1 /*
2  * $FreeBSD$
3  *
4  * Copyright (c) 2011, 2012, 2013, 2015, 2016, Juniper Networks, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifndef	_SECURITY_MAC_VERIEXEC_H
30 #define	_SECURITY_MAC_VERIEXEC_H
31 
32 #ifdef _KERNEL
33 #include <sys/types.h>
34 #include <sys/kernel.h>
35 #include <sys/queue.h>
36 #include <sys/module.h>
37 #endif
38 
39 /**
40  * Name of the MAC module
41  */
42 #define	MAC_VERIEXEC_NAME	"mac_veriexec"
43 
44 /* MAC/veriexec syscalls */
45 #define	MAC_VERIEXEC_CHECK_FD_SYSCALL	1
46 #define	MAC_VERIEXEC_CHECK_PATH_SYSCALL	2
47 
48 /**
49  * Enough room for the largest signature...
50  */
51 #define MAXFINGERPRINTLEN	64	/* enough room for largest signature */
52 
53 /*
54  * Types of veriexec inodes we can have
55  */
56 #define VERIEXEC_INDIRECT	(1<<0)  /* Only allow indirect execution */
57 #define VERIEXEC_FILE		(1<<1)  /* Fingerprint of a plain file */
58 #define VERIEXEC_NOTRACE	(1<<2)	/**< PTRACE not allowed */
59 #define VERIEXEC_TRUSTED	(1<<3)	/**< Safe to write /dev/mem */
60 /* XXX these are currently unimplemented */
61 #define VERIEXEC_NOFIPS		(1<<4)	/**< Not allowed in FIPS mode */
62 
63 #define VERIEXEC_STATE_INACTIVE	0	/**< Ignore */
64 #define VERIEXEC_STATE_LOADED	(1<<0)	/**< Sigs have been loaded */
65 #define VERIEXEC_STATE_ACTIVE	(1<<1)	/**< Pay attention to it */
66 #define VERIEXEC_STATE_ENFORCE	(1<<2)	/**< Fail execs for files that do not
67 					     match signature */
68 #define VERIEXEC_STATE_LOCKED	(1<<3)	/**< Do not allow further changes */
69 
70 #ifdef _KERNEL
71 /**
72  * Version of the MAC/veriexec module
73  */
74 #define	MAC_VERIEXEC_VERSION	1
75 
76 /* Valid states for the fingerprint flag - if signed exec is being used */
77 typedef enum fingerprint_status {
78 	FINGERPRINT_INVALID,	/**< Fingerprint has not been evaluated */
79 	FINGERPRINT_VALID,	/**< Fingerprint evaluated and matches list */
80 	FINGERPRINT_INDIRECT,	/**< Fingerprint eval'd/matched but only
81 				     indirect execs allowed */
82 	FINGERPRINT_FILE,	/**< Fingerprint evaluated/matched but
83 				     not executable */
84 	FINGERPRINT_NOMATCH,	/**< Fingerprint evaluated but does not match */
85 	FINGERPRINT_NOENTRY,	/**< Fingerprint evaluated but no list entry */
86 	FINGERPRINT_NODEV,	/**< Fingerprint evaluated but no dev list */
87 } fingerprint_status_t;
88 
89 typedef void (*mac_veriexec_fpop_init_t)(void *);
90 typedef void (*mac_veriexec_fpop_update_t)(void *, const uint8_t *, size_t);
91 typedef void (*mac_veriexec_fpop_final_t)(uint8_t *, void *);
92 
93 struct mac_veriexec_fpops {
94 	const char *type;
95 	size_t digest_len;
96 	size_t context_size;
97 	mac_veriexec_fpop_init_t init;
98 	mac_veriexec_fpop_update_t update;
99 	mac_veriexec_fpop_final_t final;
100 	LIST_ENTRY(mac_veriexec_fpops) entries;
101 };
102 
103 /**
104  * Verified execution subsystem debugging level
105  */
106 extern int	mac_veriexec_debug;
107 
108 /**
109  * @brief Define a fingerprint module.
110  *
111  * @param _name		Name of the fingerprint module
112  * @param _digest_len	Length of the digest string, in number of characters
113  * @param _context_size	Size of the context structure, in bytes
114  * @param _init		Initialization function of type
115  * 			mac_veriexec_fpop_init_t
116  * @param _update	Update function of type mac_veriexec_fpop_update_t
117  * @param _final	Finalize function of type mac_veriexec_fpop_final_t
118  * @param _vers		Module version
119  */
120 #define MAC_VERIEXEC_FPMOD(_name, _digest_len, _context_size, _init,	\
121 	    _update, _final, _vers)					\
122 	static struct mac_veriexec_fpops				\
123 	    mac_veriexec_##_name##_fpops = {				\
124 		.type = #_name,						\
125 		.digest_len = _digest_len,				\
126 		.context_size = _context_size,				\
127 		.init = _init,						\
128 		.update = _update,					\
129 		.final = _final,					\
130 	};								\
131 	static moduledata_t mac_veriexec_##_name##_mod = {		\
132 		"mac_veriexec/" #_name,					\
133 		mac_veriexec_fingerprint_modevent,			\
134 		&(mac_veriexec_##_name##_fpops)				\
135 	};								\
136 	MODULE_VERSION(mac_veriexec_##_name, _vers);			\
137 	DECLARE_MODULE(mac_veriexec_##_name,				\
138 	    mac_veriexec_##_name##_mod, SI_SUB_MAC_POLICY,		\
139 	    SI_ORDER_ANY);						\
140 	MODULE_DEPEND(mac_veriexec_##_name, mac_veriexec,		\
141 	    MAC_VERIEXEC_VERSION, MAC_VERIEXEC_VERSION,			\
142 	    MAC_VERIEXEC_VERSION)
143 
144 /*
145  * The following function should not be called directly. The prototype is
146  * included here to satisfy the compiler when using the macro above.
147  */
148 int	mac_veriexec_fingerprint_modevent(module_t mod, int type, void *data);
149 
150 /*
151  * Public functions
152  */
153 int	mac_veriexec_metadata_add_file(int file_dev, dev_t fsid, long fileid,
154 	    unsigned long gen, unsigned char fingerprint[MAXFINGERPRINTLEN],
155 	    int flags, const char *fp_type, int override);
156 int	mac_veriexec_metadata_has_file(dev_t fsid, long fileid,
157 	    unsigned long gen);
158 int	mac_veriexec_proc_is_trusted(struct ucred *cred, struct proc *p);
159 #endif
160 
161 #endif	/* _SECURITY_MAC_VERIEXEC_H */
162