func GenPrivateKey(c *Curve, rand io.Reader) (*PrivateKey, error) {
raw := make([]byte, c.PointSize())
if _, err := io.ReadFull(rand, raw); err != nil {
func GenPrivateKey(c *Curve, rand io.Reader) (*PrivateKey, error) {
raw := make([]byte, c.PointSize())
if _, err := io.ReadFull(rand, raw); err != nil {