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/sha.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
286