bsd/sys/cprotect.h

   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_ */