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