Google OAuth Device Flow support for FNL

services/authentication/google_authentication_impl.cc

Index: services/authentication/google_authentication_impl.cc
diff --git a/services/authentication/google_authentication_impl.cc b/services/authentication/google_authentication_impl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fa5360dff9154b94713a07729242e49b83e72e0b
--- /dev/null
+++ b/services/authentication/google_authentication_impl.cc
@@ -0,0 +1,457 @@
+// Copyright 2016 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 "services/authentication/google_authentication_impl.h"
+
+#include "base/json/json_reader.h"
+#include "base/json/json_writer.h"
+#include "base/message_loop/message_loop.h"
+#include "base/strings/string_piece.h"
+#include "base/strings/string_split.h"
+#include "base/strings/string_tokenizer.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+#include "base/synchronization/waitable_event.h"
+#include "base/threading/platform_thread.h"
+#include "base/trace_event/trace_event.h"
+#include "base/values.h"
+#include "mojo/common/binding_set.h"
+#include "mojo/data_pipe_utils/data_pipe_drainer.h"
+#include "mojo/data_pipe_utils/data_pipe_utils.h"
+#include "mojo/public/c/system/main.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+#include "mojo/public/cpp/system/macros.h"
+#include "mojo/services/network/interfaces/url_loader.mojom.h"
+#include "services/authentication/credentials_impl_db.mojom.h"
+
+namespace authentication {
+
+// Mojo Shell OAuth2 Client configuration.
+// TODO: These should be retrieved from a secure storage or a configuration file
+// in the future.
+char kMojoShellOAuth2ClientId[] =
+    "962611923869-3avg0b4vlisgjhin0l98dgp6d8sd634r.apps.googleusercontent.com";
+char kMojoShellOAuth2ClientSecret[] = "41IxvPPAt1HyRoYw2hO84dRI";
+
+// Query params used in Google OAuth2 handshake
+char kOAuth2ClientIdParamName[] = "client_id";
+char kOAuth2ClientSecretParamName[] = "client_secret";
+char kOAuth2ScopeParamName[] = "scope";
+char kOAuth2GrantTypeParamName[] = "grant_type";
+char kOAuth2CodeParamName[] = "code";
+char kOAuth2RefreshTokenParamName[] = "refresh_token";
+char kOAuth2DeviceFlowGrantType[] = "http://oauth.net/grant_type/device/1.0";
+char kOAuth2RefreshTokenGrantType[] = "refresh_token";
+
+// TODO(ukode) : Verify the char list
+char kEscapableUrlParamChars[] = ".$[]/";
+
+std::string EncodeParam(std::string param) {
+  for (size_t i = 0; i < strlen(kEscapableUrlParamChars); ++i) {
+    base::ReplaceSubstringsAfterOffset(
+        &param, 0, std::string(1, kEscapableUrlParamChars[i]),
+        base::StringPrintf("%%%x", kEscapableUrlParamChars[i]));
+  }
+  return param;
+}
+
+mojo::String BuildUrlQuery(mojo::Map<mojo::String, mojo::String> params) {
+  std::string message;
+  for (auto it = params.begin(); it != params.end(); ++it) {
+    message += EncodeParam(it.GetKey()) + "=" + EncodeParam(it.GetValue());
+    message += "&";
+  }
+
+  if (!message.empty()) {
+    message = message.substr(0, message.size() - 1);  // Trims extra "&".
+  }
+  return message;
+}
+
+static base::DictionaryValue* ParseOAuth2Response(const std::string& response) {
+  if (response.empty()) {
+    return nullptr;
+  }
+
+  scoped_ptr<base::Value> root(base::JSONReader::Read(response));
+  if (!root || !root->IsType(base::Value::TYPE_DICTIONARY)) {
+    LOG(ERROR) << "Unexpected json response:" << std::endl << response;
+    return nullptr;
+  }
+
+  return static_cast<base::DictionaryValue*>(root.release());
+}
+
+GoogleAuthenticationServiceImpl::GoogleAuthenticationServiceImpl(
+    mojo::InterfaceRequest<AuthenticationService> request,
+    const mojo::String app_url,
+    mojo::NetworkServicePtr& network_service,
+    mojo::files::DirectoryPtr& directory)
+    : binding_(this, request.Pass()),
+      app_url_(app_url),
+      network_service_(network_service) {
+  accounts_db_manager_ = new AccountsDbManager(directory.Pass());
+}
+
+GoogleAuthenticationServiceImpl::~GoogleAuthenticationServiceImpl() {
+  delete accounts_db_manager_;
+}
+
+void GoogleAuthenticationServiceImpl::GetOAuth2Token(
+    const mojo::String& username,
+    mojo::Array<mojo::String> scopes,
+    const GetOAuth2TokenCallback& callback) {
+  if (!accounts_db_manager_->isValid()) {
+    callback.Run(nullptr, "Accounts db validation failed.");
+    return;
+  }
+
+  authentication::CredentialsPtr creds =
+      accounts_db_manager_->GetCredentials(username);
+
+  if (!creds->token) {
+    callback.Run(nullptr, "User grant not found");
+    return;
+  }
+
+  // TODO: Scopes are not used with the scoped refresh tokens. When we start
+  // supporting full login scoped tokens, then the scopes here gets used for
+  // Sidescoping.
