Prohibit empty KeyUsage in certificates
Prohibit empty KeyUsage in certificates

Otherwise we treated an empty critical KeyUsage as equivalent to
the KeyUsage not being there at all.

Such KeyUsage encoding is prohibited by RFC 5280 and is additionally
non-sensical, so simply reject it at parse time.

Bug reported by Mario Korth of Ruhr-Universität Bochum.

randombit/botan,randombit/botan,randombit/botan,randombit/botan,randombit/botan