diff options
Diffstat (limited to 'mpi/mpih-sub.c')
| -rw-r--r-- | mpi/mpih-sub.c | 47 |
1 files changed, 11 insertions, 36 deletions
diff --git a/mpi/mpih-sub.c b/mpi/mpih-sub.c index 3831d81c3..0864ef8f0 100644 --- a/mpi/mpih-sub.c +++ b/mpi/mpih-sub.c @@ -1,5 +1,6 @@ /* mpihelp-sub.c - MPI helper functions * Copyright (c) 1997 by Werner Koch (dd9jn) + * Copyright (C) 1994, 1996 Free Software Foundation, Inc. * * This file is part of G10. * @@ -16,6 +17,14 @@ * 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. */ #include <config.h> @@ -24,8 +33,7 @@ #include "mpi-internal.h" - -/*_EXTERN_INLINE*/ +#ifndef __GNUC__ 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 ) @@ -55,39 +63,6 @@ mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, } -/* FIXME: this should be done in assembly */ -mpi_limb_t -mpihelp_sub_n( mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, - mpi_ptr_t s2_ptr, mpi_size_t size) -{ - mpi_limb_t x, y, cy; - mpi_size_t j; - - /* The loop counter and index J goes from -SIZE to -1. This way - the loop becomes faster. */ - j = -size; - - /* Offset the base pointers to compensate for the negative indices. */ - s1_ptr -= j; - s2_ptr -= j; - res_ptr -= j; - - cy = 0; - do { - y = s2_ptr[j]; - x = s1_ptr[j]; - y += cy; /* add previous carry to subtrahend */ - cy = y < cy ? 1:0; /* get out carry from that addition */ - y = x - y; /* main subtract */ - cy += y > x? 1:0; /* get out carry from the subtract, combine */ - res_ptr[j] = y; - } while( ++j ); - - return cy; -} - - -/*_EXTERN_INLINE*/ 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) @@ -102,5 +77,5 @@ mpihelp_sub( mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size, s1_size - s2_size, cy); return cy; } - +#endif |