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 #ifdef pr_fmt
10 #undef pr_fmt
11 #endif
12
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15 #include <linux/types.h>
16 #include <linux/integrity.h>
17 #include <crypto/sha1.h>
18 #include <crypto/hash.h>
19 #include <linux/key.h>
20 #include <linux/audit.h>
21
22 /* iint action cache flags */
23 #define IMA_MEASURE 0x00000001
24 #define IMA_MEASURED 0x00000002
25 #define IMA_APPRAISE 0x00000004
26 #define IMA_APPRAISED 0x00000008
27 /*#define IMA_COLLECT 0x00000010 do not use this flag */
28 #define IMA_COLLECTED 0x00000020
29 #define IMA_AUDIT 0x00000040
30 #define IMA_AUDITED 0x00000080
31 #define IMA_HASH 0x00000100
32 #define IMA_HASHED 0x00000200
33
34 /* iint policy rule cache flags */
35 #define IMA_NONACTION_FLAGS 0xff000000
36 #define IMA_DIGSIG_REQUIRED 0x01000000
37 #define IMA_PERMIT_DIRECTIO 0x02000000
38 #define IMA_NEW_FILE 0x04000000
39 #define EVM_IMMUTABLE_DIGSIG 0x08000000
40 #define IMA_FAIL_UNVERIFIABLE_SIGS 0x10000000
41 #define IMA_MODSIG_ALLOWED 0x20000000
42 #define IMA_CHECK_BLACKLIST 0x40000000
43 #define IMA_VERITY_REQUIRED 0x80000000
44
45 #define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
46 IMA_HASH | IMA_APPRAISE_SUBMASK)
47 #define IMA_DONE_MASK (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
48 IMA_HASHED | IMA_COLLECTED | \
49 IMA_APPRAISED_SUBMASK)
50
51 /* iint subaction appraise cache flags */
52 #define IMA_FILE_APPRAISE 0x00001000
53 #define IMA_FILE_APPRAISED 0x00002000
54 #define IMA_MMAP_APPRAISE 0x00004000
55 #define IMA_MMAP_APPRAISED 0x00008000
56 #define IMA_BPRM_APPRAISE 0x00010000
57 #define IMA_BPRM_APPRAISED 0x00020000
58 #define IMA_READ_APPRAISE 0x00040000
59 #define IMA_READ_APPRAISED 0x00080000
60 #define IMA_CREDS_APPRAISE 0x00100000
61 #define IMA_CREDS_APPRAISED 0x00200000
62 #define IMA_APPRAISE_SUBMASK (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
63 IMA_BPRM_APPRAISE | IMA_READ_APPRAISE | \
64 IMA_CREDS_APPRAISE)
65 #define IMA_APPRAISED_SUBMASK (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
66 IMA_BPRM_APPRAISED | IMA_READ_APPRAISED | \
67 IMA_CREDS_APPRAISED)
68
69 /* iint cache atomic_flags */
70 #define IMA_CHANGE_XATTR 0
71 #define IMA_UPDATE_XATTR 1
72 #define IMA_CHANGE_ATTR 2
73 #define IMA_DIGSIG 3
74 #define IMA_MUST_MEASURE 4
75
76 enum evm_ima_xattr_type {
77 IMA_XATTR_DIGEST = 0x01,
78 EVM_XATTR_HMAC,
79 EVM_IMA_XATTR_DIGSIG,
80 IMA_XATTR_DIGEST_NG,
81 EVM_XATTR_PORTABLE_DIGSIG,
82 IMA_VERITY_DIGSIG,
83 IMA_XATTR_LAST
84 };
85
86 struct evm_ima_xattr_data {
87 u8 type;
88 u8 data[];
89 } __packed;
90
91 /* Only used in the EVM HMAC code. */
92 struct evm_xattr {
93 struct evm_ima_xattr_data data;
94 u8 digest[SHA1_DIGEST_SIZE];
95 } __packed;
96
97 #define IMA_MAX_DIGEST_SIZE HASH_MAX_DIGESTSIZE
98
99 struct ima_digest_data {
100 u8 algo;
101 u8 length;
102 union {
103 struct {
104 u8 unused;
105 u8 type;
106 } sha1;
107 struct {
108 u8 type;
109 u8 algo;
110 } ng;
111 u8 data[2];
112 } xattr;
113 u8 digest[];
114 } __packed;
115
116 /*
117 * Instead of wrapping the ima_digest_data struct inside a local structure
118 * with the maximum hash size, define ima_max_digest_data struct.
