR)
319 #else
320 #define POLICY_FILE_FLAGS S_IWUSR
321 #endif /* CONFIG_IMA_READ_POLICY */
322
323 #endif /* __LINUX_IMA_H */
324
