xref: /linux/security/integrity/evm/evm.h (revision 9cdca336677b4d15579ec462e33c8a330ab3a9de)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2005-2010 IBM Corporation
4  *
5  * Authors:
6  * Mimi Zohar <zohar@us.ibm.com>
7  * Kylene Hall <kjhall@us.ibm.com>
8  *
9  * File: evm.h
10  */
11 
12 #ifndef __INTEGRITY_EVM_H
13 #define __INTEGRITY_EVM_H
14 
15 #include <linux/xattr.h>
16 #include <linux/security.h>
17 
18 #include "../integrity.h"
19 
20 #define EVM_INIT_HMAC	0x0001
21 #define EVM_INIT_X509	0x0002
22 #define EVM_ALLOW_METADATA_WRITES	0x0004
23 #define EVM_SIGV3_REQUIRED		0x0008
24 #define EVM_SETUP_COMPLETE 0x80000000 /* userland has signaled key load */
25 
26 #define EVM_KEY_MASK (EVM_INIT_HMAC | EVM_INIT_X509)
27 #define EVM_INIT_MASK (EVM_INIT_HMAC | EVM_INIT_X509 | EVM_SETUP_COMPLETE | \
28 		       EVM_ALLOW_METADATA_WRITES | EVM_SIGV3_REQUIRED)
29 
30 struct xattr_list {
31 	struct list_head list;
32 	char *name;
33 	bool enabled;
34 };
35 
36 #define EVM_NEW_FILE			0x00000001
37 #define EVM_IMMUTABLE_DIGSIG		0x00000002
38 
39 /* EVM integrity metadata associated with an inode */
40 struct evm_iint_cache {
41 	unsigned long flags;
42 	enum integrity_status evm_status:4;
43 	struct integrity_inode_attributes metadata_inode;
44 };
45 
46 extern struct lsm_blob_sizes evm_blob_sizes;
47 
48 static inline struct evm_iint_cache *evm_iint_inode(const struct inode *inode)
49 {
50 	if (unlikely(!inode->i_security))
51 		return NULL;
52 
53 	return inode->i_security + evm_blob_sizes.lbs_inode;
54 }
55 
56 extern int evm_initialized;
57 
58 #define EVM_ATTR_FSUUID		0x0001
59 
60 extern int evm_hmac_attrs;
61 
62 /* List of EVM protected security xattrs */
63 extern struct list_head evm_config_xattrnames;
64 
65 struct evm_digest {
66 	struct ima_digest_data_hdr hdr;
67 	char digest[IMA_MAX_DIGEST_SIZE];
68 } __packed;
69 
70 int evm_protected_xattr(const char *req_xattr_name);
71 
72 int evm_init_key(void);
73 int evm_update_evmxattr(struct dentry *dentry,
74 			const char *req_xattr_name,
75 			const char *req_xattr_value,
76 			size_t req_xattr_value_len);
77 int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
78 		  const char *req_xattr_value,
79 		  size_t req_xattr_value_len, struct evm_digest *data,
80 		  struct evm_iint_cache *iint);
81 int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name,
82 		  const char *req_xattr_value,
83 		  size_t req_xattr_value_len, char type,
84 		  struct evm_digest *data, struct evm_iint_cache *iint);
85 int evm_init_hmac(struct inode *inode, const struct xattr *xattrs,
86 		  char *hmac_val);
87 int evm_init_secfs(void);
88 
89 #endif
90