osfmk/prng/random.h

   1 /*
   2  * Copyright (c) 2013 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 _PRNG_RANDOM_H_
  30 #define _PRNG_RANDOM_H_
  31
  32 __BEGIN_DECLS
  33
  34 #ifdef XNU_KERNEL_PRIVATE
  35
  36 #define ENTROPY_BUFFER_BYTE_SIZE 64
  37
  38 #define ENTROPY_BUFFER_SIZE (ENTROPY_BUFFER_BYTE_SIZE / sizeof(uint32_t))
  39
  40 typedef struct entropy_data {
  41         /*
  42          * TODO: Should index_ptr be volatile?  Are we exposed to any races that
  43          * we care about if it is not?
  44          */
  45         uint32_t * index_ptr;
  46         uint32_t buffer[ENTROPY_BUFFER_SIZE];
  47 } entropy_data_t;
  48
  49 extern entropy_data_t EntropyData;
  50
  51 /* Trace codes for DBG_SEC_KERNEL: */
  52 #define ENTROPY_READ(n) SECURITYDBG_CODE(DBG_SEC_KERNEL, n) /* n: 0 .. 3 */
  53
  54 /*
  55  * Early_random implementation params: */
  56 #define EARLY_RANDOM_SEED_SIZE (16)
  57 #define EARLY_RANDOM_STATE_STATIC_SIZE (264)
  58
  59 void early_random_cpu_init(int cpu);
  60
  61 /*
  62  * Wrapper for requesting a CCKPRNG operation.
  63  * This macro makes the DRBG call with pre-emption disabled to ensure that
  64  * any attempt to block will cause a panic. And the operation is timed and
  65  * cannot exceed 10msec (for development kernels).
  66  * But skip this while we retain Yarrow.
  67  */
  68 #define YARROW 1
  69 #if YARROW
  70 #define PRNG_CCKPRNG(op) \
  71         MACRO_BEGIN          \
  72         op;                  \
  73         MACRO_END
  74 #else
  75 #define PRNG_CCKPRNG(op)                                                      \
  76         MACRO_BEGIN                                                               \
  77         uint64_t start;                                                           \
  78         uint64_t stop;                                                            \
  79         disable_preemption();                                                     \
  80         start = mach_absolute_time();                                             \
  81         op;                                                                       \
  82         stop = mach_absolute_time();                                              \
  83         enable_preemption();                                                      \
  84         assert(stop - start < 10 * NSEC_PER_MSEC || machine_timeout_suspended()); \
  85         (void)start;                                                              \
  86         (void)stop;                                                               \
  87         MACRO_END
  88 #endif
  89
  90 #endif /* XNU_KERNEL_PRIVATE */
  91
  92 #include <corecrypto/cckprng.h>
  93
  94 /* kernel prng */
  95 typedef const struct prng_fns {
  96         int (*init)(cckprng_ctx_t ctx, size_t nbytes, const void * seed);
  97         int (*reseed)(cckprng_ctx_t ctx, size_t nbytes, const void * seed);
  98         int (*addentropy)(cckprng_ctx_t ctx, size_t nbytes, const void * entropy);
  99         int (*generate)(cckprng_ctx_t ctx, size_t nbytes, void * out);
 100 } * prng_fns_t;
 101
 102 void register_and_init_prng(prng_fns_t fns);
 103
 104 #include <kern/simple_lock.h>
 105 /* Definitions for boolean PRNG */
 106 #define RANDOM_BOOL_GEN_SEED_COUNT 4
 107 struct bool_gen {
 108         unsigned int seed[RANDOM_BOOL_GEN_SEED_COUNT];
 109         unsigned int state;
 110         decl_simple_lock_data(, lock)
 111 };
 112
 113 extern void random_bool_init(struct bool_gen * bg);
 114
 115 extern void random_bool_gen_entropy(struct bool_gen * bg, unsigned int * buffer, int count);
 116
 117 extern unsigned int random_bool_gen_bits(struct bool_gen * bg, unsigned int * buffer, unsigned int count, unsigned int numbits);
 118
 119 __END_DECLS
 120
 121 #endif /* _PRNG_RANDOM_H_ */