release/src/router/nettle/yarrow.h

   1 /* yarrow.h
   2  *
   3  * The yarrow pseudo-randomness generator.
   4  */
   5
   6 /* nettle, low-level cryptographics library
   7  *
   8  * Copyright (C) 2001 Niels Möller
   9  *
  10  * The nettle library is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or (at your
  13  * option) any later version.
  14  *
  15  * The nettle library is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  17  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  18  * License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with the nettle library; see the file COPYING.LIB.  If not, write to
  22  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  23  * MA 02111-1301, USA.
  24  */
  25
  26 #ifndef NETTLE_YARROW_H_INCLUDED
  27 #define NETTLE_YARROW_H_INCLUDED
  28
  29 #include "aes.h"
  30 #include "sha2.h"
  31
  32 #ifdef __cplusplus
  33 extern "C" {
  34 #endif
  35
  36 /* Name mangling */
  37 #define yarrow256_init nettle_yarrow256_init
  38 #define yarrow256_seed nettle_yarrow256_seed
  39 #define yarrow256_update nettle_yarrow256_update
  40 #define yarrow256_random nettle_yarrow256_random
  41 #define yarrow256_is_seeded nettle_yarrow256_is_seeded
  42 #define yarrow256_needed_sources nettle_yarrow256_needed_sources
  43 #define yarrow256_fast_reseed nettle_yarrow256_fast_reseed
  44 #define yarrow256_slow_reseed nettle_yarrow256_slow_reseed
  45 #define yarrow_key_event_init nettle_yarrow_key_event_init
  46 #define yarrow_key_event_estimate nettle_yarrow_key_event_estimate
  47
  48 /* Obsolete alias for backwards compatibility. Will be deleted in some
  49    later version. */
  50 #define yarrow256_force_reseed yarrow256_slow_reseed
  51
  52 enum yarrow_pool_id { YARROW_FAST = 0, YARROW_SLOW = 1 };
  53
  54 struct yarrow_source
  55 {
  56   /* Indexed by yarrow_pool_id */
  57   uint32_t estimate[2];
  58
  59   /* The pool next sample should go to. */
  60   enum yarrow_pool_id next;
  61 };
  62
  63
  64 #define YARROW256_SEED_FILE_SIZE (2 * AES_BLOCK_SIZE)
  65
  66 /* Yarrow-256, based on SHA-256 and AES-256 */
  67 struct yarrow256_ctx
  68 {
  69   /* Indexed by yarrow_pool_id */
  70   struct sha256_ctx pools[2];
  71
  72   int seeded;
  73
  74   /* The current key and counter block */
  75   struct aes_ctx key;
  76   uint8_t counter[AES_BLOCK_SIZE];
  77
  78   /* The entropy sources */
  79   unsigned nsources;
  80   struct yarrow_source *sources;
  81 };
  82
  83 void
  84 yarrow256_init(struct yarrow256_ctx *ctx,
  85                unsigned nsources,
  86                struct yarrow_source *sources);
  87
  88 void
  89 yarrow256_seed(struct yarrow256_ctx *ctx,
  90                unsigned length,
  91                const uint8_t *seed_file);
  92
  93 /* Returns 1 on reseed */
  94 int
  95 yarrow256_update(struct yarrow256_ctx *ctx,
  96                  unsigned source, unsigned entropy,
  97                  unsigned length, const uint8_t *data);
  98
  99 void
 100 yarrow256_random(struct yarrow256_ctx *ctx, unsigned length, uint8_t *dst);
 101
 102 int
 103 yarrow256_is_seeded(struct yarrow256_ctx *ctx);
 104
 105 unsigned
 106 yarrow256_needed_sources(struct yarrow256_ctx *ctx);
 107
 108 void
 109 yarrow256_fast_reseed(struct yarrow256_ctx *ctx);
 110
 111 void
 112 yarrow256_slow_reseed(struct yarrow256_ctx *ctx);
 113
 114
 115 /* Key event estimator */
 116 #define YARROW_KEY_EVENT_BUFFER 16
 117
 118 struct yarrow_key_event_ctx
 119 {
 120   /* Counter for initial priming of the state */
 121   unsigned index;
 122   unsigned chars[YARROW_KEY_EVENT_BUFFER];
 123   unsigned previous;
 124 };
 125
 126 void
 127 yarrow_key_event_init(struct yarrow_key_event_ctx *ctx);
 128
 129 unsigned
 130 yarrow_key_event_estimate(struct yarrow_key_event_ctx *ctx,
 131                           unsigned key, unsigned time);
 132
 133 #ifdef __cplusplus
 134 }
 135 #endif
 136
 137 #endif /* NETTLE_YARROW_H_INCLUDED */