From 6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:29:51 +0200 Subject: Adding upstream version 2.06. Signed-off-by: Daniel Baumann --- grub-core/lib/libgcrypt/mpi/mpi-gcd.c | 51 +++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 grub-core/lib/libgcrypt/mpi/mpi-gcd.c (limited to 'grub-core/lib/libgcrypt/mpi/mpi-gcd.c') diff --git a/grub-core/lib/libgcrypt/mpi/mpi-gcd.c b/grub-core/lib/libgcrypt/mpi/mpi-gcd.c new file mode 100644 index 0000000..5cbefa1 --- /dev/null +++ b/grub-core/lib/libgcrypt/mpi/mpi-gcd.c @@ -0,0 +1,51 @@ +/* mpi-gcd.c - MPI functions + * Copyright (C) 1998, 2001, 2002, 2003 Free Software Foundation, Inc. + * + * This file is part of Libgcrypt. + * + * Libgcrypt 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. + * + * Libgcrypt 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 program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#include +#include +#include +#include "mpi-internal.h" + +/**************** + * Find the greatest common divisor G of A and B. + * Return: true if this 1, false in all other cases + */ +int +gcry_mpi_gcd( gcry_mpi_t g, gcry_mpi_t xa, gcry_mpi_t xb ) +{ + gcry_mpi_t a, b; + + a = mpi_copy(xa); + b = mpi_copy(xb); + + /* TAOCP Vol II, 4.5.2, Algorithm A */ + a->sign = 0; + b->sign = 0; + while( gcry_mpi_cmp_ui( b, 0 ) ) { + _gcry_mpi_fdiv_r( g, a, b ); /* g used as temorary variable */ + mpi_set(a,b); + mpi_set(b,g); + } + mpi_set(g, a); + + mpi_free(a); + mpi_free(b); + return !gcry_mpi_cmp_ui( g, 1); +} -- cgit v1.2.3