crypto: GnuPG based MPI lib - additional sources (part 4)
Adds the multi-precision-integer maths library which was originally taken from GnuPG and ported to the kernel by (among others) David Howells. This version is taken from Fedora kernel 2.6.32-71.14.1.el6. The difference is that checkpatch reported errors and warnings have been fixed. This library is used to implemenet RSA digital signature verification used in IMA/EVM integrity protection subsystem. Due to patch size limitation, the patch is divided into 4 parts. This code is unnecessary for RSA digital signature verification, but for completeness it is included here and can be compiled, if CONFIG_MPILIB_EXTRA is enabled. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
This commit is contained in:
Dmitry Kasatkin
parent
d9c46b184f
commit
7e8dec918e
10
lib/Kconfig
10
lib/Kconfig
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@ -283,4 +283,14 @@ config MPILIB
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It is used to implement RSA digital signature verification,
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which is used by IMA/EVM digital signature extension.
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config MPILIB_EXTRA
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bool "Multiprecision maths library - additional sources"
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depends on MPILIB
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help
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Multiprecision maths library from GnuPG.
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It is used to implement RSA digital signature verification,
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which is used by IMA/EVM digital signature extension.
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This code in unnecessary for RSA digital signature verification,
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and can be compiled if needed.
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endmenu
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@ -19,3 +19,14 @@ mpi-y = \
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mpih-mul.o \
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mpi-pow.o \
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mpiutil.o
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mpi-$(CONFIG_MPILIB_EXTRA) += \
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mpi-add.o \
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mpi-div.o \
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mpi-cmp.o \
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mpi-gcd.o \
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mpi-inline.o \
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mpi-inv.o \
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mpi-mpow.o \
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mpi-mul.o \
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mpi-scan.o
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@ -0,0 +1,4 @@
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/* This file defines some basic constants for the MPI machinery. We
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* need to define the types on a per-CPU basis, so it is done with
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* this file here. */
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#define BYTES_PER_MPI_LIMB (SIZEOF_UNSIGNED_LONG)
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@ -0,0 +1,234 @@
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/* mpi-add.c - MPI functions
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* Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
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* Copyright (C) 1994, 1996 Free Software Foundation, Inc.
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*
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* This file is part of GnuPG.
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*
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* GnuPG is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* GnuPG is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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*
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* Note: This code is heavily based on the GNU MP Library.
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* Actually it's the same code with only minor changes in the
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* way the data is stored; this is to support the abstraction
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* of an optional secure memory allocation which may be used
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* to avoid revealing of sensitive data due to paging etc.
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* The GNU MP Library itself is published under the LGPL;
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* however I decided to publish this code under the plain GPL.
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*/
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#include "mpi-internal.h"
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/****************
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* Add the unsigned integer V to the mpi-integer U and store the
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* result in W. U and V may be the same.
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*/
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int mpi_add_ui(MPI w, const MPI u, unsigned long v)
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{
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mpi_ptr_t wp, up;
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mpi_size_t usize, wsize;
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int usign, wsign;
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usize = u->nlimbs;
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usign = u->sign;
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wsign = 0;
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/* If not space for W (and possible carry), increase space. */
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wsize = usize + 1;
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if (w->alloced < wsize)
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if (mpi_resize(w, wsize) < 0)
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return -ENOMEM;
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/* These must be after realloc (U may be the same as W). */
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up = u->d;
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wp = w->d;
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if (!usize) { /* simple */
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wp[0] = v;
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wsize = v ? 1 : 0;
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} else if (!usign) { /* mpi is not negative */
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mpi_limb_t cy;
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cy = mpihelp_add_1(wp, up, usize, v);
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wp[usize] = cy;
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wsize = usize + cy;
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} else { /* The signs are different. Need exact comparison to determine
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* which operand to subtract from which. */
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if (usize == 1 && up[0] < v) {
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wp[0] = v - up[0];
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wsize = 1;
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} else {
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mpihelp_sub_1(wp, up, usize, v);
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/* Size can decrease with at most one limb. */
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wsize = usize - (wp[usize - 1] == 0);
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wsign = 1;
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}
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}
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w->nlimbs = wsize;
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w->sign = wsign;
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return 0;
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}
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int mpi_add(MPI w, MPI u, MPI v)
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{
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mpi_ptr_t wp, up, vp;
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mpi_size_t usize, vsize, wsize;
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int usign, vsign, wsign;
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if (u->nlimbs < v->nlimbs) { /* Swap U and V. */
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usize = v->nlimbs;
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usign = v->sign;
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vsize = u->nlimbs;
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vsign = u->sign;
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wsize = usize + 1;
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if (RESIZE_IF_NEEDED(w, wsize) < 0)
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return -ENOMEM;
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/* These must be after realloc (u or v may be the same as w). */
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up = v->d;
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vp = u->d;
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} else {
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usize = u->nlimbs;
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usign = u->sign;
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vsize = v->nlimbs;
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vsign = v->sign;
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wsize = usize + 1;
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if (RESIZE_IF_NEEDED(w, wsize) < 0)
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return -ENOMEM;
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/* These must be after realloc (u or v may be the same as w). */
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up = u->d;
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vp = v->d;
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}
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wp = w->d;
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wsign = 0;
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if (!vsize) { /* simple */
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MPN_COPY(wp, up, usize);
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wsize = usize;
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wsign = usign;
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} else if (usign != vsign) { /* different sign */
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/* This test is right since USIZE >= VSIZE */
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if (usize != vsize) {
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mpihelp_sub(wp, up, usize, vp, vsize);
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wsize = usize;
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MPN_NORMALIZE(wp, wsize);
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wsign = usign;
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} else if (mpihelp_cmp(up, vp, usize) < 0) {
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mpihelp_sub_n(wp, vp, up, usize);
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wsize = usize;
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MPN_NORMALIZE(wp, wsize);
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if (!usign)
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wsign = 1;
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} else {
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mpihelp_sub_n(wp, up, vp, usize);
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wsize = usize;
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MPN_NORMALIZE(wp, wsize);
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if (usign)
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wsign = 1;
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}
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} else { /* U and V have same sign. Add them. */
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mpi_limb_t cy = mpihelp_add(wp, up, usize, vp, vsize);
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wp[usize] = cy;
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wsize = usize + cy;
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if (usign)
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wsign = 1;
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}
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w->nlimbs = wsize;
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w->sign = wsign;
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return 0;
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}
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/****************
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* Subtract the unsigned integer V from the mpi-integer U and store the
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* result in W.
