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/* 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 crypto.h
* @brief Interface of the crypto primitives.
* @author Markus Teich
*/
#ifndef _BRANDT_CRYPTO_H
#define _BRANDT_CRYPTO_H
#include <gcrypt.h>
#include <stdint.h>
#include <gnunet/gnunet_util_lib.h>
#include "internals.h"
void brandt_crypto_init (struct GNUNET_CRYPTO_EccDlogContext *dlogctx);
/* --- EC --- */
/* used for serialized mpis and serialized curve points (they are the same size
* when compressed) */
struct ec_mpi {
unsigned char data[256 / 8];
};
gcry_mpi_point_t *smc_init1 (uint16_t size1);
gcry_mpi_point_t **smc_init2 (uint16_t size1, uint16_t size2);
gcry_mpi_point_t ***smc_init3 (uint16_t size1, uint16_t size2, uint16_t size3);
void smc_free1 (gcry_mpi_point_t *dst, uint16_t size1);
void smc_free2 (gcry_mpi_point_t **dst, uint16_t size1, uint16_t size2);
void smc_free3 (gcry_mpi_point_t ***dst,
uint16_t size1,
uint16_t size2,
uint16_t size3);
void ec_point_copy (gcry_mpi_point_t dst, const gcry_mpi_point_t src);
int ec_point_cmp (const gcry_mpi_point_t a, const gcry_mpi_point_t b);
void ec_skey_create (gcry_mpi_t skey);
void ec_keypair_create (gcry_mpi_point_t pkey, gcry_mpi_t skey);
void ec_keypair_create_base (gcry_mpi_point_t pkey,
gcry_mpi_t skey,
const gcry_mpi_point_t base);
/* --- Zero knowledge proofs --- */
struct proof_dl {
struct ec_mpi r;
struct ec_mpi a;
};
struct proof_2dle {
struct ec_mpi r;
struct ec_mpi a;
struct ec_mpi b;
};
struct proof_0og {
struct ec_mpi a1;
struct ec_mpi a2;
struct ec_mpi b1;
struct ec_mpi b2;
struct ec_mpi d1;
struct ec_mpi d2;
struct ec_mpi r1;
struct ec_mpi r2;
};
void smc_zkp_dl (gcry_mpi_point_t v,
const gcry_mpi_t x,
struct proof_dl *proof);
int smc_zkp_dl_check (const gcry_mpi_point_t v,
const struct proof_dl *proof);
void smc_zkp_2dle (const gcry_mpi_point_t v,
const gcry_mpi_point_t w,
const gcry_mpi_point_t g1,
const gcry_mpi_point_t g2,
const gcry_mpi_t x,
struct proof_2dle *proof);
int smc_zkp_2dle_check (const gcry_mpi_point_t v,
const gcry_mpi_point_t w,
const gcry_mpi_point_t g1,
const gcry_mpi_point_t g2,
const struct proof_2dle *proof);
void smc_zkp_0og (int m_is_gen,
const gcry_mpi_point_t y,
gcry_mpi_t r,
gcry_mpi_point_t alpha,
gcry_mpi_point_t beta,
struct proof_0og *proof);
int smc_zkp_0og_check (const gcry_mpi_point_t y,
const gcry_mpi_point_t alpha,
const gcry_mpi_point_t beta,
const struct proof_0og *proof);
/* --- Protocol implementation --- */
unsigned char *smc_gen_keyshare (struct BRANDT_Auction *ad, size_t *buflen);
int smc_recv_keyshare (struct BRANDT_Auction *ad,
const unsigned char *buf,
size_t buflen,
uint16_t sender_index);
unsigned char *smc_encrypt_bid (struct BRANDT_Auction *ad, size_t *buflen);
int smc_recv_encrypted_bid (struct BRANDT_Auction *ad,
const unsigned char *buf,
size_t buflen,
uint16_t sender_index);
unsigned char *fp_priv_compute_outcome (struct BRANDT_Auction *ad,
size_t *buflen);
int fp_priv_recv_outcome (struct BRANDT_Auction *ad,
const unsigned char *buf,
size_t buflen,
uint16_t sender);
