crypto/elliptic: fix IsOnCurve for big.Int values that are not valid coordinates
Some big.Int values that are not valid field elements (negative or overflowing)
might cause Curve.IsOnCurve to incorrectly return true. Operating on those values
may cause a panic or an invalid curve operation. Note that Unmarshal will never
return such values.
Upstream-Status: Backport [https://go.dev/issue/50974]
CVE: CVE-2022-23806
Signed-off-by:Minjae Kim <flowergom@gmail.com> Signed-off-by: Steve Sakoman <steve@sakoman.com>
