research-lab/source-code/RingCT/rctOps.h

#define DBG
// Copyright (c) 2016, Monero Research Labs
//
// Author: Shen Noether <shen.noether@gmx.com>
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//    of conditions and the following disclaimer in the documentation and/or other
//    materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
//    used to endorse or promote products derived from this software without specific
//    prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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#pragma once

#ifndef RCTOPS_H
#define	RCTOPS_H

#include <cstddef>
#include <mutex>
#include <vector>
#include <tuple>

#include "generic-ops.h"

#include "crypto-ops.h"
#include "random.h"
#include "keccak.h"
#include "crypto.h"

#include "rctTypes.h"


using namespace std;
using namespace crypto;

namespace rct {

	//Various key initialization functions

	//Creates a zero scalar
	key zero();
	void zero(key &z);
	//Creates a zero elliptic curve point
	key identity();
	void identity(key &Id);
	//copies a scalar or point
	void copy(key &AA, const key &A);
	key copy(const key & AA);
    //initializes a key matrix;
    //first parameter is rows, 
    //second is columns
    keyM keyMInit(int, int);

	//Various key generation functions        

	//generates a random scalar which can be used as a secret key or mask
	key skGen();
	void skGen(key &);
    
    //generates a vector of secret keys of size "int"
    keyV skvGen(int );
    
	//generates a random curve point (for testing)
	key pkGen();
	//generates a random secret and corresponding public key
	void skpkGen(key &sk, key &pk);
	tuple<key, key> skpkGen();
	//generates a <secret , public> / Pedersen commitment to the amount
	tuple<ctkey, ctkey> ctskpkGen(xmr_amount amount);
    //this one is mainly for testing, can take arbitrary amounts..
    tuple<ctkey, ctkey> ctskpkGen(key bH);
	//generates a random uint long long
	xmr_amount randXmrAmount(xmr_amount upperlimit);

	//Scalar multiplications of curve points        

	//does a * G where a is a scalar and G is the curve basepoint
	void scalarmultBase(key & aG, const key &a);
	key scalarmultBase(const key & a);
	//does a * P where a is a scalar and P is an arbitrary point
	void scalarmultKey(key &aP, const key &P, const key &a);
	key scalarmultKey(const key &P, const key &a);
    //Computes aH where H= toPoint(cn_fast_hash(G)), G the basepoint
	key scalarmultH(const key & a);

	//Curve addition / subtractions

	//for curve points: AB = A + B
	void addKeys(key &AB, const key &A, const key &B);
	//aGB = aG + B where a is a scalar, G is the basepoint, and B is a point
	void addKeys1(key &aGB, const key &a, const key & B);
	//aGbB = aG + bB where a, b are scalars, G is the basepoint and B is a point
	void addKeys2(key &aGbB, const key &a, const key &b, const key &B);
	//Does some precomputation to make addKeys3 more efficient
	// input B a curve point and output a ge_dsmp which has precomputation applied
	void precomp(ge_dsmp rv, const key &B);
	//aAbB = a*A + b*B where a, b are scalars, A, B are curve points
	//B must be input after applying "precomp"
	void addKeys3(key &aAbB, const key &a, const key &A, const key &b, const ge_dsmp B);
	//AB = A - B where A, B are curve points
	void subKeys(key &AB, const key &A, const  key &B);
	//checks if A, B are equal as curve points
	bool equalKeys(key & A, key & B);

	//Hashing - cn_fast_hash
	//be careful these are also in crypto namespace
	//cn_fast_hash for arbitrary multiples of 32 bytes 
	void cn_fast_hash(key &hash, const void * data, const size_t l);
	//cn_fast_hash for a 32 byte key
	void cn_fast_hash(key &hash, const key &in);
	//cn_fast_hash for a 32 byte key
	key cn_fast_hash(const key &in);
    //for mg sigs
    key cn_fast_hash96(const void * in);

	//returns cn_fast_hash(input) * G where G is the basepoint
	key hashToPoint(const key &in);
	void hashToPoint(key &out, const key &in);

	//sums a vector of curve points (for scalars use sc_add)
	void sumKeys(key & Csum, const key &Cis);

	//Elliptic Curve Diffie Helman: encodes and decodes the amount b and mask a
	// where C= aG + bH
	void ecdhEncode(ecdhTuple & unmasked, const key & receiverPk);
	void ecdhDecode(ecdhTuple & masked, const key & receiverSk);
}
#endif	/* RCTOPS_H */