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*/
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int mpi_sub_ui(MPI w, MPI u, unsigned long v)
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{
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mpi_ptr_t wp, up;
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mpi_size_t usize, wsize;
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int usign, wsign;
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usize = u->nlimbs;
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usign = u->sign;
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wsign = 0;
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/* If not space for W (and possible carry), increase space. */
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wsize = usize + 1;
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if (w->alloced < wsize)
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if (mpi_resize(w, wsize) < 0)
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return -ENOMEM;
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/* These must be after realloc (U may be the same as W). */
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up = u->d;
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wp = w->d;
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if (!usize) { /* simple */
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wp[0] = v;
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wsize = v ? 1 : 0;
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wsign = 1;
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} else if (usign) { /* mpi and v are negative */
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mpi_limb_t cy;
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cy = mpihelp_add_1(wp, up, usize, v);
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wp[usize] = cy;
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wsize = usize + cy;
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} else { /* The signs are different. Need exact comparison to determine
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* which operand to subtract from which. */
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if (usize == 1 && up[0] < v) {
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wp[0] = v - up[0];
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wsize = 1;
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wsign = 1;
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} else {
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mpihelp_sub_1(wp, up, usize, v);
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/* Size can decrease with at most one limb. */
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wsize = usize - (wp[usize - 1] == 0);
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}
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}
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w->nlimbs = wsize;
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w->sign = wsign;
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return 0;
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}
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int mpi_sub(MPI w, MPI u, MPI v)
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{
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int rc;
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if (w == v) {
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MPI vv;
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if (mpi_copy(&vv, v) < 0)
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return -ENOMEM;
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vv->sign = !vv->sign;
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rc = mpi_add(w, u, vv);
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mpi_free(vv);
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} else {
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/* fixme: this is not thread-save (we temp. modify v) */
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v->sign = !v->sign;
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rc = mpi_add(w, u, v);
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v->sign = !v->sign;
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}
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return rc;
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}
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int mpi_addm(MPI w, MPI u, MPI v, MPI m)
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{
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if (mpi_add(w, u, v) < 0 || mpi_fdiv_r(w, w, m) < 0)
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return -ENOMEM;
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return 0;
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}
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int mpi_subm(MPI w, MPI u, MPI v, MPI m)
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{
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if (mpi_sub(w, u, v) < 0 || mpi_fdiv_r(w, w, m) < 0)
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return -ENOMEM;
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return 0;
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}
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@ -0,0 +1,68 @@
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/* mpi-cmp.c - MPI functions
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* Copyright (C) 1998, 1999 Free Software Foundation, Inc.
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*
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* This file is part of GnuPG.
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*
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* GnuPG is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* GnuPG is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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*/
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#include "mpi-internal.h"
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int mpi_cmp_ui(MPI u, unsigned long v)
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{
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mpi_limb_t limb = v;
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mpi_normalize(u);
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if (!u->nlimbs && !limb)
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return 0;
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if (u->sign)
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return -1;
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if (u->nlimbs > 1)
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return 1;
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if (u->d[0] == limb)
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return 0;
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else if (u->d[0] > limb)
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return 1;
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else
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return -1;
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}
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int mpi_cmp(MPI u, MPI v)
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{
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mpi_size_t usize, vsize;
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int cmp;
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mpi_normalize(u);
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mpi_normalize(v);
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usize = u->nlimbs;
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vsize = v->nlimbs;
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if (!u->sign && v->sign)
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return 1;
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if (u->sign && !v->sign)
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return -1;
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if (usize != vsize && !u->sign && !v->sign)
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return usize - vsize;
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if (usize != vsize && u->sign && v->sign)
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return vsize + usize;
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if (!usize)
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return 0;
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cmp = mpihelp_cmp(u->d, v->d, usize);
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if (!cmp)
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return 0;
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if ((cmp < 0 ? 1 : 0) == (u->sign ? 1 : 0))
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return 1;
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return -1;
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}
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@ -0,0 +1,333 @@
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/* mpi-div.c - MPI functions
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* Copyright (C) 1994, 1996 Free Software Foundation, Inc.
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* Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
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*
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||||
* 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
|
||||
*
|
||||
* Note: This code is heavily based on the GNU MP Library.
|
||||
* Actually it's the same code with only minor changes in the
|
||||
* way the data is stored; this is to support the abstraction
|
||||
* of an optional secure memory allocation which may be used
|
||||
* to avoid revealing of sensitive data due to paging etc.
|
||||
* The GNU MP Library itself is published under the LGPL;
|
||||
* however I decided to publish this code under the plain GPL.
|
||||
*/
|
||||
|
||||
#include <linux/string.h>
|
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#include "mpi-internal.h"
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#include "longlong.h"
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|
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int mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor)
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{
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int rc = -ENOMEM;
|
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int divisor_sign = divisor->sign;
|
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MPI temp_divisor = NULL;
|
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|
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/* We need the original value of the divisor after the remainder has been
|
||||
* preliminary calculated. We have to copy it to temporary space if it's
|
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* the same variable as REM. */
|
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if (rem == divisor) {
|
||||
if (mpi_copy(&temp_divisor, divisor) < 0)
|
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goto nomem;
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divisor = temp_divisor;
|
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}
|
||||
|
||||
if (mpi_tdiv_qr(NULL, rem, dividend, divisor) < 0)
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goto nomem;
|
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if (((divisor_sign ? 1 : 0) ^ (dividend->sign ? 1 : 0)) && rem->nlimbs)
|
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if (mpi_add(rem, rem, divisor) < 0)
|
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goto nomem;
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||||
|
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rc = 0;
|
||||
|
||||
nomem:
|
||||
if (temp_divisor)
|
||||
mpi_free(temp_divisor);
|
||||
return rc;
|
||||
}
|
||||
|
||||
/****************
|
||||
* Division rounding the quotient towards -infinity.
