include/internal/rand.h

   1 /*
   2  * Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #ifndef HEADER_DRBG_RAND_H
  11 # define HEADER_DRBG_RAND_H
  12
  13 /* In CTR mode, disable derivation function ctr_df */
  14 #define RAND_DRBG_FLAG_CTR_NO_DF            0x1
  15
  16 /*
  17  * Default security strength (in the sense of [NIST SP 800-90Ar1])
  18  *
  19  * NIST SP 800-90Ar1 supports the strength of the DRBG being smaller than that
  20  * of the cipher by collecting less entropy. The current DRBG implemantion does
  21  * not take RAND_DRBG_STRENGTH into account and sets the strength of the DRBG
  22  * to that of the cipher.
  23  *
  24  * RAND_DRBG_STRENGTH is currently only used for the legacy RAND
  25  * implementation.
  26  *
  27  * Currently supported ciphers are: NID_aes_128_ctr, NID_aes_192_ctr and
  28  * NID_aes_256_ctr
  29  *
  30  * TODO(DRBG): would be nice to have the NID and strength configurable
  31  */
  32 # define RAND_DRBG_STRENGTH             256
  33 # define RAND_DRBG_NID                  NID_aes_256_ctr
  34
  35 /*
  36  * Object lifetime functions.
  37  */
  38 RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent);
  39 RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent);
  40 int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags);
  41 int RAND_DRBG_instantiate(RAND_DRBG *drbg,
  42                           const unsigned char *pers, size_t perslen);
  43 int RAND_DRBG_uninstantiate(RAND_DRBG *drbg);
  44 void RAND_DRBG_free(RAND_DRBG *drbg);
  45
  46 /*
  47  * Object "use" functions.
  48  */
  49 int RAND_DRBG_reseed(RAND_DRBG *drbg,
  50                      const unsigned char *adin, size_t adinlen);
  51 int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
  52                        int prediction_resistance,
  53                        const unsigned char *adin, size_t adinlen);
  54 int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen);
  55
  56 int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval);
  57 int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval);
  58
  59 int RAND_DRBG_set_reseed_defaults(
  60                                   unsigned int master_reseed_interval,
  61                                   unsigned int slave_reseed_interval,
  62                                   time_t master_reseed_time_interval,
  63                                   time_t slave_reseed_time_interval
  64                                   );
  65
  66 RAND_DRBG *RAND_DRBG_get0_master(void);
  67 RAND_DRBG *RAND_DRBG_get0_public(void);
  68 RAND_DRBG *RAND_DRBG_get0_private(void);
  69
  70 /*
  71  * EXDATA
  72  */
  73 #define RAND_DRBG_get_ex_new_index(l, p, newf, dupf, freef) \
  74     CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DRBG, l, p, newf, dupf, freef)
  75 int RAND_DRBG_set_ex_data(RAND_DRBG *dctx, int idx, void *arg);
  76 void *RAND_DRBG_get_ex_data(const RAND_DRBG *dctx, int idx);
  77
  78 /*
  79  * Callback functions.  See comments in drbg_lib.c
  80  */
  81 typedef size_t (*RAND_DRBG_get_entropy_fn)(RAND_DRBG *ctx,
  82                                            unsigned char **pout,
  83                                            int entropy, size_t min_len,
  84                                            size_t max_len);
  85 typedef void (*RAND_DRBG_cleanup_entropy_fn)(RAND_DRBG *ctx,
  86                                              unsigned char *out, size_t outlen);
  87 typedef size_t (*RAND_DRBG_get_nonce_fn)(RAND_DRBG *ctx, unsigned char **pout,
  88                                          int entropy, size_t min_len,
  89                                          size_t max_len);
  90 typedef void (*RAND_DRBG_cleanup_nonce_fn)(RAND_DRBG *ctx,
  91                                            unsigned char *out, size_t outlen);
  92
  93 int RAND_DRBG_set_callbacks(RAND_DRBG *dctx,
  94                             RAND_DRBG_get_entropy_fn get_entropy,
  95                             RAND_DRBG_cleanup_entropy_fn cleanup_entropy,
  96                             RAND_DRBG_get_nonce_fn get_nonce,
  97                             RAND_DRBG_cleanup_nonce_fn cleanup_nonce);
  98
  99 /*
 100  * RAND_POOL functions
 101  */
 102 RAND_POOL *RAND_POOL_new(int entropy_requested, size_t min_len, size_t max_len);
 103 void RAND_POOL_free(RAND_POOL *pool);
 104
 105 const unsigned char *RAND_POOL_buffer(RAND_POOL *pool);
 106 unsigned char *RAND_POOL_detach(RAND_POOL *pool);
 107
 108 size_t RAND_POOL_entropy(RAND_POOL *pool);
 109 size_t RAND_POOL_length(RAND_POOL *pool);
 110
 111 size_t RAND_POOL_entropy_available(RAND_POOL *pool);
 112 size_t RAND_POOL_entropy_needed(RAND_POOL *pool);
 113 size_t RAND_POOL_bytes_needed(RAND_POOL *pool, unsigned int entropy_per_byte);
 114 size_t RAND_POOL_bytes_remaining(RAND_POOL *pool);
 115
 116 size_t RAND_POOL_add(RAND_POOL *pool,
 117                      const unsigned char *buffer, size_t len, size_t entropy);
 118 unsigned char *RAND_POOL_add_begin(RAND_POOL *pool, size_t len);
 119 size_t RAND_POOL_add_end(RAND_POOL *pool, size_t len, size_t entropy);
 120
 121
 122 /*
 123  * Add random bytes to the pool to acquire requested amount of entropy
 124  *
 125  * This function is platform specific and tries to acquire the requested
 126  * amount of entropy by polling platform specific entropy sources.
 127  *
 128  * If the function succeeds in acquiring at least |entropy_requested| bits
 129  * of entropy, the total entropy count is returned. If it fails, it returns
 130  * an entropy count of 0.
 131  */
 132 size_t RAND_POOL_acquire_entropy(RAND_POOL *pool);
 133 #endif