more consistent user/group/tenant handling and serialization

Change-Id: Ib7621e2cbddb913db0e32e2607d122e38505d87b

java/com.sap.sailing.domain.common/src/com/sap/sailing/domain/common/security/Permission.java

@@ -1,7 +1,6 @@
 package com.sap.sailing.domain.common.security;
 
-
-
+import com.sap.sse.security.shared.WildcardPermission;
 
 public enum Permission implements com.sap.sse.security.shared.Permission {
     // AdminConsole permissions
@@ -63,6 +62,11 @@ public enum Permission implements com.sap.sse.security.shared.Permission {
         return result;
     }
 
+    @Override
+    public WildcardPermission getPermission(com.sap.sse.security.shared.Permission.Mode... modes) {
+        return new WildcardPermission(getStringPermission(modes));
+    }
+
     // TODO once we can use Java8 here, move this up into a "default" method on the Permission interface
     @Override
     public String getStringPermissionForObjects(com.sap.sse.security.shared.Permission.Mode mode, String... objectIdentifiers) {
@@ -82,6 +86,11 @@ public enum Permission implements com.sap.sse.security.shared.Permission {
         return result.toString();
     }
     
+    @Override
+    public WildcardPermission getPermissionForObjects(com.sap.sse.security.shared.Permission.Mode mode, String... objectIdentifiers) {
+        return new WildcardPermission(getStringPermissionForObjects(mode, objectIdentifiers));
+    }
+
     /**
      * The mode of interaction with a resource; used as the second element of a wildcard permission
      * 

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/adminconsole/EventListComposite.java

@@ -352,11 +352,12 @@ public class EventListComposite extends Composite implements EventsRefresher, Le
             public Iterable<Action> getAllowedActions(EventDTO event) {
                 ArrayList<Action> allowedActions = new ArrayList<>();
                 for (Action action : Arrays.asList(DefaultActions.EDIT, DefaultActions.REMOVE)) {
-                    if (user.hasPermission(
-                            PermissionBuilderImpl.getInstance().getPermission("com.sap.sailing.domain.base.Event", action, event.id.toString()),
-                            event.getAcl(), event.getOwnership())) {
-                        allowedActions.add(action);
-                    }
+                            if (user.hasPermission(
+                                    PermissionBuilderImpl.getInstance().getPermission(
+                                            "com.sap.sailing.domain.base.Event", action, event.id.toString()),
+                                    event.getOwnership(), event.getAcl())) {
+                                allowedActions.add(action);
+                            }
                 }
                 return allowedActions;
             }

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/client/RaceTimePanel.java

@@ -60,7 +60,7 @@ public class RaceTimePanel extends TimePanel<RaceTimePanelSettings> implements R
         @Override
         public void onUserStatusChange(UserDTO user, boolean preAuthenticated) {
             RaceTimePanel.this.hasCanReplayDuringLiveRacesPermission = user != null && user.hasPermission(
-                    Permission.CAN_REPLAY_DURING_LIVE_RACES.getStringPermission());
+                    Permission.CAN_REPLAY_DURING_LIVE_RACES.getPermission(), /* TODO race ownership */ null, /* TODO race acl */ null);
         }
     };
 

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/client/media/MediaPlayerManagerComponent.java

@@ -489,7 +489,7 @@ public class MediaPlayerManagerComponent extends AbstractComponent<MediaPlayerSe
         final VideoSynchPlayer videoPlayer;
         final UserDTO currentUser = userService.getCurrentUser();
         boolean showSynchControls = currentUser != null
-                && currentUser.hasPermission(Permission.MANAGE_MEDIA.getStringPermission());
+                && currentUser.hasPermission(Permission.MANAGE_MEDIA.getPermission(), /* TODO race ownership */ null, /* TODO race ACL */ null);
         if (videoTrack.isYoutube()) {
             videoPlayer = new VideoYoutubePlayer(videoTrack, getRaceStartTime(), showSynchControls, raceTimer);
         } else {
@@ -673,7 +673,7 @@ public class MediaPlayerManagerComponent extends AbstractComponent<MediaPlayerSe
     public boolean allowsEditing() {
         UserDTO currentUser = userService.getCurrentUser();
         return currentUser != null
-                && currentUser.hasPermission(Permission.MANAGE_MEDIA.getStringPermission());
+                && currentUser.hasPermission(Permission.MANAGE_MEDIA.getPermission(), /* TODO race ownership */ null, /* TODO race ACL */ null);
     }
 