|
||||
* The remainder gets the same sign as the denominator.
|
||||
* rem is optional
|
||||
*/
|
||||
|
||||
ulong mpi_fdiv_r_ui(MPI rem, MPI dividend, ulong divisor)
|
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{
|
||||
mpi_limb_t rlimb;
|
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|
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rlimb = mpihelp_mod_1(dividend->d, dividend->nlimbs, divisor);
|
||||
if (rlimb && dividend->sign)
|
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rlimb = divisor - rlimb;
|
||||
|
||||
if (rem) {
|
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rem->d[0] = rlimb;
|
||||
rem->nlimbs = rlimb ? 1 : 0;
|
||||
}
|
||||
return rlimb;
|
||||
}
|
||||
|
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int mpi_fdiv_q(MPI quot, MPI dividend, MPI divisor)
|
||||
{
|
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MPI tmp = mpi_alloc(mpi_get_nlimbs(quot));
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if (!tmp)
|
||||
return -ENOMEM;
|
||||
mpi_fdiv_qr(quot, tmp, dividend, divisor);
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mpi_free(tmp);
|
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return 0;
|
||||
}
|
||||
|
||||
int mpi_fdiv_qr(MPI quot, MPI rem, MPI dividend, MPI divisor)
|
||||
{
|
||||
int divisor_sign = divisor->sign;
|
||||
MPI temp_divisor = NULL;
|
||||
|
||||
if (quot == divisor || rem == divisor) {
|
||||
if (mpi_copy(&temp_divisor, divisor) < 0)
|
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return -ENOMEM;
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divisor = temp_divisor;
|
||||
}
|
||||
|
||||
if (mpi_tdiv_qr(quot, rem, dividend, divisor) < 0)
|
||||
goto nomem;
|
||||
|
||||
if ((divisor_sign ^ dividend->sign) && rem->nlimbs) {
|
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if (mpi_sub_ui(quot, quot, 1) < 0)
|
||||
goto nomem;
|
||||
if (mpi_add(rem, rem, divisor) < 0)
|
||||
goto nomem;
|
||||
}
|
||||
|
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if (temp_divisor)
|
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mpi_free(temp_divisor);
|
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|
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return 0;
|
||||
|
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nomem:
|
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mpi_free(temp_divisor);
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return -ENOMEM;
|
||||
}
|
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|
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/* If den == quot, den needs temporary storage.
|
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* If den == rem, den needs temporary storage.
|
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* If num == quot, num needs temporary storage.
|
||||
* If den has temporary storage, it can be normalized while being copied,
|
||||
* i.e no extra storage should be allocated.
|
||||
*/
|
||||
|
||||
int mpi_tdiv_r(MPI rem, MPI num, MPI den)
|
||||
{
|
||||
return mpi_tdiv_qr(NULL, rem, num, den);
|
||||
}
|
||||
|
||||
int mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den)
|
||||
{
|
||||
int rc = -ENOMEM;
|
||||
mpi_ptr_t np, dp;
|
||||
mpi_ptr_t qp, rp;
|
||||
mpi_size_t nsize = num->nlimbs;
|
||||
mpi_size_t dsize = den->nlimbs;
|
||||
mpi_size_t qsize, rsize;
|
||||
mpi_size_t sign_remainder = num->sign;
|
||||
mpi_size_t sign_quotient = num->sign ^ den->sign;
|
||||
unsigned normalization_steps;
|
||||
mpi_limb_t q_limb;
|
||||
mpi_ptr_t marker[5];
|
||||
int markidx = 0;
|
||||
|
||||
memset(marker, 0, sizeof(marker));
|
||||
|
||||
/* Ensure space is enough for quotient and remainder.
|
||||
* We need space for an extra limb in the remainder, because it's
|
||||
* up-shifted (normalized) below. */
|
||||
rsize = nsize + 1;
|
||||
if (mpi_resize(rem, rsize) < 0)
|
||||
goto nomem;
|
||||
|
||||
qsize = rsize - dsize; /* qsize cannot be bigger than this. */
|
||||
if (qsize <= 0) {
|
||||
if (num != rem) {
|
||||
rem->nlimbs = num->nlimbs;
|
||||
rem->sign = num->sign;
|
||||
MPN_COPY(rem->d, num->d, nsize);
|
||||
}
|
||||
if (quot) {
|
||||
/* This needs to follow the assignment to rem, in case the
|
||||
* numerator and quotient are the same. */
|
||||
quot->nlimbs = 0;
|
||||
quot->sign = 0;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
if (quot)
|
||||
if (mpi_resize(quot, qsize) < 0)
|
||||
goto nomem;
|
||||
|
||||
/* Read pointers here, when reallocation is finished. */
|
||||
np = num->d;
|
||||
dp = den->d;
|
||||
rp = rem->d;
|
||||
|
||||
/* Optimize division by a single-limb divisor. */
|
||||
if (dsize == 1) {
|
||||
mpi_limb_t rlimb;
|
||||
if (quot) {
|
||||
qp = quot->d;
|
||||
rlimb = mpihelp_divmod_1(qp, np, nsize, dp[0]);
|
||||
qsize -= qp[qsize - 1] == 0;
|
||||
quot->nlimbs = qsize;
|
||||
quot->sign = sign_quotient;
|
||||
} else
|
||||
rlimb = mpihelp_mod_1(np, nsize, dp[0]);
|
||||
rp[0] = rlimb;
|
||||
rsize = rlimb != 0 ? 1 : 0;
|
||||
rem->nlimbs = rsize;
|
||||
rem->sign = sign_remainder;
|
||||
return 0;
|
||||
}
|
||||
|
||||
if (quot) {
|
||||
qp = quot->d;
|
||||
/* Make sure QP and NP point to different objects. Otherwise the
|
||||
* numerator would be gradually overwritten by the quotient limbs. */
|
||||
if (qp == np) { /* Copy NP object to temporary space. */
|
||||
np = marker[markidx++] = mpi_alloc_limb_space(nsize);
|
||||
MPN_COPY(np, qp, nsize);
|
||||
}
|
||||
} else /* Put quotient at top of remainder. */
|
||||
qp = rp + dsize;
|
||||
|
||||
count_leading_zeros(normalization_steps, dp[dsize - 1]);
|
||||
|
||||
/* Normalize the denominator, i.e. make its most significant bit set by
|
||||
* shifting it NORMALIZATION_STEPS bits to the left. Also shift the
|
||||
* numerator the same number of steps (to keep the quotient the same!).
