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authorSoniEx2 <endermoneymod@gmail.com>2021-04-09 07:19:03 -0300
committerSoniEx2 <endermoneymod@gmail.com>2021-04-09 07:19:03 -0300
commit0e752a6e215aee21dc73da097c3225495d54a5b6 (patch)
treeb81be02cbf2f06aebf322ac4a5d014b44176bba5 /libotr/libgcrypt-1.8.7/mpi/mpi-bit.c
parent7754076c715285173311a1b6811ce377950e18a6 (diff)
Add libotr/etc sources
Diffstat (limited to 'libotr/libgcrypt-1.8.7/mpi/mpi-bit.c')
-rw-r--r--libotr/libgcrypt-1.8.7/mpi/mpi-bit.c411
1 files changed, 411 insertions, 0 deletions
diff --git a/libotr/libgcrypt-1.8.7/mpi/mpi-bit.c b/libotr/libgcrypt-1.8.7/mpi/mpi-bit.c
new file mode 100644
index 0000000..e217040
--- /dev/null
+++ b/libotr/libgcrypt-1.8.7/mpi/mpi-bit.c
@@ -0,0 +1,411 @@
+/* mpi-bit.c  -  MPI bit level functions
+ * Copyright (C) 1998, 1999, 2001, 2002, 2006 Free Software Foundation, Inc.
+ * Copyright (C) 2013  g10 Code GmbH
+ *
+ * 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 i, limbno, bitno;
+
+  if (mpi_is_immutable (a))
+    {
+      mpi_immutable_failed ();
+      return;
+    }
+
+  limbno = n / BITS_PER_MPI_LIMB;
+  bitno  = n % BITS_PER_MPI_LIMB;
+
+  if ( limbno >= a->nlimbs )
+    {
+      for (i=a->nlimbs; i < a->alloced; i++)
+        a->d[i] = 0;
+      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 i, limbno, bitno;
+
+  if (mpi_is_immutable (a))
+    {
+      mpi_immutable_failed ();
+      return;
+    }
+
+  limbno = n / BITS_PER_MPI_LIMB;
+  bitno  = n % BITS_PER_MPI_LIMB;
+
+  if ( limbno >= a->nlimbs )
+    {
+      for (i=a->nlimbs; i < a->alloced; i++)
+        a->d[i] = 0;
+      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;
+
+  if (mpi_is_immutable (a))
+    {
+      mpi_immutable_failed ();
+      return;
+    }
+
+  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;
+
+  if (mpi_is_immutable (a))
+    {
+      mpi_immutable_failed ();
+      return;
+    }
+
+  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 far too 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 (mpi_is_immutable (a))
+    {
+      mpi_immutable_failed ();
+      return;
+    }
+
+  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 (mpi_is_immutable (x))
+    {
+      mpi_immutable_failed ();
+      return;
+    }
+
+  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 (mpi_is_immutable (x))
+    {
+      mpi_immutable_failed ();
+      return;
+    }
+
+  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);
+      mpi_rshift (x, x, BITS_PER_MPI_LIMB - nbits);
+    }
+
+  MPN_NORMALIZE (x->d, x->nlimbs);
+}