[gnome-online-accounts/gnome-3-6] google: Offer a PasswordBased interface

[Debarshi Ray <debarshir src gnome org>]

commit 81ed7e0e1d88069f4bd23bb233aa5352b6aa1ae0
Author: Debarshi Ray <debarshir gnome org>
Date:   Sun Nov 4 21:29:22 2012 +0100

    google: Offer a PasswordBased interface
    
    We are not sure when, or if at all, Google will support OAuth for
    CalDAV. Instead of spoiling the user experience by asking for the
    password again, lets offer applications a way to fetch it without
    bothering the user.
    
    Fixes: https://bugzilla.gnome.org/687578

 src/goabackend/goagoogleprovider.c |  210 ++++++++++++++++++++++++++++++++++++
 1 files changed, 210 insertions(+), 0 deletions(-)
---
diff --git a/src/goabackend/goagoogleprovider.c b/src/goabackend/goagoogleprovider.c
index a12cef3..b6d5299 100644
--- a/src/goabackend/goagoogleprovider.c
+++ b/src/goabackend/goagoogleprovider.c
@@ -29,6 +29,8 @@
 #include "goaprovider.h"
 #include "goaoauthprovider.h"
 #include "goagoogleprovider.h"
+#include "goahttpclient.h"
+#include "goautils.h"
 
 /**
  * GoaGoogleProvider:
@@ -65,6 +67,8 @@ G_DEFINE_TYPE_WITH_CODE (GoaGoogleProvider, goa_google_provider, GOA_TYPE_OAUTH_
 
 /* ---------------------------------------------------------------------------------------------------- */
 
+static const gchar *CALDAV_ENDPOINT = "https://www.google.com/calendar/dav/%s/events/";;
+
 static const gchar *
 get_provider_type (GoaProvider *_provider)
 {
@@ -323,6 +327,41 @@ is_identity_node (GoaOAuth2Provider *provider, WebKitDOMHTMLInputElement *elemen
   return ret;
 }
 
+static gboolean
+is_password_node (GoaOAuthProvider *provider, WebKitDOMHTMLInputElement *element)
+{
+  gboolean ret;
+  gchar *element_type;
+  gchar *id;
+  gchar *name;
+
+  element_type = NULL;
+  id = NULL;
+  name = NULL;
+
+  ret = FALSE;
+
+  g_object_get (element, "type", &element_type, NULL);
+  if (g_strcmp0 (element_type, "password") != 0)
+    goto out;
+
+  id = webkit_dom_html_element_get_id (WEBKIT_DOM_HTML_ELEMENT (element));
+  if (g_strcmp0 (id, "Passwd") != 0)
+    goto out;
+
+  name = webkit_dom_html_input_element_get_name (element);
+  if (g_strcmp0 (name, "Passwd") != 0)
+    goto out;
+
+  ret = TRUE;
+
+ out:
+  g_free (element_type);
+  g_free (id);
+  g_free (name);
+  return ret;
+}
+
 /* ---------------------------------------------------------------------------------------------------- */
 
 static gchar *
@@ -345,6 +384,11 @@ parse_request_token_error (GoaOAuthProvider *provider, RestProxyCall *call)
 
 /* ---------------------------------------------------------------------------------------------------- */
 
+static gboolean on_handle_get_password (GoaPasswordBased      *interface,
+                                        GDBusMethodInvocation *invocation,
+                                        const gchar           *id,
+                                        gpointer               user_data);
+
 static gboolean
 build_object (GoaProvider         *provider,
               GoaObjectSkeleton   *object,
@@ -360,6 +404,7 @@ build_object (GoaProvider         *provider,
   GoaContacts *contacts;
   GoaChat *chat;
   GoaDocuments *documents;
+  GoaPasswordBased *password_based;
   gboolean ret;
   gboolean mail_enabled;
   gboolean calendar_enabled;
@@ -385,6 +430,20 @@ build_object (GoaProvider         *provider,
                                                                             error))
     goto out;
 
+  password_based = goa_object_get_password_based (GOA_OBJECT (object));
+  if (password_based == NULL)
+    {
+      password_based = goa_password_based_skeleton_new ();
+      /* Ensure D-Bus method invocations run in their own thread */
+      g_dbus_interface_skeleton_set_flags (G_DBUS_INTERFACE_SKELETON (password_based),
+                                           G_DBUS_INTERFACE_SKELETON_FLAGS_HANDLE_METHOD_INVOCATIONS_IN_THREAD);
+      goa_object_skeleton_set_password_based (object, password_based);
+      g_signal_connect (password_based,
+                        "handle-get-password",
+                        G_CALLBACK (on_handle_get_password),
+                        NULL);
+    }
+
   account = goa_object_get_account (GOA_OBJECT (object));
 
   /* Email */
@@ -550,6 +609,102 @@ get_use_mobile_browser (GoaOAuthProvider *provider)
 
 /* ---------------------------------------------------------------------------------------------------- */
 
