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/* pubkey.c - pubkey dispatcher
* Copyright (C) 1998 Free Software Foundation, Inc.
*
* This file is part of GNUPG.
*
* GNUPG 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 2 of the License, or
* (at your option) any later version.
*
* GNUPG 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include "util.h"
#include "errors.h"
#include "mpi.h"
#include "cipher.h"
#include "dynload.h"
/****************
* This is the interface for the public key decryption.
* ALGO gives the algorithm to use and this implicitly determines
* the size of the arrays.
* result is a pointer to a mpi variable which will receive a
* newly allocated mpi or NULL in case of an error.
*/
int
pubkey_decrypt( int algo, MPI *result, int ndata, MPI *data,
int nskey, MPI *skey )
{
MPI plain = NULL;
*result = NULL; /* so the caller can do always do an mpi_free */
if( DBG_CIPHER ) {
int i;
log_debug("pubkey_decrypt: algo=%d\n", algo );
for(i=0; i < nskey; i++ )
log_mpidump(" skey:", skey[i] );
for(i=0; i < ndata; i++ )
log_mpidump(" data:", data[i] );
}
if( is_ELGAMAL(algo) ) {
ELG_secret_key sk;
assert( ndata == 2 && nskey == 4 );
sk.p = skey[0];
sk.g = skey[1];
sk.y = skey[2];
sk.x = skey[3];
plain = mpi_alloc_secure( mpi_get_nlimbs( sk.p ) );
elg_decrypt( plain, data[0], data[1], &sk );
}
else if( is_RSA(k->pubkey_algo) ) {
RSA_secret_key sk;
assert( ndata == 1 && nskey == 6 );
sk.e = skey[0];
sk.n = skey[1];
sk.p = skey[2];
sk.q = skey[3];
sk.d = skey[4];
sk.u = skey[5];
plain = mpi_alloc_secure( mpi_get_nlimbs(sk.n) );
rsa_secret( plain, data[0], &sk );
}
else
return G10ERR_PUBKEY_ALGO;
*result = plain;
return 0;
}
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