From 70c1cc7ed45ff4f6fa3cf0601c98ca40a168ac57 Mon Sep 17 00:00:00 2001

From: Vinzenz Feenstra <evilissimo@redhat.com>

Date: Thu, 10 Oct 2013 10:21:47 +0200

Subject: [PATCH] gdm: support pre-authenticated logins from oVirt

oVirt is software for managing medium-to-large scale deployments of

virtual machine guests across multiple hosts. It supports a feature

where users can authenticate with a central server and get

transparently connected to a guest system and then automatically get logged

into that guest to an associated user session.

Guests using old versions of GDM support this single-sign-on capability

by means of a greeter plugin, using the old greeter's extension

API.

This commit adds similar support to the gnome-shell based login screen.

How it works:

* The OVirtCredentialsManager singleton listens for

  'org.ovirt.vdsm.Credentials.UserAuthenticated'

  D-Bus signal on the system bus from the

  'org.ovirt.vdsm.Credentials'

  bus name. The service that provides that bus name is called

  the oVirt guest agent. It is also responsible for interacting

  with the the central server to get user credentials.

* This UserAuthenticated signal passes, as a parameter, the a token

  which needs to be passed through to the PAM service that is specifically

  set up to integrate with the oVirt authentication architecture.

  The singleton object keeps the token internally so it can be queried

  later on.

* The OVirtCredentialsManager emits a signal 'user-authenticated' on

  it's object once the dbus signal is triggered

* When the 'user-authenticated' signal is emitted, the login screen

  tells GDM to start user verification using the PAM service. The

  authentication stack of the service includes a PAM module

  provided by oVirt that securely retrieves user credentials

  from the oVirt guest agent. The PAM module then forwards those

  credentials on to other modules in the stack so, e.g.,

  the user's gnome keyring can be automatically unlocked.

* In case of the screen shield being visible, it also will react on that

  'user-authenticated' signal and lift the shield.

  In that case the login screen will check on construction time if

  the signal has already been triggered, and a token is available.

  If a token is available it will immediately trigger the functionality

  as described above.

Upstream-Bug-Url: https://bugzilla.gnome.org/show_bug.cgi?id=702162

Signed-off-by: Vinzenz Feenstra <evilissimo@redhat.com>

Bug-Url: https://bugzilla.redhat.com/854712

---

 js/Makefile.am        |  1 +

 js/gdm/authPrompt.js  | 13 ++++++++---

 js/gdm/oVirt.js       | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++

 js/gdm/util.js        | 31 ++++++++++++++++++++++++++

 js/ui/screenShield.js |  8 +++++++

 5 files changed, 112 insertions(+), 3 deletions(-)

 create mode 100644 js/gdm/oVirt.js

diff --git a/js/Makefile.am b/js/Makefile.am

index 425b6fb..bfcc714 100644

--- a/js/Makefile.am

+++ b/js/Makefile.am

@@ -21,6 +21,7 @@ nobase_dist_js_DATA = 	\

 	gdm/batch.js		\

 	gdm/fingerprint.js	\

 	gdm/loginDialog.js	\

+	gdm/oVirt.js		\

 	gdm/powerMenu.js	\

 	gdm/realmd.js		\

 	gdm/util.js		\

diff --git a/js/gdm/authPrompt.js b/js/gdm/authPrompt.js

index 2121f2e..ba66c42 100644

--- a/js/gdm/authPrompt.js

+++ b/js/gdm/authPrompt.js

@@ -59,6 +59,7 @@ const AuthPrompt = new Lang.Class({

         this._userVerifier.connect('verification-complete', Lang.bind(this, this._onVerificationComplete));

         this._userVerifier.connect('reset', Lang.bind(this, this._onReset));

         this._userVerifier.connect('smartcard-status-changed', Lang.bind(this, this._onSmartcardStatusChanged));

+        this._userVerifier.connect('ovirt-user-authenticated', Lang.bind(this, this._onOVirtUserAuthenticated));

         this.smartcardDetected = this._userVerifier.smartcardDetected;

         this.connect('next', Lang.bind(this, function() {

@@ -219,6 +220,11 @@ const AuthPrompt = new Lang.Class({

         this.emit('prompted');