     @Override

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/raceboard/SideBySideComponentViewer.java

@@ -307,7 +307,7 @@ public class SideBySideComponentViewer implements UserStatusEventHandler {
         final Splitter markPassingsSplitter = splitLayoutPanel.getAssociatedSplitter(markPassingsPanel);
         final Splitter markPositionSplitter = splitLayoutPanel.getAssociatedSplitter(markPositionPanel);
         boolean forceLayout = false;
-        if (user != null && user.hasPermission(Permission.MANAGE_MARK_PASSINGS.getStringPermission())) {
+        if (user != null && user.hasPermission(Permission.MANAGE_MARK_PASSINGS.getPermission(), /* TODO race ownership */ null, /* TODO race acl */ null)) {
             if (markPassingsSplitter != null) { // if the panel is not present, the splitter may not be found
                 markPassingsSplitter.getToggleButton().setVisible(true);
             }
@@ -318,7 +318,7 @@ public class SideBySideComponentViewer implements UserStatusEventHandler {
                 markPassingsSplitter.getToggleButton().setVisible(false);
             }
         }
-        if (user != null && user.hasPermission(Permission.MANAGE_MARK_POSITIONS.getStringPermission())) {
+        if (user != null && user.hasPermission(Permission.MANAGE_MARK_POSITIONS.getPermission(), /* TODO race ownership */ null, /* TODO race acl */ null)) {
             if (markPositionSplitter != null) { // if the panel is not present, the splitter may not be found
                 markPositionSplitter.getToggleButton().setVisible(true);
             }

java/com.sap.sailing.server.gateway/src/com/sap/sailing/server/gateway/jaxrs/api/EventsResource.java

@@ -191,7 +191,7 @@ public class EventsResource extends AbstractSailingServerResource {
             @FormParam("numberofraces") String numberOfRacesParam) throws ParseException, NotFoundException,
             NumberFormatException, IOException, org.json.simple.parser.ParseException, InvalidDateException {
         if (enforceSecurityChecks) {
-            SecurityUtils.getSubject().checkPermission(Permission.EVENT.getStringPermission(Mode.CREATE));
+            SecurityUtils.getSubject().checkPermission(Permission.EVENT.getStringPermissionForObjects(Mode.CREATE, eventId));
         }
         final Response response;
         UUID id;

java/com.sap.sse.gwt.adminconsole/src/com/sap/sse/gwt/adminconsole/AdminConsolePanel.java

@@ -441,7 +441,7 @@ public class AdminConsolePanel extends HeaderPanel implements HandleTabSelectabl
      */
     private boolean userHasPermissionsToSeeWidget(UserDTO user, Widget widget) {
         for (Permission requiredStringPermission : permissionsAnyOfWhichIsRequiredToSeeWidget.get(widget)) {
-            WildcardPermission requiredPermission = new WildcardPermission(requiredStringPermission.getStringPermission());
+            WildcardPermission requiredPermission = requiredStringPermission.getPermission();
             // TODO use PermissionChecker instead of enumerating all permissions
             for (WildcardPermission userPermission : user.getAllPermissions()) {
                 if (requiredPermission.implies(userPermission) || userPermission.implies(requiredPermission)) {

java/com.sap.sse.security.common/src/com/sap/sse/security/shared/DefaultPermissions.java

@@ -28,6 +28,11 @@ public enum DefaultPermissions implements Permission {
         return result;
     }
     
+    @Override
+    public WildcardPermission getPermission(Mode... modes) {
+        return new WildcardPermission(getStringPermission(modes));
+    }
+
     // TODO once we can use Java8 here, move this up into a "default" method on the Permission interface
     public String getStringPermissionForObjects(Mode mode, String... objectIdentifiers) {
         final StringBuilder result = new StringBuilder(getStringPermission(mode));
@@ -46,5 +51,11 @@ public enum DefaultPermissions implements Permission {
         return result.toString();
     }
     