|
||||
*/
|
||||
if (normalization_steps) {
|
||||
mpi_ptr_t tp;
|
||||
mpi_limb_t nlimb;
|
||||
|
||||
/* Shift up the denominator setting the most significant bit of
|
||||
* the most significant word. Use temporary storage not to clobber
|
||||
* the original contents of the denominator. */
|
||||
tp = marker[markidx++] = mpi_alloc_limb_space(dsize);
|
||||
if (!tp)
|
||||
goto nomem;
|
||||
mpihelp_lshift(tp, dp, dsize, normalization_steps);
|
||||
dp = tp;
|
||||
|
||||
/* Shift up the numerator, possibly introducing a new most
|
||||
* significant word. Move the shifted numerator in the remainder
|
||||
* meanwhile. */
|
||||
nlimb = mpihelp_lshift(rp, np, nsize, normalization_steps);
|
||||
if (nlimb) {
|
||||
rp[nsize] = nlimb;
|
||||
rsize = nsize + 1;
|
||||
} else
|
||||
rsize = nsize;
|
||||
} else {
|
||||
/* The denominator is already normalized, as required. Copy it to
|
||||
* temporary space if it overlaps with the quotient or remainder. */
|
||||
if (dp == rp || (quot && (dp == qp))) {
|
||||
mpi_ptr_t tp;
|
||||
|
||||
tp = marker[markidx++] = mpi_alloc_limb_space(dsize);
|
||||
if (!tp)
|
||||
goto nomem;
|
||||
MPN_COPY(tp, dp, dsize);
|
||||
dp = tp;
|
||||
}
|
||||
|
||||
/* Move the numerator to the remainder. */
|
||||
if (rp != np)
|
||||
MPN_COPY(rp, np, nsize);
|
||||
|
||||
rsize = nsize;
|
||||
}
|
||||
|
||||
q_limb = mpihelp_divrem(qp, 0, rp, rsize, dp, dsize);
|
||||
|
||||
if (quot) {
|
||||
qsize = rsize - dsize;
|
||||
if (q_limb) {
|
||||
qp[qsize] = q_limb;
|
||||
qsize += 1;
|
||||
}
|
||||
|
||||
quot->nlimbs = qsize;
|
||||
quot->sign = sign_quotient;
|
||||
}
|
||||
|
||||
rsize = dsize;
|
||||
MPN_NORMALIZE(rp, rsize);
|
||||
|
||||
if (normalization_steps && rsize) {
|
||||
mpihelp_rshift(rp, rp, rsize, normalization_steps);
|
||||
rsize -= rp[rsize - 1] == 0 ? 1 : 0;
|
||||
}
|
||||
|
||||
rem->nlimbs = rsize;
|
||||
rem->sign = sign_remainder;
|
||||
|
||||
rc = 0;
|
||||
nomem:
|
||||
while (markidx)
|
||||
mpi_free_limb_space(marker[--markidx]);
|
||||
return rc;
|
||||
}
|
||||
|
||||
int mpi_tdiv_q_2exp(MPI w, MPI u, unsigned count)
|
||||
{
|
||||
mpi_size_t usize, wsize;
|
||||
mpi_size_t limb_cnt;
|
||||
|
||||
usize = u->nlimbs;
|
||||
limb_cnt = count / BITS_PER_MPI_LIMB;
|
||||
wsize = usize - limb_cnt;
|
||||
if (limb_cnt >= usize)
|
||||
w->nlimbs = 0;
|
||||
else {
|
||||
mpi_ptr_t wp;
|
||||
mpi_ptr_t up;
|
||||
|
||||
if (RESIZE_IF_NEEDED(w, wsize) < 0)
|
||||
return -ENOMEM;
|
||||
wp = w->d;
|
||||
up = u->d;
|
||||
|
||||
count %= BITS_PER_MPI_LIMB;
|
||||
if (count) {
|
||||
mpihelp_rshift(wp, up + limb_cnt, wsize, count);
|
||||
wsize -= !wp[wsize - 1];
|
||||
} else {
|
||||
MPN_COPY_INCR(wp, up + limb_cnt, wsize);
|
||||
}
|
||||
|
||||
w->nlimbs = wsize;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
/****************
|
||||
* Check whether dividend is divisible by divisor
|
||||
* (note: divisor must fit into a limb)
|
||||
*/
|
||||
int mpi_divisible_ui(MPI dividend, ulong divisor)
|
||||
{
|
||||
return !mpihelp_mod_1(dividend->d, dividend->nlimbs, divisor);
|
||||
}
|
||||
|
|
@ -0,0 +1,59 @@
|
|||
/* mpi-gcd.c - MPI functions
|
||||
* Copyright (C) 1998, 1999, 2000, 2001 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"
|
||||
|
||||
/****************
|
||||
* Find the greatest common divisor G of A and B.
