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 <crypto/hash.h>
19#include <linux/key.h>
20#include <linux/audit.h>
21#include <linux/lsm_hooks.h>
22
23enum evm_ima_xattr_type {
24	IMA_XATTR_DIGEST = 0x01,
25	EVM_XATTR_HMAC,
26	EVM_IMA_XATTR_DIGSIG,
27	IMA_XATTR_DIGEST_NG,
28	EVM_XATTR_PORTABLE_DIGSIG,
29	IMA_VERITY_DIGSIG,
30	IMA_XATTR_LAST
31};
32
33struct evm_ima_xattr_data {
34	u8 type;
35	u8 data[];
36} __packed;
37
38/* Only used in the EVM HMAC code. */
39struct evm_xattr {
40	struct evm_ima_xattr_data data;
41	u8 digest[SHA1_DIGEST_SIZE];
42} __packed;
43
44#define IMA_MAX_DIGEST_SIZE	HASH_MAX_DIGESTSIZE
45
46struct ima_digest_data {
47	u8 algo;
48	u8 length;
49	union {
50		struct {
51			u8 unused;
52			u8 type;
53		} sha1;
54		struct {
55			u8 type;
56			u8 algo;
57		} ng;
58		u8 data[2];
59	} xattr;
60	u8 digest[];
61} __packed;
62
63/*
64 * Instead of wrapping the ima_digest_data struct inside a local structure
65 * with the maximum hash size, define ima_max_digest_data struct.
66 */
67struct ima_max_digest_data {
68	struct ima_digest_data hdr;
69	u8 digest[HASH_MAX_DIGESTSIZE];
70} __packed;
71
72/*
73 * signature header format v2 - for using with asymmetric keys
74 *
75 * The signature_v2_hdr struct includes a signature format version
76 * to simplify defining new signature formats.
77 *
78 * signature format:
79 * version 2: regular file data hash based signature
80 * version 3: struct ima_file_id data based signature
81 */
82struct signature_v2_hdr {
83	uint8_t type;		/* xattr type */
84	uint8_t version;	/* signature format version */
85	uint8_t	hash_algo;	/* Digest algorithm [enum hash_algo] */
86	__be32 keyid;		/* IMA key identifier - not X509/PGP specific */
87	__be16 sig_size;	/* signature size */
88	uint8_t sig[];		/* signature payload */
89} __packed;
90
91/*
92 * IMA signature version 3 disambiguates the data that is signed, by
93 * indirectly signing the hash of the ima_file_id structure data,
94 * containing either the fsverity_descriptor struct digest or, in the
95 * future, the regular IMA file hash.
96 *
97 * (The hash of the ima_file_id structure is only of the portion used.)
98 */
99struct ima_file_id {
100	__u8 hash_type;		/* xattr type [enum evm_ima_xattr_type] */
101	__u8 hash_algorithm;	/* Digest algorithm [enum hash_algo] */
102	__u8 hash[HASH_MAX_DIGESTSIZE];
103} __packed;
104
105int integrity_kernel_read(struct file *file, loff_t offset,
106			  void *addr, unsigned long count);
107
108#define INTEGRITY_KEYRING_EVM		0
109#define INTEGRITY_KEYRING_IMA		1
110#define INTEGRITY_KEYRING_PLATFORM	2
111#define INTEGRITY_KEYRING_MACHINE	3
112#define INTEGRITY_KEYRING_MAX		4
113
114extern struct dentry *integrity_dir;
115
116struct modsig;
117
118#ifdef CONFIG_INTEGRITY_SIGNATURE
119
120int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
121			    const char *digest, int digestlen);
122int integrity_modsig_verify(unsigned int id, const struct modsig *modsig);
123
124int __init integrity_init_keyring(const unsigned int id);
125int __init integrity_load_x509(const unsigned int id, const char *path);
126int __init integrity_load_cert(const unsigned int id, const char *source,
127			       const void *data, size_t len, key_perm_t perm);
128#else
129
130static inline int integrity_digsig_verify(const unsigned int id,
131					  const char *sig, int siglen,
132					  const char *digest, int digestlen)
133{
134	return -EOPNOTSUPP;
135}
136
137static inline int integrity_modsig_verify(unsigned int id,
138					  const struct modsig *modsig)
139{
140	return -EOPNOTSUPP;
141}
142
143static inline int integrity_init_keyring(const unsigned int id)
144{
145	return 0;
146}
147
148static inline int __init integrity_load_cert(const unsigned int id,
149					     const char *source,
150					     const void *data, size_t len,
151					     key_perm_t perm)
152{
153	return 0;
154}
155#endif /* CONFIG_INTEGRITY_SIGNATURE */
156
157#ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
158int asymmetric_verify(struct key *keyring, const char *sig,
159		      int siglen, const char *data, int datalen);
160#else
161static inline int asymmetric_verify(struct key *keyring, const char *sig,
162				    int siglen, const char *data, int datalen)
163{
164	return -EOPNOTSUPP;
165}
166#endif
167
168#ifdef CONFIG_IMA_APPRAISE_MODSIG
169int ima_modsig_verify(struct key *keyring, const struct modsig *modsig);
170#else
171static inline int ima_modsig_verify(struct key *keyring,
172				    const struct modsig *modsig)
173{
174	return -EOPNOTSUPP;
175}
176#endif
177
178#ifdef CONFIG_IMA_LOAD_X509
179void __init ima_load_x509(void);
180#else
181static inline void ima_load_x509(void)
182{
183}
184#endif
185
186#ifdef CONFIG_EVM_LOAD_X509
187void __init evm_load_x509(void);
188#else
189static inline void evm_load_x509(void)
190{
191}
192#endif
193
194#ifdef CONFIG_INTEGRITY_AUDIT
195/* declarations */
196void integrity_audit_msg(int audit_msgno, struct inode *inode,
197			 const unsigned char *fname, const char *op,
198			 const char *cause, int result, int info);
199
200void integrity_audit_message(int audit_msgno, struct inode *inode,
201			     const unsigned char *fname, const char *op,
202			     const char *cause, int result, int info,
203			     int errno);
204
205static inline struct audit_buffer *
206integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
207{
208	return audit_log_start(ctx, gfp_mask, type);
209}
210
211#else
212static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
213				       const unsigned char *fname,
214				       const char *op, const char *cause,
215				       int result, int info)
216{
217}
218
219static inline void integrity_audit_message(int audit_msgno,
220					   struct inode *inode,
221					   const unsigned char *fname,
222					   const char *op, const char *cause,
223					   int result, int info, int errno)
224{
225}
226
227static inline struct audit_buffer *
228integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
229{
230	return NULL;
231}
232
233#endif
234
235#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
236void __init add_to_platform_keyring(const char *source, const void *data,
237				    size_t len);
238#else
239static inline void __init add_to_platform_keyring(const char *source,
240						  const void *data, size_t len)
241{
242}
243#endif
244
245#ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
246void __init add_to_machine_keyring(const char *source, const void *data, size_t len);
247bool __init imputed_trust_enabled(void);
248#else
249static inline void __init add_to_machine_keyring(const char *source,
250						  const void *data, size_t len)
251{
252}
253
254static inline bool __init imputed_trust_enabled(void)
255{
256	return false;
257}
258#endif
259