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Diffstat (limited to 'plugins/MirOTR/libgcrypt-1.4.6/mpi/mpi-bit.c')
-rw-r--r--plugins/MirOTR/libgcrypt-1.4.6/mpi/mpi-bit.c365
1 files changed, 365 insertions, 0 deletions
diff --git a/plugins/MirOTR/libgcrypt-1.4.6/mpi/mpi-bit.c b/plugins/MirOTR/libgcrypt-1.4.6/mpi/mpi-bit.c
new file mode 100644
index 0000000000..32c820c291
--- /dev/null
+++ b/plugins/MirOTR/libgcrypt-1.4.6/mpi/mpi-bit.c
@@ -0,0 +1,365 @@
+/* mpi-bit.c - MPI bit level fucntions
+ * Copyright (C) 1998, 1999, 2001, 2002, 2006 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 <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "mpi-internal.h"
+#include "longlong.h"
+
+
+#ifdef MPI_INTERNAL_NEED_CLZ_TAB
+#ifdef __STDC__
+const
+#endif
+unsigned char
+_gcry_clz_tab[] =
+{
+ 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
+ 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+ 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+ 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+};
+#endif
+
+
+#define A_LIMB_1 ((mpi_limb_t)1)
+
+
+/****************
+ * Sometimes we have MSL (most significant limbs) which are 0;
+ * this is for some reasons not good, so this function removes them.
+ */
+void
+_gcry_mpi_normalize( gcry_mpi_t a )
+{
+ if( mpi_is_opaque(a) )
+ return;
+
+ for( ; a->nlimbs && !a->d[a->nlimbs-1]; a->nlimbs-- )
+ ;
+}
+
+
+
+/****************
+ * Return the number of bits in A.
+ */
+unsigned int
+gcry_mpi_get_nbits( gcry_mpi_t a )
+{
+ unsigned n;
+
+ if( mpi_is_opaque(a) ) {
+ return a->sign; /* which holds the number of bits */
+ }
+
+ _gcry_mpi_normalize( a );
+ if( a->nlimbs ) {
+ mpi_limb_t alimb = a->d[a->nlimbs-1];
+ if( alimb )
+ count_leading_zeros( n, alimb );
+ else
+ n = BITS_PER_MPI_LIMB;
+ n = BITS_PER_MPI_LIMB - n + (a->nlimbs-1) * BITS_PER_MPI_LIMB;
+ }
+ else
+ n = 0;
+ return n;
+}
+
+
+/****************
+ * Test whether bit N is set.
+ */
+int
+gcry_mpi_test_bit( gcry_mpi_t a, unsigned int n )
+{
+ unsigned int limbno, bitno;
+ mpi_limb_t limb;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if( limbno >= a->nlimbs )
+ return 0; /* too far left: this is a 0 */
+ limb = a->d[limbno];
+ return (limb & (A_LIMB_1 << bitno))? 1: 0;
+}
+
+
+/****************
+ * Set bit N of A.
+ */
+void
+gcry_mpi_set_bit( gcry_mpi_t a, unsigned int n )
+{
+ unsigned int limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if ( limbno >= a->nlimbs )
+ {
+ mpi_resize (a, limbno+1 );
+ a->nlimbs = limbno+1;
+ }
+ a->d[limbno] |= (A_LIMB_1<<bitno);
+}
+
+/****************
+ * Set bit N of A. and clear all bits above
+ */
+void
+gcry_mpi_set_highbit( gcry_mpi_t a, unsigned int n )
+{
+ unsigned int limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if ( limbno >= a->nlimbs )
+ {
+ mpi_resize (a, limbno+1 );
+ a->nlimbs = limbno+1;
+ }
+ a->d[limbno] |= (A_LIMB_1<<bitno);
+ for ( bitno++; bitno < BITS_PER_MPI_LIMB; bitno++ )
+ a->d[limbno] &= ~(A_LIMB_1 << bitno);
+ a->nlimbs = limbno+1;
+}
+
+/****************
+ * clear bit N of A and all bits above
+ */
+void
+gcry_mpi_clear_highbit( gcry_mpi_t a, unsigned int n )
+{
+ unsigned int limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if( limbno >= a->nlimbs )
+ return; /* not allocated, therefore no need to clear bits
+ :-) */
+
+ for( ; bitno < BITS_PER_MPI_LIMB; bitno++ )
+ a->d[limbno] &= ~(A_LIMB_1 << bitno);
+ a->nlimbs = limbno+1;
+}
+
+/****************
+ * Clear bit N of A.
+ */
+void
+gcry_mpi_clear_bit( gcry_mpi_t a, unsigned int n )
+{
+ unsigned int limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if( limbno >= a->nlimbs )
+ return; /* don't need to clear this bit, it's to far to left */
+ a->d[limbno] &= ~(A_LIMB_1 << bitno);
+}
+
+
+/****************
+ * Shift A by COUNT limbs to the right
+ * This is used only within the MPI library
+ */
+void
+_gcry_mpi_rshift_limbs( gcry_mpi_t a, unsigned int count )
+{
+ mpi_ptr_t ap = a->d;
+ mpi_size_t n = a->nlimbs;
+ unsigned int i;
+
+ if( count >= n ) {
+ a->nlimbs = 0;
+ return;
+ }
+
+ for( i = 0; i < n - count; i++ )
+ ap[i] = ap[i+count];
+ ap[i] = 0;
+ a->nlimbs -= count;
+}
+
+
+/*
+ * Shift A by N bits to the right.