     },

+    _onOVirtUserAuthenticated: function() {

+        if (this.verificationStatus != AuthPromptStatus.VERIFICATION_SUCCEEDED)

+            this.reset();

+    },

+

     _onSmartcardStatusChanged: function() {

         this.smartcardDetected = this._userVerifier.smartcardDetected;

@@ -443,10 +449,11 @@ const AuthPrompt = new Lang.Class({

             // The user is constant at the unlock screen, so it will immediately

             // respond to the request with the username

             beginRequestType = BeginRequestType.PROVIDE_USERNAME;

-        } else if (this.smartcardDetected &&

-                   this._userVerifier.serviceIsForeground(GdmUtil.SMARTCARD_SERVICE_NAME)) {

+        } else if (this._userVerifier.serviceIsForeground(GdmUtil.OVIRT_SERVICE_NAME) ||

+                   (this.smartcardDetected &&

+                    this._userVerifier.serviceIsForeground(GdmUtil.SMARTCARD_SERVICE_NAME))) {

             // We don't need to know the username if the user preempted the login screen

-            // with a smartcard.

+            // with a smartcard or with preauthenticated oVirt credentials

             beginRequestType = BeginRequestType.DONT_PROVIDE_USERNAME;

         } else {

             // In all other cases, we should get the username up front.

diff --git a/js/gdm/oVirt.js b/js/gdm/oVirt.js

new file mode 100644

index 0000000..1a31f43

--- /dev/null

+++ b/js/gdm/oVirt.js

@@ -0,0 +1,62 @@

+// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-

+

+const Gio = imports.gi.Gio;

+const Lang = imports.lang;

+const Signals = imports.signals;

+

+const OVirtCredentialsIface = <interface name='org.ovirt.vdsm.Credentials'>

+<signal name="UserAuthenticated">

+    <arg type="s" name="token"/>

+</signal>

+</interface>;

+

+const OVirtCredentialsInfo = Gio.DBusInterfaceInfo.new_for_xml(OVirtCredentialsIface);

+

+let _oVirtCredentialsManager = null;

+

+function OVirtCredentials() {

+    var self = new Gio.DBusProxy({ g_connection: Gio.DBus.system,

+                                   g_interface_name: OVirtCredentialsInfo.name,

+                                   g_interface_info: OVirtCredentialsInfo,

+                                   g_name: 'org.ovirt.vdsm.Credentials',

+                                   g_object_path: '/org/ovirt/vdsm/Credentials',

+                                   g_flags: (Gio.DBusProxyFlags.DO_NOT_LOAD_PROPERTIES) });

+    self.init(null);

+    return self;

+}

+

+const OVirtCredentialsManager = new Lang.Class({

+    Name: 'OVirtCredentialsManager',

+    _init: function() {

+        this._token = null;

+

+        this._credentials = new OVirtCredentials();

+        this._credentials.connectSignal('UserAuthenticated',

+                                        Lang.bind(this, this._onUserAuthenticated));

+    },

+

+    _onUserAuthenticated: function(proxy, sender, [token]) {

+        this._token = token;

+        this.emit('user-authenticated', token);

+    },

+

+    hasToken: function() {

+        return this._token != null;

+    },

+

+    getToken: function() {

+        return this._token;

+    },

+

+    resetToken: function() {

+        this._token = null;

+    }

+});

+Signals.addSignalMethods(OVirtCredentialsManager.prototype);

+

+function getOVirtCredentialsManager() {

+    if (!_oVirtCredentialsManager)

+        _oVirtCredentialsManager = new OVirtCredentialsManager();

+

+    return _oVirtCredentialsManager;

+}

diff --git a/js/gdm/util.js b/js/gdm/util.js

index f421902..66852fd 100644

--- a/js/gdm/util.js

+++ b/js/gdm/util.js

@@ -10,6 +10,7 @@ const St = imports.gi.St;

 const Batch = imports.gdm.batch;

 const Fprint = imports.gdm.fingerprint;

