xchacha20-poly1305

https://github.com/SagerNet/sing/blob/59dfe1dbfdbf319db27d2f00432f023b66f12c6d/protocol/socks/packet.go#L59-L73 My observation is that because the `buffer` passed to `WriteTo` includes the header, the returned `n` (number of bytes written) reflects the total length, including this header. I have...