+
+int EC_GROUP_get_basis_type(const EC_GROUP *group)
+ {
+ int i=0;
+
+ if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
+ NID_X9_62_characteristic_two_field)
+ /* everything else is currently not supported */
+ return 0;
+
+ while (group->poly[i] != 0)
+ i++;
+
+ if (i == 4)
+ return NID_X9_62_ppBasis;
+ else if (i == 2)
+ return NID_X9_62_tpBasis;
+ else
+ /* everything else is currently not supported */
+ return 0;
+ }
+
+int EC_GROUP_get_trinomial_basis(const EC_GROUP *group, unsigned int *k)
+ {
+ if (group == NULL)
+ return 0;
+
+ if (EC_GROUP_method_of(group)->group_set_curve != ec_GF2m_simple_group_set_curve
+ || !((group->poly[0] != 0) && (group->poly[1] != 0) && (group->poly[2] == 0)))
+ {
+ ECerr(EC_F_EC_GROUP_GET_TRINOMIAL_BASIS, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
+ return 0;
+ }
+
+ if (k)
+ *k = group->poly[1];
+
+ return 1;
+ }
+
+int EC_GROUP_get_pentanomial_basis(const EC_GROUP *group, unsigned int *k1,
+ unsigned int *k2, unsigned int *k3)
+ {
+ if (group == NULL)
+ return 0;
+
+ if (EC_GROUP_method_of(group)->group_set_curve != ec_GF2m_simple_group_set_curve
+ || !((group->poly[0] != 0) && (group->poly[1] != 0) && (group->poly[2] != 0) && (group->poly[3] != 0) && (group->poly[4] == 0)))
+ {
+ ECerr(EC_F_EC_GROUP_GET_PENTANOMIAL_BASIS, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
+ return 0;
+ }
+
+ if (k1)
+ *k1 = group->poly[3];
+ if (k2)
+ *k2 = group->poly[2];
+ if (k3)
+ *k3 = group->poly[1];
+
+ return 1;
+ }
+
+
+