1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2009-2010 IBM Corporation
4  *
5  * Authors:
6  * Mimi Zohar <zohar@us.ibm.com>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/integrity.h>
11 #include <crypto/sha.h>
12 #include <linux/key.h>
13 #include <linux/audit.h>
14 
15 /* iint action cache flags */
16 #define IMA_MEASURE		0x00000001
17 #define IMA_MEASURED		0x00000002
18 #define IMA_APPRAISE		0x00000004
19 #define IMA_APPRAISED		0x00000008
20 /*#define IMA_COLLECT		0x00000010  do not use this flag */
21 #define IMA_COLLECTED		0x00000020
22 #define IMA_AUDIT		0x00000040
23 #define IMA_AUDITED		0x00000080
24 #define IMA_HASH		0x00000100
25 #define IMA_HASHED		0x00000200
26 
27 /* iint cache flags */
28 #define IMA_ACTION_FLAGS	0xff000000
29 #define IMA_DIGSIG_REQUIRED	0x01000000
30 #define IMA_PERMIT_DIRECTIO	0x02000000
31 #define IMA_NEW_FILE		0x04000000
32 #define EVM_IMMUTABLE_DIGSIG	0x08000000
33 #define IMA_FAIL_UNVERIFIABLE_SIGS	0x10000000
34 
35 #define IMA_DO_MASK		(IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
36 				 IMA_HASH | IMA_APPRAISE_SUBMASK)
37 #define IMA_DONE_MASK		(IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
38 				 IMA_HASHED | IMA_COLLECTED | \
39 				 IMA_APPRAISED_SUBMASK)
40 
41 /* iint subaction appraise cache flags */
42 #define IMA_FILE_APPRAISE	0x00001000
43 #define IMA_FILE_APPRAISED	0x00002000
44 #define IMA_MMAP_APPRAISE	0x00004000
45 #define IMA_MMAP_APPRAISED	0x00008000
46 #define IMA_BPRM_APPRAISE	0x00010000
47 #define IMA_BPRM_APPRAISED	0x00020000
48 #define IMA_READ_APPRAISE	0x00040000
49 #define IMA_READ_APPRAISED	0x00080000
50 #define IMA_CREDS_APPRAISE	0x00100000
51 #define IMA_CREDS_APPRAISED	0x00200000
52 #define IMA_APPRAISE_SUBMASK	(IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
53 				 IMA_BPRM_APPRAISE | IMA_READ_APPRAISE | \
54 				 IMA_CREDS_APPRAISE)
55 #define IMA_APPRAISED_SUBMASK	(IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
56 				 IMA_BPRM_APPRAISED | IMA_READ_APPRAISED | \
57 				 IMA_CREDS_APPRAISED)
58 
59 /* iint cache atomic_flags */
60 #define IMA_CHANGE_XATTR	0
61 #define IMA_UPDATE_XATTR	1
62 #define IMA_CHANGE_ATTR		2
63 #define IMA_DIGSIG		3
64 #define IMA_MUST_MEASURE	4
65 
66 enum evm_ima_xattr_type {
67 	IMA_XATTR_DIGEST = 0x01,
68 	EVM_XATTR_HMAC,
69 	EVM_IMA_XATTR_DIGSIG,
70 	IMA_XATTR_DIGEST_NG,
71 	EVM_XATTR_PORTABLE_DIGSIG,
72 	IMA_XATTR_LAST
73 };
74 
75 struct evm_ima_xattr_data {
76 	u8 type;
77 	u8 digest[SHA1_DIGEST_SIZE];
78 } __packed;
79 
80 #define IMA_MAX_DIGEST_SIZE	64
81 
82 struct ima_digest_data {
83 	u8 algo;
84 	u8 length;
85 	union {
86 		struct {
87 			u8 unused;
88 			u8 type;
89 		} sha1;
90 		struct {
91 			u8 type;
92 			u8 algo;
93 		} ng;
94 		u8 data[2];
95 	} xattr;
96 	u8 digest[0];
97 } __packed;
98 
99 /*
100  * signature format v2 - for using with asymmetric keys
101  */
102 struct signature_v2_hdr {
103 	uint8_t type;		/* xattr type */
104 	uint8_t version;	/* signature format version */
105 	uint8_t	hash_algo;	/* Digest algorithm [enum hash_algo] */
106 	__be32 keyid;		/* IMA key identifier - not X509/PGP specific */
107 	__be16 sig_size;	/* signature size */
108 	uint8_t sig[0];		/* signature payload */
109 } __packed;
110 
111 /* integrity data associated with an inode */
112 struct integrity_iint_cache {
113 	struct rb_node rb_node;	/* rooted in integrity_iint_tree */
114 	struct mutex mutex;	/* protects: version, flags, digest */
115 	struct inode *inode;	/* back pointer to inode in question */
116 	u64 version;		/* track inode changes */
117 	unsigned long flags;
118 	unsigned long measured_pcrs;
119 	unsigned long atomic_flags;
120 	enum integrity_status ima_file_status:4;
121 	enum integrity_status ima_mmap_status:4;
122 	enum integrity_status ima_bprm_status:4;
123 	enum integrity_status ima_read_status:4;
124 	enum integrity_status ima_creds_status:4;
125 	enum integrity_status evm_status:4;
126 	struct ima_digest_data *ima_hash;
127 };
128 
129 /* rbtree tree calls to lookup, insert, delete
130  * integrity data associated with an inode.