|
||||
* Return: true if this 1, false in all other cases
|
||||
*/
|
||||
int mpi_gcd(MPI g, const MPI xa, const MPI xb)
|
||||
{
|
||||
MPI a = NULL, b = NULL;
|
||||
|
||||
if (mpi_copy(&a, xa) < 0)
|
||||
goto nomem;
|
||||
|
||||
if (mpi_copy(&b, xb) < 0)
|
||||
goto nomem;
|
||||
|
||||
/* TAOCP Vol II, 4.5.2, Algorithm A */
|
||||
a->sign = 0;
|
||||
b->sign = 0;
|
||||
while (mpi_cmp_ui(b, 0)) {
|
||||
if (mpi_fdiv_r(g, a, b) < 0) /* g used as temorary variable */
|
||||
goto nomem;
|
||||
if (mpi_set(a, b) < 0)
|
||||
goto nomem;
|
||||
if (mpi_set(b, g) < 0)
|
||||
goto nomem;
|
||||
}
|
||||
if (mpi_set(g, a) < 0)
|
||||
goto nomem;
|
||||
|
||||
mpi_free(a);
|
||||
mpi_free(b);
|
||||
return !mpi_cmp_ui(g, 1);
|
||||
|
||||
nomem:
|
||||
mpi_free(a);
|
||||
mpi_free(b);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
|
@ -0,0 +1,31 @@
|
|||
/* mpi-inline.c
|
||||
* Copyright (C) 1999, 2000, 2001 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
|
||||
*/
|
||||
|
||||
/* put the inline functions as real functions into the lib */
|
||||
#define G10_MPI_INLINE_DECL
|
||||
|
||||
#include "mpi-internal.h"
|
||||
|
||||
/* always include the header becuase it is only
|
||||
* included by mpi-internal if __GCC__ is defined but we
|
||||
* need it here in all cases and the above definition of
|
||||
* of the macro allows us to do so
|
||||
*/
|
||||
#include "mpi-inline.h"
|
||||
|
|
@ -0,0 +1,187 @@
|
|||
/* mpi-inv.c - MPI functions
|
||||
* Copyright (C) 1998, 1999, 2000, 2001 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"
|
||||
|
||||
/****************
|
||||
* Calculate the multiplicative inverse X of A mod N
|
||||
* That is: Find the solution x for
|
||||
* 1 = (a*x) mod n
|
||||
*/
|
||||
int mpi_invm(MPI x, const MPI a, const MPI n)
|
||||
{
|
||||
/* Extended Euclid's algorithm (See TAOPC Vol II, 4.5.2, Alg X)
|
||||
* modified according to Michael Penk's solution for Exercice 35
|
||||
* with further enhancement */
|
||||
MPI u = NULL, v = NULL;
|
||||
MPI u1 = NULL, u2 = NULL, u3 = NULL;
|
||||
MPI v1 = NULL, v2 = NULL, v3 = NULL;
|
||||
MPI t1 = NULL, t2 = NULL, t3 = NULL;
|
||||
unsigned k;
|
||||
int sign;
|
||||
int odd = 0;
|
||||
int rc = -ENOMEM;
|
||||
|
||||
if (mpi_copy(&u, a) < 0)
|
||||
goto cleanup;
|
||||
if (mpi_copy(&v, n) < 0)
|
||||
goto cleanup;
|
||||
|
||||
for (k = 0; !mpi_test_bit(u, 0) && !mpi_test_bit(v, 0); k++) {
|
||||
if (mpi_rshift(u, u, 1) < 0)
|
||||
goto cleanup;
|
||||
if (mpi_rshift(v, v, 1) < 0)
|
||||
goto cleanup;
|
||||
}
|
||||
odd = mpi_test_bit(v, 0);
|
||||
|
||||
u1 = mpi_alloc_set_ui(1);
|
||||
if (!u1)
|
||||
goto cleanup;
|
||||
if (!odd) {
|
||||
u2 = mpi_alloc_set_ui(0);
|
||||
if (!u2)
|
||||
goto cleanup;
|
||||
}
|
||||
if (mpi_copy(&u3, u) < 0)
|
||||
goto cleanup;
|
||||
if (mpi_copy(&v1, v) < 0)
|
||||
goto cleanup;
|
||||
if (!odd) {
|
||||
v2 = mpi_alloc(mpi_get_nlimbs(u));
|
||||
if (!v2)
|
||||
goto cleanup;
|
||||
if (mpi_sub(v2, u1, u) < 0)
|
||||
goto cleanup; /* U is used as const 1 */
|
||||
}
|
||||
if (mpi_copy(&v3, v) < 0)
|
||||
goto cleanup;
|
||||
if (mpi_test_bit(u, 0)) { /* u is odd */
|
||||
t1 = mpi_alloc_set_ui(0);
|
||||
if (!t1)
|
||||
goto cleanup;
|
||||
if (!odd) {
|
||||
t2 = mpi_alloc_set_ui(1);
|
||||
if (!t2)
|
||||
goto cleanup;
|
||||
t2->sign = 1;
|
||||
}
|
||||
if (mpi_copy(&t3, v) < 0)
|
||||
goto cleanup;
|
||||
t3->sign = !t3->sign;
|
||||
goto Y4;
|
||||
} else {
|
||||
t1 = mpi_alloc_set_ui(1);
|
||||
if (!t1)
|
||||
goto cleanup;
|
||||
if (!odd) {
|
||||
t2 = mpi_alloc_set_ui(0);
|
||||
if (!t2)
|
||||
goto cleanup;
|
||||
}
|
||||
if (mpi_copy(&t3, u) < 0)
|
||||
goto cleanup;
|
||||
}
|
||||
do {
|
||||
do {
|
||||
if (!odd) {
|
||||
if (mpi_test_bit(t1, 0) || mpi_test_bit(t2, 0)) { /* one is odd */
|
||||
if (mpi_add(t1, t1, v) < 0)
|
||||
