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_READ_APPRAISE	0x00004000
49 #define IMA_READ_APPRAISED	0x00008000
50 #define IMA_APPRAISE_SUBMASK	(IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
51 				 IMA_BPRM_APPRAISE | IMA_READ_APPRAISE)
52 #define IMA_APPRAISED_SUBMASK	(IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
53 				 IMA_BPRM_APPRAISED | IMA_READ_APPRAISED)
54 
55 enum evm_ima_xattr_type {
56 	IMA_XATTR_DIGEST = 0x01,
57 	EVM_XATTR_HMAC,
58 	EVM_IMA_XATTR_DIGSIG,
59 	IMA_XATTR_DIGEST_NG,
60 	IMA_XATTR_LAST
61 };
62 
63 struct evm_ima_xattr_data {
64 	u8 type;
65 	u8 digest[SHA1_DIGEST_SIZE];
66 } __packed;
67 
68 #define IMA_MAX_DIGEST_SIZE	64
69 
70 struct ima_digest_data {
71 	u8 algo;
72 	u8 length;
73 	union {
74 		struct {
75 			u8 unused;
76 			u8 type;
77 		} sha1;
78 		struct {
79 			u8 type;
80 			u8 algo;
81 		} ng;
82 		u8 data[2];
83 	} xattr;
84 	u8 digest[0];
85 } __packed;
86 
87 /*
88  * signature format v2 - for using with asymmetric keys
89  */
90 struct signature_v2_hdr {
91 	uint8_t type;		/* xattr type */
92 	uint8_t version;	/* signature format version */
93 	uint8_t	hash_algo;	/* Digest algorithm [enum hash_algo] */
94 	uint32_t keyid;		/* IMA key identifier - not X509/PGP specific */
95 	uint16_t sig_size;	/* signature size */
96 	uint8_t sig[0];		/* signature payload */
97 } __packed;
98 
99 /* integrity data associated with an inode */
100 struct integrity_iint_cache {
101 	struct rb_node rb_node;	/* rooted in integrity_iint_tree */
102 	struct inode *inode;	/* back pointer to inode in question */
103 	u64 version;		/* track inode changes */
104 	unsigned long flags;
105 	enum integrity_status ima_file_status:4;
106 	enum integrity_status ima_mmap_status:4;
107 	enum integrity_status ima_bprm_status:4;
108 	enum integrity_status ima_read_status:4;
109 	enum integrity_status evm_status:4;
110 	struct ima_digest_data *ima_hash;
111 };
112 
113 /* rbtree tree calls to lookup, insert, delete
114  * integrity data associated with an inode.
115  */
116 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
117 
118 int integrity_kernel_read(struct file *file, loff_t offset,
119 			  char *addr, unsigned long count);
120 int __init integrity_read_file(const char *path, char **data);
121 
122 #define INTEGRITY_KEYRING_EVM		0
123 #define INTEGRITY_KEYRING_IMA		1
124 #define INTEGRITY_KEYRING_MODULE	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 __init integrity_init_keyring(const unsigned int id);
133 int __init integrity_load_x509(const unsigned int id, const char *path);
134 #else
135 
136 static inline int integrity_digsig_verify(const unsigned int id,
137 					  const char *sig, int siglen,
138 					  const char *digest, int digestlen)
139 {
140 	return -EOPNOTSUPP;
141 }
142 
143 static inline int integrity_init_keyring(const unsigned int id)
144 {
145 	return 0;
146 }
147 #endif /* CONFIG_INTEGRITY_SIGNATURE */
148 
149 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
150 int asymmetric_verify(struct key *keyring, const char *sig,
151 		      int siglen, const char *data, int datalen);
152 #else
153 static inline int asymmetric_verify(struct key *keyring, const char *sig,
154 				    int siglen, const char *data, int datalen)
155 {
156 	return -EOPNOTSUPP;
157 }
158 #endif
159 
160 #ifdef CONFIG_IMA_LOAD_X509
161 void __init ima_load_x509(void);
162 #else
163 static inline void ima_load_x509(void)
164 {
165 }
166 #endif
167 
168 #ifdef CONFIG_EVM_LOAD_X509
169 void __init evm_load_x509(void);
170 #else
171 static inline void evm_load_x509(void)
172 {
173 }
174 #endif
175 
176 #ifdef CONFIG_INTEGRITY_AUDIT
177 /* declarations */
178 void integrity_audit_msg(int audit_msgno, struct inode *inode,
179 			 const unsigned char *fname, const char *op,
180 			 const char *cause, int result, int info);
181 #else
182 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
183 				       const unsigned char *fname,
184 				       const char *op, const char *cause,
185 				       int result, int info)
186 {
187 }
188 #endif
189