Third Party authentication protocol.

remoting/protocol/third_party_host_authenticator.cc

+// Copyright 2013 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/third_party_host_authenticator.h"
+
+#include "base/base64.h"
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/logging.h"
+#include "remoting/base/constants.h"
+#include "remoting/base/rsa_key_pair.h"
+#include "remoting/protocol/v2_authenticator.h"
+#include "third_party/libjingle/source/talk/xmllite/xmlelement.h"
+
+namespace remoting {
+namespace protocol {
+
+ThirdPartyHostAuthenticator::ThirdPartyHostAuthenticator(
+    const std::string& local_cert,
+    scoped_refptr<RsaKeyPair> key_pair,
+    scoped_ptr<TokenValidator> token_validator)
+    : ThirdPartyAuthenticatorBase(MESSAGE_READY),
+      local_cert_(local_cert),
+      key_pair_(key_pair),
+      token_validator_(token_validator.Pass()) {
+}
+
+ThirdPartyHostAuthenticator::~ThirdPartyHostAuthenticator() {
+}
+
+void ThirdPartyHostAuthenticator::ProcessTokenMessage(
+    const buzz::XmlElement* message,
+    const base::Closure& resume_callback) {
+  // Host has already sent the URL and expects a token from the client.
+  std::string token = message->TextNamed(kTokenTag);
+  if (!token.empty()) {
+    token_state_ = PROCESSING_MESSAGE;
+    // This message also contains the client's first SPAKE message. Copy the
+    // message into the callback, so that OnThirdPartyTokenValidated can give it
+    // to the underlying SPAKE authenticator that will be created.
+    // |token_validator_| is owned, so Unretained() is safe here.
+    token_validator_->ValidateThirdPartyToken(token, base::Bind(
+            &ThirdPartyHostAuthenticator::OnThirdPartyTokenValidated,
+            base::Unretained(this),

[Sergey Ulanov, 2013/03/20 07:24:12]

base::Unretained() is not safe unless you have a way to cancel it.

[rmsousa, 2013/03/21 01:23:25]

token_validator_ is owned. this object's destructor will destroy
token_validator_, ensuring the callback can't run after that.

+            base::Owned(new buzz::XmlElement(*message)),
+            resume_callback));
+    return;
+  }
+
+  LOG(ERROR) << "Third-party authentication protocol error: missing token.";
+  token_state_ = REJECTED;
+  rejection_reason_ = PROTOCOL_ERROR;
+  resume_callback.Run();
+}
+
+void ThirdPartyHostAuthenticator::AddTokenElements(
+    buzz::XmlElement* message) {
+  DCHECK(token_state_ == MESSAGE_READY);
+  DCHECK(token_validator_->token_url().is_valid());
+  DCHECK(!token_validator_->token_scope().empty());
+
+  buzz::XmlElement* token_url_tag = new buzz::XmlElement(
+      kTokenUrlTag);
+  token_url_tag->SetBodyText(token_validator_->token_url().spec());
+  message->AddElement(token_url_tag);
+  buzz::XmlElement* token_scope_tag = new buzz::XmlElement(
+      kTokenScopeTag);
+  token_scope_tag->SetBodyText(token_validator_->token_scope());
+  message->AddElement(token_scope_tag);
+  token_state_ = WAITING_MESSAGE;
+}
+
+void ThirdPartyHostAuthenticator::OnThirdPartyTokenValidated(
+    const buzz::XmlElement* message,
+    const base::Closure& resume_callback,
+    const std::string& shared_secret) {
+  if (!shared_secret.empty()) {
+    // The other side already started the SPAKE authentication.
+    token_state_ = ACCEPTED;
+    underlying_ = V2Authenticator::CreateForHost(
+        local_cert_, key_pair_, shared_secret, WAITING_MESSAGE);
+    underlying_->ProcessMessage(message, resume_callback);
+  } else {
+    token_state_ = REJECTED;
+    rejection_reason_ = INVALID_CREDENTIALS;
+    resume_callback.Run();
+  }
+}
+
+}  // namespace protocol
+}  // namespace remoting