unsigned char *fp_priv_decrypt_outcome (struct BRANDT_Auction *ad,
size_t *buflen);
int fp_priv_recv_decryption (struct BRANDT_Auction *ad,
const unsigned char *buf,
size_t buflen,
uint16_t sender);
unsigned char *fp_pub_compute_outcome (struct BRANDT_Auction *ad,
size_t *buflen);
int fp_pub_recv_outcome (struct BRANDT_Auction *ad,
const unsigned char *buf,
size_t buflen,
uint16_t sender);
unsigned char *fp_pub_decrypt_outcome (struct BRANDT_Auction *ad,
size_t *buflen);
int fp_pub_recv_decryption (struct BRANDT_Auction *ad,
const unsigned char *buf,
size_t buflen,
uint16_t sender);
int32_t fp_priv_determine_outcome (struct BRANDT_Auction *ad);
/* --- Round dictionaries --- */
typedef int
(*msg_in)(struct BRANDT_Auction *ad,
const unsigned char *buf,
size_t buflen,
uint16_t sender);
typedef unsigned char *
(*msg_out)(struct BRANDT_Auction *ad,
size_t *buflen);
/**
* stores the function pointers to receive functions for each state.
*
* The first index denotes if a first price auction or a M+1st price auction is
* used. If it is 0, it is a first price auction, if it is 1, it is a M+1st
* price auction.
*
* The second index denotes if the outcome should be public or private. A value
* of 0 means a private outcome, while a value of 1 means public outcome.
*/
static const msg_in handler_in[auction_last][outcome_last][msg_last] = {
[auction_firstPrice] = {
[outcome_private] = {
[msg_init] = &smc_recv_keyshare,
[msg_bid] = &smc_recv_encrypted_bid,
[msg_outcome] = &fp_priv_recv_outcome,
[msg_decrypt] = &fp_priv_recv_decryption,
},
[outcome_public] = {
[msg_init] = &smc_recv_keyshare,
[msg_bid] = &smc_recv_encrypted_bid,
[msg_outcome] = &fp_pub_recv_outcome,
[msg_decrypt] = &fp_pub_recv_decryption,
},
},
[auction_mPlusFirstPrice] = {
[outcome_private] = {
[msg_init] = &smc_recv_keyshare,
[msg_bid] = &smc_recv_encrypted_bid,
},
[outcome_public] = {
[msg_init] = &smc_recv_keyshare,
[msg_bid] = &smc_recv_encrypted_bid,
},
},
};
/**
* stores the function pointers to message buffer creating functions for each
* state.
*
* The first index denotes if a first price auction or a M+1st price auction is
* used. If it is 0, it is a first price auction, if it is 1, it is a M+1st
* price auction.
*
* The second index denotes if the outcome should be public or private. A value
* of 0 means a private outcome, while a value of 1 means public outcome.
*/
static const msg_out handler_out[auction_last][outcome_last][msg_last] = {
[auction_firstPrice] = {
[outcome_private] = {
[msg_init] = &smc_gen_keyshare,
[msg_bid] = &smc_encrypt_bid,
[msg_outcome] = &fp_priv_compute_outcome,
[msg_decrypt] = &fp_priv_decrypt_outcome,
},
[outcome_public] = {
[msg_init] = &smc_gen_keyshare,
[msg_bid] = &smc_encrypt_bid,
[msg_outcome] = &fp_pub_compute_outcome,
[msg_decrypt] = &fp_pub_decrypt_outcome,
},
},
[auction_mPlusFirstPrice] = {
[outcome_private] = {
[msg_init] = &smc_gen_keyshare,
[msg_bid] = &smc_encrypt_bid,
},
[outcome_public] = {
[msg_init] = &smc_gen_keyshare,
[msg_bid] = &smc_encrypt_bid,
},
},
};
#endif /* ifndef _BRANDT_CRYPTO_H */
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