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Commit 12f008b6 authored by David Howells's avatar David Howells Committed by Rusty Russell
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MPILIB: Reinstate mpi_cmp[_ui]() and export for RSA signature verification 



Reinstate and export mpi_cmp() and mpi_cmp_ui() from the MPI library for use by
RSA signature verification as per RFC3447 section 5.2.2 step 1.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 4ae71c1d

lib/mpi/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ mpi-y = \ 
	generic_mpih-add1.o		\

	mpicoder.o			\

	mpi-bit.o			\

	mpi-cmp.o			\

	mpih-cmp.o			\

	mpih-div.o			\

	mpih-mul.o			\

lib/mpi/mpi-cmp.c

0 → 100644
+70 −0
Original line number Diff line number Diff line 
/* mpi-cmp.c  -  MPI functions

 * Copyright (C) 1998, 1999 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"



int mpi_cmp_ui(MPI u, unsigned long v)

{

	mpi_limb_t limb = v;



	mpi_normalize(u);

	if (!u->nlimbs && !limb)

		return 0;

	if (u->sign)

		return -1;

	if (u->nlimbs > 1)

		return 1;



	if (u->d[0] == limb)

		return 0;

	else if (u->d[0] > limb)

		return 1;

	else

		return -1;

}

EXPORT_SYMBOL_GPL(mpi_cmp_ui);



int mpi_cmp(MPI u, MPI v)

{

	mpi_size_t usize, vsize;

	int cmp;



	mpi_normalize(u);

	mpi_normalize(v);

	usize = u->nlimbs;

	vsize = v->nlimbs;

	if (!u->sign && v->sign)

		return 1;

	if (u->sign && !v->sign)

		return -1;

	if (usize != vsize && !u->sign && !v->sign)

		return usize - vsize;

	if (usize != vsize && u->sign && v->sign)

		return vsize + usize;

	if (!usize)

		return 0;

	cmp = mpihelp_cmp(u->d, v->d, usize);

	if (!cmp)

		return 0;

	if ((cmp < 0 ? 1 : 0) == (u->sign ? 1 : 0))

		return 1;

	return -1;

}

EXPORT_SYMBOL_GPL(mpi_cmp);