xref: /xnu-8020.101.4/bsd/sys/cprotect.h (revision e7776783b89a353188416a9a346c6cdb4928faad)
1 /*
2  * Copyright (c) 2009-2014 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 
29 #ifndef _SYS_CPROTECT_H_
30 #define _SYS_CPROTECT_H_
31 
32 #ifdef KERNEL_PRIVATE
33 
34 #include <sys/cdefs.h>
35 #include <sys/param.h>
36 #include <sys/buf.h>
37 #include <sys/kdebug.h>
38 #include <crypto/aes.h>
39 #include <stdbool.h>
40 #include <uuid/uuid.h>
41 #include <libkern/crypto/sha1.h>
42 
43 __BEGIN_DECLS
44 
45 #define CP_CODE(code) FSDBG_CODE(DBG_CONTENT_PROT, code)
46 /*
47  * Class DBG_FSYSTEM == 0x03
48  * Subclass DBG_CONTENT_PROT == 0xCF
49  * These debug codes are of the form 0x03CFzzzz
50  */
51 
52 enum {
53 	CPDBG_OFFSET_IO = CP_CODE(0),   /* 0x03CF0000 */
54 };
55 
56 /* normally the debug events are no-ops */
57 #define CP_DEBUG(x, a, b, c, d, e) do {} while (0);
58 
59 /* dev kernels only! */
60 #if !SECURE_KERNEL
61 
62 /* KDEBUG events used by content protection subsystem */
63 #if 0
64 #undef CP_DEBUG
65 #define CP_DEBUG KERNEL_DEBUG_CONSTANT
66 #endif
67 
68 #endif
69 
70 #define CP_MAX_WRAPPEDKEYSIZE     128   /* The size of the largest allowed key */
71 #define VFS_CP_MAX_CACHEBUFLEN    64    /* Maximum size of the cached key */
72 
73 /* lock events from AppleKeyStore */
74 enum {
75 	CP_ACTION_LOCKED        = 0,
76 	CP_ACTION_UNLOCKED      = 1,
77 };
78 /*
79  * Ideally, cp_key_store_action_t would be an enum, but we cannot fix
80  * that until AppleKeyStore is updated.
81  */
82 typedef int cp_key_store_action_t;
83 
84 /*
85  * It was once the case (and it may still be the case) where the lock
86  * state got conflated with the possible actions/events that
87  * AppleKeyStore can send.  For that reason, the locked states below
88  * should numerically match their corresponding actions above.
89  */
90 typedef unsigned char cp_lock_state_t;
91 enum {
92 	CP_LOCKED_STATE         = 0,
93 	CP_UNLOCKED_STATE       = 1,
94 };
95 
96 typedef uint32_t cp_key_class_t;
97 typedef uint32_t cp_key_os_version_t;
98 typedef uint16_t cp_key_revision_t;
99 typedef uint64_t cp_crypto_id_t;
100 
101 typedef struct cprotect *cprotect_t;
102 typedef struct cpx *cpx_t;
103 
104 #ifdef BSD_KERNEL_PRIVATE
105 /* Not for consumption outside of XNU */
106 typedef uint32_t cpx_flags_t;
107 /*
108  * This is a CPX structure with a fixed-length key buffer. We need this defined in a header
109  * so that we can use this structure to allocate the memory for the zone(s) properly.
