File libgcrypt-CVE-2015-7511.patch of Package libgcrypt.25806

Index: libgcrypt-1.6.1/mpi/ec.c
===================================================================
--- libgcrypt-1.6.1.orig/mpi/ec.c
+++ libgcrypt-1.6.1/mpi/ec.c
@@ -1106,16 +1106,27 @@ _gcry_mpi_ec_mul_point (mpi_point_t resu
   unsigned int i, loops;
   mpi_point_struct p1, p2, p1inv;
 
-  if (ctx->model == MPI_EC_TWISTEDEDWARDS)
+  if (ctx->model == MPI_EC_TWISTEDEDWARDS
+      || (ctx->model == MPI_EC_WEIERSTRASS
+          && mpi_is_secure (scalar)))
     {
       /* Simple left to right binary method.  GECC Algorithm 3.27 */
       unsigned int nbits;
       int j;
 
       nbits = mpi_get_nbits (scalar);
-      mpi_set_ui (result->x, 0);
-      mpi_set_ui (result->y, 1);
-      mpi_set_ui (result->z, 1);
+      if (ctx->model == MPI_EC_WEIERSTRASS)
+        {
+          mpi_set_ui (result->x, 1);
+          mpi_set_ui (result->y, 1);
+          mpi_set_ui (result->z, 0);
+        }
+      else
+        {
+          mpi_set_ui (result->x, 0);
+          mpi_set_ui (result->y, 1);
+          mpi_set_ui (result->z, 1);
+        }
 
       if (mpi_is_secure (scalar))
         {