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
22/* iint action cache flags */
23#define IMA_MEASURE		0x00000001
24#define IMA_MEASURED		0x00000002
25#define IMA_APPRAISE		0x00000004
26#define IMA_APPRAISED		0x00000008
27/*#define IMA_COLLECT		0x00000010  do not use this flag */
28#define IMA_COLLECTED		0x00000020
29#define IMA_AUDIT		0x00000040
30#define IMA_AUDITED		0x00000080
31#define IMA_HASH		0x00000100
32#define IMA_HASHED		0x00000200
33
34/* iint policy rule cache flags */
35#define IMA_NONACTION_FLAGS	0xff000000
36#define IMA_DIGSIG_REQUIRED	0x01000000
37#define IMA_PERMIT_DIRECTIO	0x02000000
38#define IMA_NEW_FILE		0x04000000
39#define EVM_IMMUTABLE_DIGSIG	0x08000000
40#define IMA_FAIL_UNVERIFIABLE_SIGS	0x10000000
41#define IMA_MODSIG_ALLOWED	0x20000000
42#define IMA_CHECK_BLACKLIST	0x40000000
43#define IMA_VERITY_REQUIRED	0x80000000
44
45#define IMA_DO_MASK		(IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
46				 IMA_HASH | IMA_APPRAISE_SUBMASK)
47#define IMA_DONE_MASK		(IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED | \
48				 IMA_HASHED | IMA_COLLECTED | \
49				 IMA_APPRAISED_SUBMASK)
50
51/* iint subaction appraise cache flags */
52#define IMA_FILE_APPRAISE	0x00001000
53#define IMA_FILE_APPRAISED	0x00002000
54#define IMA_MMAP_APPRAISE	0x00004000
55#define IMA_MMAP_APPRAISED	0x00008000
56#define IMA_BPRM_APPRAISE	0x00010000
57#define IMA_BPRM_APPRAISED	0x00020000
58#define IMA_READ_APPRAISE	0x00040000
59#define IMA_READ_APPRAISED	0x00080000
60#define IMA_CREDS_APPRAISE	0x00100000
61#define IMA_CREDS_APPRAISED	0x00200000
62#define IMA_APPRAISE_SUBMASK	(IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \
63				 IMA_BPRM_APPRAISE | IMA_READ_APPRAISE | \
64				 IMA_CREDS_APPRAISE)
65#define IMA_APPRAISED_SUBMASK	(IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \
66				 IMA_BPRM_APPRAISED | IMA_READ_APPRAISED | \
67				 IMA_CREDS_APPRAISED)
68
69/* iint cache atomic_flags */
70#define IMA_CHANGE_XATTR	0
71#define IMA_UPDATE_XATTR	1
72#define IMA_CHANGE_ATTR		2
73#define IMA_DIGSIG		3
74#define IMA_MUST_MEASURE	4
75
76enum evm_ima_xattr_type {
77	IMA_XATTR_DIGEST = 0x01,
78	EVM_XATTR_HMAC,
79	EVM_IMA_XATTR_DIGSIG,
80	IMA_XATTR_DIGEST_NG,
81	EVM_XATTR_PORTABLE_DIGSIG,
82	IMA_VERITY_DIGSIG,
83	IMA_XATTR_LAST
84};
85
86struct evm_ima_xattr_data {
87	u8 type;
88	u8 data[];
89} __packed;
90
91/* Only used in the EVM HMAC code. */
92struct evm_xattr {
93	struct evm_ima_xattr_data data;
94	u8 digest[SHA1_DIGEST_SIZE];
95} __packed;
96
97#define IMA_MAX_DIGEST_SIZE	HASH_MAX_DIGESTSIZE
98
99struct ima_digest_data {
100	u8 algo;
101	u8 length;
102	union {
103		struct {
104			u8 unused;
105			u8 type;
106		} sha1;
107		struct {
108			u8 type;
109			u8 algo;
110		} ng;
111		u8 data[2];
112	} xattr;
113	u8 digest[];
114} __packed;
115
116/*
117 * Instead of wrapping the ima_digest_data struct inside a local structure
118 * with the maximum hash size, define ima_max_digest_data struct.
119 */
120struct ima_max_digest_data {
121	struct ima_digest_data hdr;
122	u8 digest[HASH_MAX_DIGESTSIZE];
123} __packed;
124
125/*
126 * signature header format v2 - for using with asymmetric keys
127 *
128 * The signature_v2_hdr struct includes a signature format version
129 * to simplify defining new signature formats.
130 *
131 * signature format:
132 * version 2: regular file data hash based signature
133 * version 3: struct ima_file_id data based signature
134 */
135struct signature_v2_hdr {
136	uint8_t type;		/* xattr type */
137	uint8_t version;	/* signature format version */
138	uint8_t	hash_algo;	/* Digest algorithm [enum hash_algo] */
139	__be32 keyid;		/* IMA key identifier - not X509/PGP specific */
140	__be16 sig_size;	/* signature size */
141	uint8_t sig[];		/* signature payload */
142} __packed;
143
144/*
145 * IMA signature version 3 disambiguates the data that is signed, by
146 * indirectly signing the hash of the ima_file_id structure data,
147 * containing either the fsverity_descriptor struct digest or, in the
148 * future, the regular IMA file hash.
149 *
150 * (The hash of the ima_file_id structure is only of the portion used.)