+    @Override
+    public WildcardPermission getPermissionForObjects(Mode mode, String... objectIdentifiers) {
+        return new WildcardPermission(getStringPermissionForObjects(mode, objectIdentifiers));
+    }
+
     private final String stringPermission;
 }
+

java/com.sap.sse.security.common/src/com/sap/sse/security/shared/Permission.java

@@ -2,30 +2,42 @@ package com.sap.sse.security.shared;
 
 public interface Permission {
     String name();
-    
+
     int ordinal();
-    
+
     /**
      * If one or more modes are specified, a string permission is rendered that has the
      * {@link Mode#getStringPermission() permission strings} of those modes listed in the second wildcard permission
      * component. Otherwise, only the primary permission with one segment is returned.
      */
     String getStringPermission(Mode... modes);
-    
+
     /**
-     * Produces a string permission for this permission, the <code>mode</code> specified as the second wildcard permission
-     * segment, and the <code>objectIdentifier</code> as the third wildcard permission segment.
+     * Same as {@link #getStringPermission(Mode...)}, only that the result is a {@link WildcardPermission} instead of a
+     * {@link String}
+     */
+    WildcardPermission getPermission(Mode... modes);
+
+    /**
+     * Produces a string permission for this permission, the <code>mode</code> specified as the second wildcard
+     * permission segment, and the <code>objectIdentifier</code> as the third wildcard permission segment.
      */
     String getStringPermissionForObjects(Mode mode, String... objectIdentifiers);
-    
+
+    /**
+     * Same as {@link #getStringPermissionForObjects(Mode, String...)}, only that the result is a
+     * {@link WildcardPermission} instead of a {@link String}
+     */
+    WildcardPermission getPermissionForObjects(Mode mode, String... objectIdentifiers);
+
     public static interface Mode {
         String name();
-        
+
         int ordinal();
-        
+
         String getStringPermission();
     }
-    
+
     public enum DefaultModes implements Mode {
         CREATE, READ, UPDATE, DELETE;
 

java/com.sap.sse.security.common/src/com/sap/sse/security/shared/PermissionChecker.java

@@ -27,9 +27,14 @@ public class PermissionChecker {
     }
     
     /**
-     * @param permission Permission of the form "data_object_type:action:instance_id".
-     *          The instance id can be omitted when a general permission for the data
-     *          object type is asked after (e.g. "event:create").
+     * @param permission
+     *            Permission of the form "data_object_type:action:instance_id". The instance id can be omitted when a
+     *            general permission for the data object type is asked after (e.g. "event:create").
+     * @param ownership
+     *            may be {@code null}, causing user- or tenant-parameterized roles and no user ownership override to be
+     *            applied
+     * @param acl
+     *            may be {@code null} in which case no ACL-specific checks are performed
      */
     public static boolean isPermitted(WildcardPermission permission, SecurityUser user, Iterable<UserGroup> groupsOfWhichUserIsMember,
             Iterable<Role> roles, Ownership ownership,

java/com.sap.sse.security.common/src/com/sap/sse/security/shared/SecurityUser.java

@@ -15,8 +15,33 @@ import com.sap.sse.common.WithID;
 public interface SecurityUser extends NamedWithID {
     Tenant getDefaultTenant();
 
+    /**
+     * Checks whether this user has the {@code permission} requested. For this, the {@link #getRoles() roles}
+     * and {@link #getPermissions() permissions} are checked; however, since this method does not accept
+     * {@link Ownership} or {@link AccessControlList} parameters, no further inferences are made.
+     */
     boolean hasPermission(WildcardPermission permission);
     
