This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / crypto / mpi / mpi-inline.h

diff --git a/crypto/mpi/mpi-inline.h b/crypto/mpi/mpi-inline.h
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+/* mpi-inline.h  -  Internal to the Multi Precision Integers
+ *     Copyright (C) 1994, 1996, 1998, 1999 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.
+ */
+
+#ifndef G10_MPI_INLINE_H
+#define G10_MPI_INLINE_H
+
+#ifndef G10_MPI_INLINE_DECL
+  #define G10_MPI_INLINE_DECL  extern __inline__
+#endif
+
+G10_MPI_INLINE_DECL  mpi_limb_t
+mpihelp_add_1( mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+              mpi_size_t s1_size, mpi_limb_t s2_limb)
+{
+    mpi_limb_t x;
+
+    x = *s1_ptr++;
+    s2_limb += x;
+    *res_ptr++ = s2_limb;
+    if( s2_limb < x ) { /* sum is less than the left operand: handle carry */
+       while( --s1_size ) {
+           x = *s1_ptr++ + 1;  /* add carry */
+           *res_ptr++ = x;     /* and store */
+           if( x )             /* not 0 (no overflow): we can stop */
+               goto leave;
+       }
+       return 1; /* return carry (size of s1 to small) */
+    }
+
+  leave:
+    if( res_ptr != s1_ptr ) { /* not the same variable */
+       mpi_size_t i;          /* copy the rest */
+       for( i=0; i < s1_size-1; i++ )
+           res_ptr[i] = s1_ptr[i];
+    }
+    return 0; /* no carry */
+}
+
+
+
+G10_MPI_INLINE_DECL mpi_limb_t
+mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
+                              mpi_ptr_t s2_ptr, mpi_size_t s2_size)
+{
+    mpi_limb_t cy = 0;
+
+    if( s2_size )
+       cy = mpihelp_add_n( res_ptr, s1_ptr, s2_ptr, s2_size );
+
+    if( s1_size - s2_size )
+       cy = mpihelp_add_1( res_ptr + s2_size, s1_ptr + s2_size,
+                           s1_size - s2_size, cy);
+    return cy;
+}
+
+
+G10_MPI_INLINE_DECL mpi_limb_t
+mpihelp_sub_1(mpi_ptr_t res_ptr,  mpi_ptr_t s1_ptr,
+             mpi_size_t s1_size, mpi_limb_t s2_limb )
+{
+    mpi_limb_t x;
+
+    x = *s1_ptr++;
+    s2_limb = x - s2_limb;
+    *res_ptr++ = s2_limb;
+    if( s2_limb > x ) {
+       while( --s1_size ) {
+           x = *s1_ptr++;
+           *res_ptr++ = x - 1;
+           if( x )
+               goto leave;
+       }
+       return 1;
+    }
+
+  leave:
+    if( res_ptr != s1_ptr ) {
+       mpi_size_t i;
+       for( i=0; i < s1_size-1; i++ )
+           res_ptr[i] = s1_ptr[i];
+    }
+    return 0;
+}
+
+
+
+G10_MPI_INLINE_DECL   mpi_limb_t
+mpihelp_sub( mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
+                               mpi_ptr_t s2_ptr, mpi_size_t s2_size)
+{
+    mpi_limb_t cy = 0;
+
+    if( s2_size )
+       cy = mpihelp_sub_n(res_ptr, s1_ptr, s2_ptr, s2_size);
+
+    if( s1_size - s2_size )
+       cy = mpihelp_sub_1(res_ptr + s2_size, s1_ptr + s2_size,
+                                     s1_size - s2_size, cy);
+    return cy;
+}
+
+
+#endif /*G10_MPI_INLINE_H*/