Merge tag 'docs-5.12-2' of git://git.lwn.net/linux
[sfrench/cifs-2.6.git] / security / integrity / integrity.h
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 <linux/key.h>
19 #include <linux/audit.h>
20
21 /* iint action cache flags */
22 #define IMA_MEASURE             0x00000001
23 #define IMA_MEASURED            0x00000002
24 #define IMA_APPRAISE            0x00000004
25 #define IMA_APPRAISED           0x00000008
26 /*#define IMA_COLLECT           0x00000010  do not use this flag */
27 #define IMA_COLLECTED           0x00000020
28 #define IMA_AUDIT               0x00000040
29 #define IMA_AUDITED             0x00000080
30 #define IMA_HASH                0x00000100
31 #define IMA_HASHED              0x00000200
32
33 /* iint cache flags */
34 #define IMA_ACTION_FLAGS        0xff000000
35 #define IMA_DIGSIG_REQUIRED     0x01000000
36 #define IMA_PERMIT_DIRECTIO     0x02000000
37 #define IMA_NEW_FILE            0x04000000
38 #define EVM_IMMUTABLE_DIGSIG    0x08000000
39 #define IMA_FAIL_UNVERIFIABLE_SIGS      0x10000000
40 #define IMA_MODSIG_ALLOWED      0x20000000
41 #define IMA_CHECK_BLACKLIST     0x40000000
42
43 #define IMA_DO_MASK             (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
44                                  IMA_HASH | IMA_APPRAISE_SUBMASK)
45 #define IMA_DONE_MASK           (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
46                                  IMA_HASHED | IMA_COLLECTED | \
47                                  IMA_APPRAISED_SUBMASK)
48
49 /* iint subaction appraise cache flags */
50 #define IMA_FILE_APPRAISE       0x00001000
51 #define IMA_FILE_APPRAISED      0x00002000
52 #define IMA_MMAP_APPRAISE       0x00004000
53 #define IMA_MMAP_APPRAISED      0x00008000
54 #define IMA_BPRM_APPRAISE       0x00010000
55 #define IMA_BPRM_APPRAISED      0x00020000
56 #define IMA_READ_APPRAISE       0x00040000
57 #define IMA_READ_APPRAISED      0x00080000
58 #define IMA_CREDS_APPRAISE      0x00100000
59 #define IMA_CREDS_APPRAISED     0x00200000
60 #define IMA_APPRAISE_SUBMASK    (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
61                                  IMA_BPRM_APPRAISE | IMA_READ_APPRAISE | \
62                                  IMA_CREDS_APPRAISE)
63 #define IMA_APPRAISED_SUBMASK   (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
64                                  IMA_BPRM_APPRAISED | IMA_READ_APPRAISED | \
65                                  IMA_CREDS_APPRAISED)
66
67 /* iint cache atomic_flags */
68 #define IMA_CHANGE_XATTR        0
69 #define IMA_UPDATE_XATTR        1
70 #define IMA_CHANGE_ATTR         2
71 #define IMA_DIGSIG              3
72 #define IMA_MUST_MEASURE        4
73
74 enum evm_ima_xattr_type {
75         IMA_XATTR_DIGEST = 0x01,
76         EVM_XATTR_HMAC,
77         EVM_IMA_XATTR_DIGSIG,
78         IMA_XATTR_DIGEST_NG,
79         EVM_XATTR_PORTABLE_DIGSIG,
80         IMA_XATTR_LAST
81 };
82
83 struct evm_ima_xattr_data {
84         u8 type;
85         u8 data[];
86 } __packed;
87
88 /* Only used in the EVM HMAC code. */
89 struct evm_xattr {
90         struct evm_ima_xattr_data data;
91         u8 digest[SHA1_DIGEST_SIZE];
92 } __packed;
93
94 #define IMA_MAX_DIGEST_SIZE     64
95
96 struct ima_digest_data {
97         u8 algo;
98         u8 length;
99         union {
100                 struct {
101                         u8 unused;
102                         u8 type;
103                 } sha1;
104                 struct {
105                         u8 type;
106                         u8 algo;
107                 } ng;
108                 u8 data[2];
109         } xattr;
110         u8 digest[];
111 } __packed;
112
113 /*
114  * signature format v2 - for using with asymmetric keys
115  */
116 struct signature_v2_hdr {
117         uint8_t type;           /* xattr type */
118         uint8_t version;        /* signature format version */
119         uint8_t hash_algo;      /* Digest algorithm [enum hash_algo] */
120         __be32 keyid;           /* IMA key identifier - not X509/PGP specific */
121         __be16 sig_size;        /* signature size */
122         uint8_t sig[];          /* signature payload */
123 } __packed;
124
125 /* integrity data associated with an inode */
126 struct integrity_iint_cache {
127         struct rb_node rb_node; /* rooted in integrity_iint_tree */
128         struct mutex mutex;     /* protects: version, flags, digest */
129         struct inode *inode;    /* back pointer to inode in question */
130         u64 version;            /* track inode changes */
131         unsigned long flags;
132         unsigned long measured_pcrs;
133         unsigned long atomic_flags;
134         enum integrity_status ima_file_status:4;
135         enum integrity_status ima_mmap_status:4;
136         enum integrity_status ima_bprm_status:4;
137         enum integrity_status ima_read_status:4;
138         enum integrity_status ima_creds_status:4;
139         enum integrity_status evm_status:4;
140         struct ima_digest_data *ima_hash;
141 };
142
143 /* rbtree tree calls to lookup, insert, delete
144  * integrity data associated with an inode.
