include/internal/rand.h

   1 /*
   2  * Copyright 2017 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, use derivation function ctr_df */
  14 #define RAND_DRBG_FLAG_CTR_USE_DF            0x2
  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 int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags);
  32 int RAND_DRBG_instantiate(RAND_DRBG *drbg,
  33                           const unsigned char *pers, size_t perslen);
  34 int RAND_DRBG_uninstantiate(RAND_DRBG *drbg);
  35 void RAND_DRBG_free(RAND_DRBG *drbg);
  36
  37 /*
  38  * Object "use" functions.
  39  */
  40 int RAND_DRBG_reseed(RAND_DRBG *drbg,
  41                      const unsigned char *adin, size_t adinlen);
  42 int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
  43                        int prediction_resistance,
  44                        const unsigned char *adin, size_t adinlen);
  45 int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval);
  46
  47 RAND_DRBG *RAND_DRBG_get0_master(void);
  48 RAND_DRBG *RAND_DRBG_get0_public(void);
  49 RAND_DRBG *RAND_DRBG_get0_private(void);
  50
  51 /*
  52  * EXDATA
  53  */
  54 #define RAND_DRBG_get_ex_new_index(l, p, newf, dupf, freef) \
  55     CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DRBG, l, p, newf, dupf, freef)
  56 int RAND_DRBG_set_ex_data(RAND_DRBG *dctx, int idx, void *arg);
  57 void *RAND_DRBG_get_ex_data(const RAND_DRBG *dctx, int idx);
  58
  59 /*
  60  * Callback functions.  See comments in drbg_lib.c
  61  */
  62 typedef size_t (*RAND_DRBG_get_entropy_fn)(RAND_DRBG *ctx,
  63                                            unsigned char **pout,
  64                                            int entropy, size_t min_len,
  65                                            size_t max_len);
  66 typedef void (*RAND_DRBG_cleanup_entropy_fn)(RAND_DRBG *ctx,
  67                                              unsigned char *out, size_t outlen);
  68 typedef size_t (*RAND_DRBG_get_nonce_fn)(RAND_DRBG *ctx, unsigned char **pout,
  69                                          int entropy, size_t min_len,
  70                                          size_t max_len);
  71 typedef void (*RAND_DRBG_cleanup_nonce_fn)(RAND_DRBG *ctx,
  72                                            unsigned char *out, size_t outlen);
  73
  74 int RAND_DRBG_set_callbacks(RAND_DRBG *dctx,
  75                             RAND_DRBG_get_entropy_fn get_entropy,
  76                             RAND_DRBG_cleanup_entropy_fn cleanup_entropy,
  77                             RAND_DRBG_get_nonce_fn get_nonce,
  78                             RAND_DRBG_cleanup_nonce_fn cleanup_nonce);
  79
  80 /*
  81  * RAND_POOL functions
  82  */
  83 RAND_POOL *RAND_POOL_new(int entropy_requested, size_t min_len, size_t max_len);
  84 void RAND_POOL_free(RAND_POOL *pool);
  85
  86 const unsigned char *RAND_POOL_buffer(RAND_POOL *pool);
  87 unsigned char *RAND_POOL_detach(RAND_POOL *pool);
  88
  89 size_t RAND_POOL_entropy(RAND_POOL *pool);
  90 size_t RAND_POOL_length(RAND_POOL *pool);
  91
  92 size_t RAND_POOL_entropy_available(RAND_POOL *pool);
  93 size_t RAND_POOL_entropy_needed(RAND_POOL *pool);
  94 size_t RAND_POOL_bytes_needed(RAND_POOL *pool, unsigned int entropy_per_byte);
  95 size_t RAND_POOL_bytes_remaining(RAND_POOL *pool);
  96
  97 size_t RAND_POOL_add(RAND_POOL *pool,
  98                      const unsigned char *buffer, size_t len, size_t entropy);
  99 unsigned char *RAND_POOL_add_begin(RAND_POOL *pool, size_t len);
 100 size_t RAND_POOL_add_end(RAND_POOL *pool, size_t len, size_t entropy);
 101
 102
 103 /*
 104  * Add random bytes to the pool to acquire requested amount of entropy
 105  *
 106  * This function is platform specific and tries to acquire the requested
 107  * amount of entropy by polling platform specific entropy sources.
 108  *
 109  * If the function succeeds in acquiring at least |entropy_requested| bits
 110  * of entropy, the total entropy count is returned. If it fails, it returns
 111  * an entropy count of 0.
 112  */
 113 size_t RAND_POOL_acquire_entropy(RAND_POOL *pool);
 114 #endif