fix(shuttle): handshake buffer after 4k is discarded due to a change …

…in rustls

tunnel/src/client.rs

@@ -249,10 +249,16 @@ async fn tls12_handshake(
  stream.peer_addr().unwrap(),
  TlsContentType::from(buf[0]),
  );
- let n = tlsconn
- .read_tls(&mut io::Cursor::new(&mut buf[..5 + len]))
- .unwrap();
- debug_assert_eq!(n, 5 + len);
+ // rustls reads at most 4k for once, while it accepts 16k at most if feed multiple times.
+ // ref: https://github.com/rustls/rustls/blob/1164380b2e40a1db8b3909323581bd2647d82b0c/rustls/src/msgs/deframer.rs#L295
+ let mut i = 0;
+ while i < 5 + len {
+ let n = tlsconn
+ .read_tls(&mut io::Cursor::new(&mut buf[i..5 + len]))
+ .unwrap();
+ assert!(n > 0, "TLS feed zero");
+ i += n;
+ }
  tlsconn.process_new_packets().map_err(|e| {
  debug!(
  "tls state error when handshaking {} <-> {}: {:?}",