1 /*
2  * Copyright (C) 2009-2010 IBM Corporation
3  *
4  * Authors:
5  * Mimi Zohar <zohar@us.ibm.com>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation, version 2 of the
10  * License.
11  *
12  */
13 
14 #include <linux/types.h>
15 #include <linux/integrity.h>
16 #include <crypto/sha.h>
17 #include <linux/key.h>
18 
19 /* iint action cache flags */
20 #define IMA_MEASURE		0x00000001
21 #define IMA_MEASURED		0x00000002
22 #define IMA_APPRAISE		0x00000004
23 #define IMA_APPRAISED		0x00000008
24 /*#define IMA_COLLECT		0x00000010  do not use this flag */
25 #define IMA_COLLECTED		0x00000020
26 #define IMA_AUDIT		0x00000040
27 #define IMA_AUDITED		0x00000080
28 
29 /* iint cache flags */
30 #define IMA_ACTION_FLAGS	0xff000000
31 #define IMA_DIGSIG		0x01000000
32 #define IMA_DIGSIG_REQUIRED	0x02000000
33 #define IMA_PERMIT_DIRECTIO	0x04000000
34 #define IMA_NEW_FILE		0x08000000
35 
36 #define IMA_DO_MASK		(IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
37 				 IMA_APPRAISE_SUBMASK)
38 #define IMA_DONE_MASK		(IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
39 				 IMA_COLLECTED | IMA_APPRAISED_SUBMASK)
40 
41 /* iint subaction appraise cache flags */
42 #define IMA_FILE_APPRAISE	0x00000100
43 #define IMA_FILE_APPRAISED	0x00000200
44 #define IMA_MMAP_APPRAISE	0x00000400
45 #define IMA_MMAP_APPRAISED	0x00000800
46 #define IMA_BPRM_APPRAISE	0x00001000
47 #define IMA_BPRM_APPRAISED	0x00002000
48 #define IMA_MODULE_APPRAISE	0x00004000
49 #define IMA_MODULE_APPRAISED	0x00008000
50 #define IMA_FIRMWARE_APPRAISE	0x00010000
51 #define IMA_FIRMWARE_APPRAISED	0x00020000
52 #define IMA_APPRAISE_SUBMASK	(IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
53 				 IMA_BPRM_APPRAISE | IMA_MODULE_APPRAISE | \
54 				 IMA_FIRMWARE_APPRAISE)
55 #define IMA_APPRAISED_SUBMASK	(IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
56 				 IMA_BPRM_APPRAISED | IMA_MODULE_APPRAISED | \
57 				 IMA_FIRMWARE_APPRAISED)
58 
59 enum evm_ima_xattr_type {
60 	IMA_XATTR_DIGEST = 0x01,
61 	EVM_XATTR_HMAC,
62 	EVM_IMA_XATTR_DIGSIG,
63 	IMA_XATTR_DIGEST_NG,
64 };
65 
66 struct evm_ima_xattr_data {
67 	u8 type;
68 	u8 digest[SHA1_DIGEST_SIZE];
69 } __packed;
70 
71 #define IMA_MAX_DIGEST_SIZE	64
72 
73 struct ima_digest_data {
74 	u8 algo;
75 	u8 length;
76 	union {
77 		struct {
78 			u8 unused;
79 			u8 type;
80 		} sha1;
81 		struct {
82 			u8 type;
83 			u8 algo;
84 		} ng;
85 		u8 data[2];
86 	} xattr;
87 	u8 digest[0];
88 } __packed;
89 
90 /*
91  * signature format v2 - for using with asymmetric keys
92  */
93 struct signature_v2_hdr {
94 	uint8_t type;		/* xattr type */
95 	uint8_t version;	/* signature format version */
96 	uint8_t	hash_algo;	/* Digest algorithm [enum pkey_hash_algo] */
97 	uint32_t keyid;		/* IMA key identifier - not X509/PGP specific */
98 	uint16_t sig_size;	/* signature size */
99 	uint8_t sig[0];		/* signature payload */
100 } __packed;
101 
102 /* integrity data associated with an inode */
103 struct integrity_iint_cache {
104 	struct rb_node rb_node;	/* rooted in integrity_iint_tree */
105 	struct inode *inode;	/* back pointer to inode in question */
106 	u64 version;		/* track inode changes */
107 	unsigned long flags;
108 	enum integrity_status ima_file_status:4;
109 	enum integrity_status ima_mmap_status:4;
110 	enum integrity_status ima_bprm_status:4;
111 	enum integrity_status ima_module_status:4;
112 	enum integrity_status ima_firmware_status:4;
113 	enum integrity_status evm_status:4;
114 	struct ima_digest_data *ima_hash;
115 };
116 
117 /* rbtree tree calls to lookup, insert, delete
118  * integrity data associated with an inode.
119  */
120 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
121 
122 #define INTEGRITY_KEYRING_EVM		0
123 #define INTEGRITY_KEYRING_MODULE	1
124 #define INTEGRITY_KEYRING_IMA		2
125 #define INTEGRITY_KEYRING_MAX		3
126 
127 #ifdef CONFIG_INTEGRITY_SIGNATURE
128 
129 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
130 			    const char *digest, int digestlen);
131 
132 int integrity_init_keyring(const unsigned int id);
133 #else
134 
135 static inline int integrity_digsig_verify(const unsigned int id,
136 					  const char *sig, int siglen,
137 					  const char *digest, int digestlen)
138 {
139 	return -EOPNOTSUPP;
140 }
141 
142 static inline int integrity_init_keyring(const unsigned int id)
143 {
144 	return 0;
145 }
146 #endif /* CONFIG_INTEGRITY_SIGNATURE */
147 
148 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
149 int asymmetric_verify(struct key *keyring, const char *sig,
150 		      int siglen, const char *data, int datalen);
151 #else
152 static inline int asymmetric_verify(struct key *keyring, const char *sig,
153 				    int siglen, const char *data, int datalen)
154 {
155 	return -EOPNOTSUPP;
156 }
157 #endif
158 
159 #ifdef CONFIG_INTEGRITY_AUDIT
160 /* declarations */
161 void integrity_audit_msg(int audit_msgno, struct inode *inode,
162 			 const unsigned char *fname, const char *op,
163 			 const char *cause, int result, int info);
164 #else
165 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
166 				       const unsigned char *fname,
167 				       const char *op, const char *cause,
168 				       int result, int info)
169 {
170 }
171 #endif
172 
173 /* set during initialization */
174 extern int iint_initialized;
175