rpm/beecrypt/dlsvdp-dh.c

64 lines
1.7 KiB
C

/*
* Copyright (c) 1999, 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 dlsvdp-dh.c
* \brief Diffie-Hellman algorithm.
*
* The IEEE P.1363 designation is:
* Discrete Logarithm Secret Value Derivation Primitive, Diffie-Hellman style.
*
* \author Bob Deblier <bob.deblier@pandora.be>
* \ingroup DL_m DL_dh_m
*/
#include "system.h"
#include "dlsvdp-dh.h"
#include "debug.h"
/*!\addtogroup DL_dh_m
* \{
*/
/*!\fn dlsvdp_pDHSecret(const dhparam* dp, const mpnumber* x, const mpnumber* y, mpnumber* s)
* \brief Computes the shared secret.
*
* Equation:
*
* \li \f$s=y^{x}\ \textrm{mod}\ p\f$
*
* \param dp The domain parameters.
* \param x The private value.
* \param y The public value (of the peer).
* \param s The computed secret value.
*
* \retval 0 on success.
* \retval -1 on failure.
*/
int dlsvdp_pDHSecret(const dhparam* dp, const mpnumber* x, const mpnumber* y, mpnumber* s)
{
mpbnpowmod(&dp->p, y, x, s);
return 0;
}
/*!\}
*/