goto cleanup;
|
||||
if (mpi_sub(t2, t2, u) < 0)
|
||||
goto cleanup;
|
||||
}
|
||||
if (mpi_rshift(t1, t1, 1) < 0)
|
||||
goto cleanup;
|
||||
if (mpi_rshift(t2, t2, 1) < 0)
|
||||
goto cleanup;
|
||||
if (mpi_rshift(t3, t3, 1) < 0)
|
||||
goto cleanup;
|
||||
} else {
|
||||
if (mpi_test_bit(t1, 0))
|
||||
if (mpi_add(t1, t1, v) < 0)
|
||||
goto cleanup;
|
||||
if (mpi_rshift(t1, t1, 1) < 0)
|
||||
goto cleanup;
|
||||
if (mpi_rshift(t3, t3, 1) < 0)
|
||||
goto cleanup;
|
||||
}
|
||||
Y4:
|
||||
;
|
||||
} while (!mpi_test_bit(t3, 0)); /* while t3 is even */
|
||||
|
||||
if (!t3->sign) {
|
||||
if (mpi_set(u1, t1) < 0)
|
||||
goto cleanup;
|
||||
if (!odd)
|
||||
if (mpi_set(u2, t2) < 0)
|
||||
goto cleanup;
|
||||
if (mpi_set(u3, t3) < 0)
|
||||
goto cleanup;
|
||||
} else {
|
||||
if (mpi_sub(v1, v, t1) < 0)
|
||||
goto cleanup;
|
||||
sign = u->sign;
|
||||
u->sign = !u->sign;
|
||||
if (!odd)
|
||||
if (mpi_sub(v2, u, t2) < 0)
|
||||
goto cleanup;
|
||||
u->sign = sign;
|
||||
sign = t3->sign;
|
||||
t3->sign = !t3->sign;
|
||||
if (mpi_set(v3, t3) < 0)
|
||||
goto cleanup;
|
||||
t3->sign = sign;
|
||||
}
|
||||
if (mpi_sub(t1, u1, v1) < 0)
|
||||
goto cleanup;
|
||||
if (!odd)
|
||||
if (mpi_sub(t2, u2, v2) < 0)
|
||||
goto cleanup;
|
||||
if (mpi_sub(t3, u3, v3) < 0)
|
||||
goto cleanup;
|
||||
if (t1->sign) {
|
||||
if (mpi_add(t1, t1, v) < 0)
|
||||
goto cleanup;
|
||||
if (!odd)
|
||||
if (mpi_sub(t2, t2, u) < 0)
|
||||
goto cleanup;
|
||||
}
|
||||
} while (mpi_cmp_ui(t3, 0)); /* while t3 != 0 */
|
||||
/* mpi_lshift( u3, k ); */
|
||||
rc = mpi_set(x, u1);
|
||||
|
||||
cleanup:
|
||||
mpi_free(u1);
|
||||
mpi_free(v1);
|
||||
mpi_free(t1);
|
||||
if (!odd) {
|
||||
mpi_free(u2);
|
||||
mpi_free(v2);
|
||||
mpi_free(t2);
|
||||
}
|
||||
mpi_free(u3);
|
||||
mpi_free(v3);
|
||||
mpi_free(t3);
|
||||
|
||||
mpi_free(u);
|
||||
mpi_free(v);
|
||||
return rc;
|
||||
}
|
||||
|
|
@ -0,0 +1,133 @@
|
|||
/* 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) {
|
||||
pr_emerg("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) {
|
||||
pr_emerg("mpi_mulpowm: assert(i==k) failed\n");
|
||||
BUG();
|
||||
}
|
||||
if (!t) {
|
||||
pr_emerg("mpi_mulpowm: assert(t) failed\n");
|
||||
BUG();
|
||||
}
|
||||
if (k >= 10) {
|
||||
pr_emerg("mpi_mulpowm: assert(k<10) failed\n");
|
||||
BUG();
|
||||
}
|
||||
|
||||
G = kzalloc((1 << k) * sizeof *G, GFP_KERNEL);
|
||||
if (!G)
|
||||
goto nomem;
|
||||
|
||||
/* and calculate */
|
||||
tmp = mpi_alloc(mpi_get_nlimbs(m) + 1);
|
||||
if (!tmp)
|
||||
goto nomem;
|
||||
if (mpi_set_ui(res, 1) < 0)
|
||||
goto nomem;
|
||||
for (i = 1; i <= t; i++) {
|
||||
if (mpi_mulm(tmp, res, res, m) < 0)
|
||||
goto nomem;
|
||||
idx = build_index(exparray, k, i, t);
|
||||
if (!(idx >= 0 && idx < (1 << k))) {
|
||||
pr_emerg("mpi_mulpowm: assert(idx >= 0 && idx < (1<<k)) failed\n");
|
||||
BUG();
|
||||
}
|
||||
if (!G[idx]) {
|
||||
if (!idx) {
|
||||
G[0] = mpi_alloc_set_ui(1);
|
||||
if (!G[0])
|
||||
goto nomem;
|
||||
} else {
|
||||
for (j = 0; j < k; j++) {
|
||||
if ((idx & (1 << j))) {
|
||||
if (!G[idx]) {
|
||||
if (mpi_copy
|
||||
(&G[idx],
|
||||
basearray[j]) < 0)
|
||||
goto nomem;
|
||||
} else {
|
||||
if (mpi_mulm
|
||||
(G[idx], G[idx],
|
||||
basearray[j],
|
||||
m) < 0)
|
||||
goto nomem;
|
||||
}
|
||||
}
|
||||
}
|
||||
if (!G[idx]) {
|
||||
G[idx] = mpi_alloc(0);
|
||||
if (!G[idx])
|
||||
goto nomem;
|
||||
}
|
||||
}
|
||||
}
|
||||
if (mpi_mulm(res, tmp, G[idx], m) < 0)
|
||||
goto nomem;
|
||||
}
|
||||
|
||||
rc = 0;
|
||||
nomem:
|
||||
/* cleanup */
|
||||
mpi_free(tmp);
|
||||
for (i = 0; i < (1 << k); i++)
|
||||
mpi_free(G[i]);
|
||||
kfree(G);
|
||||
return rc;
|
||||
}
|
||||
|
|
@ -0,0 +1,194 @@
|
|||
/* mpi-mul.c - MPI functions
|
||||
* Copyright (C) 1994, 1996 Free Software Foundation, Inc.