+    /**
+     * Checks whether this user has the {@code permission} requested. For this, the {@link #getRoles() roles} and
+     * {@link #getPermissions() permissions} are checked, furthermore if this user is the
+     * {@link Ownership#getUserOwner() user owner} as per the {@code ownership} information, the permission will be
+     * granted because users have all rights to the objects they own. Furthermore, tenant and user parameterized roles
+     * will be applied based on the {@code ownership} information. No {@link AccessControlList} rules are applied here.
+     */
+    boolean hasPermission(WildcardPermission permission, Ownership ownership);
+    
+    /**
+     * Checks whether this user has the {@code permission} requested. For this, the {@link #getRoles() roles} and
+     * {@link #getPermissions() permissions} are checked, furthermore if this user is the
+     * {@link Ownership#getUserOwner() user owner} as per the {@code ownership} information, the permission will be
+     * granted because users have all rights to the objects they own. Furthermore, tenant and user parameterized roles
+     * will be applied based on the {@code ownership} information. If the user belongs to one or more groups
+     * ({@code groupsThisUserIsPartOf}) and a non-{@code null} {@code acl} is provided, the access control list
+     * permissions are applied accordingly.
+     */
+    boolean hasPermission(WildcardPermission permission, Ownership ownership, Iterable<UserGroup> groupsThisUserIsPartOf, AccessControlList acl);
+    
     /**
      * Returns the "raw" permissions explicitly set for this user. This does not include permissions
      * inferred by any {@link PermissionsForRoleProvider} for the {@link #getRoles() roles} that this

java/com.sap.sse.security.common/src/com/sap/sse/security/shared/impl/SecurityUserImpl.java

@@ -5,9 +5,13 @@ import java.util.HashSet;
 import java.util.Set;
 
 import com.sap.sse.common.Util;
+import com.sap.sse.security.shared.AccessControlList;
+import com.sap.sse.security.shared.Ownership;
+import com.sap.sse.security.shared.PermissionChecker;
 import com.sap.sse.security.shared.Role;
 import com.sap.sse.security.shared.SecurityUser;
 import com.sap.sse.security.shared.Tenant;
+import com.sap.sse.security.shared.UserGroup;
 import com.sap.sse.security.shared.WildcardPermission;
 
 public class SecurityUserImpl implements SecurityUser {
@@ -76,9 +80,20 @@ public class SecurityUserImpl implements SecurityUser {
     
     @Override
     public boolean hasPermission(WildcardPermission permission) {
-        return permissions.contains(permission);
+        return hasPermission(permission, /* ownership */ null);
     }
     
+    @Override
+    public boolean hasPermission(WildcardPermission permission, Ownership ownership) {
+        return hasPermission(permission, ownership, /* user groups */ null, /* ACL */ null);
+    }
+
+    @Override
+    public boolean hasPermission(WildcardPermission permission, Ownership ownership,
+            Iterable<UserGroup> groupsThisUserIsPartOf, AccessControlList acl) {
+        return PermissionChecker.isPermitted(permission, this, groupsThisUserIsPartOf, getRoles(), ownership, acl);
+    }
+
     public void addRole(Role role) {
         roles.add(role);
     }

java/com.sap.sse.security.ui/src/main/java/com/sap/sse/security/ui/authentication/app/AuthenticationContextImpl.java

@@ -14,7 +14,7 @@ public class AuthenticationContextImpl implements AuthenticationContext {
 
     private final UserDTO currentUser;
     private final static UserDTO ANONYMOUS = new UserDTO("Anonymous", "", "", "", null, false, new ArrayList<AccountDTO>(),
-            new ArrayList<Role>(), /* default tenant */ null, new ArrayList<WildcardPermission>());
+            new ArrayList<Role>(), /* default tenant */ null, new ArrayList<WildcardPermission>(), /* groups */ null);
 
     /**
      * Creating an {@link AuthenticationContextImpl} containing an anonymous {@link UserDTO} object.

java/com.sap.sse.security.ui/src/main/java/com/sap/sse/security/ui/client/component/UserList.java

@@ -5,6 +5,7 @@ import com.google.gwt.resources.client.ImageResource;
 import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
 import com.google.gwt.user.cellview.client.CellList;
 import com.google.gwt.user.client.ui.ImageResourceRenderer;
+import com.sap.sse.common.Util;
 import com.sap.sse.security.ui.client.IconResources;
 import com.sap.sse.security.ui.shared.UserDTO;
 
