text: /*
   * Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the OpenSSL license (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  #ifndef HEADER_DRBG_RAND_H
  # define HEADER_DRBG_RAND_H
  
  # include <time.h>
  # include <openssl/ossl_typ.h>
  
  
  /* In CTR mode, disable derivation function ctr_df */
  # define RAND_DRBG_FLAG_CTR_NO_DF            0x1
  
  /*
   * Default security strength (in the sense of [NIST SP 800-90Ar1])
   *
   * NIST SP 800-90Ar1 supports the strength of the DRBG being smaller than that
   * of the cipher by collecting less entropy. The current DRBG implemantion does
   * not take RAND_DRBG_STRENGTH into account and sets the strength of the DRBG
   * to that of the cipher.
   *
   * RAND_DRBG_STRENGTH is currently only used for the legacy RAND
   * implementation.
   *
   * Currently supported ciphers are: NID_aes_128_ctr, NID_aes_192_ctr and
   * NID_aes_256_ctr
   *
   * TODO(DRBG): would be nice to have the NID and strength configurable
   */
  # define RAND_DRBG_STRENGTH             256
  # define RAND_DRBG_NID                  NID_aes_256_ctr
  
  
  # ifdef  __cplusplus
  extern "C" {
  # endif
  
  /*
   * Object lifetime functions.
   */
  RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent);
  RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent);
  int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags);
  int RAND_DRBG_instantiate(RAND_DRBG *drbg,
                            const unsigned char *pers, size_t perslen);
  int RAND_DRBG_uninstantiate(RAND_DRBG *drbg);
  void RAND_DRBG_free(RAND_DRBG *drbg);
  
  /*
   * Object "use" functions.
   */
  int RAND_DRBG_reseed(RAND_DRBG *drbg,
                       const unsigned char *adin, size_t adinlen);
  int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
                         int prediction_resistance,
                         const unsigned char *adin, size_t adinlen);
  int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen);
  
  int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval);
  int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval);
  
  int RAND_DRBG_set_reseed_defaults(
                                    unsigned int master_reseed_interval,
                                    unsigned int slave_reseed_interval,
                                    time_t master_reseed_time_interval,
                                    time_t slave_reseed_time_interval
                                    );
  
  RAND_DRBG *RAND_DRBG_get0_master(void);
  RAND_DRBG *RAND_DRBG_get0_public(void);
  RAND_DRBG *RAND_DRBG_get0_private(void);
  
  /*
   * EXDATA
   */
  # define RAND_DRBG_get_ex_new_index(l, p, newf, dupf, freef) \
      CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DRBG, l, p, newf, dupf, freef)
  int RAND_DRBG_set_ex_data(RAND_DRBG *dctx, int idx, void *arg);
  void *RAND_DRBG_get_ex_data(const RAND_DRBG *dctx, int idx);
  
  /*
   * Callback function typedefs
   */
  typedef size_t (*RAND_DRBG_get_entropy_fn)(RAND_DRBG *ctx,
                                             unsigned char **pout,
                                             int entropy, size_t min_len,
                                             size_t max_len);
  typedef void (*RAND_DRBG_cleanup_entropy_fn)(RAND_DRBG *ctx,
                                               unsigned char *out, size_t outlen);
  typedef size_t (*RAND_DRBG_get_nonce_fn)(RAND_DRBG *ctx, unsigned char **pout,
                                           int entropy, size_t min_len,
                                           size_t max_len);
  typedef void (*RAND_DRBG_cleanup_nonce_fn)(RAND_DRBG *ctx,
                                             unsigned char *out, size_t outlen);
  
  int RAND_DRBG_set_callbacks(RAND_DRBG *dctx,
                              RAND_DRBG_get_entropy_fn get_entropy,
                              RAND_DRBG_cleanup_entropy_fn cleanup_entropy,
                              RAND_DRBG_get_nonce_fn get_nonce,
                              RAND_DRBG_cleanup_nonce_fn cleanup_nonce);
  
  
  # ifdef  __cplusplus
  }
  # endif
  
  #endif
  