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  * of the default OpenSSL DRBG, and the corresponding NID.
  19  *
  20  * Currently supported values: 128, 192, 256
  21  *
  22  * TODO(DRBG): would be nice to have the strength configurable
  23  */
  24 # define RAND_DRBG_STRENGTH             128
  25 # define RAND_DRBG_NID                  NID_aes_128_ctr
  26
  27 /*
  28  * Object lifetime functions.
  29  */
  30 RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent);
  31 RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent);
  32 int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags);
  33 int RAND_DRBG_instantiate(RAND_DRBG *drbg,
  34                           const unsigned char *pers, size_t perslen);
  35 int RAND_DRBG_uninstantiate(RAND_DRBG *drbg);
  36 void RAND_DRBG_free(RAND_DRBG *drbg);
  37
  38 /*
  39  * Object "use" functions.
  40  */
  41 int RAND_DRBG_reseed(RAND_DRBG *drbg,
  42                      const unsigned char *adin, size_t adinlen);
  43 int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
  44                        int prediction_resistance,
  45                        const unsigned char *adin, size_t adinlen);
  46 int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen);
  47
  48 int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval);
  49 int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval);
  50
  51 RAND_DRBG *RAND_DRBG_get0_master(void);
  52 RAND_DRBG *RAND_DRBG_get0_public(void);
  53 RAND_DRBG *RAND_DRBG_get0_private(void);
  54
  55 /*
  56  * EXDATA
  57  */
  58 #define RAND_DRBG_get_ex_new_index(l, p, newf, dupf, freef) \
  59     CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DRBG, l, p, newf, dupf, freef)
  60 int RAND_DRBG_set_ex_data(RAND_DRBG *dctx, int idx, void *arg);
  61 void *RAND_DRBG_get_ex_data(const RAND_DRBG *dctx, int idx);
  62
  63 /*
  64  * Callback functions.  See comments in drbg_lib.c
  65  */
  66 typedef size_t (*RAND_DRBG_get_entropy_fn)(RAND_DRBG *ctx,
  67                                            unsigned char **pout,
  68                                            int entropy, size_t min_len,
  69                                            size_t max_len);
  70 typedef void (*RAND_DRBG_cleanup_entropy_fn)(RAND_DRBG *ctx,
  71                                              unsigned char *out, size_t outlen);
  72 typedef size_t (*RAND_DRBG_get_nonce_fn)(RAND_DRBG *ctx, unsigned char **pout,
  73                                          int entropy, size_t min_len,
  74                                          size_t max_len);
  75 typedef void (*RAND_DRBG_cleanup_nonce_fn)(RAND_DRBG *ctx,
  76                                            unsigned char *out, size_t outlen);
  77
  78 int RAND_DRBG_set_callbacks(RAND_DRBG *dctx,
  79                             RAND_DRBG_get_entropy_fn get_entropy,
  80                             RAND_DRBG_cleanup_entropy_fn cleanup_entropy,
  81                             RAND_DRBG_get_nonce_fn get_nonce,
  82                             RAND_DRBG_cleanup_nonce_fn cleanup_nonce);
  83
  84 /*
  85  * RAND_POOL functions
  86  */
  87 RAND_POOL *RAND_POOL_new(int entropy_requested, size_t min_len, size_t max_len);
  88 void RAND_POOL_free(RAND_POOL *pool);
  89
  90 const unsigned char *RAND_POOL_buffer(RAND_POOL *pool);
  91 unsigned char *RAND_POOL_detach(RAND_POOL *pool);
  92
  93 size_t RAND_POOL_entropy(RAND_POOL *pool);
  94 size_t RAND_POOL_length(RAND_POOL *pool);
  95
  96 size_t RAND_POOL_entropy_available(RAND_POOL *pool);
  97 size_t RAND_POOL_entropy_needed(RAND_POOL *pool);
  98 size_t RAND_POOL_bytes_needed(RAND_POOL *pool, unsigned int entropy_per_byte);
  99 size_t RAND_POOL_bytes_remaining(RAND_POOL *pool);
 100
 101 size_t RAND_POOL_add(RAND_POOL *pool,
 102                      const unsigned char *buffer, size_t len, size_t entropy);
 103 unsigned char *RAND_POOL_add_begin(RAND_POOL *pool, size_t len);
 104 size_t RAND_POOL_add_end(RAND_POOL *pool, size_t len, size_t entropy);
 105
 106
 107 /*
 108  * Add random bytes to the pool to acquire requested amount of entropy
 109  *
 110  * This function is platform specific and tries to acquire the requested
 111  * amount of entropy by polling platform specific entropy sources.
 112  *
 113  * If the function succeeds in acquiring at least |entropy_requested| bits
 114  * of entropy, the total entropy count is returned. If it fails, it returns
 115  * an entropy count of 0.
 116  */
 117 size_t RAND_POOL_acquire_entropy(RAND_POOL *pool);
 118 #endif