libbrandt/internals.h

/* This file is part of libbrandt.
 * Copyright (C) 2016 GNUnet e.V.
 *
 * libbrandt is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 *
 * libbrandt is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * libbrandt.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * @file internals.h
 * @brief This header contains library internal structs.
 * @author Markus Teich
 */

#ifndef _BRANDT_INTERNALS_H
#define _BRANDT_INTERNALS_H

#include <gcrypt.h>

#include "brandt.h"


enum rounds {
	msg_init,
	msg_bid,
	msg_outcome,
	msg_decrypt,
	msg_last
};


/**
 * This struct describes an auction and has to be followed by #description_len
 * bytes of arbitrary data where the description of the item to be sold is
 * stored. */
struct AuctionDescr {
	/** The length of the description in bytes directly following this struct */
	uint32_t description_len;

	/** Auction type. 0 means first price Auction, >= 0 means M+1st price
	 * auction with an amount of m items being sold. */
	uint16_t m;

	/** Outcome type. 0 means private outcome, everything else means public
	 * outcome. */
	uint16_t outcome_public;

	/** The amount of possible prices */
	uint16_t price_range;
};


struct BRANDT_Auction {
	struct AuctionDescr *desc;  /** pointer to the auction information */

	BRANDT_CbBroadcast bcast;   /** broadcast callback */
	BRANDT_CbUnicast   ucast;   /** unicast callback */
	BRANDT_CbResult    result;  /** result reporting callback */

	int         seller_mode;    /** If 0 we are bidding, selling otherwise */
	enum rounds cur_round;      /** The round we expect messages from */
	gcry_mpi_t  round_progress; /** Stores which round messages were received */

	uint16_t n;                 /** The amount of bidders/agents */
	uint16_t k;                 /** The amount of possible prices */
	uint16_t i;                 /** Own agents index, only used when bidding */
	uint16_t b;                 /** Own bid */

	gcry_mpi_t       x;         /** Own private additive key share */
	gcry_mpi_point_t *y;        /** public multiplicative key shares, size: n */
	gcry_mpi_point_t Y;         /** Shared public key */

	gcry_mpi_point_t **alpha;   /** alphas, size: n*k */
	gcry_mpi_point_t **beta;    /** betas, size: n*k */

	gcry_mpi_point_t **gamma2;  /** gamma2, for public outcome, size: n*k */
	gcry_mpi_point_t ***gamma3; /** gamma3, for private outcome, size: n*n*k */
	gcry_mpi_point_t **delta2;  /** delta2, for public outcome, size: n*k */
	gcry_mpi_point_t ***delta3; /** delta3, for private outcome, size: n*n*k */
	gcry_mpi_point_t **phi2;    /** phi2, for public outcome, size: n*k */
	gcry_mpi_point_t ***phi3;   /** phi3, for private outcome, size: n*n*k */

	gcry_mpi_point_t *tmpa1;    /** used for temporary storage, size: k */
	gcry_mpi_point_t *tmpb1;    /** used for temporary storage, size: k */
};

#endif /* ifndef _BRANDT_INTERNALS_H */