|
||||
* Copyright (C) 1998, 2001 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
|
||||
*
|
||||
* Note: This code is heavily based on the GNU MP Library.
|
||||
* Actually it's the same code with only minor changes in the
|
||||
* way the data is stored; this is to support the abstraction
|
||||
* of an optional secure memory allocation which may be used
|
||||
* to avoid revealing of sensitive data due to paging etc.
|
||||
* The GNU MP Library itself is published under the LGPL;
|
||||
* however I decided to publish this code under the plain GPL.
|
||||
*/
|
||||
|
||||
#include "mpi-internal.h"
|
||||
|
||||
int mpi_mul_ui(MPI prod, MPI mult, unsigned long small_mult)
|
||||
{
|
||||
mpi_size_t size, prod_size;
|
||||
mpi_ptr_t prod_ptr;
|
||||
mpi_limb_t cy;
|
||||
int sign;
|
||||
|
||||
size = mult->nlimbs;
|
||||
sign = mult->sign;
|
||||
|
||||
if (!size || !small_mult) {
|
||||
prod->nlimbs = 0;
|
||||
prod->sign = 0;
|
||||
return 0;
|
||||
}
|
||||
|
||||
prod_size = size + 1;
|
||||
if (prod->alloced < prod_size)
|
||||
if (mpi_resize(prod, prod_size) < 0)
|
||||
return -ENOMEM;
|
||||
prod_ptr = prod->d;
|
||||
|
||||
cy = mpihelp_mul_1(prod_ptr, mult->d, size, (mpi_limb_t) small_mult);
|
||||
if (cy)
|
||||
prod_ptr[size++] = cy;
|
||||
prod->nlimbs = size;
|
||||
prod->sign = sign;
|
||||
return 0;
|
||||
}
|
||||
|
||||
int mpi_mul_2exp(MPI w, MPI u, unsigned long cnt)
|
||||
{
|
||||
mpi_size_t usize, wsize, limb_cnt;
|
||||
mpi_ptr_t wp;
|
||||
mpi_limb_t wlimb;
|
||||
int usign, wsign;
|
||||
|
||||
usize = u->nlimbs;
|
||||
usign = u->sign;
|
||||
|
||||
if (!usize) {
|
||||
w->nlimbs = 0;
|
||||
w->sign = 0;
|
||||
return 0;
|
||||
}
|
||||
|
||||
limb_cnt = cnt / BITS_PER_MPI_LIMB;
|
||||
wsize = usize + limb_cnt + 1;
|
||||
if (w->alloced < wsize)
|
||||
if (mpi_resize(w, wsize) < 0)
|
||||
return -ENOMEM;
|
||||
wp = w->d;
|
||||
wsize = usize + limb_cnt;
|
||||
wsign = usign;
|
||||
|
||||
cnt %= BITS_PER_MPI_LIMB;
|
||||
if (cnt) {
|
||||
wlimb = mpihelp_lshift(wp + limb_cnt, u->d, usize, cnt);
|
||||
if (wlimb) {
|
||||
wp[wsize] = wlimb;
|
||||
wsize++;
|
||||
}
|
||||
} else {
|
||||
MPN_COPY_DECR(wp + limb_cnt, u->d, usize);
|
||||
}
|
||||
|
||||
/* Zero all whole limbs at low end. Do it here and not before calling
|
||||
* mpn_lshift, not to lose for U == W. */
|
||||
MPN_ZERO(wp, limb_cnt);
|
||||
|
||||
w->nlimbs = wsize;
|
||||
w->sign = wsign;
|
||||
return 0;
|
||||
}
|
||||
|
||||
int mpi_mul(MPI w, MPI u, MPI v)
|
||||
{
|
||||
int rc = -ENOMEM;
|
||||
mpi_size_t usize, vsize, wsize;
|
||||
mpi_ptr_t up, vp, wp;
|
||||
mpi_limb_t cy;
|
||||
int usign, vsign, sign_product;
|
||||
int assign_wp = 0;
|
||||
mpi_ptr_t tmp_limb = NULL;
|
||||
|
||||
if (u->nlimbs < v->nlimbs) { /* Swap U and V. */
|
||||
usize = v->nlimbs;
|
||||
usign = v->sign;
|
||||
up = v->d;
|
||||
vsize = u->nlimbs;
|
||||
vsign = u->sign;
|
||||
vp = u->d;
|
||||
} else {
|
||||
usize = u->nlimbs;
|
||||
usign = u->sign;
|
||||
up = u->d;
|
||||
vsize = v->nlimbs;
|
||||
vsign = v->sign;
|
||||
vp = v->d;
|
||||
}
|
||||
sign_product = usign ^ vsign;
|
||||
wp = w->d;
|
||||
|
||||
/* Ensure W has space enough to store the result. */
|
||||
wsize = usize + vsize;
|
||||
if (w->alloced < (size_t) wsize) {
|
||||
if (wp == up || wp == vp) {
|
||||
wp = mpi_alloc_limb_space(wsize);
|
||||
if (!wp)
|
||||
goto nomem;
|
||||
assign_wp = 1;
|
||||
} else {
|
||||
if (mpi_resize(w, wsize) < 0)
|
||||
goto nomem;
|
||||
wp = w->d;
|
||||
}
|
||||
} else { /* Make U and V not overlap with W. */
|
||||
if (wp == up) {
|
||||
/* W and U are identical. Allocate temporary space for U. */
|
||||
up = tmp_limb = mpi_alloc_limb_space(usize);
|
||||
if (!up)
|
||||
goto nomem;
|
||||
/* Is V identical too? Keep it identical with U. */
|
||||
if (wp == vp)
|
||||
vp = up;
|
||||
/* Copy to the temporary space. */
|
||||
MPN_COPY(up, wp, usize);
|
||||
} else if (wp == vp) {
|
||||
/* W and V are identical. Allocate temporary space for V. */
|
||||
vp = tmp_limb = mpi_alloc_limb_space(vsize);
|
||||
if (!vp)
|
||||
goto nomem;
|
||||
/* Copy to the temporary space. */
|
||||
MPN_COPY(vp, wp, vsize);
|
||||
}
|
||||
}
|
||||
|
||||
if (!vsize)
|
||||
wsize = 0;
|
||||
else {
|
||||
if (mpihelp_mul(wp, up, usize, vp, vsize, &cy) < 0)
|
||||
goto nomem;
|
||||
wsize -= cy ? 0 : 1;
|
||||
}
|
||||
|
||||
if (assign_wp)
|
||||
mpi_assign_limb_space(w, wp, wsize);
|
||||
|
||||
w->nlimbs = wsize;
|
||||
w->sign = sign_product;
|
||||
rc = 0;
|
||||
nomem:
|
||||
if (tmp_limb)
|
||||
mpi_free_limb_space(tmp_limb);
|
||||
return rc;
|
||||
}
|
||||
|
||||
int mpi_mulm(MPI w, MPI u, MPI v, MPI m)
|
||||
{
|
||||
if (mpi_mul(w, u, v) < 0)
|
||||
return -ENOMEM;
|
||||
return mpi_fdiv_r(w, w, m);
|
||||
}
|
||||
|
|
@ -0,0 +1,136 @@
|
|||
/* mpi-scan.c - MPI functions
|
||||
* Copyright (C) 1998, 1999, 2000, 2001 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"
|
||||
|
||||
/****************
|
||||
* Scan through an mpi and return byte for byte. a -1 is returned to indicate
|
||||
* the end of the mpi. Scanning is done from the lsb to the msb, returned
|
||||
* values are in the range of 0 .. 255.
