Just an unnecessary allocation. The AsnEncodedData ctor makes a copy regardless of whether the input is a span or an array, so may as well avoid allocating another array on top of that.
//
// This is due to one version of the ASN.1 not including OPTIONAL, and that was
// the version that got predominately implemented for RSA. Now it's convention.
- new AsnEncodedData(oid, new byte[] { 0x05, 0x00 }),
+ new AsnEncodedData(oid, stackalloc byte[] { 0x05, 0x00 }),
new AsnEncodedData(oid, rsa.ExportRSAPublicKey()));
}