+  mojo::Map<mojo::String, mojo::String> params;
+  params[kOAuth2ClientIdParamName] = kMojoShellOAuth2ClientId;
+  params[kOAuth2ClientSecretParamName] = kMojoShellOAuth2ClientSecret;
+  params[kOAuth2GrantTypeParamName] = kOAuth2RefreshTokenGrantType;
+  params[kOAuth2RefreshTokenParamName] = creds->token;
+
+  Request("https://www.googleapis.com/oauth2/v3/token", "POST",
+          BuildUrlQuery(params.Pass()),
+          base::Bind(&GoogleAuthenticationServiceImpl::OnGetOAuth2Token,
+                     base::Unretained(this), callback));
+}
+
+void GoogleAuthenticationServiceImpl::SelectAccount(
+    bool returnLastSelected,
+    const SelectAccountCallback& callback) {
+  if (!accounts_db_manager_->isValid()) {
+    callback.Run(nullptr, "Accounts db validation failed.");
+    return;
+  }
+
+  mojo::String username;
+  if (returnLastSelected) {
+    username = accounts_db_manager_->GetAuthorizedUserForApp(app_url_);
+    if (!username.is_null()) {
+      callback.Run(username, nullptr);
+      return;
+    }
+  }
+
+  // TODO(ukode): Select one among the list of accounts using an AccountPicker
+  // UI instead of the first account always.
+  mojo::Array<mojo::String> users = accounts_db_manager_->GetAllUsers();
+  if (!users.size()) {
+    callback.Run(nullptr, "No user accounts found.");
+    return;
+  }
+
+  username = users[0];
+  accounts_db_manager_->UpdateAuthorization(app_url_, username);
+  callback.Run(username, nullptr);
+}
+
+void GoogleAuthenticationServiceImpl::ClearOAuth2Token(
+    const mojo::String& token) {}
+
+void GoogleAuthenticationServiceImpl::GetOAuth2DeviceCode(
+    mojo::Array<mojo::String> scopes,
+    const GetOAuth2DeviceCodeCallback& callback) {
+  std::string scopes_str("email");
+  for (size_t i = 0; i < scopes.size(); i++) {
+    scopes_str += " ";
+    scopes_str += std::string(scopes[i].data());
+  }
+
+  mojo::Map<mojo::String, mojo::String> params;
+  params[kOAuth2ClientIdParamName] = kMojoShellOAuth2ClientId;
+  params[kOAuth2ScopeParamName] = scopes_str;
+
+  Request("https://accounts.google.com/o/oauth2/device/code", "POST",
+          BuildUrlQuery(params.Pass()),
+          base::Bind(&GoogleAuthenticationServiceImpl::OnGetOAuth2DeviceCode,
+                     base::Unretained(this), callback));
+}
+
+void GoogleAuthenticationServiceImpl::AddAccount(
+    const mojo::String& device_code,
+    const AddAccountCallback& callback) {
+  // Resets the poll count to "1"
+  AddAccountInternal(device_code, 1, callback);
+}
+
+void GoogleAuthenticationServiceImpl::AddAccountInternal(
+    const mojo::String& device_code,
+    const uint32_t num_poll_attempts,
+    const AddAccountCallback& callback) {
+  mojo::Map<mojo::String, mojo::String> params;
+  params[kOAuth2ClientIdParamName] = kMojoShellOAuth2ClientId;
+  params[kOAuth2ClientSecretParamName] = kMojoShellOAuth2ClientSecret;
+  params[kOAuth2GrantTypeParamName] = kOAuth2DeviceFlowGrantType;
+  params[kOAuth2CodeParamName] = device_code;
+
+  Request("https://www.googleapis.com/oauth2/v3/token", "POST",
+          BuildUrlQuery(params.Pass()),
+          base::Bind(&GoogleAuthenticationServiceImpl::OnAddAccount,
+                     base::Unretained(this), callback, device_code,
+                     num_poll_attempts));
+}
+
+void GoogleAuthenticationServiceImpl::OnGetOAuth2Token(
+    const GetOAuth2TokenCallback& callback,
+    const std::string& response,
+    const std::string& error) {
+  if (response.empty()) {
+    callback.Run(nullptr, "Error from server:" + error);
+    return;
+  }
+
+  scoped_ptr<base::DictionaryValue> dict(ParseOAuth2Response(response.c_str()));
+  if (!dict.get() || dict->HasKey("error")) {
+    callback.Run(nullptr, "Error in parsing response:" + response);
+    return;
+  }
+
+  std::string access_token;
+  dict->GetString("access_token", &access_token);
+
+  callback.Run(access_token, nullptr);
+}
+
+void GoogleAuthenticationServiceImpl::OnGetOAuth2DeviceCode(
+    const GetOAuth2DeviceCodeCallback& callback,
+    const std::string& response,
+    const std::string& error) {
+  if (response.empty()) {
+    callback.Run(nullptr, nullptr, nullptr, "Error from server:" + error);
