xref: /openbmc/linux/security/integrity/ima/ima.h (revision af958a38)
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 /* set during initialization */
47 extern int ima_initialized;
48 extern int ima_used_chip;
49 extern int ima_hash_algo;
50 extern int ima_appraise;
51 
52 /* IMA template field data definition */
53 struct ima_field_data {
54 	u8 *data;
55 	u32 len;
56 };
57 
58 /* IMA template field definition */
59 struct ima_template_field {
60 	const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
61 	int (*field_init) (struct integrity_iint_cache *iint, struct file *file,
62 			   const unsigned char *filename,
63 			   struct evm_ima_xattr_data *xattr_value,
64 			   int xattr_len, struct ima_field_data *field_data);
65 	void (*field_show) (struct seq_file *m, enum ima_show_type show,
66 			    struct ima_field_data *field_data);
67 };
68 
69 /* IMA template descriptor definition */
70 struct ima_template_desc {
71 	char *name;
72 	char *fmt;
73 	int num_fields;
74 	struct ima_template_field **fields;
75 };
76 
77 struct ima_template_entry {
78 	u8 digest[TPM_DIGEST_SIZE];	/* sha1 or md5 measurement hash */
79 	struct ima_template_desc *template_desc; /* template descriptor */
80 	u32 template_data_len;
81 	struct ima_field_data template_data[0];	/* template related data */
82 };
83 
84 struct ima_queue_entry {
85 	struct hlist_node hnext;	/* place in hash collision list */
86 	struct list_head later;		/* place in ima_measurements list */
87 	struct ima_template_entry *entry;
88 };
89 extern struct list_head ima_measurements;	/* list of all measurements */
90 
91 /* Internal IMA function definitions */
92 int ima_init(void);
93 void ima_cleanup(void);
94 int ima_fs_init(void);
95 void ima_fs_cleanup(void);
96 int ima_inode_alloc(struct inode *inode);
97 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
98 			   const char *op, struct inode *inode,
99 			   const unsigned char *filename);
100 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
101 int ima_calc_field_array_hash(struct ima_field_data *field_data,
102 			      struct ima_template_desc *desc, int num_fields,
103 			      struct ima_digest_data *hash);
104 int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
105 void ima_add_violation(struct file *file, const unsigned char *filename,
106 		       const char *op, const char *cause);
107 int ima_init_crypto(void);
108 void ima_putc(struct seq_file *m, void *data, int datalen);
109 void ima_print_digest(struct seq_file *m, u8 *digest, int size);
110 struct ima_template_desc *ima_template_desc_current(void);
111 int ima_init_template(void);
112 
113 int ima_init_template(void);
114 
115 /*
116  * used to protect h_table and sha_table
117  */
118 extern spinlock_t ima_queue_lock;
119 
120 struct ima_h_table {
121 	atomic_long_t len;	/* number of stored measurements in the list */
122 	atomic_long_t violations;
123 	struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
124 };
125 extern struct ima_h_table ima_htable;
126 
127 static inline unsigned long ima_hash_key(u8 *digest)
128 {
129 	return hash_long(*digest, IMA_HASH_BITS);
130 }
131 
132 /* LIM API function definitions */
133 int ima_get_action(struct inode *inode, int mask, int function);
134 int ima_must_measure(struct inode *inode, int mask, int function);
135 int ima_collect_measurement(struct integrity_iint_cache *iint,
136 			    struct file *file,
137 			    struct evm_ima_xattr_data **xattr_value,
138 			    int *xattr_len);
139 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
140 			   const unsigned char *filename,
141 			   struct evm_ima_xattr_data *xattr_value,
142 			   int xattr_len);
143 void ima_audit_measurement(struct integrity_iint_cache *iint,
144 			   const unsigned char *filename);
145 int ima_alloc_init_template(struct integrity_iint_cache *iint,
146 			    struct file *file, const unsigned char *filename,
147 			    struct evm_ima_xattr_data *xattr_value,
148 			    int xattr_len, struct ima_template_entry **entry);
149 int ima_store_template(struct ima_template_entry *entry, int violation,
150 		       struct inode *inode, const unsigned char *filename);
151 void ima_free_template_entry(struct ima_template_entry *entry);
152 const char *ima_d_path(struct path *path, char **pathbuf);
153 
154 /* rbtree tree calls to lookup, insert, delete
155  * integrity data associated with an inode.
156  */
157 struct integrity_iint_cache *integrity_iint_insert(struct inode *inode);
158 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
159 
160 /* IMA policy related functions */
161 enum ima_hooks { FILE_CHECK = 1, MMAP_CHECK, BPRM_CHECK, MODULE_CHECK, FIRMWARE_CHECK, POST_SETATTR };
162 
163 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
164 		     int flags);
165 void ima_init_policy(void);
166 void ima_update_policy(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_MODULES	0x04
174 #define IMA_APPRAISE_FIRMWARE	0x08
175 
176 #ifdef CONFIG_IMA_APPRAISE
177 int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
178 			     struct file *file, const unsigned char *filename,
179 			     struct evm_ima_xattr_data *xattr_value,
180 			     int xattr_len);
181 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
182 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
183 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
184 					   int func);
185 void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len,
186 		       struct ima_digest_data *hash);
187 int ima_read_xattr(struct dentry *dentry,
188 		   struct evm_ima_xattr_data **xattr_value);
189 
190 #else
191 static inline int ima_appraise_measurement(int func,
192 					   struct integrity_iint_cache *iint,
193 					   struct file *file,
194 					   const unsigned char *filename,
195 					   struct evm_ima_xattr_data *xattr_value,
196 					   int xattr_len)
197 {
198 	return INTEGRITY_UNKNOWN;
199 }
200 
201 static inline int ima_must_appraise(struct inode *inode, int mask,
202 				    enum ima_hooks func)
203 {
204 	return 0;
205 }
206 
207 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
208 				    struct file *file)
209 {
210 }
211 
212 static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
213 							 *iint, int func)
214 {
215 	return INTEGRITY_UNKNOWN;
216 }
217 
218 static inline void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
219 				     int xattr_len,
220 				     struct ima_digest_data *hash)
221 {
222 }
223 
224 static inline int ima_read_xattr(struct dentry *dentry,
225 				 struct evm_ima_xattr_data **xattr_value)
226 {
227 	return 0;
228 }
229 
230 #endif
231 
232 /* LSM based policy rules require audit */
233 #ifdef CONFIG_IMA_LSM_RULES
234 
235 #define security_filter_rule_init security_audit_rule_init
236 #define security_filter_rule_match security_audit_rule_match
237 
238 #else
239 
240 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
241 					    void **lsmrule)
242 {
243 	return -EINVAL;
244 }
245 
246 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
247 					     void *lsmrule,
248 					     struct audit_context *actx)
249 {
250 	return -EINVAL;
251 }
252 #endif /* CONFIG_IMA_LSM_RULES */
253 
254 #ifdef CONFIG_IMA_TRUSTED_KEYRING
255 static inline int ima_init_keyring(const unsigned int id)
256 {
257 	return integrity_init_keyring(id);
258 }
259 #else
260 static inline int ima_init_keyring(const unsigned int id)
261 {
262 	return 0;
263 }
264 #endif /* CONFIG_IMA_TRUSTED_KEYRING */
265 #endif
266