@@ -28,7 +29,7 @@ public class UserList extends CellList<UserDTO> {
             sb.appendHtmlConstant("</td>");
             sb.appendHtmlConstant("<td>");
             sb.appendHtmlConstant("<div>");
-            sb.appendEscaped(value.getName());
+            sb.appendEscaped(value.getName()+" ("+Util.join(", ", value.getUserGroups())+")");
             sb.appendHtmlConstant("</div>");
             sb.appendHtmlConstant("</td>");
             sb.appendHtmlConstant("</tr>");

java/com.sap.sse.security.ui/src/main/java/com/sap/sse/security/ui/server/UserManagementServiceImpl.java

@@ -55,6 +55,7 @@ import com.sap.sse.security.shared.UsernamePasswordAccount;
 import com.sap.sse.security.shared.WildcardPermission;
 import com.sap.sse.security.shared.impl.SecurityUserImpl;
 import com.sap.sse.security.shared.impl.TenantImpl;
+import com.sap.sse.security.shared.impl.UserGroupImpl;
 import com.sap.sse.security.ui.client.UserManagementService;
 import com.sap.sse.security.ui.oauth.client.CredentialDTO;
 import com.sap.sse.security.ui.oauth.client.SocialUserDTO;
@@ -100,13 +101,14 @@ public class UserManagementServiceImpl extends RemoteServiceServlet implements U
         }.start();
     }
 
-    private SecurityUser createUserDTOFromUser(SecurityUser user, Map<Tenant, Tenant> fromOriginalToStrippedDownTenant, Map<SecurityUser, SecurityUser> fromOriginalToStrippedDownUser) {
+    private SecurityUser createUserDTOFromUser(SecurityUser user, Map<Tenant, Tenant> fromOriginalToStrippedDownTenant, Map<SecurityUser, SecurityUser> fromOriginalToStrippedDownUser,
+            Map<UserGroup, UserGroup> fromOriginalToStrippedDownUserGroup) {
         SecurityUser result = fromOriginalToStrippedDownUser.get(user);
         if (result == null) {
             final SecurityUserImpl preResult = new SecurityUserImpl(user.getName(), /* default tenant to be set later: */ null);
             result = preResult;
             fromOriginalToStrippedDownUser.put(user, result);
-            preResult.setDefaultTenant(createTenantDTOFromTenant(user.getDefaultTenant(), fromOriginalToStrippedDownTenant, fromOriginalToStrippedDownUser));
+            preResult.setDefaultTenant(createTenantDTOFromTenant(user.getDefaultTenant(), fromOriginalToStrippedDownTenant, fromOriginalToStrippedDownUser, fromOriginalToStrippedDownUserGroup));
         }
         return result;
     }
@@ -125,10 +127,12 @@ public class UserManagementServiceImpl extends RemoteServiceServlet implements U
      * as will for tenants.
      */
     private Tenant createTenantDTOFromTenant(Tenant tenant) {
-        return createTenantDTOFromTenant(tenant, new HashMap<>(), new HashMap<>());
+        return createTenantDTOFromTenant(tenant, new HashMap<>(), new HashMap<>(), new HashMap<>());
     }
     
-    private Tenant createTenantDTOFromTenant(Tenant tenant, Map<Tenant, Tenant> fromOriginalToStrippedDownTenant, Map<SecurityUser, SecurityUser> fromOriginalToStrippedDownUser) {
+    private Tenant createTenantDTOFromTenant(Tenant tenant, Map<Tenant, Tenant> fromOriginalToStrippedDownTenant,
+            Map<SecurityUser, SecurityUser> fromOriginalToStrippedDownUser,
+            Map<UserGroup, UserGroup> fromOriginalToStrippedDownUserGroup) {
         final Tenant result;
         if (tenant == null) {
             result = null;
@@ -138,7 +142,8 @@ public class UserManagementServiceImpl extends RemoteServiceServlet implements U
             result = new TenantImpl(tenant.getId(), tenant.getName());
             fromOriginalToStrippedDownTenant.put(tenant, result);
             for (final SecurityUser user : tenant.getUsers()) {
-                result.add(createUserDTOFromUser(user, fromOriginalToStrippedDownTenant, fromOriginalToStrippedDownUser));
+                result.add(createUserDTOFromUser(user, fromOriginalToStrippedDownTenant, fromOriginalToStrippedDownUser,
+                        fromOriginalToStrippedDownUserGroup));
             }
         }
         return result;
@@ -261,10 +266,11 @@ public class UserManagementServiceImpl extends RemoteServiceServlet implements U
         if (SecurityUtils.getSubject().isPermitted("tenant:delete:" + tenantIdAsString)) {
             try {
                 UUID tenantId = UUID.fromString(tenantIdAsString);
-                getSecurityService().deleteTenant(getSecurityService().getTenant(tenantId));
+                final Tenant tenant = getSecurityService().getTenant(tenantId);
+                getSecurityService().deleteTenant(tenant);
                 getSecurityService().deleteACL(tenantIdAsString);
                 getSecurityService().deleteOwnership(tenantIdAsString);
-                return new SuccessInfo(true, "Deleted tenant: " + tenantIdAsString + ".", /* redirectURL */ null, null);
+                return new SuccessInfo(true, "Deleted tenant: " + tenant.getName() + ".", /* redirectURL */ null, null);
             } catch (UserGroupManagementException e) {
                 return new SuccessInfo(false, "Could not delete tenant.", /* redirectURL */ null, null);
             }
@@ -518,10 +524,11 @@ public class UserManagementServiceImpl extends RemoteServiceServlet implements U
     }
 