+    return;
+  }
+
+  scoped_ptr<base::DictionaryValue> dict(ParseOAuth2Response(response.c_str()));
+  if (!dict.get() || dict->HasKey("error")) {
+    callback.Run(nullptr, nullptr, nullptr,
+                 "Error in parsing response:" + response);
+    return;
+  }
+
+  std::string url;
+  std::string device_code;
+  std::string user_code;
+  dict->GetString("verification_url", &url);
+  dict->GetString("device_code", &device_code);
+  dict->GetString("user_code", &user_code);
+
+  callback.Run(url, device_code, user_code, nullptr);
+}
+
+void GoogleAuthenticationServiceImpl::GetTokenInfo(
+    const std::string& access_token) {
+  std::string url("https://www.googleapis.com/oauth2/v1/tokeninfo");
+  url += "?access_token=" + EncodeParam(access_token);
+
+  Request(url, "GET", "",
+          base::Bind(&GoogleAuthenticationServiceImpl::OnGetTokenInfo,
+                     base::Unretained(this)));
+}
+
+void GoogleAuthenticationServiceImpl::OnGetTokenInfo(
+    const std::string& response,
+    const std::string& error) {
+  if (response.empty()) {
+    return;
+  }
+
+  scoped_ptr<base::DictionaryValue> dict(ParseOAuth2Response(response.c_str()));
+  if (!dict.get() || dict->HasKey("error")) {
+    return;
+  }
+
+  // This field is only present if the profile scope was present in the
+  // request. The value of this field is an immutable identifier for the
+  // logged-in user, and may be used when creating and managing user
+  // sessions in your application.
+  dict->GetString("user_id", &user_id_);
+  dict->GetString("email", &email_);
+  // The space-delimited set of scopes that the user consented to.
+  dict->GetString("scope", &scope_);
+  return;
+}
+
+void GoogleAuthenticationServiceImpl::GetUserInfo(const std::string& id_token) {
+  std::string url("https://www.googleapis.com/oauth2/v1/tokeninfo");
+  url += "?id_token=" + EncodeParam(id_token);
+
+  Request(url, "GET", "",
+          base::Bind(&GoogleAuthenticationServiceImpl::OnGetUserInfo,
+                     base::Unretained(this)));
+}
+
+void GoogleAuthenticationServiceImpl::OnGetUserInfo(const std::string& response,
+                                                    const std::string& error) {
+  if (response.empty()) {
+    return;
+  }
+
+  scoped_ptr<base::DictionaryValue> dict(ParseOAuth2Response(response.c_str()));
+  if (!dict.get() || dict->HasKey("error")) {
+    return;
+  }
+
+  // This field is only present if the email scope was requested
+  dict->GetString("email", &email_);
+}
+
+void GoogleAuthenticationServiceImpl::OnAddAccount(
+    const AddAccountCallback& callback,
+    const mojo::String& device_code,
+    const uint32_t num_poll_attempts,
+    const std::string& response,
+    const std::string& error) {
+  if (response.empty()) {
+    callback.Run(nullptr, "Error from server:" + error);
+    return;
+  }
+
+  if (!response.empty() && error.empty()) {
+    scoped_ptr<base::Value> root(base::JSONReader::Read(response));
+    if (!root || !root->IsType(base::Value::TYPE_DICTIONARY)) {
+      callback.Run(response, nullptr);
+      return;
+    }
+  }
+
+  // Parse response and fetch refresh, access and idtokens
+  scoped_ptr<base::DictionaryValue> dict(ParseOAuth2Response(response.c_str()));
+  std::string error_code;
+  if (!dict.get()) {
+    callback.Run(nullptr, "Error in parsing response:" + response);
+    return;
+  } else if (dict->HasKey("error") && dict->GetString("error", &error_code)) {
+    if (error_code != "authorization_pending") {
+      callback.Run(nullptr, "Server error:" + response);
+      return;
+    }
+
+    if (num_poll_attempts > 15) {
+      callback.Run(nullptr, "Timed out after max number of polling attempts");
+      return;
+    }
+
+    // Rate limit by waiting 7 seconds before polling for a new grant
+    base::MessageLoop::current()->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&GoogleAuthenticationServiceImpl::AddAccountInternal,
+                   base::Unretained(this), device_code, num_poll_attempts + 1,
+                   callback),
+        base::TimeDelta::FromMilliseconds(7000));
+    return;
+  }
+
+  // Poll success, after detecting user grant.
