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_ACTION_RULE_FLAGS	0x06000000
32 #define IMA_DIGSIG		0x01000000
33 #define IMA_DIGSIG_REQUIRED	0x02000000
34 #define IMA_PERMIT_DIRECTIO	0x04000000
35 #define IMA_NEW_FILE		0x08000000
36 
37 #define IMA_DO_MASK		(IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
38 				 IMA_APPRAISE_SUBMASK)
39 #define IMA_DONE_MASK		(IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
40 				 IMA_COLLECTED | IMA_APPRAISED_SUBMASK)
41 
42 /* iint subaction appraise cache flags */
43 #define IMA_FILE_APPRAISE	0x00000100
44 #define IMA_FILE_APPRAISED	0x00000200
45 #define IMA_MMAP_APPRAISE	0x00000400
46 #define IMA_MMAP_APPRAISED	0x00000800
47 #define IMA_BPRM_APPRAISE	0x00001000
48 #define IMA_BPRM_APPRAISED	0x00002000
49 #define IMA_READ_APPRAISE	0x00004000
50 #define IMA_READ_APPRAISED	0x00008000
51 #define IMA_APPRAISE_SUBMASK	(IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
52 				 IMA_BPRM_APPRAISE | IMA_READ_APPRAISE)
53 #define IMA_APPRAISED_SUBMASK	(IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
54 				 IMA_BPRM_APPRAISED | IMA_READ_APPRAISED)
55 
56 enum evm_ima_xattr_type {
57 	IMA_XATTR_DIGEST = 0x01,
58 	EVM_XATTR_HMAC,
59 	EVM_IMA_XATTR_DIGSIG,
60 	IMA_XATTR_DIGEST_NG,
61 	IMA_XATTR_LAST
62 };
63 
64 struct evm_ima_xattr_data {
65 	u8 type;
66 	u8 digest[SHA1_DIGEST_SIZE];
67 } __packed;
68 
69 #define IMA_MAX_DIGEST_SIZE	64
70 
71 struct ima_digest_data {
72 	u8 algo;
73 	u8 length;
74 	union {
75 		struct {
76 			u8 unused;
77 			u8 type;
78 		} sha1;
79 		struct {
80 			u8 type;
81 			u8 algo;
82 		} ng;
83 		u8 data[2];
84 	} xattr;
85 	u8 digest[0];
86 } __packed;
87 
88 /*
89  * signature format v2 - for using with asymmetric keys
90  */
91 struct signature_v2_hdr {
92 	uint8_t type;		/* xattr type */
93 	uint8_t version;	/* signature format version */
94 	uint8_t	hash_algo;	/* Digest algorithm [enum hash_algo] */
95 	__be32 keyid;		/* IMA key identifier - not X509/PGP specific */
96 	__be16 sig_size;	/* signature size */
97 	uint8_t sig[0];		/* signature payload */
98 } __packed;
99 
100 /* integrity data associated with an inode */
101 struct integrity_iint_cache {
102 	struct rb_node rb_node;	/* rooted in integrity_iint_tree */
103 	struct inode *inode;	/* back pointer to inode in question */
104 	u64 version;		/* track inode changes */
105 	unsigned long flags;
106 	unsigned long measured_pcrs;
107 	enum integrity_status ima_file_status:4;
108 	enum integrity_status ima_mmap_status:4;
109 	enum integrity_status ima_bprm_status:4;
110 	enum integrity_status ima_read_status:4;
111 	enum integrity_status evm_status:4;
112 	struct ima_digest_data *ima_hash;
113 };
114 
115 /* rbtree tree calls to lookup, insert, delete
116  * integrity data associated with an inode.
117  */
118 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
119 
120 int integrity_kernel_read(struct file *file, loff_t offset,
121 			  void *addr, unsigned long count);
122 
123 int __init integrity_read_file(const char *path, char **data);
124 
125 #define INTEGRITY_KEYRING_EVM		0
126 #define INTEGRITY_KEYRING_IMA		1
127 #define INTEGRITY_KEYRING_MODULE	2
128 #define INTEGRITY_KEYRING_MAX		3
129 
130 #ifdef CONFIG_INTEGRITY_SIGNATURE
131 
132 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
133 			    const char *digest, int digestlen);
134 
135 int __init integrity_init_keyring(const unsigned int id);
136 int __init integrity_load_x509(const unsigned int id, const char *path);
137 #else
138 
139 static inline int integrity_digsig_verify(const unsigned int id,
140 					  const char *sig, int siglen,
141 					  const char *digest, int digestlen)
142 {
143 	return -EOPNOTSUPP;
144 }
145 
146 static inline int integrity_init_keyring(const unsigned int id)
147 {
148 	return 0;
149 }
150 #endif /* CONFIG_INTEGRITY_SIGNATURE */
151 
152 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
153 int asymmetric_verify(struct key *keyring, const char *sig,
154 		      int siglen, const char *data, int datalen);
155 #else
156 static inline int asymmetric_verify(struct key *keyring, const char *sig,
157 				    int siglen, const char *data, int datalen)
158 {
159 	return -EOPNOTSUPP;
160 }
161 #endif
162 
163 #ifdef CONFIG_IMA_LOAD_X509
164 void __init ima_load_x509(void);
165 #else
166 static inline void ima_load_x509(void)
167 {
168 }
169 #endif
170 
171 #ifdef CONFIG_EVM_LOAD_X509
172 void __init evm_load_x509(void);
173 #else
174 static inline void evm_load_x509(void)
175 {
176 }
177 #endif
178 
179 #ifdef CONFIG_INTEGRITY_AUDIT
180 /* declarations */
181 void integrity_audit_msg(int audit_msgno, struct inode *inode,
182 			 const unsigned char *fname, const char *op,
183 			 const char *cause, int result, int info);
184 #else
185 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
186 				       const unsigned char *fname,
187 				       const char *op, const char *cause,
188 				       int result, int info)
189 {
190 }
191 #endif
192