     private UserDTO createUserDTOFromUser(User user) {
-        return createUserDTOFromUser(user, new HashMap<>(), new HashMap<>());
+        return createUserDTOFromUser(user, new HashMap<>(), new HashMap<>(), new HashMap<>());
     }
     
-    private UserDTO createUserDTOFromUser(User user, Map<Tenant, Tenant> fromOriginalToStrippedDownTenant, Map<SecurityUser, SecurityUser> fromOriginalToStrippedDownUser) {
+    private UserDTO createUserDTOFromUser(User user, Map<Tenant, Tenant> fromOriginalToStrippedDownTenant, Map<SecurityUser, SecurityUser> fromOriginalToStrippedDownUser,
+            Map<UserGroup, UserGroup> fromOriginalToStrippedDownUserGroup) {
         UserDTO userDTO;
         Map<AccountType, Account> accounts = user.getAllAccounts();
         List<AccountDTO> accountDTOs = new ArrayList<>();
@@ -544,12 +551,50 @@ public class UserManagementServiceImpl extends RemoteServiceServlet implements U
         userDTO = new UserDTO(user.getName(), user.getEmail(), user.getFullName(), user.getCompany(),
                 user.getLocale() != null ? user.getLocale().toLanguageTag() : null, user.isEmailValidated(),
                 accountDTOs, user.getRoles(), /* default tenant filled in later */ null,
-                user.getPermissions());
+                user.getPermissions(),
+                createUserGroupDTOsFromUserGroups(getSecurityService().getUserGroupsOfUser(user),
+                        fromOriginalToStrippedDownTenant, fromOriginalToStrippedDownUser,
+                        fromOriginalToStrippedDownUserGroup));
         fromOriginalToStrippedDownUser.put(user, userDTO);
-        userDTO.setDefaultTenant(createTenantDTOFromTenant(user.getDefaultTenant(), fromOriginalToStrippedDownTenant, fromOriginalToStrippedDownUser));
+        userDTO.setDefaultTenant(createTenantDTOFromTenant(user.getDefaultTenant(), fromOriginalToStrippedDownTenant,
+                fromOriginalToStrippedDownUser, fromOriginalToStrippedDownUserGroup));
         return userDTO;
     }
 