+  std::string access_token;
+  dict->GetString("access_token", &access_token);
+  GetTokenInfo(access_token);  // gets scope, email and user_id
+
+  if (email_.empty()) {
+    std::string id_token;
+    dict->GetString("id_token", &id_token);
+    GetUserInfo(id_token);  // gets user's email
+  }
+
+  // TODO(ukode): Store access token in cache for the duration set in
+  // response
+  if (!accounts_db_manager_->isValid()) {
+    callback.Run(nullptr, "Accounts db validation failed.");
+    return;
+  }
+
+  std::string refresh_token;
+  dict->GetString("refresh_token", &refresh_token);
+  authentication::CredentialsPtr creds = authentication::Credentials::New();
+  creds->token = refresh_token;
+  creds->scopes = scope_;
+  creds->auth_provider = AuthProvider::GOOGLE;
+  creds->credential_type = CredentialType::DOWNSCOPED_OAUTH_REFRESH_TOKEN;
+  std::string username = email_.empty() ? user_id_ : email_;
+  accounts_db_manager_->UpdateCredentials(username, creds.Pass());
+
+  callback.Run(username, nullptr);
+}
+
+void GoogleAuthenticationServiceImpl::Request(
+    const std::string& url,
+    const std::string& method,
+    const std::string& message,
+    const mojo::Callback<void(std::string, std::string)>& callback) {
+  Request(url, method, message, callback, nullptr, 0);
+}
+
+void GoogleAuthenticationServiceImpl::Request(
+    const std::string& url,
+    const std::string& method,
+    const std::string& message,
+    const mojo::Callback<void(std::string, std::string)>& callback,
+    const mojo::String& device_code,
+    const uint32_t num_poll_attempts) {
+  mojo::URLRequestPtr request(mojo::URLRequest::New());
+  request->url = url;
+  request->method = method;
+  request->auto_follow_redirects = true;
+
+  // Add headers
+  auto content_type_header = mojo::HttpHeader::New();
+  content_type_header->name = "Content-Type";
+  content_type_header->value = "application/x-www-form-urlencoded";
+  request->headers.push_back(content_type_header.Pass());
+
+  if (!message.empty()) {
+    request->body.push_back(
+        mojo::common::WriteStringToConsumerHandle(message).Pass());
+  }
+
+  mojo::URLLoaderPtr url_loader;
+  network_service_->CreateURLLoader(GetProxy(&url_loader));
+
+  url_loader->Start(
+      request.Pass(),
+      base::Bind(&GoogleAuthenticationServiceImpl::HandleServerResponse,
+                 base::Unretained(this), callback, device_code,
+                 num_poll_attempts));
+
+  url_loader.WaitForIncomingResponse();
+}
+
+void GoogleAuthenticationServiceImpl::HandleServerResponse(
+    const mojo::Callback<void(std::string, std::string)>& callback,
+    const mojo::String& device_code,
+    const uint32_t num_poll_attempts,
+    mojo::URLResponsePtr response) {
+  if (response.is_null()) {
+    LOG(WARNING) << "Something went horribly wrong...exiting!!";
+    callback.Run("", "Empty response");
+    return;
+  }
+
+  if (response->error) {
+    LOG(ERROR) << "Got error (" << response->error->code
+               << "), reason: " << response->error->description.get().c_str();
+    callback.Run("", response->error->description.get().c_str());
+    return;
+  }
+
+  std::string response_body;
+  mojo::common::BlockingCopyToString(response->body.Pass(), &response_body);
+
+  callback.Run(response_body, "");
+}
+
+}  // authentication namespace