xref: /linux/security/integrity/evm/evm.h (revision 353ad6c0839431146fdee3ff16f9dd17a2809ee4)
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_SETUP_COMPLETE 0x80000000 /* userland has signaled key load */
24 
25 #define EVM_KEY_MASK (EVM_INIT_HMAC | EVM_INIT_X509)
26 #define EVM_INIT_MASK (EVM_INIT_HMAC | EVM_INIT_X509 | EVM_SETUP_COMPLETE | \
27 		       EVM_ALLOW_METADATA_WRITES)
28 
29 struct xattr_list {
30 	struct list_head list;
31 	char *name;
32 	bool enabled;
33 };
34 
35 #define EVM_NEW_FILE			0x00000001
36 #define EVM_IMMUTABLE_DIGSIG		0x00000002
37 
38 /* EVM integrity metadata associated with an inode */
39 struct evm_iint_cache {
40 	unsigned long flags;
41 	enum integrity_status evm_status:4;
42 	struct integrity_inode_attributes metadata_inode;
43 };
44 
45 extern struct lsm_blob_sizes evm_blob_sizes;
46 
evm_iint_inode(const struct inode * inode)47 static inline struct evm_iint_cache *evm_iint_inode(const struct inode *inode)
48 {
49 	if (unlikely(!inode->i_security))
50 		return NULL;
51 
52 	return inode->i_security + evm_blob_sizes.lbs_inode;
53 }
54 
55 extern int evm_initialized;
56 
57 #define EVM_ATTR_FSUUID		0x0001
58 
59 extern int evm_hmac_attrs;
60 
61 /* List of EVM protected security xattrs */
62 extern struct list_head evm_config_xattrnames;
63 
64 struct evm_digest {
65 	struct ima_digest_data_hdr hdr;
66 	char digest[IMA_MAX_DIGEST_SIZE];
67 } __packed;
68 
69 int evm_protected_xattr(const char *req_xattr_name);
70 
71 int evm_init_key(void);
72 int evm_update_evmxattr(struct dentry *dentry,
73 			const char *req_xattr_name,
74 			const char *req_xattr_value,
75 			size_t req_xattr_value_len);
76 int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
77 		  const char *req_xattr_value,
78 		  size_t req_xattr_value_len, struct evm_digest *data,
79 		  struct evm_iint_cache *iint);
80 int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name,
81 		  const char *req_xattr_value,
82 		  size_t req_xattr_value_len, char type,
83 		  struct evm_digest *data, struct evm_iint_cache *iint);
84 int evm_init_hmac(struct inode *inode, const struct xattr *xattrs,
85 		  char *hmac_val);
86 int evm_init_secfs(void);
87 
88 #endif
89