145  */
146 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
147
148 int integrity_kernel_read(struct file *file, loff_t offset,
149                           void *addr, unsigned long count);
150
151 #define INTEGRITY_KEYRING_EVM           0
152 #define INTEGRITY_KEYRING_IMA           1
153 #define INTEGRITY_KEYRING_PLATFORM      2
154 #define INTEGRITY_KEYRING_MAX           3
155
156 extern struct dentry *integrity_dir;
157
158 struct modsig;
159
160 #ifdef CONFIG_INTEGRITY_SIGNATURE
161
162 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
163                             const char *digest, int digestlen);
164 int integrity_modsig_verify(unsigned int id, const struct modsig *modsig);
165
166 int __init integrity_init_keyring(const unsigned int id);
167 int __init integrity_load_x509(const unsigned int id, const char *path);
168 int __init integrity_load_cert(const unsigned int id, const char *source,
169                                const void *data, size_t len, key_perm_t perm);
170 #else
171
172 static inline int integrity_digsig_verify(const unsigned int id,
173                                           const char *sig, int siglen,
174                                           const char *digest, int digestlen)
175 {
176         return -EOPNOTSUPP;
177 }
178
179 static inline int integrity_modsig_verify(unsigned int id,
180                                           const struct modsig *modsig)
181 {
182         return -EOPNOTSUPP;
183 }
184
185 static inline int integrity_init_keyring(const unsigned int id)
186 {
187         return 0;
188 }
189
190 static inline int __init integrity_load_cert(const unsigned int id,
191                                              const char *source,
192                                              const void *data, size_t len,
193                                              key_perm_t perm)
194 {
195         return 0;
196 }
197 #endif /* CONFIG_INTEGRITY_SIGNATURE */
198
199 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
200 int asymmetric_verify(struct key *keyring, const char *sig,
201                       int siglen, const char *data, int datalen);
202 #else
203 static inline int asymmetric_verify(struct key *keyring, const char *sig,
204                                     int siglen, const char *data, int datalen)
205 {
206         return -EOPNOTSUPP;
207 }
208 #endif
209
210 #ifdef CONFIG_IMA_APPRAISE_MODSIG
211 int ima_modsig_verify(struct key *keyring, const struct modsig *modsig);
212 #else
213 static inline int ima_modsig_verify(struct key *keyring,
214                                     const struct modsig *modsig)
215 {
216         return -EOPNOTSUPP;
217 }
218 #endif
219
220 #ifdef CONFIG_IMA_LOAD_X509
221 void __init ima_load_x509(void);
222 #else
223 static inline void ima_load_x509(void)
224 {
225 }
226 #endif
227
228 #ifdef CONFIG_EVM_LOAD_X509
229 void __init evm_load_x509(void);
230 #else
231 static inline void evm_load_x509(void)
232 {
233 }
234 #endif
235
236 #ifdef CONFIG_INTEGRITY_AUDIT
237 /* declarations */
238 void integrity_audit_msg(int audit_msgno, struct inode *inode,
239                          const unsigned char *fname, const char *op,
240                          const char *cause, int result, int info);
241
242 void integrity_audit_message(int audit_msgno, struct inode *inode,
243                              const unsigned char *fname, const char *op,
244                              const char *cause, int result, int info,
245                              int errno);
246
247 static inline struct audit_buffer *
248 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
249 {
250         return audit_log_start(ctx, gfp_mask, type);
251 }
252
253 #else
254 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
255                                        const unsigned char *fname,
256                                        const char *op, const char *cause,
257                                        int result, int info)
258 {
259 }
260
261 static inline void integrity_audit_message(int audit_msgno,
262                                            struct inode *inode,
263                                            const unsigned char *fname,
264                                            const char *op, const char *cause,
265                                            int result, int info, int errno)
266 {
267 }
268
269 static inline struct audit_buffer *
270 integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
271 {
272         return NULL;
273 }
274
275 #endif
276
277 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
278 void __init add_to_platform_keyring(const char *source, const void *data,
279                                     size_t len);
280 #else
281 static inline void __init add_to_platform_keyring(const char *source,
282                                                   const void *data, size_t len)
283 {
284 }
285 #endif