110  */
111 typedef struct fcpx {
112 #ifdef DEBUG
113 	uint32_t                cpx_magic1;
114 #endif // DEBUG
115 	aes_encrypt_ctx         *cpx_iv_aes_ctx_ptr;// Context used for generating the IV
116 	cpx_flags_t             cpx_flags;
117 	uint16_t                cpx_max_key_len;
118 	uint16_t                cpx_key_len;
119 	uint8_t                 cpx_cached_key[VFS_CP_MAX_CACHEBUFLEN];
120 	//Fixed length all the way through
121 } fcpx_t;
122 
123 #endif // BSD_KERNEL_PRIVATE
124 
125 typedef struct cp_key {
126 	uint8_t len;
127 	void *key;
128 } cp_key_t;
129 
130 /* Interface to AKS kext */
131 typedef struct {
132 	void     *key;
133 	unsigned key_len;
134 	void     *iv_key;
135 	unsigned iv_key_len;
136 	uint32_t flags;
137 } cp_raw_key_s;
138 
139 typedef cp_raw_key_s* cp_raw_key_t;
140 
141 typedef struct {
142 	void     *key;
143 	unsigned key_len;
144 	cp_key_class_t dp_class;
145 } cp_wrapped_key_s;
146 
147 typedef cp_wrapped_key_s* cp_wrapped_key_t;
148 
149 typedef struct {
150 	union {
151 		ino64_t                 inode;
152 		cp_crypto_id_t  crypto_id;
153 	};
154 	uint32_t                        volume;
155 	pid_t                           pid;
156 	uid_t                           uid;
157 	cp_key_revision_t       key_revision;
158 } cp_cred_s;
159 
160 typedef cp_cred_s* cp_cred_t;
161 
162 /* The wrappers are invoked on the AKS kext */
163 typedef int unwrapper_t(cp_cred_t access, const cp_wrapped_key_t wrapped_key_in, cp_raw_key_t key_out);
164 typedef int rewrapper_t(cp_cred_t access, cp_key_class_t dp_class, const cp_wrapped_key_t wrapped_key_in, cp_wrapped_key_t wrapped_key_out);
165 typedef int new_key_t(cp_cred_t access, cp_key_class_t dp_class, cp_raw_key_t key_out, cp_wrapped_key_t wrapped_key_out);
166 typedef int invalidater_t(cp_cred_t access); /* invalidates keys */
167 typedef int backup_key_t(cp_cred_t access, const cp_wrapped_key_t wrapped_key_in, cp_wrapped_key_t wrapped_key_out);
168 
169 /*
170  * Flags for Interaction between AKS / Kernel
171  * These are twiddled via the input/output structs in the above
172  * wrapper/unwrapper functions.
173  */
174 #define CP_RAW_KEY_WRAPPEDKEY   0x00000001
175 
176 /*
177  * Function prototypes for kexts to interface with our internal cprotect
178  * fields;  cpx provides opacity and allows us to modify behavior internally
179  * without requiring kext changes.
180  */
181 cpx_t cpx_alloc(size_t key_size, bool needs_ctx);
182 int cpx_alloc_ctx(cpx_t cpx);
183 void cpx_free_ctx(cpx_t cpx);
184 void cpx_init(cpx_t, size_t key_len);
185 void cpx_init_ctx_ptr(cpx_t cpx);
186 void cpx_free(cpx_t);
187 void cpx_writeprotect(cpx_t cpx);
188 __attribute__((const)) size_t cpx_size(size_t key_len);
189 __attribute__((pure)) bool cpx_is_sep_wrapped_key(const struct cpx *);
190 void cpx_set_is_sep_wrapped_key(struct cpx *, bool);
191 __attribute__((pure)) bool cpx_is_composite_key(const struct cpx *);
192 void cpx_set_is_composite_key(struct cpx *, bool);
193 __attribute__((pure)) bool cpx_use_offset_for_iv(const struct cpx *);
194 void cpx_set_use_offset_for_iv(struct cpx *, bool);
195 __attribute__((pure)) bool cpx_synthetic_offset_for_iv(const struct cpx *);
196 void cpx_set_synthetic_offset_for_iv(struct cpx *, bool);
197 __attribute__((pure)) uint16_t cpx_key_len(const struct cpx *);
198 void cpx_set_key_len(struct cpx *, uint16_t key_len);
199 __attribute__((pure)) void *cpx_key(const struct cpx *);
200 aes_encrypt_ctx *cpx_iv_aes_ctx(struct cpx *);
201 void cpx_flush(cpx_t cpx);
202 bool cpx_can_copy(const struct cpx *src, const struct cpx *dst);
203 void cpx_copy(const struct cpx *src, cpx_t dst);
204 uint16_t cpx_max_key_len(const struct cpx *cpx);
205 bool cpx_has_key(const struct cpx *cpx);
206 size_t cpx_sizex(const struct cpx *cpx);
207 void cpx_set_aes_iv_key(struct cpx *cpx, void *iv_key);
208 
209 int cp_key_store_action(cp_key_store_action_t);
210 int cp_key_store_action_for_volume(uuid_t volume_uuid, cp_key_store_action_t action);
211 cp_key_os_version_t cp_os_version(void);
212 // Should be cp_key_class_t but HFS has a conflicting definition
213 int cp_is_valid_class(int isdir, int32_t protectionclass);
214 
215 __END_DECLS
216 
217 #endif /* KERNEL_PRIVATE */
218 #endif /* !_SYS_CPROTECT_H_ */
219