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