diff --git a/quic/test_tools/crypto_test_utils.cc b/quic/test_tools/crypto_test_utils.cc
index 634c16f..cbf4fe2 100644
--- a/quic/test_tools/crypto_test_utils.cc
+++ b/quic/test_tools/crypto_test_utils.cc
@@ -393,6 +393,53 @@
   }
 }
 
+bool CommunicateHandshakeMessagesUntil(PacketSavingConnection* client_conn,
+                                       QuicCryptoStream* client,
+                                       std::function<bool()> client_condition,
+                                       PacketSavingConnection* server_conn,
+                                       QuicCryptoStream* server,
+                                       std::function<bool()> server_condition) {
+  size_t client_next_packet_to_deliver =
+      client_conn->number_of_packets_delivered_;
+  size_t server_next_packet_to_deliver =
+      server_conn->number_of_packets_delivered_;
+  while (
+      client_conn->connected() && server_conn->connected() &&
+      (!client_condition() || !server_condition()) &&
+      (client_conn->encrypted_packets_.size() > client_next_packet_to_deliver ||
+       server_conn->encrypted_packets_.size() >
+           server_next_packet_to_deliver)) {
+    if (!server_condition()) {
+      QUIC_LOG(INFO) << "Processing "
+                     << client_conn->encrypted_packets_.size() -
+                            client_next_packet_to_deliver
+                     << " packets client->server";
+      MovePackets(client_conn, &client_next_packet_to_deliver, server,
+                  server_conn, Perspective::IS_SERVER);
+    }
+    if (!client_condition()) {
+      QUIC_LOG(INFO) << "Processing "
+                     << server_conn->encrypted_packets_.size() -
+                            server_next_packet_to_deliver
+                     << " packets server->client";
+      MovePackets(server_conn, &server_next_packet_to_deliver, client,
+                  client_conn, Perspective::IS_CLIENT);
+    }
+  }
+  client_conn->number_of_packets_delivered_ = client_next_packet_to_deliver;
+  server_conn->number_of_packets_delivered_ = server_next_packet_to_deliver;
+  bool result = client_condition() && server_condition();
+  if (!result) {
+    QUIC_LOG(INFO) << "CommunicateHandshakeMessagesUnti failed with state: "
+                      "client connected? "
+                   << client_conn->connected() << " server connected? "
+                   << server_conn->connected() << " client condition met? "
+                   << client_condition() << " server condition met? "
+                   << server_condition();
+  }
+  return result;
+}
+
 std::pair<size_t, size_t> AdvanceHandshake(PacketSavingConnection* client_conn,
                                            QuicCryptoStream* client,
                                            size_t client_i,
diff --git a/quic/test_tools/crypto_test_utils.h b/quic/test_tools/crypto_test_utils.h
index 87e354a..b4d772a 100644
--- a/quic/test_tools/crypto_test_utils.h
+++ b/quic/test_tools/crypto_test_utils.h
@@ -109,6 +109,19 @@
                                   PacketSavingConnection* server_conn,
                                   QuicCryptoStream* server);
 
+// CommunicateHandshakeMessagesUntil:
+// 1) Moves messages from |client| to |server| until |server_condition| is met.
+// 2) Moves messages from |server| to |client| until |client_condition| is met.
+// 3) Returns true if both conditions are met.
+// 4) Returns false if either connection is closed or there is no more packet to
+// deliver before both conditions are met.
+bool CommunicateHandshakeMessagesUntil(PacketSavingConnection* client_conn,
+                                       QuicCryptoStream* client,
+                                       std::function<bool()> client_condition,
+                                       PacketSavingConnection* server_conn,
+                                       QuicCryptoStream* server,
+                                       std::function<bool()> server_condition);
+
 // AdvanceHandshake attempts to moves messages from |client| to |server| and
 // |server| to |client|. Returns the number of messages moved.
 std::pair<size_t, size_t> AdvanceHandshake(PacketSavingConnection* client_conn,
diff --git a/quic/test_tools/quic_connection_peer.cc b/quic/test_tools/quic_connection_peer.cc
index b511949..ec579be 100644
--- a/quic/test_tools/quic_connection_peer.cc
+++ b/quic/test_tools/quic_connection_peer.cc
@@ -57,6 +57,12 @@
 }
 
 // static
+QuicTime::Delta QuicConnectionPeer::GetHandshakeTimeout(
+    QuicConnection* connection) {
+  return connection->idle_network_detector_.handshake_timeout_;
+}
+
+// static
 void QuicConnectionPeer::SetPerspective(QuicConnection* connection,
                                         Perspective perspective) {
   connection->perspective_ = perspective;
diff --git a/quic/test_tools/quic_connection_peer.h b/quic/test_tools/quic_connection_peer.h
index aa30c24..26d2f41 100644
--- a/quic/test_tools/quic_connection_peer.h
+++ b/quic/test_tools/quic_connection_peer.h
@@ -50,6 +50,8 @@
 
   static QuicTime::Delta GetNetworkTimeout(QuicConnection* connection);
 
+  static QuicTime::Delta GetHandshakeTimeout(QuicConnection* connection);
+
   static void SetPerspective(QuicConnection* connection,
                              Perspective perspective);
 
diff --git a/quic/test_tools/quic_test_utils.h b/quic/test_tools/quic_test_utils.h
index 051ab62..44e9ca2 100644
--- a/quic/test_tools/quic_test_utils.h
+++ b/quic/test_tools/quic_test_utils.h
@@ -745,6 +745,9 @@
   MOCK_METHOD(void, OnPacketSent, (EncryptionLevel, TransmissionType));
 
   std::vector<std::unique_ptr<QuicEncryptedPacket>> encrypted_packets_;
+  // Number of packets in encrypted_packets that has been delivered to the peer
+  // connection.
+  size_t number_of_packets_delivered_ = 0;
   MockClock clock_;
 };