8178135: Additional elliptic curve support

Reviewed-by: mullan

src/share/native/sun/security/ec/impl/ecp_jac.c

@@ -180,6 +180,15 @@ ec_GFp_pt_add_jac_aff(const mp_int *px, const mp_int *py, const mp_int *pz,
         MP_CHECKOK(group->meth->field_mul(&A, qx, &A, group->meth));
         MP_CHECKOK(group->meth->field_mul(&B, qy, &B, group->meth));
 
+        /*
+         * Additional checks for point equality and point at infinity
+         */
+        if (mp_cmp(px, &A) == 0 && mp_cmp(py, &B) == 0) {
+            /* POINT_DOUBLE(P) */
+            MP_CHECKOK(ec_GFp_pt_dbl_jac(px, py, pz, rx, ry, rz, group));
+            goto CLEANUP;
+        }
+
         /* C = A - px, D = B - py */
         MP_CHECKOK(group->meth->field_sub(&A, px, &C, group->meth));
         MP_CHECKOK(group->meth->field_sub(&B, py, &D, group->meth));

src/share/native/sun/security/ec/impl/ecp_jm.c

@@ -165,6 +165,16 @@ ec_GFp_pt_add_jm_aff(const mp_int *px, const mp_int *py, const mp_int *pz,
         MP_CHECKOK(group->meth->field_mul(A, qx, A, group->meth));
         MP_CHECKOK(group->meth->field_mul(B, qy, B, group->meth));
 
+        /*
+         * Additional checks for point equality and point at infinity
+         */
+        if (mp_cmp(px, A) == 0 && mp_cmp(py, B) == 0) {
+            /* POINT_DOUBLE(P) */
+            MP_CHECKOK(ec_GFp_pt_dbl_jm(px, py, pz, paz4, rx, ry, rz, raz4,
+                                        scratch, group));
+            goto CLEANUP;
+        }
+
         /* C = A - px, D = B - py */
         MP_CHECKOK(group->meth->field_sub(A, px, C, group->meth));
         MP_CHECKOK(group->meth->field_sub(B, py, D, group->meth));