xref: /linux/security/integrity/ima/ima.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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/security.h>
23 #include <linux/hash.h>
24 #include <linux/tpm.h>
25 #include <linux/audit.h>
26 
27 #include "../integrity.h"
28 
29 enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN,
30 		     IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII };
31 enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
32 
33 /* digest size for IMA, fits SHA1 or MD5 */
34 #define IMA_DIGEST_SIZE		SHA1_DIGEST_SIZE
35 #define IMA_EVENT_NAME_LEN_MAX	255
36 
37 #define IMA_HASH_BITS 9
38 #define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)
39 
40 #define IMA_TEMPLATE_FIELD_ID_MAX_LEN	16
41 #define IMA_TEMPLATE_NUM_FIELDS_MAX	15
42 
43 #define IMA_TEMPLATE_IMA_NAME "ima"
44 #define IMA_TEMPLATE_IMA_FMT "d|n"
45 
46 /* current content of the policy */
47 extern int ima_policy_flag;
48 
49 /* set during initialization */
50 extern int ima_initialized;
51 extern int ima_used_chip;
52 extern int ima_hash_algo;
53 extern int ima_appraise;
54 
55 /* IMA event related data */
56 struct ima_event_data {
57 	struct integrity_iint_cache *iint;
58 	struct file *file;
59 	const unsigned char *filename;
60 	struct evm_ima_xattr_data *xattr_value;
61 	int xattr_len;
62 	const char *violation;
63 };
64 
65 /* IMA template field data definition */
66 struct ima_field_data {
67 	u8 *data;
68 	u32 len;
69 };
70 
71 /* IMA template field definition */
72 struct ima_template_field {
73 	const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
74 	int (*field_init)(struct ima_event_data *event_data,
75 			  struct ima_field_data *field_data);
76 	void (*field_show)(struct seq_file *m, enum ima_show_type show,
77 			   struct ima_field_data *field_data);
78 };
79 
80 /* IMA template descriptor definition */
81 struct ima_template_desc {
82 	char *name;
83 	char *fmt;
84 	int num_fields;
85 	struct ima_template_field **fields;
86 };
87 
88 struct ima_template_entry {
89 	u8 digest[TPM_DIGEST_SIZE];	/* sha1 or md5 measurement hash */
90 	struct ima_template_desc *template_desc; /* template descriptor */
91 	u32 template_data_len;
92 	struct ima_field_data template_data[0];	/* template related data */
93 };
94 
95 struct ima_queue_entry {
96 	struct hlist_node hnext;	/* place in hash collision list */
97 	struct list_head later;		/* place in ima_measurements list */
98 	struct ima_template_entry *entry;
99 };
100 extern struct list_head ima_measurements;	/* list of all measurements */
101 
102 /* Internal IMA function definitions */
103 int ima_init(void);
104 int ima_fs_init(void);
105 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
106 			   const char *op, struct inode *inode,
107 			   const unsigned char *filename);
108 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
109 int ima_calc_field_array_hash(struct ima_field_data *field_data,
110 			      struct ima_template_desc *desc, int num_fields,
111 			      struct ima_digest_data *hash);
112 int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
113 void ima_add_violation(struct file *file, const unsigned char *filename,
114 		       struct integrity_iint_cache *iint,
115 		       const char *op, const char *cause);
116 int ima_init_crypto(void);
117 void ima_putc(struct seq_file *m, void *data, int datalen);
118 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size);
119 struct ima_template_desc *ima_template_desc_current(void);
120 int ima_init_template(void);
121 
122 /*
123  * used to protect h_table and sha_table
124  */
125 extern spinlock_t ima_queue_lock;
126 
127 struct ima_h_table {
128 	atomic_long_t len;	/* number of stored measurements in the list */
129 	atomic_long_t violations;
130 	struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
131 };
132 extern struct ima_h_table ima_htable;
133 
134 static inline unsigned long ima_hash_key(u8 *digest)
135 {
136 	return hash_long(*digest, IMA_HASH_BITS);
137 }
138 
139 /* LIM API function definitions */
140 int ima_get_action(struct inode *inode, int mask, int function);
