/*
 * Copyright (c) 2000, 2001, 2002 Virtual Unlimited B.V.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

/*!\file dldp.h
 * \brief Discrete Logarithm domain parameters, headers.
 * \author Bob Deblier <bob.deblier@pandora.be>
 * \ingroup DL_m
 */

#ifndef _DLDP_H
#define _DLDP_H

#include "mpbarrett.h"

/*
 * Discrete Logarithm Domain Parameters - Prime
 *
 * Standard definition where p = qr+1; in case where p=2q+1, r=2
 *
 * In IEEE P1363 naming is p = rk+1
 *
 * Hence, IEEE prime r = q and cofactor k = r
 *
 * Make sure q is large enough to foil Pohlig-Hellman attacks
 *  See: "Handbook of Applied Cryptography", Chapter 3.6.4
 *
 * g is either a generator of a subgroup of order q, or a generator of order
 *  n = (p-1)
 */

/*!\brief Discrete Logarithm Domain Parameters over a prime field.
 *
 * For the variables in this structure /f$p=qr+1/f$; if /f$p=2q+1 then r=2/f$.
 *
 * \ingroup DL_m
 */
#ifdef __cplusplus
struct BEECRYPTAPI dldp_p
#else
struct _dldp_p
#endif
{
	/*!\var p
	 * \brief The prime.
	 *
	 */
	mpbarrett p;
	/*!\var q
	 * \brief The cofactor.
	 *
	 * \f$q\f$ is a prime divisor of \f$p-1\f$.
	 */
	mpbarrett q;
	/*!\var r
	 *
	 * \f$p=qr+1\f$
	 */
	mpnumber r;
	/*!\var g
	 * \brief The generator.
	 *
 	 * \f$g\f$ is either a generator of \f$\mathds{Z}^{*}_p\f$, or a generator
	 * of a cyclic subgroup \f$G\f$ of \f$\mathds{Z}^{*}_p\f$ of order \f$q\f$.
	 */
	mpnumber g;
	/*!\var n
	 *
	 * \f$n=p-1=qr\f$
	 */
	mpbarrett n;
#ifdef __cplusplus
	dldp_p();
	dldp_p(const dldp_p&);
	~dldp_p();
#endif
};

#ifndef __cplusplus
typedef struct _dldp_p dldp_p;
#endif

#ifdef __cplusplus
extern "C" {
#endif

/*
 * Functions for setting up and copying
 */

BEECRYPTAPI
int dldp_pInit(dldp_p* dp)
	/*@modifies dp @*/;
BEECRYPTAPI
int dldp_pFree(dldp_p* dp)
	/*@modifies dp @*/;
BEECRYPTAPI
int dldp_pCopy(dldp_p* dst, const dldp_p* src)
	/*@modifies dst @*/;

/*
 * Functions for generating keys
 */

BEECRYPTAPI
int dldp_pPrivate  (const dldp_p* dp, randomGeneratorContext* rgc, mpnumber* wksp)
	/*@modifies wksp @*/;
BEECRYPTAPI
int dldp_pPrivate_s(const dldp_p* dp, randomGeneratorContext* rgc, mpnumber* x, size_t xbits)
	/*@modifies x @*/;
BEECRYPTAPI
int dldp_pPublic   (const dldp_p* dp, const mpnumber* x, mpnumber* y)
	/*@modifies y @*/;
BEECRYPTAPI
int dldp_pPair     (const dldp_p* dp, randomGeneratorContext* rgc, mpnumber* x, mpnumber* y)
	/*@modifies x, y @*/;
BEECRYPTAPI
int dldp_pPair_s   (const dldp_p* dp, randomGeneratorContext* rgc, mpnumber* x, mpnumber* y, size_t xbits)
	/*@modifies x, y @*/;

/*
 * Function for comparing domain parameters
 */

BEECRYPTAPI
int  dldp_pEqual  (const dldp_p* a, const dldp_p* b)
	/*@*/;

/*
 * Functions for generating and validating dldp_pgoq variant domain parameters
 */

BEECRYPTAPI
int dldp_pgoqMake     (dldp_p* dp, randomGeneratorContext* rgc, size_t pbits, size_t qbits, int cofactor)
	/*@modifies dp @*/;
BEECRYPTAPI
int dldp_pgoqMakeSafe (dldp_p* dp, randomGeneratorContext* rgc, size_t bits)
	/*@modifies dp @*/;
BEECRYPTAPI
int dldp_pgoqGenerator(dldp_p* dp, randomGeneratorContext* rgc)
	/*@modifies dp @*/;
BEECRYPTAPI
int  dldp_pgoqValidate (const dldp_p* dp, randomGeneratorContext* rgc, int cofactor)
	/*@*/;

/*
 * Functions for generating and validating dldp_pgon variant domain parameters
 */

BEECRYPTAPI
int dldp_pgonMake     (dldp_p* dp, randomGeneratorContext* rgc, size_t pbits, size_t qbits)
	/*@modifies dp @*/;
BEECRYPTAPI
int dldp_pgonMakeSafe (dldp_p* dp, randomGeneratorContext* rgc, size_t pbits)
	/*@modifies dp @*/;
BEECRYPTAPI
int dldp_pgonGenerator(dldp_p* dp, randomGeneratorContext* rgc)
	/*@modifies dp @*/;
BEECRYPTAPI
int dldp_pgonValidate (const dldp_p* dp, randomGeneratorContext* rgc)
	/*@*/;

#ifdef __cplusplus
}
#endif

#endif