119 */
120 struct ima_max_digest_data {
121 struct ima_digest_data hdr;
122 u8 digest[HASH_MAX_DIGESTSIZE];
123 } __packed;
124
125 /*
126 * signature header format v2 - for using with asymmetric keys
127 *
128 * The signature_v2_hdr struct includes a signature format version
129 * to simplify defining new signature formats.
130 *
131 * signature format:
132 * version 2: regular file data hash based signature
133 * version 3: struct ima_file_id data based signature
134 */
135 struct signature_v2_hdr {
136 uint8_t type; /* xattr type */
137 uint8_t version; /* signature format version */
138 uint8_t hash_algo; /* Digest algorithm [enum hash_algo] */
139 __be32 keyid; /* IMA key identifier - not X509/PGP specific */
140 __be16 sig_size; /* signature size */
141 uint8_t sig[]; /* signature payload */
142 } __packed;
143
144 /*
145 * IMA signature version 3 disambiguates the data that is signed, by
146 * indirectly signing the hash of the ima_file_id structure data,
147 * containing either the fsverity_descriptor struct digest or, in the
148 * future, the regular IMA file hash.
149 *
150 * (The hash of the ima_file_id structure is only of the portion used.)
151 */
152 struct ima_file_id {
153 __u8 hash_type; /* xattr type [enum evm_ima_xattr_type] */
154 __u8 hash_algorithm; /* Digest algorithm [enum hash_algo] */
155 __u8 hash[HASH_MAX_DIGESTSIZE];
156 } __packed;
157
158 /* integrity data associated with an inode */
159 struct integrity_iint_cache {
160 struct rb_node rb_node; /* rooted in integrity_iint_tree */
161 struct mutex mutex; /* protects: version, flags, digest */
162 struct inode *inode; /* back pointer to inode in question */
163 u64 version; /* track inode changes */
164 unsigned long flags;
165 unsigned long measured_pcrs;
166 unsigned long atomic_flags;
167 enum integrity_status ima_file_status:4;
168 enum integrity_status ima_mmap_status:4;
169 enum integrity_status ima_bprm_status:4;
170 enum integrity_status ima_read_status:4;
171 enum integrity_status ima_creds_status:4;
172 enum integrity_status evm_status:4;
173 struct ima_digest_data *ima_hash;
174 };
175
176 /* rbtree tree calls to lookup, insert, delete
177 * integrity data associated with an inode.
178 */
179 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
180
181 int integrity_kernel_read(struct file *file, loff_t offset,
182 void *addr, unsigned long count);
183
184 #define INTEGRITY_KEYRING_EVM 0
185 #define INTEGRITY_KEYRING_IMA 1
186 #define INTEGRITY_KEYRING_PLATFORM 2
187 #define INTEGRITY_KEYRING_MACHINE 3
188 #define INTEGRITY_KEYRING_MAX 4
189
190 extern struct dentry *integrity_dir;
191
192 struct modsig;
193
194 #ifdef CONFIG_INTEGRITY_SIGNATURE
195
196 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
197 const char *digest, int digestlen);
198 int integrity_modsig_verify(unsigned int id, const struct modsig *modsig);
199
200 int __init integrity_init_keyring(const unsigned int id);
201 int __init integrity_load_x509(const unsigned int id, const char *path);
202 int __init integrity_load_cert(const unsigned int id, const char *source,
203 const void *data, size_t len, key_perm_t perm);
204 #else
205
integrity_digsig_verify(const unsigned int id,const char * sig,int siglen,const char * digest,int digestlen)206 static inline int integrity_digsig_verify(const unsigned int id,
207 const char *sig, int siglen,
208 const char *digest, int digestlen)
209 {
210 return -EOPNOTSUPP;
211 }
212
integrity_modsig_verify(unsigned int id,const struct modsig * modsig)213 static inline int integrity_modsig_verify(unsigned int id,
214 const struct modsig *modsig)
215 {
216 return -EOPNOTSUPP;
217 }
218
integrity_init_keyring(const unsigned int id)219 static inline int integrity_init_keyring(const unsigned int id)
220 {
221 return 0;
222 }
223