+static gboolean
+ensure_credentials_sync (GoaProvider   *provider,
+                         GoaObject     *object,
+                         gint          *out_expires_in,
+                         GCancellable  *cancellable,
+                         GError       **error)
+{
+  GVariant *credentials;
+  GoaAccount *account;
+  GoaHttpClient *http_client;
+  gboolean ret;
+  const gchar *username;
+  gchar *password;
+  gchar *uri_caldav;
+
+  credentials = NULL;
+  http_client = NULL;
+  password = NULL;
+  uri_caldav = NULL;
+
+  ret = FALSE;
+
+  /* Chain up */
+  if (!GOA_PROVIDER_CLASS (goa_google_provider_parent_class)->ensure_credentials_sync (provider,
+                                                                                       object,
+                                                                                       out_expires_in,
+                                                                                       cancellable,
+                                                                                       error))
+    goto out;
+
+  credentials = goa_utils_lookup_credentials_sync (provider,
+                                                   object,
+                                                   cancellable,
+                                                   error);
+  if (credentials == NULL)
+    {
+      if (error != NULL)
+        {
+          g_prefix_error (error,
+                          _("Credentials not found in keyring (%s, %d): "),
+                          g_quark_to_string ((*error)->domain),
+                          (*error)->code);
+          (*error)->domain = GOA_ERROR;
+          (*error)->code = GOA_ERROR_NOT_AUTHORIZED;
+        }
+      goto out;
+    }
+
+  account = goa_object_peek_account (object);
+  username = goa_account_get_presentation_identity (account);
+  uri_caldav = g_strdup_printf (CALDAV_ENDPOINT, username);
+
+  if (!g_variant_lookup (credentials, "password", "s", &password))
+    {
+      if (error != NULL)
+        {
+          *error = g_error_new (GOA_ERROR,
+                                GOA_ERROR_NOT_AUTHORIZED,
+                                _("Did not find password with username `%s' in credentials"),
+                                username);
+        }
+      goto out;
+    }
+
+  http_client = goa_http_client_new ();
+  ret = goa_http_client_check_sync (http_client,
+                                    uri_caldav,
+                                    username,
+                                    password,
+                                    cancellable,
+                                    error);
+  if (!ret)
+    {
+      if (error != NULL)
+        {
+          g_prefix_error (error,
+                          _("Invalid password with username `%s' (%s, %d): "),
+                          username,
+                          g_quark_to_string ((*error)->domain),
+                          (*error)->code);
+          (*error)->domain = GOA_ERROR;
+          (*error)->code = GOA_ERROR_NOT_AUTHORIZED;
+        }
+      goto out;
+    }
+
+ out:
+  g_clear_object (&http_client);
+  g_free (password);
+  g_free (uri_caldav);
+  g_clear_pointer (&credentials, (GDestroyNotify) g_variant_unref);
+  return ret;
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
 static void
 show_account (GoaProvider         *provider,
               GoaClient           *client,
@@ -622,6 +777,7 @@ goa_google_provider_class_init (GoaGoogleProviderClass *klass)
   provider_class->get_provider_type          = get_provider_type;
   provider_class->get_provider_name          = get_provider_name;
   provider_class->build_object               = build_object;
+  provider_class->ensure_credentials_sync    = ensure_credentials_sync;
   provider_class->show_account               = show_account;
   provider_class->get_credentials_generation = get_credentials_generation;
 
@@ -629,6 +785,7 @@ goa_google_provider_class_init (GoaGoogleProviderClass *klass)
   oauth_class->get_identity_sync        = get_identity_sync;
   oauth_class->is_deny_node             = is_deny_node;
   oauth_class->is_identity_node         = is_identity_node;
+  oauth_class->is_password_node         = is_password_node;
   oauth_class->get_consumer_key         = get_consumer_key;
   oauth_class->get_consumer_secret      = get_consumer_secret;
   oauth_class->get_request_uri          = get_request_uri;
@@ -645,3 +802,56 @@ goa_google_provider_class_init (GoaGoogleProviderClass *klass)
 }
 
 /* ---------------------------------------------------------------------------------------------------- */
+
+/* runs in a thread dedicated to handling @invocation */
+static gboolean
+on_handle_get_password (GoaPasswordBased      *interface,
+                        GDBusMethodInvocation *invocation,
+                        const gchar           *id,
+                        gpointer               user_data)
+{
+  GoaObject *object;
+  GoaAccount *account;
+  GoaProvider *provider;
+  GError *error;
+  GVariant *credentials;
+  gchar *password;
+
+  /* TODO: maybe log what app is requesting access */
+
+  password = NULL;
+  credentials = NULL;
+
+  object = GOA_OBJECT (g_dbus_interface_get_object (G_DBUS_INTERFACE (interface)));
+  account = goa_object_peek_account (object);
+  provider = goa_provider_get_for_provider_type (goa_account_get_provider_type (account));
+
+  error = NULL;
+  credentials = goa_utils_lookup_credentials_sync (provider,
+                                                   object,
+                                                   NULL, /* GCancellable* */
+                                                   &error);
+  if (credentials == NULL)
+    {
+      g_dbus_method_invocation_take_error (invocation, error);
+      goto out;
+    }
+
+  if (!g_variant_lookup (credentials, "password", "s", &password))
+    {
+      g_dbus_method_invocation_return_error (invocation,
+                                             GOA_ERROR,
+                                             GOA_ERROR_FAILED, /* TODO: more specific */
+                                             _("Did not find password with username `%s' in credentials"),
+                                             id);
+      goto out;
+    }
+
+  goa_password_based_complete_get_password (interface, invocation, password);
+
+ out:
+  g_free (password);
+  g_clear_pointer (&credentials, (GDestroyNotify) g_variant_unref);
+  g_object_unref (provider);
+  return TRUE; /* invocation was handled */
+}