+    private Iterable<UserGroup> createUserGroupDTOsFromUserGroups(Iterable<UserGroup> userGroups,
+            Map<Tenant, Tenant> fromOriginalToStrippedDownTenant,
+            Map<SecurityUser, SecurityUser> fromOriginalToStrippedDownUser,
+            Map<UserGroup, UserGroup> fromOriginalToStrippedDownUserGroup) {
+        final List<UserGroup> result;
+        if (userGroups == null) {
+            result = null;
+        } else {
+            result = new ArrayList<>();
+            for (final UserGroup userGroup : userGroups) {
+                result.add(createUserDTOFromUserGroup(userGroup, fromOriginalToStrippedDownTenant,
+                        fromOriginalToStrippedDownUser, fromOriginalToStrippedDownUserGroup));
+            }
+        }
+        return result;
+    }
+
+    private UserGroup createUserDTOFromUserGroup(UserGroup userGroup,
+            Map<Tenant, Tenant> fromOriginalToStrippedDownTenant,
+            Map<SecurityUser, SecurityUser> fromOriginalToStrippedDownUser,
+            Map<UserGroup, UserGroup> fromOriginalToStrippedDownUserGroup) {
+        final UserGroup result;
+        if (fromOriginalToStrippedDownUserGroup.containsKey(userGroup)) {
+            result = fromOriginalToStrippedDownUserGroup.get(userGroup);
+        } else {
+            result = new UserGroupImpl(userGroup.getId(), userGroup.getName());
+            fromOriginalToStrippedDownUserGroup.put(userGroup, result);
+            for (final SecurityUser user : userGroup.getUsers()) {
+                result.add(createUserDTOFromUser(user, fromOriginalToStrippedDownTenant, fromOriginalToStrippedDownUser, fromOriginalToStrippedDownUserGroup));
+            }
+        }
+        return result;
+    }
+
     @Override
     public Map<String, String> getSettings() {
         Map<String, String> settings = new TreeMap<String, String>();

java/com.sap.sse.security.ui/src/main/java/com/sap/sse/security/ui/shared/UserDTO.java

@@ -10,7 +10,6 @@ import com.google.gwt.user.client.rpc.IsSerializable;
 import com.sap.sse.common.Util;
 import com.sap.sse.security.shared.AccessControlList;
 import com.sap.sse.security.shared.Ownership;
-import com.sap.sse.security.shared.PermissionChecker;
 import com.sap.sse.security.shared.Role;
 import com.sap.sse.security.shared.Tenant;
 import com.sap.sse.security.shared.UserGroup;
@@ -26,6 +25,7 @@ public class UserDTO extends SecurityUserImpl implements IsSerializable {
     private String locale;
     private List<AccountDTO> accounts;
     private boolean emailValidated;
+    private List<UserGroup> groups;
 
     // for GWT serialization only
     @Deprecated
@@ -33,8 +33,12 @@ public class UserDTO extends SecurityUserImpl implements IsSerializable {
         super();
     }
 
+    /**
+     * @param groups may be {@code null} which is equivalent to passing an empty groups collection
+     */
     public UserDTO(String name, String email, String fullName, String company, String locale, boolean emailValidated,
-            List<AccountDTO> accounts, Iterable<Role> roles, Tenant defaultTenant, Iterable<WildcardPermission> permissions) {
+            List<AccountDTO> accounts, Iterable<Role> roles, Tenant defaultTenant, Iterable<WildcardPermission> permissions,
+            Iterable<UserGroup> groups) {
         super(name, roles, defaultTenant, permissions);
         this.email = email;
         this.fullName = fullName;
@@ -42,6 +46,8 @@ public class UserDTO extends SecurityUserImpl implements IsSerializable {
         this.locale = locale;
         this.emailValidated = emailValidated;
         this.accounts = accounts;
+        this.groups = new ArrayList<>();
+        Util.addAll(groups, this.groups);
     }
 
     public String getFullName() {
@@ -105,20 +111,16 @@ public class UserDTO extends SecurityUserImpl implements IsSerializable {
         return result;
     }
     
+    public List<UserGroup> getUserGroups() {
+        return groups;
+    }
+    
     public boolean hasPermission(String permission) {
         return hasPermission(new WildcardPermission(permission));
     }
-    
-    public boolean hasPermission(String permission, AccessControlList acl, Ownership ownership) {
-        return hasPermission(new WildcardPermission(permission), acl, ownership);
-    }
-    
-    public boolean hasPermission(WildcardPermission permission, AccessControlList acl, Ownership ownership) {
-        ArrayList<UserGroup> groupsTheUserBelongsTo = new ArrayList<>();
-        if (acl != null) {
-            groupsTheUserBelongsTo = new ArrayList<>(acl.getActionsByUserGroup().keySet());
-        }
-        return PermissionChecker.isPermitted(permission, this, groupsTheUserBelongsTo, getRoles(), ownership, acl);
+
+    public boolean hasPermission(WildcardPermission permission, Ownership ownership, AccessControlList acl) {
+        return hasPermission(permission, ownership, getUserGroups(), acl);
     }
     
     public List<AccountDTO> getAccounts() {

java/com.sap.sse.security.userstore.mongodb/src/com/sap/sse/security/userstore/mongodb/UserStoreImpl.java

