/* mpi-mpow.c - MPI functions * Copyright (C) 1998, 1999, 2000 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 "mpi-internal.h" #include "longlong.h" static int build_index(const MPI *exparray, int k, int i, int t ) { int j, bitno; int index = 0; bitno = t-i; for(j=k-1; j >= 0; j-- ) { index <<= 1; if( mpi_test_bit( exparray[j], bitno ) ) index |= 1; } return index; } /**************** * RES = (BASE[0] ^ EXP[0]) * (BASE[1] ^ EXP[1]) * ... * mod M */ int mpi_mulpowm( MPI res, MPI *basearray, MPI *exparray, MPI m) { int rc = -ENOMEM; int k; /* number of elements */ int t; /* bit size of largest exponent */ int i, j, idx; MPI *G = NULL; /* table with precomputed values of size 2^k */ MPI tmp = NULL; for(k=0; basearray[k]; k++ ) ; if (!k) { printk("mpi_mulpowm: assert(k) failed\n"); BUG(); } for(t=0, i=0; (tmp=exparray[i]); i++ ) { j = mpi_get_nbits(tmp); if( j > t ) t = j; } if (i!=k) { printk("mpi_mulpowm: assert(i==k) failed\n"); BUG(); } if (!t) { printk("mpi_mulpowm: assert(t) failed\n"); BUG(); } if (k>=10) { printk("mpi_mulpowm: assert(k<10) failed\n"); BUG(); } G = kmalloc( (1<= 0 && idx < (1<= 0 && idx < (1<