commit e0c16922f934b864a034f11d4e0d2db4d008d80e
author Manuel Pégourié-Gonnard <mpg@elzevir.fr> Thu Nov 08 23:27:28 2012 +0100
committer Paul Bakker <p.j.bakker@polarssl.org> Wed Jan 16 16:31:51 2013 +0100
tree 2621f197d529cdc769a5ec779a72556b29957f41
parent 7e0adfbcc5bf444457049620f75b8aea40d78adc

Point multiplication using Jacobian coordinates

include/polarssl/ecp.h

diff --git a/include/polarssl/ecp.h b/include/polarssl/ecp.h
index 8763fc1..0de84aa 100644
--- a/include/polarssl/ecp.h
+++ b/include/polarssl/ecp.h
@@ -245,9 +245,6 @@
  *
  * \return          0 if successful,
  *                  POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed,
- *                  POLARSSL_ERR_MPI_DIVISION_BY_ZERO (shouldn't happen)
- *                  (temporary, a faster version not using division will be
- *                  used in the future)
  */
 int ecp_add( const ecp_group *grp, ecp_point *R,
              const ecp_point *P, const ecp_point *Q );
@@ -262,9 +259,6 @@
  *
  * \return          0 if successful,
  *                  POLARSSL_ERR_MPI_MALLOC_FAILED if memory allocation failed,
- *                  POLARSSL_ERR_MPI_DIVISION_BY_ZERO (shouldn't happen)
- *                  (temporary, a faster version not using division will be
- *                  used in the future)
  */
 int ecp_mul( const ecp_group *grp, ecp_point *R,
              const mpi *m, const ecp_point *P );

library/ecp.c

diff --git a/library/ecp.c b/library/ecp.c
index 92599e5..d64fd05 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -464,9 +464,9 @@
 {
     int ret = 0;
     size_t pos;
-    ecp_point Q[2];
+    ecp_ptjac Q[2];
 
-    ecp_point_init( &Q[0] ); ecp_point_init( &Q[1] );
+    ecp_ptjac_init( &Q[0] ); ecp_ptjac_init( &Q[1] );
 
     /*
      * The general method works only for m >= 1
@@ -476,23 +476,23 @@
         goto cleanup;
     }
 
-    ecp_set_zero( &Q[0] );
+    ecp_ptjac_set_zero( &Q[0] );
 
     for( pos = mpi_msb( m ) - 1 ; ; pos-- )
     {
-        MPI_CHK( ecp_add( grp, &Q[0], &Q[0], &Q[0] ) );
-        MPI_CHK( ecp_add( grp, &Q[1], &Q[0], P ) );
-        MPI_CHK( ecp_copy( &Q[0], &Q[ mpi_get_bit( m, pos ) ] ) );
+        MPI_CHK( ecp_double_jac( grp, &Q[0], &Q[0] ) );
+        MPI_CHK( ecp_add_mixed( grp, &Q[1], &Q[0], P ) );
+        MPI_CHK( ecp_ptjac_copy( &Q[0], &Q[ mpi_get_bit( m, pos ) ] ) );
 
         if( pos == 0 )
             break;
     }
 
-    MPI_CHK( ecp_copy( R, &Q[0] ) );
+    MPI_CHK( ecp_jac_to_aff( grp, R, &Q[0] ) );
 
 cleanup:
 
-    ecp_point_free( &Q[0] ); ecp_point_free( &Q[1] );
+    ecp_ptjac_free( &Q[0] ); ecp_ptjac_free( &Q[1] );
 
     return( ret );
 }