mpih: Expose const-time MPI helper functions.

* mpi/Makefile.am (libmpi_la_SOURCES): Add mpih-const-time.c.
* mpi/ec.c (mpih_set_cond): Move to mpih-const-time.c.
* mpi/mpi-internal.h: Add macros and declarations.
* mpi/mpi-inv.c (mpih_add_n_cond): Likewise.
(mpih_sub_n_cond, mpih_swap_cond, mpih_abs_cond): Likewise.
* mpi/mpih-const-time.c: New.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>

1 files changed, 0 insertions, 101 deletions

diff --git a/mpi/mpi-inv.c b/mpi/mpi-inv.c
index 0114622d..0efe12ce 100644
--- a/mpi/mpi-inv.c
+++ b/mpi/mpi-inv.c
@@ -24,107 +24,6 @@
 #include "g10lib.h"
 
 /*
- *  W = U + V when OP_ENABLED=1
- *  otherwise, W = U
- */
-static mpi_limb_t
-mpih_add_n_cond (mpi_ptr_t wp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t usize,
-                 unsigned long op_enable)
-{
-  mpi_size_t i;
-  mpi_limb_t cy;
-  mpi_limb_t mask = ((mpi_limb_t)0) - op_enable;
-
-  cy = 0;
-  for (i = 0; i < usize; i++)
-    {
-      mpi_limb_t x = up[i] + (vp[i] & mask);
-      mpi_limb_t cy1 = x < up[i];
-      mpi_limb_t cy2;
-
-      x = x + cy;
-      cy2 = x < cy;
-      cy = cy1 | cy2;
-      wp[i] = x;
-    }
-
-  return cy;
-}
-
-
-/*
- *  W = U - V when OP_ENABLED=1
- *  otherwise, W = U
- */
-static mpi_limb_t
-mpih_sub_n_cond (mpi_ptr_t wp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t usize,
-                 unsigned long op_enable)
-{
-  mpi_size_t i;
-  mpi_limb_t cy;
-  mpi_limb_t mask = ((mpi_limb_t)0) - op_enable;
-
-  cy = 0;
-  for (i = 0; i < usize; i++)
-    {
-      mpi_limb_t x = up[i] - (vp[i] & mask);
-      mpi_limb_t cy1 = x > up[i];
-      mpi_limb_t cy2;
-
-      cy2 = x < cy;
-      x = x - cy;
-      cy = cy1 | cy2;
-      wp[i] = x;
-    }
-
-  return cy;
-}
-
-
-/*
- *  Swap value of U and V when OP_ENABLED=1
- *  otherwise, no change
- */
-static void
-mpih_swap_cond (mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t usize,
-                unsigned long op_enable)
-{
-  mpi_size_t i;
-  mpi_limb_t mask = ((mpi_limb_t)0) - op_enable;
-
-  for (i = 0; i < usize; i++)
-    {
-      mpi_limb_t x = mask & (up[i] ^ vp[i]);
-
-      up[i] = up[i] ^ x;
-      vp[i] = vp[i] ^ x;
-    }
-}
-
-
-/*
- *  W = -U when OP_ENABLED=1
- *  otherwise, W = U
- */
-static void
-mpih_abs_cond (mpi_limb_t *wp, const mpi_limb_t *up, mpi_size_t usize,
-               unsigned long op_enable)
-{
-  mpi_size_t i;
-  mpi_limb_t mask = ((mpi_limb_t)0) - op_enable;
-  mpi_limb_t cy = op_enable;
-
-  for (i = 0; i < usize; i++)
-    {
-      mpi_limb_t x = ~up[i] + cy;
-
-      cy = (x < ~up[i]);
-      wp[i] = up[i] ^ (mask & (x ^ up[i]));
-    }
-}
-
-
-/*
  * This uses a modular inversion algorithm designed by Niels Möller
  * which was implemented in Nettle.  The same algorithm was later also
  * adapted to GMP in mpn_sec_invert.