@@ -72,7 +72,9 @@ public class UserStoreImpl implements UserStore {
     
     /**
      * Protects access to the two maps {@link #userGroupsContainingUser} and {@link #usersInUserGroups} which implement
-     * an efficient lookup for the m:n association between {@link UserGroup#getUsers()} and {@link SecurityUser}.
+     * an efficient lookup for the m:n association between {@link UserGroup#getUsers()} and {@link SecurityUser}. The
+     * collections also contain the relationships for the specialized {@link Tenant} objects which are not part of
+     * {@link #userGroups} but of {@link #tenants}.
      */
     private final NamedReentrantReadWriteLock userGroupsUserCacheLock = new NamedReentrantReadWriteLock("User Groups Cache", /* fair */ false);
     private final ConcurrentHashMap<SecurityUser, Set<UserGroup>> userGroupsContainingUser;

java/com.sap.sse.security.userstore.mongodb/src/com/sap/sse/security/userstore/mongodb/impl/DomainObjectFactoryImpl.java

@@ -170,7 +170,10 @@ public class DomainObjectFactoryImpl implements DomainObjectFactory {
         BasicDBList usersO = (BasicDBList) groupDBObject.get(FieldNames.UserGroup.USERNAMES.name());
         if (usersO != null) {
             for (Object o : usersO) {
-                users.add(usersByName.get((String) o));
+                final UserImpl user = usersByName.get((String) o);
+                if (user != null) {
+                    users.add(user);
+                }
             }
         }
         UserGroup result = new UserGroupImpl(id, name, users);

java/com.sap.sse.security/src/com/sap/sse/security/SecurityService.java

@@ -104,6 +104,8 @@ public interface SecurityService extends ReplicableWithObjectInputStream<Replica
     UserGroup getUserGroup(UUID id);
 
     UserGroup getUserGroupByName(String name);
+    
+    Iterable<UserGroup> getUserGroupsOfUser(SecurityUser user);
 
     Iterable<Tenant> getTenants();
 

java/com.sap.sse.security/src/com/sap/sse/security/impl/SecurityServiceImpl.java

@@ -490,6 +490,11 @@ public class SecurityServiceImpl implements ReplicableSecurityService, ClearStat
         return userStore.getUserGroupByName(name);
     }
 
+    @Override
+    public Iterable<UserGroup> getUserGroupsOfUser(SecurityUser user) {
+        return userStore.getUserGroupsOfUser(user);
+    }
+
     @Override
     public Iterable<Tenant> getTenants() {
         return userStore.getTenants();
@@ -552,7 +557,8 @@ public class SecurityServiceImpl implements ReplicableSecurityService, ClearStat
     @Override
     public void deleteTenant(Tenant tenant) throws TenantManagementException, UserGroupManagementException {
         for (Ownership ownership : accessControlStore.getOwnerships()) {
-            if (ownership.getTenantOwner().equals(tenant)) {
+            if (!Util.equalsWithNull(ownership.getIdOfOwnedObjectAsString(), tenant.getId().toString()) &&
+                    Util.equalsWithNull(ownership.getTenantOwner(), tenant)) {
                 throw new TenantManagementException("The tenant "+tenant.getName()+
                         " is still used as tenant owner and therefore cannot be removed");
             }
@@ -620,7 +626,12 @@ public class SecurityServiceImpl implements ReplicableSecurityService, ClearStat
     
     @Override
     public Void internalDeleteUserGroup(UUID groupId) throws UserGroupManagementException {
-        userStore.deleteUserGroup(getUserGroup(groupId));
+        final UserGroup userGroup = getUserGroup(groupId);
+        if (userGroup == null) {
+            logger.warning("Strange: the user group with ID "+groupId+" which is about to be deleted couldn't be found");
+        } else {
+            userStore.deleteUserGroup(userGroup);
+        }
         return null;
     }