131  */
132 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
133 
134 int integrity_kernel_read(struct file *file, loff_t offset,
135 			  void *addr, unsigned long count);
136 
137 #define INTEGRITY_KEYRING_EVM		0
138 #define INTEGRITY_KEYRING_IMA		1
139 #define INTEGRITY_KEYRING_PLATFORM	2
140 #define INTEGRITY_KEYRING_MAX		3
141 
142 extern struct dentry *integrity_dir;
143 
144 #ifdef CONFIG_INTEGRITY_SIGNATURE
145 
146 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
147 			    const char *digest, int digestlen);
148 
149 int __init integrity_init_keyring(const unsigned int id);
150 int __init integrity_load_x509(const unsigned int id, const char *path);
151 int __init integrity_load_cert(const unsigned int id, const char *source,
152 			       const void *data, size_t len, key_perm_t perm);
153 #else
154 
155 static inline int integrity_digsig_verify(const unsigned int id,
156 					  const char *sig, int siglen,
157 					  const char *digest, int digestlen)
158 {
159 	return -EOPNOTSUPP;
160 }
161 
162 static inline int integrity_init_keyring(const unsigned int id)
163 {
164 	return 0;
165 }
166 
167 static inline int __init integrity_load_cert(const unsigned int id,
168 					     const char *source,
169 					     const void *data, size_t len,
170 					     key_perm_t perm)
171 {
172 	return 0;
173 }
174 #endif /* CONFIG_INTEGRITY_SIGNATURE */
175 
176 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
177 int asymmetric_verify(struct key *keyring, const char *sig,
178 		      int siglen, const char *data, int datalen);
179 #else
180 static inline int asymmetric_verify(struct key *keyring, const char *sig,
181 				    int siglen, const char *data, int datalen)
182 {
183 	return -EOPNOTSUPP;
184 }
185 #endif
186 
187 #ifdef CONFIG_IMA_LOAD_X509
188 void __init ima_load_x509(void);
189 #else
190 static inline void ima_load_x509(void)
191 {
192 }
193 #endif
194 
195 #ifdef CONFIG_EVM_LOAD_X509
196 void __init evm_load_x509(void);
197 #else
198 static inline void evm_load_x509(void)
199 {
200 }
201 #endif
202 
203 #ifdef CONFIG_INTEGRITY_AUDIT
204 /* declarations */
205 void integrity_audit_msg(int audit_msgno, struct inode *inode,
206 			 const unsigned char *fname, const char *op,
207 			 const char *cause, int result, int info);
208 
209 static inline struct audit_buffer *
210 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
211 {
212 	return audit_log_start(ctx, gfp_mask, type);
213 }
214 
215 #else
216 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
217 				       const unsigned char *fname,
218 				       const char *op, const char *cause,
219 				       int result, int info)
220 {
221 }
222 
223 static inline struct audit_buffer *
224 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
225 {
226 	return NULL;
227 }
228 
229 #endif
230 
231 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
232 void __init add_to_platform_keyring(const char *source, const void *data,
233 				    size_t len);
234 #else
235 static inline void __init add_to_platform_keyring(const char *source,
236 						  const void *data, size_t len)
237 {
238 }
239 #endif
240