refactor open AEAD selection
No functional change, just cosmetic. It still looks kind of gross, but
IMO better than before.
diff --git a/src/lib.rs b/src/lib.rs
index f2a85de..b5759ad 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1597,39 +1597,25 @@
// Select packet number space epoch based on the received packet's type.
let epoch = hdr.ty.to_epoch()?;
- // TODO: somehow deal with re-ordered 0-RTT data.
- let aead = if hdr.ty == packet::Type::ZeroRTT &&
- self.pkt_num_spaces[epoch].crypto_0rtt_open.is_some()
- {
- // TODO: buffer 0-RTT packets instead of discarding when key is not
- // available yet, as an optimization.
- self.pkt_num_spaces[epoch]
- .crypto_0rtt_open
- .as_ref()
- .unwrap()
- } else {
- match self.pkt_num_spaces[epoch].crypto_open {
- Some(ref v) => v,
-
- // Ignore packets that can't be decrypted because we don't have
- // the necessary decryption key (either because we don't yet
- // have it or because we already dropped it).
- //
- // For example, this is necessary to prevent packet reordering
- // (e.g. between Initial and Handshake) from causing the
- // connection to be closed.
- //
- // TODO: buffer 1-RTT packets instead of discarding when key is
- // not available yet, as an optimization.
- None =>
- return Err(drop_pkt_on_err(
- Error::CryptoFail,
- self.recv_count,
- self.is_server,
- &self.trace_id,
- )),
- }
- };
+ // Select AEAD context used to open incoming packet.
+ #[allow(clippy::or_fun_call)]
+ let aead = (self.pkt_num_spaces[epoch].crypto_0rtt_open.as_ref())
+ // Only use 0-RTT key if incoming packet is 0-RTT.
+ .filter(|_| hdr.ty == packet::Type::ZeroRTT)
+ // Otherwise use the packet number space's main key.
+ .or(self.pkt_num_spaces[epoch].crypto_open.as_ref())
+ // Finally, discard packet if no usable key is available.
+ //
+ // TODO: buffer 0-RTT/1-RTT packets instead of discarding when the
+ // required key is not available yet, as an optimization.
+ .ok_or_else(|| {
+ drop_pkt_on_err(
+ Error::CryptoFail,
+ self.recv_count,
+ self.is_server,
+ &self.trace_id,
+ )
+ })?;
let aead_tag_len = aead.alg().tag_len();