integrity_load_cert(const unsigned int id,const char * source,const void * data,size_t len,key_perm_t perm)224 static inline int __init integrity_load_cert(const unsigned int id,
225 const char *source,
226 const void *data, size_t len,
227 key_perm_t perm)
228 {
229 return 0;
230 }
231 #endif /* CONFIG_INTEGRITY_SIGNATURE */
232
233 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
234 int asymmetric_verify(struct key *keyring, const char *sig,
235 int siglen, const char *data, int datalen);
236 #else
asymmetric_verify(struct key * keyring,const char * sig,int siglen,const char * data,int datalen)237 static inline int asymmetric_verify(struct key *keyring, const char *sig,
238 int siglen, const char *data, int datalen)
239 {
240 return -EOPNOTSUPP;
241 }
242 #endif
243
244 #ifdef CONFIG_IMA_APPRAISE_MODSIG
245 int ima_modsig_verify(struct key *keyring, const struct modsig *modsig);
246 #else
ima_modsig_verify(struct key * keyring,const struct modsig * modsig)247 static inline int ima_modsig_verify(struct key *keyring,
248 const struct modsig *modsig)
249 {
250 return -EOPNOTSUPP;
251 }
252 #endif
253
254 #ifdef CONFIG_IMA_LOAD_X509
255 void __init ima_load_x509(void);
256 #else
ima_load_x509(void)257 static inline void ima_load_x509(void)
258 {
259 }
260 #endif
261
262 #ifdef CONFIG_EVM_LOAD_X509
263 void __init evm_load_x509(void);
264 #else
evm_load_x509(void)265 static inline void evm_load_x509(void)
266 {
267 }
268 #endif
269
270 #ifdef CONFIG_INTEGRITY_AUDIT
271 /* declarations */
272 void integrity_audit_msg(int audit_msgno, struct inode *inode,
273 const unsigned char *fname, const char *op,
274 const char *cause, int result, int info);
275
276 void integrity_audit_message(int audit_msgno, struct inode *inode,
277 const unsigned char *fname, const char *op,
278 const char *cause, int result, int info,
279 int errno);
280
281 static inline struct audit_buffer *
integrity_audit_log_start(struct audit_context * ctx,gfp_t gfp_mask,int type)282 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
283 {
284 return audit_log_start(ctx, gfp_mask, type);
285 }
286
287 #else
integrity_audit_msg(int audit_msgno,struct inode * inode,const unsigned char * fname,const char * op,const char * cause,int result,int info)288 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
289 const unsigned char *fname,
290 const char *op, const char *cause,
291 int result, int info)
292 {
293 }
294
integrity_audit_message(int audit_msgno,struct inode * inode,const unsigned char * fname,const char * op,const char * cause,int result,int info,int errno)295 static inline void integrity_audit_message(int audit_msgno,
296 struct inode *inode,
297 const unsigned char *fname,
298 const char *op, const char *cause,
299 int result, int info, int errno)
300 {
301 }
302
303 static inline struct audit_buffer *
integrity_audit_log_start(struct audit_context * ctx,gfp_t gfp_mask,int type)304 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
305 {
306 return NULL;
307 }
308
309 #endif
310
311 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
312 void __init add_to_platform_keyring(const char *source, const void *data,
313 size_t len);
314 #else
add_to_platform_keyring(const char * source,const void * data,size_t len)315 static inline void __init add_to_platform_keyring(const char *source,
316 const void *data, size_t len)
317 {
318 }
319 #endif
320
321 #ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
322 void __init add_to_machine_keyring(const char *source, const void *data, size_t len);
323 bool __init imputed_trust_enabled(void);
324 #else
add_to_machine_keyring(const char * source,const void * data,size_t len)325 static inline void __init add_to_machine_keyring(const char *source,
326 const void *data, size_t len)
327 {
328 }
329
imputed_trust_enabled(void)330 static inline bool __init imputed_trust_enabled(void)
331 {
332 return false;
333 }
334 #endif
335