+const OVirt = imports.gdm.oVirt;

 const Main = imports.ui.main;

 const Params = imports.misc.params;

 const ShellEntry = imports.ui.shellEntry;

@@ -19,6 +20,7 @@ const Tweener = imports.ui.tweener;

 const PASSWORD_SERVICE_NAME = 'gdm-password';

 const FINGERPRINT_SERVICE_NAME = 'gdm-fingerprint';

 const SMARTCARD_SERVICE_NAME = 'gdm-smartcard';

+const OVIRT_SERVICE_NAME = 'gdm-ovirtcred';

 const FADE_ANIMATION_TIME = 0.16;

 const CLONE_FADE_ANIMATION_TIME = 0.25;

@@ -151,6 +153,14 @@ const ShellUserVerifier = new Lang.Class({

         this.reauthenticating = false;

         this._failCounter = 0;

+

+        this._oVirtCredentialsManager = OVirt.getOVirtCredentialsManager();

+

+        if (this._oVirtCredentialsManager.hasToken())

+            this._oVirtUserAuthenticated(this._oVirtCredentialsManager.getToken());

+

+        this._oVirtCredentialsManager.connect('user-authenticated',

+                                              Lang.bind(this, this._oVirtUserAuthenticated));

     },

     begin: function(userName, hold) {

@@ -277,6 +287,11 @@ const ShellUserVerifier = new Lang.Class({

             }));

     },

+    _oVirtUserAuthenticated: function(token) {

+        this._preemptingService = OVIRT_SERVICE_NAME;

+        this.emit('ovirt-user-authenticated');

+    },

+

     _checkForSmartcard: function() {

         let smartcardDetected;

@@ -455,6 +470,12 @@ const ShellUserVerifier = new Lang.Class({

         if (!this.serviceIsForeground(serviceName))

             return;

+        if (serviceName == OVIRT_SERVICE_NAME) {

+            // The only question asked by this service is "Token?"

+            this.answerQuery(serviceName, this._oVirtCredentialsManager.getToken());

+            return;

+        }

+

         this.emit('ask-question', serviceName, secretQuestion, '\u25cf');

     },

@@ -515,6 +536,16 @@ const ShellUserVerifier = new Lang.Class({

     },

     _onConversationStopped: function(client, serviceName) {

+        // If the login failed with the preauthenticated oVirt credentials

+        // then discard the credentials and revert to default authentication

+        // mechanism.

+        if (this.serviceIsForeground(OVIRT_SERVICE_NAME)) {

+            this._oVirtCredentialsManager.resetToken();

+            this._preemptingService = null;

+            this._verificationFailed(false);

+            return;

+        }

+

         // if the password service fails, then cancel everything.

         // But if, e.g., fingerprint fails, still give

         // password authentication a chance to succeed

diff --git a/js/ui/screenShield.js b/js/ui/screenShield.js

index 1d296a2..ecc0bfa 100644

--- a/js/ui/screenShield.js

+++ b/js/ui/screenShield.js

@@ -17,6 +17,7 @@ const Background = imports.ui.background;

 const GnomeSession = imports.misc.gnomeSession;

 const Hash = imports.misc.hash;

 const Layout = imports.ui.layout;

+const OVirt = imports.gdm.oVirt;

 const LoginManager = imports.misc.loginManager;

 const Lightbox = imports.ui.lightbox;

 const Main = imports.ui.main;

@@ -514,6 +515,13 @@ const ScreenShield = new Lang.Class({

                                                this._liftShield(true, 0);

                                        }));

+        this._oVirtCredentialsManager = OVirt.getOVirtCredentialsManager();

+        this._oVirtCredentialsManager.connect('user-authenticated',

+                                              Lang.bind(this, function() {

+                                                  if (this._isLocked)

+                                                      this._liftShield(true, 0);

+                                              }));

+

         this._inhibitor = null;

         this._aboutToSuspend = false;

         this._loginManager = LoginManager.getLoginManager();

-- 

1.8.3.1