summaryrefslogtreecommitdiffstats
path: root/security/integrity/integrity.h
blob: c2c2da6911233bac1a7a41a52ae2c249b45bbcef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2009-2010 IBM Corporation
 *
 * Authors:
 * Mimi Zohar <zohar@us.ibm.com>
 */

#ifdef pr_fmt
#undef pr_fmt
#endif

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/types.h>
#include <linux/integrity.h>
#include <crypto/sha1.h>
#include <crypto/hash.h>
#include <linux/key.h>
#include <linux/audit.h>
#include <linux/lsm_hooks.h>

enum evm_ima_xattr_type {
	IMA_XATTR_DIGEST = 0x01,
	EVM_XATTR_HMAC,
	EVM_IMA_XATTR_DIGSIG,
	IMA_XATTR_DIGEST_NG,
	EVM_XATTR_PORTABLE_DIGSIG,
	IMA_VERITY_DIGSIG,
	IMA_XATTR_LAST
};

struct evm_ima_xattr_data {
	/* New members must be added within the __struct_group() macro below. */
	__struct_group(evm_ima_xattr_data_hdr, hdr, __packed,
		u8 type;
	);
	u8 data[];
} __packed;
static_assert(offsetof(struct evm_ima_xattr_data, data) == sizeof(struct evm_ima_xattr_data_hdr),
	      "struct member likely outside of __struct_group()");

/* Only used in the EVM HMAC code. */
struct evm_xattr {
	struct evm_ima_xattr_data_hdr data;
	u8 digest[SHA1_DIGEST_SIZE];
} __packed;

#define IMA_MAX_DIGEST_SIZE	HASH_MAX_DIGESTSIZE

struct ima_digest_data {
	/* New members must be added within the __struct_group() macro below. */
	__struct_group(ima_digest_data_hdr, hdr, __packed,
	u8 algo;
	u8 length;
	union {
		struct {
			u8 unused;
			u8 type;
		} sha1;
		struct {
			u8 type;
			u8 algo;
		} ng;
		u8 data[2];
	} xattr;
	);
	u8 digest[];
} __packed;
static_assert(offsetof(struct ima_digest_data, digest) == sizeof(struct ima_digest_data_hdr),
	      "struct member likely outside of __struct_group()");

/*
 * Instead of wrapping the ima_digest_data struct inside a local structure
 * with the maximum hash size, define ima_max_digest_data struct.
 */
struct ima_max_digest_data {
	struct ima_digest_data_hdr hdr;
	u8 digest[HASH_MAX_DIGESTSIZE];
} __packed;

/*
 * signature header format v2 - for using with asymmetric keys
 *
 * The signature_v2_hdr struct includes a signature format version
 * to simplify defining new signature formats.
 *
 * signature format:
 * version 2: regular file data hash based signature
 * version 3: struct ima_file_id data based signature
 */
struct signature_v2_hdr {
	uint8_t type;		/* xattr type */
	uint8_t version;	/* signature format version */
	uint8_t	hash_algo;	/* Digest algorithm [enum hash_algo] */
	__be32 keyid;		/* IMA key identifier - not X509/PGP specific */
	__be16 sig_size;	/* signature size */
	uint8_t sig[];		/* signature payload */
} __packed;

/*
 * IMA signature version 3 disambiguates the data that is signed, by
 * indirectly signing the hash of the ima_file_id structure data,
 * containing either the fsverity_descriptor struct digest or, in the
 * future, the regular IMA file hash.
 *
 * (The hash of the ima_file_id structure is only of the portion used.)
 */
struct ima_file_id {
	__u8 hash_type;		/* xattr type [enum evm_ima_xattr_type] */
	__u8 hash_algorithm;	/* Digest algorithm [enum hash_algo] */
	__u8 hash[HASH_MAX_DIGESTSIZE];
} __packed;

int integrity_kernel_read(struct file *file, loff_t offset,
			  void *addr, unsigned long count);

#define INTEGRITY_KEYRING_EVM		0
#define INTEGRITY_KEYRING_IMA		1
#define INTEGRITY_KEYRING_PLATFORM	2
#define INTEGRITY_KEYRING_MACHINE	3
#define INTEGRITY_KEYRING_MAX		4

extern struct dentry *integrity_dir;

struct modsig;

#ifdef CONFIG_INTEGRITY_SIGNATURE

int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
			    const char *digest, int digestlen);
int integrity_modsig_verify(unsigned int id, const struct modsig *modsig);

int __init integrity_init_keyring(const unsigned int id);
int __init integrity_load_x509(const unsigned int id, const char *path);
int __init integrity_load_cert(const unsigned int id, const char *source,
			       const void *data, size_t len, key_perm_t perm);
#else

static inline int integrity_digsig_verify(const unsigned int id,
					  const char *sig, int siglen,
					  const char *digest, int digestlen)
{
	return -EOPNOTSUPP;
}

static inline int integrity_modsig_verify(unsigned int id,
					  const struct modsig *modsig)
{
	return -EOPNOTSUPP;
}

static inline int integrity_init_keyring(const unsigned int id)
{
	return 0;
}

static inline int __init integrity_load_cert(const unsigned int id,
					     const char *source,
					     const void *data, size_t len,
					     key_perm_t perm)
{
	return 0;
}
#endif /* CONFIG_INTEGRITY_SIGNATURE */

#ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
int asymmetric_verify(struct key *keyring, const char *sig,
		      int siglen, const char *data, int datalen);
#else
static inline int asymmetric_verify(struct key *keyring, const char *sig,
				    int siglen, const char *data, int datalen)
{
	return -EOPNOTSUPP;
}
#endif

#ifdef CONFIG_IMA_APPRAISE_MODSIG
int ima_modsig_verify(struct key *keyring, const struct modsig *modsig);
#else
static inline int ima_modsig_verify(struct key *keyring,
				    const struct modsig *modsig)
{
	return -EOPNOTSUPP;
}
#endif

#ifdef CONFIG_IMA_LOAD_X509
void __init ima_load_x509(void);
#else
static inline void ima_load_x509(void)
{
}
#endif

#ifdef CONFIG_EVM_LOAD_X509
void __init evm_load_x509(void);
#else
static inline void evm_load_x509(void)
{
}
#endif

#ifdef CONFIG_INTEGRITY_AUDIT
/* declarations */
void integrity_audit_msg(int audit_msgno, struct inode *inode,
			 const unsigned char *fname, const char *op,
			 const char *cause, int result, int info);

void 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);

static inline struct audit_buffer *
integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
{
	return audit_log_start(ctx, gfp_mask, type);
}

#else
static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
				       const unsigned char *fname,
				       const char *op, const char *cause,
				       int result, int info)
{
}

static inline void 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)
{
}

static inline struct audit_buffer *
integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
{
	return NULL;
}

#endif

#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
void __init add_to_platform_keyring(const char *source, const void *data,
				    size_t len);
#else
static inline void __init add_to_platform_keyring(const char *source,
						  const void *data, size_t len)
{
}
#endif

#ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
void __init add_to_machine_keyring(const char *source, const void *data, size_t len);
bool __init imputed_trust_enabled(void);
#else
static inline void __init add_to_machine_keyring(const char *source,
						  const void *data, size_t len)
{
}

static inline bool __init imputed_trust_enabled(void)
{
	return false;
}
#endif