/*
 * Copyright (c) 2018, Henry Corrigan-Gibbs
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

#ifndef __PRG_H__
#define __PRG_H__

#include <blapit.h>
#include <mpi.h>
#include <stdlib.h>

#include "config.h"

typedef struct prg* PRG;
typedef const struct prg* const_PRG;

/*
 * Initialize or destroy a pseudo-random generator.
 */
PRG
PRG_new(const_PrioConfig cfg, const PrioPRGSeed shared_secret);
void
PRG_clear(PRG prg);

/*
 * Produce the next bytes of output from the PRG.
 */
SECStatus
PRG_get_bytes(PRG prg, unsigned char* bytes, size_t len);

/*
 * Use the PRG output to sample a big integer x in the range
 *    0 <= x < max.
 */
SECStatus
PRG_get_int(PRG prg, mp_int* out, const mp_int* max);

/*
 * Use the PRG output to sample a big integer x in the range
 *    lower <= x < max.
 */
SECStatus
PRG_get_int_range(PRG prg, mp_int* out, const mp_int* lower, const mp_int* max);

/*
 * Use secret sharing to split the int src into two shares.
 * Use PRG to generate the value `shareB`.
 * The mp_ints must be initialized.
 */
SECStatus
PRG_share_int(PRG prg, mp_int* shareA, const mp_int* src, const_PrioConfig cfg);

/*
 * Set each item in the array to a pseudorandom value in the range
 * [0, mod), where the values are generated using the PRG.
 */
SECStatus
PRG_get_array(PRG prg, MPArray arr, const mp_int* mod);

/*
 * Secret shares the array in `src` into `arrA` using randomness
 * provided by `prgB`. The arrays `src` and `arrA` must be the same
 * length.
 */
SECStatus
PRG_share_array(PRG prgB,
                MPArray arrA,
                const_MPArray src,
                const_PrioConfig cfg);

#endif /* __PRG_H__ */