commit 6ece5004b61bff35fb3d183cb10ebc919f973cb2
author dschinazi <dschinazi@google.com> Wed May 22 06:35:49 2019 -0700
committer Copybara-Service <copybara-worker@google.com> Wed May 22 06:36:25 2019 -0700
tree 685ba8ebcba12bd00bd23b81786e42d82a80329e
parent e9dc7daca7ba90abc75c9fdffd329fea47fc4a08

Ensure we can decrypt the first packet

At the IETF interop in London we noticed that our server would always fail to decrypt the first packet when TLS is in use. This CL fixes that issue by installing the decrypter immediately on connection creation, and creates a test to make sure it doesn't happen again.

gfe-relnote: ensure first packet is decrypted, protected by disabled flag quic_supports_tls_handshake
PiperOrigin-RevId: 249437099
Change-Id: Iebcc0f5c18642a4f3db3265ab7bf669dd76e782b

quic/core/quic_connection.cc

diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index a8672f5..73959f0 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -412,6 +412,19 @@
   DCHECK(!GetQuicRestartFlag(quic_no_server_conn_ver_negotiation2) ||
          perspective_ == Perspective::IS_CLIENT ||
          supported_versions.size() == 1);
+  InstallInitialCrypters();
+}
+
+void QuicConnection::InstallInitialCrypters() {
+  if (version().handshake_protocol != PROTOCOL_TLS1_3) {
+    // Initial crypters are currently only supported with TLS.
+    return;
+  }
+  CrypterPair crypters;
+  CryptoUtils::CreateTlsInitialCrypters(perspective_, transport_version(),
+                                        server_connection_id_, &crypters);
+  SetEncrypter(ENCRYPTION_INITIAL, std::move(crypters.encrypter));
+  InstallDecrypter(ENCRYPTION_INITIAL, std::move(crypters.decrypter));
 }
 
 QuicConnection::~QuicConnection() {
@@ -770,6 +783,7 @@
 void QuicConnection::OnRetryPacket(QuicConnectionId original_connection_id,
                                    QuicConnectionId new_connection_id,
                                    QuicStringPiece retry_token) {
+  DCHECK_EQ(Perspective::IS_CLIENT, perspective_);
   if (original_connection_id != server_connection_id_) {
     QUIC_DLOG(ERROR) << "Ignoring RETRY with original connection ID "
                      << original_connection_id << " not matching expected "
@@ -792,12 +806,7 @@
   packet_generator_.SetRetryToken(retry_token);
 
   // Reinstall initial crypters because the connection ID changed.
-  CrypterPair crypters;
-  CryptoUtils::CreateTlsInitialCrypters(Perspective::IS_CLIENT,
-                                        transport_version(),
-                                        server_connection_id_, &crypters);
-  SetEncrypter(ENCRYPTION_INITIAL, std::move(crypters.encrypter));
-  InstallDecrypter(ENCRYPTION_INITIAL, std::move(crypters.decrypter));
+  InstallInitialCrypters();
 }
 
 bool QuicConnection::HasIncomingConnectionId(QuicConnectionId connection_id) {
@@ -1997,6 +2006,7 @@
     // If we are unable to decrypt this packet, it might be
     // because the CHLO or SHLO packet was lost.
     if (framer_.error() == QUIC_DECRYPTION_FAILURE) {
+      ++stats_.undecryptable_packets_received;
       if (encryption_level_ != ENCRYPTION_FORWARD_SECURE &&
           undecryptable_packets_.size() < max_undecryptable_packets_) {
         QueueUndecryptablePacket(packet);
@@ -3051,6 +3061,7 @@
       // If we are unable to decrypt this packet, it might be
       // because the CHLO or SHLO packet was lost.
       if (framer_.error() == QUIC_DECRYPTION_FAILURE) {
+        ++stats_.undecryptable_packets_received;
         if (encryption_level_ != ENCRYPTION_FORWARD_SECURE &&
             undecryptable_packets_.size() < max_undecryptable_packets_) {
           QueueUndecryptablePacket(*packet);