Fix IT2Me protocol error connecting to old hosts.

remoting/protocol/negotiating_authenticator_base.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/protocol/negotiating_authenticator_base.h"
 
 #include <algorithm>
 #include <sstream>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/strings/string_split.h"
 #include "remoting/base/constants.h"
 #include "remoting/base/rsa_key_pair.h"
 #include "remoting/protocol/channel_authenticator.h"
 #include "remoting/protocol/name_value_map.h"
 #include "third_party/webrtc/libjingle/xmllite/xmlelement.h"
 
 namespace remoting {
 namespace protocol {
 
 namespace {
 
 const NameMapElement<NegotiatingAuthenticatorBase::Method>
     kAuthenticationMethodStrings[] = {
+        {NegotiatingAuthenticatorBase::Method::SHARED_SECRET_PLAIN_SPAKE2_P224,
+         "spake2_plain"},
+
         {NegotiatingAuthenticatorBase::Method::SHARED_SECRET_SPAKE2_P224,
          "spake2_hmac"},
         {NegotiatingAuthenticatorBase::Method::SHARED_SECRET_SPAKE2_CURVE25519,
          "spake2_curve25519"},
 
         {NegotiatingAuthenticatorBase::Method::PAIRED_SPAKE2_P224,
          "spake2_pair"},
         {NegotiatingAuthenticatorBase::Method::PAIRED_SPAKE2_CURVE25519,
          "pair_spake2_curve25519"},
 
@@ skipping 118 matching lines @@
 }
 
 std::unique_ptr<ChannelAuthenticator>
 NegotiatingAuthenticatorBase::CreateChannelAuthenticator() const {
   DCHECK_EQ(state(), ACCEPTED);
   return current_authenticator_->CreateChannelAuthenticator();
 }
 
 }  // namespace protocol
 }  // namespace remoting