Fixed gcry_mpi_set_bit and enhanced mpi_rshift.

Cleaned up andom-daemon initialization.

3 files changed, 118 insertions, 42 deletions

diff --git a/mpi/ChangeLog b/mpi/ChangeLog
index c82cc6c6..176ccf22 100644
--- a/mpi/ChangeLog
+++ b/mpi/ChangeLog
@@ -1,3 +1,15 @@
+2006-08-04  Werner Koch  <wk@g10code.com>
+
+	* mpi-bit.c (gcry_mpi_rshift): Rewritten to remove the limitation
+	on N (which used to be less than BITS_PER_MPI_LIMB).
+
+2006-08-03  Werner Koch  <wk@g10code.com>
+
+	* mpi-bit.c (gcry_mpi_set_bit, gcry_mpi_set_highbit): Fixed
+	allocation.  Reported by bpgcrypt at itaparica.org.
+	* mpiutil.c (_gcry_mpi_resize): Clear the new part of the resized
+	limb space.
+
 2006-07-26  Werner Koch  <wk@g10code.com>
 
 	* mpiutil.c (gcry_mpi_randomize): Changed P to unsigned char*.
diff --git a/mpi/mpi-bit.c b/mpi/mpi-bit.c
index 2d917995..d16eaae1 100644
--- a/mpi/mpi-bit.c
+++ b/mpi/mpi-bit.c
@@ -1,5 +1,5 @@
 /* mpi-bit.c  -  MPI bit level fucntions
- * Copyright (C) 1998, 1999, 2001, 2002 Free Software Foundation, Inc.
+ * Copyright (C) 1998, 1999, 2001, 2002, 2006 Free Software Foundation, Inc.
  *
  * This file is part of Libgcrypt.
  *
@@ -116,17 +116,17 @@ gcry_mpi_test_bit( gcry_mpi_t a, unsigned int n )
 void
 gcry_mpi_set_bit( gcry_mpi_t a, unsigned int n )
 {
-    unsigned int limbno, bitno;
+  unsigned int limbno, bitno;
 
-    limbno = n / BITS_PER_MPI_LIMB;
-    bitno  = n % BITS_PER_MPI_LIMB;
+  limbno = n / BITS_PER_MPI_LIMB;
+  bitno  = n % BITS_PER_MPI_LIMB;
 
-    if( limbno >= a->nlimbs ) { /* resize */
-	if( a->alloced >= limbno )
-	    mpi_resize(a, limbno+1 );
-	a->nlimbs = limbno+1;
+  if ( limbno >= a->nlimbs ) 
+    {
+      mpi_resize (a, limbno+1 );
+      a->nlimbs = limbno+1;
     }
-    a->d[limbno] |= (A_LIMB_1<<bitno);
+  a->d[limbno] |= (A_LIMB_1<<bitno);
 }
 
 /****************
@@ -135,20 +135,20 @@ gcry_mpi_set_bit( gcry_mpi_t a, unsigned int n )
 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 ) { /* resize */
-	if( a->alloced >= limbno )
-	    mpi_resize(a, limbno+1 );
-	a->nlimbs = limbno+1;
+  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;
+  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;
 }
 
 /****************
@@ -188,26 +188,77 @@ gcry_mpi_clear_bit( gcry_mpi_t a, unsigned int n )
 }
 
 
-/****************
- * Shift A by N bits to the right
- * FIXME: should use alloc_limb if X and A are same.
+/*
+ * Shift A by N bits to the right.
  */
 void
-gcry_mpi_rshift( gcry_mpi_t x, gcry_mpi_t a, unsigned n )
+gcry_mpi_rshift ( gcry_mpi_t x, gcry_mpi_t a, unsigned int n )
 {
-    mpi_ptr_t xp;
-    mpi_size_t xsize;
-
-    xsize = a->nlimbs;
-    x->sign = a->sign;
-    RESIZE_IF_NEEDED(x, xsize);
-    xp = x->d;
-
-    if( xsize ) {
-	_gcry_mpih_rshift( xp, a->d, xsize, n);
-	MPN_NORMALIZE( xp, xsize);
+  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 )
+        _gcry_mpih_rshift (x->d, a->d, x->nlimbs, nbits );
     }
-    x->nlimbs = xsize;
+  MPN_NORMALIZE (x->d, x->nlimbs);
 }
 
 
diff --git a/mpi/mpiutil.c b/mpi/mpiutil.c
index f6f9a8b2..fe1b7617 100644
--- a/mpi/mpiutil.c
+++ b/mpi/mpiutil.c
@@ -115,17 +115,30 @@ _gcry_mpi_assign_limb_space( gcry_mpi_t a, mpi_ptr_t ap, unsigned int nlimbs )
 
 
 /****************
- * Resize the array of A to NLIMBS. the additional space is cleared
- * (set to 0) [done by gcry_realloc()]
+ * Resize the array of A to NLIMBS. The additional space is cleared
+ * (set to 0).
  */
 void
 _gcry_mpi_resize (gcry_mpi_t a, unsigned nlimbs)
 {
+  size_t i;
+
   if (nlimbs <= a->alloced)
-    return; /* no need to do it */
+    {
+      /* We only need to clear the new space (this is a nop if the
+         limb space is already of the correct size. */
+      for (i=a->nlimbs; i < a->alloced; i++)
+        a->d[i] = 0;
+      return; 
+    }
 
+  /* Actually resize the limb space.  */
   if (a->d)
-    a->d = gcry_xrealloc (a->d, nlimbs * sizeof (mpi_limb_t));
+    {
+      a->d = gcry_xrealloc (a->d, nlimbs * sizeof (mpi_limb_t));
+      for (i=a->alloced; i < nlimbs; i++)
+        a->d[i] = 0;
+    }
   else
     {
       if (a->flags & 1)