Separate access token caching logic from signaling connector.

remoting/host/oauth_token_getter.cc

+// Copyright 2014 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/host/oauth_token_getter.h"
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/strings/string_util.h"
+#include "google_apis/google_api_keys.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "remoting/base/logging.h"
+
+namespace remoting {
+
+namespace {
+
+// Maximum number of retries on network/500 errors.
+const int kMaxRetries = 3;
+
+// Time when we we try to update OAuth token before its expiration.
+const int kTokenUpdateTimeBeforeExpirySeconds = 60;
+
+}  // namespace
+
+OAuthTokenGetter::OAuthCredentials::OAuthCredentials(
+    const std::string& login,
+    const std::string& refresh_token,
+    bool is_service_account)
+    : login(login),
+      refresh_token(refresh_token),
+      is_service_account(is_service_account) {
+}
+
+OAuthTokenGetter::OAuthTokenGetter(
+    scoped_ptr<OAuthCredentials> oauth_credentials,
+    scoped_refptr<net::URLRequestContextGetter> url_request_context_getter)
+    : oauth_credentials_(oauth_credentials.Pass()),
+      gaia_oauth_client_(
+          new gaia::GaiaOAuthClient(url_request_context_getter)),
+      url_request_context_getter_(url_request_context_getter),
+      refreshing_oauth_token_(false) {
+}
+
+OAuthTokenGetter::~OAuthTokenGetter() {}
+
+void OAuthTokenGetter::OnGetTokensResponse(const std::string& user_email,
+                                           const std::string& access_token,
+                                           int expires_seconds) {
+  NOTREACHED();
+}
+
+void OAuthTokenGetter::OnRefreshTokenResponse(
+    const std::string& access_token,
+    int expires_seconds) {
+  DCHECK(CalledOnValidThread());
+  DCHECK(oauth_credentials_.get());
+  HOST_LOG << "Received OAuth token.";
+
+  oauth_access_token_ = access_token;
+  auth_token_expiry_time_ = base::Time::Now() +
+      base::TimeDelta::FromSeconds(expires_seconds) -
+      base::TimeDelta::FromSeconds(kTokenUpdateTimeBeforeExpirySeconds);
+
+  gaia_oauth_client_->GetUserEmail(access_token, kMaxRetries, this);
+}
+
+void OAuthTokenGetter::OnGetUserEmailResponse(const std::string& user_email) {
+  DCHECK(CalledOnValidThread());
+  DCHECK(oauth_credentials_.get());
+  HOST_LOG << "Received user info.";
+
+  if (user_email != oauth_credentials_->login) {
+    LOG(ERROR) << "OAuth token and email address do not refer to "
+        "the same account.";
+    OnOAuthError();
+    return;
+  }
+
+  refreshing_oauth_token_ = false;
+
+  // Now that we've refreshed the token and verified that it's for the correct
+  // user account, try to connect using the new token.
+  NotifyCallbacks(OAuthTokenGetter::SUCCESS, user_email, oauth_access_token_);
+}
+
+void OAuthTokenGetter::NotifyCallbacks(Status status,
+                     const std::string& user_email,
+                     const std::string& access_token) {
+  std::queue<TokenCallback> callbacks(pending_callbacks_);
+  pending_callbacks_ = std::queue<TokenCallback>();
+
+  while (!callbacks.empty()) {
+    callbacks.front().Run(status, user_email, access_token);
+    callbacks.pop();
+  }
+}
+
+void OAuthTokenGetter::OnOAuthError() {
+  DCHECK(CalledOnValidThread());
+  LOG(ERROR) << "OAuth: invalid credentials.";
+  refreshing_oauth_token_ = false;
+  NotifyCallbacks(OAuthTokenGetter::AUTH_ERROR, std::string(), std::string());
+}
+
+void OAuthTokenGetter::OnNetworkError(int response_code) {
+  DCHECK(CalledOnValidThread());
+  LOG(ERROR) << "Network error when trying to update OAuth token: "
+             << response_code;
+  refreshing_oauth_token_ = false;
+  NotifyCallbacks(
+      OAuthTokenGetter::NETWORK_ERROR, std::string(), std::string());
+}
+
+void OAuthTokenGetter::CallWithToken(const TokenCallback& on_access_token) {
+  DCHECK(CalledOnValidThread());
+  bool need_new_auth_token = oauth_credentials_.get() &&
+      (auth_token_expiry_time_.is_null() ||
+       base::Time::Now() >= auth_token_expiry_time_);
+  if (need_new_auth_token) {
+    pending_callbacks_.push(on_access_token);
+    if (!refreshing_oauth_token_)
+      RefreshOAuthToken();
+  } else {
+    on_access_token.Run(
+        SUCCESS, oauth_credentials_->login, oauth_access_token_);
+  }
+}
+
+void OAuthTokenGetter::RefreshOAuthToken() {
+  DCHECK(CalledOnValidThread());
+  HOST_LOG << "Refreshing OAuth token.";
+  DCHECK(!refreshing_oauth_token_);
+
+  // Service accounts use different API keys, as they use the client app flow.
+  google_apis::OAuth2Client oauth2_client =
+      oauth_credentials_->is_service_account ?
+      google_apis::CLIENT_REMOTING_HOST : google_apis::CLIENT_REMOTING;
+
+  gaia::OAuthClientInfo client_info = {
+    google_apis::GetOAuth2ClientID(oauth2_client),
+    google_apis::GetOAuth2ClientSecret(oauth2_client),
+    // Redirect URL is only used when getting tokens from auth code. It
+    // is not required when getting access tokens.
+    ""
+  };
+
+  refreshing_oauth_token_ = true;
+  std::vector<std::string> empty_scope_list;  // Use scope from refresh token.
+  gaia_oauth_client_->RefreshToken(
+      client_info, oauth_credentials_->refresh_token, empty_scope_list,
+      kMaxRetries, this);
+}
+
+}  // namespace remoting