xref: /openbmc/linux/security/integrity/ima/ima.h (revision 94cdda6b)
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 template field data definition */
56 struct ima_field_data {
57 	u8 *data;
58 	u32 len;
59 };
60 
61 /* IMA template field definition */
62 struct ima_template_field {
63 	const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
64 	int (*field_init) (struct integrity_iint_cache *iint, struct file *file,
65 			   const unsigned char *filename,
66 			   struct evm_ima_xattr_data *xattr_value,
67 			   int xattr_len, struct ima_field_data *field_data);
68 	void (*field_show) (struct seq_file *m, enum ima_show_type show,
69 			    struct ima_field_data *field_data);
70 };
71 
72 /* IMA template descriptor definition */
73 struct ima_template_desc {
74 	char *name;
75 	char *fmt;
76 	int num_fields;
77 	struct ima_template_field **fields;
78 };
79 
80 struct ima_template_entry {
81 	u8 digest[TPM_DIGEST_SIZE];	/* sha1 or md5 measurement hash */
82 	struct ima_template_desc *template_desc; /* template descriptor */
83 	u32 template_data_len;
84 	struct ima_field_data template_data[0];	/* template related data */
85 };
86 
87 struct ima_queue_entry {
88 	struct hlist_node hnext;	/* place in hash collision list */
89 	struct list_head later;		/* place in ima_measurements list */
90 	struct ima_template_entry *entry;
91 };
92 extern struct list_head ima_measurements;	/* list of all measurements */
93 
94 /* Internal IMA function definitions */
95 int ima_init(void);
96 int ima_fs_init(void);
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 /*
114  * used to protect h_table and sha_table
115  */
116 extern spinlock_t ima_queue_lock;
117 
118 struct ima_h_table {
119 	atomic_long_t len;	/* number of stored measurements in the list */
120 	atomic_long_t violations;
121 	struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
122 };
123 extern struct ima_h_table ima_htable;
124 
125 static inline unsigned long ima_hash_key(u8 *digest)
126 {
127 	return hash_long(*digest, IMA_HASH_BITS);
128 }
129 
130 /* LIM API function definitions */
131 int ima_get_action(struct inode *inode, int mask, int function);
132 int ima_must_measure(struct inode *inode, int mask, int function);
133 int ima_collect_measurement(struct integrity_iint_cache *iint,
134 			    struct file *file,
135 			    struct evm_ima_xattr_data **xattr_value,
136 			    int *xattr_len);
137 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
138 			   const unsigned char *filename,
139 			   struct evm_ima_xattr_data *xattr_value,
140 			   int xattr_len);
141 void ima_audit_measurement(struct integrity_iint_cache *iint,
142 			   const unsigned char *filename);
143 int ima_alloc_init_template(struct integrity_iint_cache *iint,
144 			    struct file *file, const unsigned char *filename,
145 			    struct evm_ima_xattr_data *xattr_value,
146 			    int xattr_len, struct ima_template_entry **entry);
147 int ima_store_template(struct ima_template_entry *entry, int violation,
148 		       struct inode *inode, const unsigned char *filename);
149 void ima_free_template_entry(struct ima_template_entry *entry);
150 const char *ima_d_path(struct path *path, char **pathbuf);
151 
152 /* IMA policy related functions */
153 enum ima_hooks { FILE_CHECK = 1, MMAP_CHECK, BPRM_CHECK, MODULE_CHECK, FIRMWARE_CHECK, POST_SETATTR };
154 
155 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
156 		     int flags);
157 void ima_init_policy(void);
158 void ima_update_policy(void);
159 void ima_update_policy_flag(void);
160 ssize_t ima_parse_add_rule(char *);
161 void ima_delete_rules(void);
162 
163 /* Appraise integrity measurements */
164 #define IMA_APPRAISE_ENFORCE	0x01
165 #define IMA_APPRAISE_FIX	0x02
166 #define IMA_APPRAISE_LOG	0x04
167 #define IMA_APPRAISE_MODULES	0x08
168 #define IMA_APPRAISE_FIRMWARE	0x10
169 
170 #ifdef CONFIG_IMA_APPRAISE
171 int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
172 			     struct file *file, const unsigned char *filename,
173 			     struct evm_ima_xattr_data *xattr_value,
174 			     int xattr_len, int opened);
175 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
176 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
177 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
178 					   int func);
179 void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len,
180 		       struct ima_digest_data *hash);
181 int ima_read_xattr(struct dentry *dentry,
182 		   struct evm_ima_xattr_data **xattr_value);
183 
184 #else
185 static inline int ima_appraise_measurement(int func,
186 					   struct integrity_iint_cache *iint,
187 					   struct file *file,
188 					   const unsigned char *filename,
189 					   struct evm_ima_xattr_data *xattr_value,
190 					   int xattr_len, int opened)
191 {
192 	return INTEGRITY_UNKNOWN;
193 }
194 
195 static inline int ima_must_appraise(struct inode *inode, int mask,
196 				    enum ima_hooks func)
197 {
198 	return 0;
199 }
200 
201 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
202 				    struct file *file)
203 {
204 }
205 
206 static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
207 							 *iint, int func)
208 {
209 	return INTEGRITY_UNKNOWN;
210 }
211 
212 static inline void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
213 				     int xattr_len,
214 				     struct ima_digest_data *hash)
215 {
216 }
217 
218 static inline int ima_read_xattr(struct dentry *dentry,
219 				 struct evm_ima_xattr_data **xattr_value)
220 {
221 	return 0;
222 }
223 
224 #endif
225 
226 /* LSM based policy rules require audit */
227 #ifdef CONFIG_IMA_LSM_RULES
228 
229 #define security_filter_rule_init security_audit_rule_init
230 #define security_filter_rule_match security_audit_rule_match
231 
232 #else
233 
234 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
235 					    void **lsmrule)
236 {
237 	return -EINVAL;
238 }
239 
240 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
241 					     void *lsmrule,
242 					     struct audit_context *actx)
243 {
244 	return -EINVAL;
245 }
246 #endif /* CONFIG_IMA_LSM_RULES */
247 
248 #ifdef CONFIG_IMA_TRUSTED_KEYRING
249 static inline int ima_init_keyring(const unsigned int id)
250 {
251 	return integrity_init_keyring(id);
252 }
253 #else
254 static inline int ima_init_keyring(const unsigned int id)
255 {
256 	return 0;
257 }
258 #endif /* CONFIG_IMA_TRUSTED_KEYRING */
259 #endif
260