141 int ima_must_measure(struct inode *inode, int mask, int function);
142 int ima_collect_measurement(struct integrity_iint_cache *iint,
143 			    struct file *file,
144 			    struct evm_ima_xattr_data **xattr_value,
145 			    int *xattr_len);
146 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
147 			   const unsigned char *filename,
148 			   struct evm_ima_xattr_data *xattr_value,
149 			   int xattr_len);
150 void ima_audit_measurement(struct integrity_iint_cache *iint,
151 			   const unsigned char *filename);
152 int ima_alloc_init_template(struct ima_event_data *event_data,
153 			    struct ima_template_entry **entry);
154 int ima_store_template(struct ima_template_entry *entry, int violation,
155 		       struct inode *inode, const unsigned char *filename);
156 void ima_free_template_entry(struct ima_template_entry *entry);
157 const char *ima_d_path(struct path *path, char **pathbuf);
158 
159 /* IMA policy related functions */
160 enum ima_hooks { FILE_CHECK = 1, MMAP_CHECK, BPRM_CHECK, MODULE_CHECK, FIRMWARE_CHECK, POST_SETATTR };
161 
162 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
163 		     int flags);
164 void ima_init_policy(void);
165 void ima_update_policy(void);
166 void ima_update_policy_flag(void);
167 ssize_t ima_parse_add_rule(char *);
168 void ima_delete_rules(void);
169 
170 /* Appraise integrity measurements */
171 #define IMA_APPRAISE_ENFORCE	0x01
172 #define IMA_APPRAISE_FIX	0x02
173 #define IMA_APPRAISE_LOG	0x04
174 #define IMA_APPRAISE_MODULES	0x08
175 #define IMA_APPRAISE_FIRMWARE	0x10
176 
177 #ifdef CONFIG_IMA_APPRAISE
178 int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
179 			     struct file *file, const unsigned char *filename,
180 			     struct evm_ima_xattr_data *xattr_value,
181 			     int xattr_len, int opened);
182 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
183 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
184 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
185 					   int func);
186 void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len,
187 		       struct ima_digest_data *hash);
188 int ima_read_xattr(struct dentry *dentry,
189 		   struct evm_ima_xattr_data **xattr_value);
190 
191 #else
192 static inline int ima_appraise_measurement(int func,
193 					   struct integrity_iint_cache *iint,
194 					   struct file *file,
195 					   const unsigned char *filename,
196 					   struct evm_ima_xattr_data *xattr_value,
197 					   int xattr_len, int opened)
198 {
199 	return INTEGRITY_UNKNOWN;
200 }
201 
202 static inline int ima_must_appraise(struct inode *inode, int mask,
203 				    enum ima_hooks func)
204 {
205 	return 0;
206 }
207 
208 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
209 				    struct file *file)
210 {
211 }
212 
213 static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
214 							 *iint, int func)
215 {
216 	return INTEGRITY_UNKNOWN;
217 }
218 
219 static inline void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
220 				     int xattr_len,
221 				     struct ima_digest_data *hash)
222 {
223 }
224 
225 static inline int ima_read_xattr(struct dentry *dentry,
226 				 struct evm_ima_xattr_data **xattr_value)
227 {
228 	return 0;
229 }
230 
231 #endif
232 
233 /* LSM based policy rules require audit */
234 #ifdef CONFIG_IMA_LSM_RULES
235 
236 #define security_filter_rule_init security_audit_rule_init
237 #define security_filter_rule_match security_audit_rule_match
238 
239 #else
240 
241 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
242 					    void **lsmrule)
243 {
244 	return -EINVAL;
245 }
246 
247 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
248 					     void *lsmrule,
249 					     struct audit_context *actx)
250 {
251 	return -EINVAL;
252 }
253 #endif /* CONFIG_IMA_LSM_RULES */
254 
255 #ifdef CONFIG_IMA_TRUSTED_KEYRING
256 static inline int ima_init_keyring(const unsigned int id)
257 {
258 	return integrity_init_keyring(id);
259 }
260 #else
261 static inline int ima_init_keyring(const unsigned int id)
262 {
263 	return 0;
264 }
265 #endif /* CONFIG_IMA_TRUSTED_KEYRING */
266 #endif
267