/*

 * 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>

# include <openssl/obj_mac.h>

/*

 * RAND_DRBG  flags

 *

 * Note: if new flags are added, the constant `rand_drbg_used_flags`

 *       in drbg_lib.c needs to be updated accordingly.

 */

/* In CTR mode, disable derivation function ctr_df */

# define RAND_DRBG_FLAG_CTR_NO_DF            0x1

# if OPENSSL_API_COMPAT < 0x10200000L

/* This #define was replaced by an internal constant and should not be used. */

#  define RAND_DRBG_USED_FLAGS  (RAND_DRBG_FLAG_CTR_NO_DF)

# endif

/*

 * 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 implementation

 * 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

 */

# define RAND_DRBG_STRENGTH             256

/* Default drbg type */

# define RAND_DRBG_TYPE                 NID_aes_256_ctr

/* Default drbg flags */

# define RAND_DRBG_FLAGS                0

# 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_set_defaults(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 prediction_resistance);

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 *drbg, int idx, void *arg);

void *RAND_DRBG_get_ex_data(const RAND_DRBG *drbg, int idx);

/*

 * Callback function typedefs

 */

typedef size_t (*RAND_DRBG_get_entropy_fn)(RAND_DRBG *drbg,

                                           unsigned char **pout,

                                           int entropy, size_t min_len,

                                           size_t max_len,

                                           int prediction_resistance);

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 *drbg, unsigned char **pout,

                                         int entropy, size_t min_len,

                                         size_t max_len);

typedef void (*RAND_DRBG_cleanup_nonce_fn)(RAND_DRBG *drbg,

                                           unsigned char *out, size_t outlen);

int RAND_DRBG_set_callbacks(RAND_DRBG *drbg,

                            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