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 #if 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
  41 __BEGIN_DECLS
  42
  43 #define CP_CODE(code) FSDBG_CODE(DBG_CONTENT_PROT, code)
  44 /*
  45  * Class DBG_FSYSTEM == 0x03
  46  * Subclass DBG_CONTENT_PROT == 0xCF
  47  * These debug codes are of the form 0x03CFzzzz
  48  */
  49
  50 enum {
  51         CPDBG_OFFSET_IO = CP_CODE(0),   /* 0x03CF0000 */
  52 };
  53
  54 /* normally the debug events are no-ops */
  55 #define CP_DEBUG(x,a,b,c,d,e) do {} while (0);
  56
  57 /* dev kernels only! */
  58 #if !SECURE_KERNEL
  59
  60 /* KDEBUG events used by content protection subsystem */
  61 #if 0
  62 #undef CP_DEBUG
  63 #define CP_DEBUG KERNEL_DEBUG_CONSTANT
  64 #endif
  65
  66 #endif
  67
  68 #define CP_MAX_WRAPPEDKEYSIZE     128   /* The size of the largest allowed key */
  69
  70 /* lock events from AppleKeyStore */
  71 enum {
  72         CP_ACTION_LOCKED        = 0,
  73         CP_ACTION_UNLOCKED      = 1,
  74 };
  75 /*
  76  * Ideally, cp_key_store_action_t would be an enum, but we cannot fix
  77  * that until AppleKeyStore is updated.
  78  */
  79 typedef int cp_key_store_action_t;
  80
  81 /*
  82  * It was once the case (and it may still be the case) where the lock
  83  * state got conflated with the possible actions/events that
  84  * AppleKeyStore can send.  For that reason, the locked states below
  85  * should numerically match their corresponding actions above.
  86  */
  87 typedef unsigned char cp_lock_state_t;
  88 enum {
  89         CP_LOCKED_STATE         = 0,
  90         CP_UNLOCKED_STATE       = 1,
  91 };
  92
  93 typedef uint32_t cp_key_class_t;
  94 typedef uint32_t cp_key_os_version_t;
  95 typedef uint16_t cp_key_revision_t;
  96 typedef uint64_t cp_crypto_id_t;
  97
  98 typedef struct cprotect *cprotect_t;
  99 typedef struct cp_wrap_func *cp_wrap_func_t;
 100 typedef struct cpx *cpx_t;
 101
 102 typedef struct cp_key {
 103         uint8_t len;
 104         void *key;
 105 } cp_key_t;
 106
 107 /* Interface to AKS kext */
 108 typedef struct {
 109         void     *key;
 110         unsigned key_len;
 111         void     *iv_key;
 112         unsigned iv_key_len;
 113         uint32_t flags;
 114 } cp_raw_key_s;
 115
 116 typedef cp_raw_key_s* cp_raw_key_t;
 117
 118 typedef struct {
 119         void     *key;
 120         unsigned key_len;
 121         cp_key_class_t dp_class;
 122 } cp_wrapped_key_s;
 123
 124 typedef cp_wrapped_key_s* cp_wrapped_key_t;
 125
 126 typedef struct {
 127         union {
 128                 ino64_t                 inode;
 129                 cp_crypto_id_t  crypto_id;
 130         };
 131         uint32_t                        volume;
 132         pid_t                           pid;
 133         uid_t                           uid;
 134         cp_key_revision_t       key_revision;
 135 } cp_cred_s;
 136
 137 typedef cp_cred_s* cp_cred_t;
 138
 139 /* The wrappers are invoked on the AKS kext */
 140 typedef int unwrapper_t(cp_cred_t access, const cp_wrapped_key_t wrapped_key_in, cp_raw_key_t key_out);
 141 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);
 142 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);
 143 typedef int invalidater_t(cp_cred_t access); /* invalidates keys */
 144 typedef int backup_key_t(cp_cred_t access, const cp_wrapped_key_t wrapped_key_in, cp_wrapped_key_t wrapped_key_out);
 145
 146 /*
 147  * Flags for Interaction between AKS / Kernel
 148  * These are twiddled via the input/output structs in the above
 149  * wrapper/unwrapper functions.
 150  */
 151 #define CP_RAW_KEY_WRAPPEDKEY   0x00000001
 152
 153 /*
 154  * Function prototypes for kexts to interface with our internal cprotect
 155  * fields;  cpx provides opacity and allows us to modify behavior internally
 156  * without requiring kext changes.
 157  */
 158 cpx_t cpx_alloc(size_t key_size);
 159 void cpx_init(cpx_t, size_t key_len);
 160 void cpx_free(cpx_t);
 161 __attribute__((const)) size_t cpx_size(size_t key_size);
 162 __attribute__((pure)) bool cpx_is_sep_wrapped_key(const struct cpx *);
 163 void cpx_set_is_sep_wrapped_key(struct cpx *, bool);
 164 __attribute__((pure)) bool cpx_use_offset_for_iv(const struct cpx *);
 165 void cpx_set_use_offset_for_iv(struct cpx *, bool);
 166 __attribute__((pure)) bool cpx_synthetic_offset_for_iv(const struct cpx *);
 167 void cpx_set_synthetic_offset_for_iv(struct cpx *, bool);
 168 __attribute__((pure)) uint16_t cpx_key_len(const struct cpx *);
 169 void cpx_set_key_len(struct cpx *, uint16_t key_len);
 170 __attribute__((pure)) void *cpx_key(const struct cpx *);
 171 aes_encrypt_ctx *cpx_iv_aes_ctx(struct cpx *);
 172 void cpx_flush(cpx_t cpx);
 173 bool cpx_can_copy(const struct cpx *src, const struct cpx *dst);
 174 void cpx_copy(const struct cpx *src, cpx_t dst);
 175 uint16_t cpx_max_key_len(const struct cpx *cpx);
 176 bool cpx_has_key(const struct cpx *cpx);
 177 size_t cpx_sizex(const struct cpx *cpx);
 178 void cpx_set_aes_iv_key(struct cpx *cpx, void *iv_key);
 179
 180 /* Structure to store pointers for AKS functions */
 181 struct cp_wrap_func {
 182         new_key_t       *new_key;
 183         unwrapper_t     *unwrapper;
 184         rewrapper_t     *rewrapper;
 185         invalidater_t   *invalidater;
 186         backup_key_t    *backup_key;
 187 };
 188
 189 int cp_key_store_action(cp_key_store_action_t);
 190 int cp_register_wraps(cp_wrap_func_t);
 191 int cp_rewrap_key(cp_cred_t access, cp_key_class_t dp_class,
 192                                   const cp_wrapped_key_t wrapped_key_in,
 193                                   cp_wrapped_key_t wrapped_key_out);
 194 int cp_new_key(cp_cred_t access, cp_key_class_t dp_class, cp_raw_key_t key_out,
 195                            cp_wrapped_key_t wrapped_key_out);
 196 int cp_unwrap_key(cp_cred_t access, const cp_wrapped_key_t wrapped_key_in,
 197                                   cp_raw_key_t key_out);
 198 int cp_get_backup_key(cp_cred_t access, const cp_wrapped_key_t wrapped_key_in,
 199                                           cp_wrapped_key_t wrapped_key_out);
 200 cp_key_os_version_t cp_os_version(void);
 201 // Should be cp_key_class_t but HFS has a conflicting definition
 202 int cp_is_valid_class (int isdir, int32_t protectionclass);
 203
 204 __END_DECLS
 205
 206 #endif /* KERNEL_PRIVATE */
 207 #endif /* !_SYS_CPROTECT_H_ */