summaryrefslogtreecommitdiffabout
path: root/pwmanager/libcrypt/mpi/mpi-mul.c
authorzautrix <zautrix>2004-10-19 20:16:14 (UTC)
committer zautrix <zautrix>2004-10-19 20:16:14 (UTC)
commiteca49bb06a71980ef61d078904573f25890fc7f2 (patch) (side-by-side diff)
treec5338e3b12430248979a9ac2c1c7e6646ea9ecdf /pwmanager/libcrypt/mpi/mpi-mul.c
parent53cc32b6e7b1f672bf91b2baf2df6c1e8baf3e0a (diff)
downloadkdepimpi-eca49bb06a71980ef61d078904573f25890fc7f2.zip
kdepimpi-eca49bb06a71980ef61d078904573f25890fc7f2.tar.gz
kdepimpi-eca49bb06a71980ef61d078904573f25890fc7f2.tar.bz2
Initial revision
Diffstat (limited to 'pwmanager/libcrypt/mpi/mpi-mul.c') (more/less context) (ignore whitespace changes)
-rw-r--r--pwmanager/libcrypt/mpi/mpi-mul.c220
1 files changed, 220 insertions, 0 deletions
diff --git a/pwmanager/libcrypt/mpi/mpi-mul.c b/pwmanager/libcrypt/mpi/mpi-mul.c
new file mode 100644
index 0000000..23beee0
--- a/dev/null
+++ b/pwmanager/libcrypt/mpi/mpi-mul.c
@@ -0,0 +1,220 @@
+/* mpi-mul.c - MPI functions
+ * Copyright (C) 1994, 1996, 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
+ *
+ * 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.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "mpi-internal.h"
+
+
+void
+gcry_mpi_mul_ui( gcry_mpi_t prod, gcry_mpi_t 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;
+ }
+
+ prod_size = size + 1;
+ if( prod->alloced < prod_size )
+ mpi_resize( prod, prod_size );
+ prod_ptr = prod->d;
+
+ cy = _gcry_mpih_mul_1( prod_ptr, mult->d, size, (mpi_limb_t)small_mult );
+ if( cy )
+ prod_ptr[size++] = cy;
+ prod->nlimbs = size;
+ prod->sign = sign;
+}
+
+
+void
+_gcry_mpi_mul_2exp( gcry_mpi_t w, gcry_mpi_t 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;
+ }
+
+ limb_cnt = cnt / BITS_PER_MPI_LIMB;
+ wsize = usize + limb_cnt + 1;
+ if( w->alloced < wsize )
+ mpi_resize(w, wsize );
+ wp = w->d;
+ wsize = usize + limb_cnt;
+ wsign = usign;
+
+ cnt %= BITS_PER_MPI_LIMB;
+ if( cnt ) {
+ wlimb = _gcry_mpih_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;
+}
+
+
+void
+gcry_mpi_mul_2exp( gcry_mpi_t w, gcry_mpi_t u, unsigned long cnt)
+{
+ _gcry_mpi_mul_2exp (w, u, cnt);
+}
+
+
+void
+gcry_mpi_mul( gcry_mpi_t w, gcry_mpi_t u, gcry_mpi_t v)
+{
+ mpi_size_t usize, vsize, wsize;
+ mpi_ptr_t up, vp, wp;
+ mpi_limb_t cy;
+ int usign, vsign, usecure, vsecure, sign_product;
+ int assign_wp=0;
+ mpi_ptr_t tmp_limb=NULL;
+ unsigned int tmp_limb_nlimbs = 0;
+
+ if( u->nlimbs < v->nlimbs ) { /* Swap U and V. */
+ usize = v->nlimbs;
+ usign = v->sign;
+ usecure = mpi_is_secure(v);
+ up = v->d;
+ vsize = u->nlimbs;
+ vsign = u->sign;
+ vsecure = mpi_is_secure(u);
+ vp = u->d;
+ }
+ else {
+ usize = u->nlimbs;
+ usign = u->sign;
+ usecure = mpi_is_secure(u);
+ up = u->d;
+ vsize = v->nlimbs;
+ vsign = v->sign;
+ vsecure = mpi_is_secure(v);
+ vp = v->d;
+ }
+ sign_product = usign ^ vsign;
+ wp = w->d;
+
+ /* Ensure W has space enough to store the result. */
+ wsize = usize + vsize;
+ if ( !mpi_is_secure (w) && (mpi_is_secure (u) || mpi_is_secure (v)) ) {
+ /* w is not allocated in secure space but u or v is. To make sure
+ * that no temporray results are stored in w, we temporary use
+ * a newly allocated limb space for w */
+ wp = mpi_alloc_limb_space( wsize, 1 );
+ assign_wp = 2; /* mark it as 2 so that we can later copy it back to
+ * mormal memory */
+ }
+ else if( w->alloced < wsize ) {
+ if( wp == up || wp == vp ) {
+ wp = mpi_alloc_limb_space( wsize, mpi_is_secure(w) );
+ assign_wp = 1;
+ }
+ else {
+ mpi_resize(w, wsize );
+ 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. */
+ tmp_limb_nlimbs = usize;
+ up = tmp_limb = mpi_alloc_limb_space( usize, usecure );
+ /* 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. */
+ tmp_limb_nlimbs = vsize;
+ vp = tmp_limb = mpi_alloc_limb_space( vsize, vsecure );
+ /* Copy to the temporary space. */
+ MPN_COPY( vp, wp, vsize );
+ }
+ }
+
+ if( !vsize )
+ wsize = 0;
+ else {
+ cy = _gcry_mpih_mul( wp, up, usize, vp, vsize );
+ wsize -= cy? 0:1;
+ }
+
+ if( assign_wp ) {
+ if (assign_wp == 2) {
+ /* copy the temp wp from secure memory back to normal memory */
+ mpi_ptr_t tmp_wp = mpi_alloc_limb_space (wsize, 0);
+ MPN_COPY (tmp_wp, wp, wsize);
+ _gcry_mpi_free_limb_space (wp, 0);
+ wp = tmp_wp;
+ }
+ _gcry_mpi_assign_limb_space( w, wp, wsize );
+ }
+ w->nlimbs = wsize;
+ w->sign = sign_product;
+ if( tmp_limb )
+ _gcry_mpi_free_limb_space (tmp_limb, tmp_limb_nlimbs);
+}
+
+
+void
+gcry_mpi_mulm( gcry_mpi_t w, gcry_mpi_t u, gcry_mpi_t v, gcry_mpi_t m)
+{
+ gcry_mpi_mul(w, u, v);
+ _gcry_mpi_fdiv_r( w, w, m );
+}
+