private static byte[] CalculateChecksum(byte[] pubkey)
{
// TORv3 CHECKSUM = H(".onion checksum" | PUBKEY | VERSION)[:2]
var prefix = Encoders.ASCII.DecodeData(".onion checksum");
var hasher = new Sha3Digest(256);
hasher.BlockUpdate(prefix, 0, prefix.Length);
hasher.BlockUpdate(pubkey, 0, pubkey.Length);
hasher.Update((byte)3);
var fullChecksum = new byte[hasher.GetByteLength()];
hasher.DoFinal(fullChecksum, 0);
return(fullChecksum.SafeSubarray(0, TORV3_ADDR_CHECKSUM_LEN));
}