151 */
152struct ima_file_id {
153	__u8 hash_type;		/* xattr type [enum evm_ima_xattr_type] */
154	__u8 hash_algorithm;	/* Digest algorithm [enum hash_algo] */
155	__u8 hash[HASH_MAX_DIGESTSIZE];
156} __packed;
157
158/* integrity data associated with an inode */
159struct integrity_iint_cache {
160	struct rb_node rb_node;	/* rooted in integrity_iint_tree */
161	struct mutex mutex;	/* protects: version, flags, digest */
162	struct inode *inode;	/* back pointer to inode in question */
163	u64 version;		/* track inode changes */
164	unsigned long flags;
165	unsigned long measured_pcrs;
166	unsigned long atomic_flags;
167	unsigned long real_ino;
168	dev_t real_dev;
169	enum integrity_status ima_file_status:4;
170	enum integrity_status ima_mmap_status:4;
171	enum integrity_status ima_bprm_status:4;
172	enum integrity_status ima_read_status:4;
173	enum integrity_status ima_creds_status:4;
174	enum integrity_status evm_status:4;
175	struct ima_digest_data *ima_hash;
176};
177
178/* rbtree tree calls to lookup, insert, delete
179 * integrity data associated with an inode.
180 */
181struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
182
183int integrity_kernel_read(struct file *file, loff_t offset,
184			  void *addr, unsigned long count);
185
186#define INTEGRITY_KEYRING_EVM		0
187#define INTEGRITY_KEYRING_IMA		1
188#define INTEGRITY_KEYRING_PLATFORM	2
189#define INTEGRITY_KEYRING_MACHINE	3
190#define INTEGRITY_KEYRING_MAX		4
191
192extern struct dentry *integrity_dir;
193
194struct modsig;
195
196#ifdef CONFIG_INTEGRITY_SIGNATURE
197
198int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
199			    const char *digest, int digestlen);
200int integrity_modsig_verify(unsigned int id, const struct modsig *modsig);
201
202int __init integrity_init_keyring(const unsigned int id);
203int __init integrity_load_x509(const unsigned int id, const char *path);
204int __init integrity_load_cert(const unsigned int id, const char *source,
205			       const void *data, size_t len, key_perm_t perm);
206#else
207
208static inline int integrity_digsig_verify(const unsigned int id,
209					  const char *sig, int siglen,
210					  const char *digest, int digestlen)
211{
212	return -EOPNOTSUPP;
213}
214
215static inline int integrity_modsig_verify(unsigned int id,
216					  const struct modsig *modsig)
217{
218	return -EOPNOTSUPP;
219}
220
221static inline int integrity_init_keyring(const unsigned int id)
222{
223	return 0;
224}
225
226static inline int __init integrity_load_cert(const unsigned int id,
227					     const char *source,
228					     const void *data, size_t len,
229					     key_perm_t perm)
230{
231	return 0;
232}
233#endif /* CONFIG_INTEGRITY_SIGNATURE */
234
235#ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
236int asymmetric_verify(struct key *keyring, const char *sig,
237		      int siglen, const char *data, int datalen);
238#else
239static inline int asymmetric_verify(struct key *keyring, const char *sig,
240				    int siglen, const char *data, int datalen)
241{
242	return -EOPNOTSUPP;
243}
244#endif
245
246#ifdef CONFIG_IMA_APPRAISE_MODSIG
247int ima_modsig_verify(struct key *keyring, const struct modsig *modsig);
248#else
249static inline int ima_modsig_verify(struct key *keyring,
250				    const struct modsig *modsig)
251{
252	return -EOPNOTSUPP;
253}
254#endif
255
256#ifdef CONFIG_IMA_LOAD_X509
257void __init ima_load_x509(void);
258#else
259static inline void ima_load_x509(void)
260{
261}
262#endif
263
264#ifdef CONFIG_EVM_LOAD_X509
265void __init evm_load_x509(void);
266#else
267static inline void evm_load_x509(void)
268{
269}
270#endif
271
272#ifdef CONFIG_INTEGRITY_AUDIT
273/* declarations */
274void integrity_audit_msg(int audit_msgno, struct inode *inode,
275			 const unsigned char *fname, const char *op,
276			 const char *cause, int result, int info);
277
278void integrity_audit_message(int audit_msgno, struct inode *inode,
279			     const unsigned char *fname, const char *op,
280			     const char *cause, int result, int info,
281			     int errno);
282
283static inline struct audit_buffer *
284integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
285{
286	return audit_log_start(ctx, gfp_mask, type);
287}
288
289#else
290static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
291				       const unsigned char *fname,
292				       const char *op, const char *cause,
293				       int result, int info)
294{
295}
296
297static inline void integrity_audit_message(int audit_msgno,
298					   struct inode *inode,
299					   const unsigned char *fname,
300					   const char *op, const char *cause,
301					   int result, int info, int errno)
302{
303}
304
305static inline struct audit_buffer *
306integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
307{
308	return NULL;
309}
310
311#endif
312
313#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
314void __init add_to_platform_keyring(const char *source, const void *data,
315				    size_t len);
316#else
317static inline void __init add_to_platform_keyring(const char *source,
318						  const void *data, size_t len)
319{
320}
321#endif
322
323#ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
324void __init add_to_machine_keyring(const char *source, const void *data, size_t len);
325bool __init imputed_trust_enabled(void);
326#else
327static inline void __init add_to_machine_keyring(const char *source,
328						  const void *data, size_t len)
329{
330}
331
332static inline bool __init imputed_trust_enabled(void)
333{
334	return false;
335}
336#endif
337