/**
 * Copyright (c) 2013-2014 Tomas Dzetkulic
 * Copyright (c) 2013-2014 Pavol Rusnak
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef __ECDSA_H__
#define __ECDSA_H__

#include <stdint.h>
#include "bignum.h"
#include "hasher.h"
#include "options.h"

// curve point x and y
typedef struct {
    bignum256 x, y;
} curve_point;

typedef struct {
    bignum256 prime; // prime order of the finite field
    curve_point G; // initial curve point
    bignum256 order; // order of G
    bignum256 order_half; // order of G divided by 2
    int a; // coefficient 'a' of the elliptic curve
    bignum256 b; // coefficient 'b' of the elliptic curve

#if USE_PRECOMPUTED_CP
    const curve_point cp[64][8];
#endif

} ecdsa_curve;

// 4 byte prefix + 40 byte data (segwit)
// 1 byte prefix + 64 byte data (cashaddr)
#define MAX_ADDR_RAW_SIZE 65
// bottle neck is cashaddr
// segwit is at most 90 characters plus NUL separator
// cashaddr: human readable prefix + 1 separator + 104 data + 8 checksum + 1 NUL
// we choose 130 as maximum (including NUL character)
#define MAX_ADDR_SIZE 130
// 4 byte prefix + 32 byte privkey + 1 byte compressed marker
#define MAX_WIF_RAW_SIZE (4 + 32 + 1)
// (4 + 32 + 1 + 4 [checksum]) * 8 / log2(58) plus NUL.
#define MAX_WIF_SIZE (57)

void point_copy(const curve_point* cp1, curve_point* cp2);
void point_add(const ecdsa_curve* curve, const curve_point* cp1, curve_point* cp2);
void point_double(const ecdsa_curve* curve, curve_point* cp);
int point_multiply(
    const ecdsa_curve* curve,
    const bignum256* k,
    const curve_point* p,
    curve_point* res);
void point_set_infinity(curve_point* p);
int point_is_infinity(const curve_point* p);
int point_is_equal(const curve_point* p, const curve_point* q);
int point_is_negative_of(const curve_point* p, const curve_point* q);
int scalar_multiply(const ecdsa_curve* curve, const bignum256* k, curve_point* res);
int ecdh_multiply(
    const ecdsa_curve* curve,
    const uint8_t* priv_key,
    const uint8_t* pub_key,
    uint8_t* session_key);
void compress_coords(const curve_point* cp, uint8_t* compressed);
void uncompress_coords(const ecdsa_curve* curve, uint8_t odd, const bignum256* x, bignum256* y);
int ecdsa_uncompress_pubkey(
    const ecdsa_curve* curve,
    const uint8_t* pub_key,
    uint8_t* uncompressed);

int ecdsa_sign(
    const ecdsa_curve* curve,
    HasherType hasher_sign,
    const uint8_t* priv_key,
    const uint8_t* msg,
    uint32_t msg_len,
    uint8_t* sig,
    uint8_t* pby,
    int (*is_canonical)(uint8_t by, uint8_t sig[64]));
int ecdsa_sign_digest(
    const ecdsa_curve* curve,
    const uint8_t* priv_key,
    const uint8_t* digest,
    uint8_t* sig,
    uint8_t* pby,
    int (*is_canonical)(uint8_t by, uint8_t sig[64]));
int ecdsa_get_public_key33(const ecdsa_curve* curve, const uint8_t* priv_key, uint8_t* pub_key);
int ecdsa_get_public_key65(const ecdsa_curve* curve, const uint8_t* priv_key, uint8_t* pub_key);
void ecdsa_get_pubkeyhash(const uint8_t* pub_key, HasherType hasher_pubkey, uint8_t* pubkeyhash);
void ecdsa_get_address_raw(
    const uint8_t* pub_key,
    uint32_t version,
    HasherType hasher_pubkey,
    uint8_t* addr_raw);
void ecdsa_get_address(
    const uint8_t* pub_key,
    uint32_t version,
    HasherType hasher_pubkey,
    HasherType hasher_base58,
    char* addr,
    int addrsize);
void ecdsa_get_address_segwit_p2sh_raw(
    const uint8_t* pub_key,
    uint32_t version,
    HasherType hasher_pubkey,
    uint8_t* addr_raw);
void ecdsa_get_address_segwit_p2sh(
    const uint8_t* pub_key,
    uint32_t version,
    HasherType hasher_pubkey,
    HasherType hasher_base58,
    char* addr,
    int addrsize);
void ecdsa_get_wif(
    const uint8_t* priv_key,
    uint32_t version,
    HasherType hasher_base58,
    char* wif,
    int wifsize);

int ecdsa_address_decode(
    const char* addr,
    uint32_t version,
    HasherType hasher_base58,
    uint8_t* out);
int ecdsa_read_pubkey(const ecdsa_curve* curve, const uint8_t* pub_key, curve_point* pub);
int ecdsa_validate_pubkey(const ecdsa_curve* curve, const curve_point* pub);
int ecdsa_verify(
    const ecdsa_curve* curve,
    HasherType hasher_sign,
    const uint8_t* pub_key,
    const uint8_t* sig,
    const uint8_t* msg,
    uint32_t msg_len);
int ecdsa_verify_digest(
    const ecdsa_curve* curve,
    const uint8_t* pub_key,
    const uint8_t* sig,
    const uint8_t* digest);
int ecdsa_recover_pub_from_sig(
    const ecdsa_curve* curve,
    uint8_t* pub_key,
    const uint8_t* sig,
    const uint8_t* digest,
    int recid);
int ecdsa_sig_to_der(const uint8_t* sig, uint8_t* der);
int ecdsa_sig_from_der(const uint8_t* der, size_t der_len, uint8_t sig[64]);

#endif
