/*
 * Copyright 2017 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

/* In CTR mode, use derivation function ctr_df */
#define RAND_DRBG_FLAG_CTR_USE_DF            0x2

/*
 * Object lifetime functions.
 */
RAND_DRBG *RAND_DRBG_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_set_reseed_interval(RAND_DRBG *drbg, int interval);
RAND_DRBG *RAND_DRBG_get0_global(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 functions.  See comments in drbg_lib.c
 */
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);
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);

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);

#endif