|
||||
*
|
||||
* FIXME: This code is VERY ugly!
|
||||
*/
|
||||
int mpi_getbyte(const MPI a, unsigned idx)
|
||||
{
|
||||
int i, j;
|
||||
unsigned n;
|
||||
mpi_ptr_t ap;
|
||||
mpi_limb_t limb;
|
||||
|
||||
ap = a->d;
|
||||
for (n = 0, i = 0; i < a->nlimbs; i++) {
|
||||
limb = ap[i];
|
||||
for (j = 0; j < BYTES_PER_MPI_LIMB; j++, n++)
|
||||
if (n == idx)
|
||||
return (limb >> j * 8) & 0xff;
|
||||
}
|
||||
return -1;
|
||||
}
|
||||
|
||||
/****************
|
||||
* Put a value at position IDX into A. idx counts from lsb to msb
|
||||
*/
|
||||
void mpi_putbyte(MPI a, unsigned idx, int xc)
|
||||
{
|
||||
int i, j;
|
||||
unsigned n;
|
||||
mpi_ptr_t ap;
|
||||
mpi_limb_t limb, c;
|
||||
|
||||
c = xc & 0xff;
|
||||
ap = a->d;
|
||||
for (n = 0, i = 0; i < a->alloced; i++) {
|
||||
limb = ap[i];
|
||||
for (j = 0; j < BYTES_PER_MPI_LIMB; j++, n++)
|
||||
if (n == idx) {
|
||||
#if BYTES_PER_MPI_LIMB == 4
|
||||
if (j == 0)
|
||||
limb = (limb & 0xffffff00) | c;
|
||||
else if (j == 1)
|
||||
limb = (limb & 0xffff00ff) | (c << 8);
|
||||
else if (j == 2)
|
||||
limb = (limb & 0xff00ffff) | (c << 16);
|
||||
else
|
||||
limb = (limb & 0x00ffffff) | (c << 24);
|
||||
#elif BYTES_PER_MPI_LIMB == 8
|
||||
if (j == 0)
|
||||
limb = (limb & 0xffffffffffffff00) | c;
|
||||
else if (j == 1)
|
||||
limb =
|
||||
(limb & 0xffffffffffff00ff) | (c <<
|
||||
8);
|
||||
else if (j == 2)
|
||||
limb =
|
||||
(limb & 0xffffffffff00ffff) | (c <<
|
||||
16);
|
||||
else if (j == 3)
|
||||
limb =
|
||||
(limb & 0xffffffff00ffffff) | (c <<
|
||||
24);
|
||||
else if (j == 4)
|
||||
limb =
|
||||
(limb & 0xffffff00ffffffff) | (c <<
|
||||
32);
|
||||
else if (j == 5)
|
||||
limb =
|
||||
(limb & 0xffff00ffffffffff) | (c <<
|
||||
40);
|
||||
else if (j == 6)
|
||||
limb =
|
||||
(limb & 0xff00ffffffffffff) | (c <<
|
||||
48);
|
||||
else
|
||||
limb =
|
||||
(limb & 0x00ffffffffffffff) | (c <<
|
||||
56);
|
||||
#else
|
||||
#error please enhance this function, its ugly - i know.
|
||||
#endif
|
||||
if (a->nlimbs <= i)
|
||||
a->nlimbs = i + 1;
|
||||
ap[i] = limb;
|
||||
return;
|
||||
}
|
||||
}
|
||||
log_bug("index out of range\n");
|
||||
}
|
||||
|
||||
/****************
|
||||
* Count the number of zerobits at the low end of A
|
||||
*/
|
||||
unsigned mpi_trailing_zeros(const MPI a)
|
||||
{
|
||||
unsigned n, count = 0;
|
||||
|
||||
for (n = 0; n < a->nlimbs; n++) {
|
||||
if (a->d[n]) {
|
||||
unsigned nn;
|
||||
mpi_limb_t alimb = a->d[n];
|
||||
|
||||
count_trailing_zeros(nn, alimb);
|
||||
count += nn;
|
||||
break;
|
||||
}
|
||||
count += BITS_PER_MPI_LIMB;
|
||||
}
|
||||
return count;
|
||||
|
||||
}
|
||||
Loading…
Reference in New Issue