+ */
+void
+gcry_mpi_rshift ( gcry_mpi_t x, gcry_mpi_t a, unsigned int n )
+{
+ mpi_size_t xsize;
+ unsigned int i;
+ unsigned int nlimbs = (n/BITS_PER_MPI_LIMB);
+ unsigned int nbits = (n%BITS_PER_MPI_LIMB);
+
+ if ( x == a )
+ {
+ /* In-place operation. */
+ if ( nlimbs >= x->nlimbs )
+ {
+ x->nlimbs = 0;
+ return;
+ }
+
+ if (nlimbs)
+ {
+ for (i=0; i < x->nlimbs - nlimbs; i++ )
+ x->d[i] = x->d[i+nlimbs];
+ x->d[i] = 0;
+ x->nlimbs -= nlimbs;
+
+ }
+ if ( x->nlimbs && nbits )
+ _gcry_mpih_rshift ( x->d, x->d, x->nlimbs, nbits );
+ }
+ else if ( nlimbs )
+ {
+ /* Copy and shift by more or equal bits than in a limb. */
+ xsize = a->nlimbs;
+ x->sign = a->sign;
+ RESIZE_IF_NEEDED (x, xsize);
+ x->nlimbs = xsize;
+ for (i=0; i < a->nlimbs; i++ )
+ x->d[i] = a->d[i];
+ x->nlimbs = i;
+
+ if ( nlimbs >= x->nlimbs )
+ {
+ x->nlimbs = 0;
+ return;
+ }
+
+ if (nlimbs)
+ {
+ for (i=0; i < x->nlimbs - nlimbs; i++ )
+ x->d[i] = x->d[i+nlimbs];
+ x->d[i] = 0;
+ x->nlimbs -= nlimbs;
+ }
+
+ if ( x->nlimbs && nbits )
+ _gcry_mpih_rshift ( x->d, x->d, x->nlimbs, nbits );
+ }
+ else
+ {
+ /* Copy and shift by less than bits in a limb. */
+ xsize = a->nlimbs;
+ x->sign = a->sign;
+ RESIZE_IF_NEEDED (x, xsize);
+ x->nlimbs = xsize;
+
+ if ( xsize )
+ {
+ if (nbits )
+ _gcry_mpih_rshift (x->d, a->d, x->nlimbs, nbits );
+ else
+ {
+ /* The rshift helper function is not specified for
+ NBITS==0, thus we do a plain copy here. */
+ for (i=0; i < x->nlimbs; i++ )
+ x->d[i] = a->d[i];
+ }
+ }
+ }
+ MPN_NORMALIZE (x->d, x->nlimbs);
+}
+
+
+/****************
+ * Shift A by COUNT limbs to the left
+ * This is used only within the MPI library
+ */
+void
+_gcry_mpi_lshift_limbs (gcry_mpi_t a, unsigned int count)
+{
+ mpi_ptr_t ap;
+ int n = a->nlimbs;
+ int i;
+
+ if (!count || !n)
+ return;
+
+ RESIZE_IF_NEEDED (a, n+count);
+
+ ap = a->d;
+ for (i = n-1; i >= 0; i--)
+ ap[i+count] = ap[i];
+ for (i=0; i < count; i++ )
+ ap[i] = 0;
+ a->nlimbs += count;
+}
+
+
+/*
+ * Shift A by N bits to the left.
+ */
+void
+gcry_mpi_lshift ( gcry_mpi_t x, gcry_mpi_t a, unsigned int n )
+{
+ unsigned int nlimbs = (n/BITS_PER_MPI_LIMB);
+ unsigned int nbits = (n%BITS_PER_MPI_LIMB);
+
+ if (x == a && !n)
+ return; /* In-place shift with an amount of zero. */
+
+ if ( x != a )
+ {
+ /* Copy A to X. */
+ unsigned int alimbs = a->nlimbs;
+ int asign = a->sign;
+ mpi_ptr_t xp, ap;
+
+ RESIZE_IF_NEEDED (x, alimbs+nlimbs+1);
+ xp = x->d;
+ ap = a->d;
+ MPN_COPY (xp, ap, alimbs);
+ x->nlimbs = alimbs;
+ x->flags = a->flags;
+ x->sign = asign;
+ }
+
+ if (nlimbs && !nbits)
+ {
+ /* Shift a full number of limbs. */
+ _gcry_mpi_lshift_limbs (x, nlimbs);
+ }
+ else if (n)
+ {
+ /* We use a very dump approach: Shift left by the number of
+ limbs plus one and than fix it up by an rshift. */
+ _gcry_mpi_lshift_limbs (x, nlimbs+1);
+ gcry_mpi_rshift (x, x, BITS_PER_MPI_LIMB - nbits);
+ }
+
+ MPN_NORMALIZE (x->d, x->nlimbs);
+}
+
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