Merge pull request #639 from nextcloud/sso

Proof of concept for SingSignOn

12 files changed, 972 insertions, 186 deletions

diff --git a/News-Android-App/build.gradle b/News-Android-App/build.gradle
index 86275f5c..abb4a14f 100644
--- a/News-Android-App/build.gradle
+++ b/News-Android-App/build.gradle
@@ -13,6 +13,7 @@ android {
     buildToolsVersion project.ANDROID_BUILD_TOOLS_VERSION
 
     defaultConfig {
+        multiDexEnabled true
         minSdkVersion Integer.parseInt(project.ANDROID_BUILD_MIN_SDK_VERSION)
         targetSdkVersion Integer.parseInt(project.ANDROID_BUILD_TARGET_SDK_VERSION)
 
@@ -89,6 +90,7 @@ repositories {
     jcenter()
     maven { url 'http://guardian.github.com/maven/repo-releases' } //needed for com.gu:option:1.3 in Android-DirectoryChooser
     maven { url  "http://dl.bintray.com/lukaville/maven" } //Needed for com.nbsp:library:1.02 in Material File Picker
+    maven { url "https://jitpack.io" }
 
 }
 
@@ -100,7 +102,7 @@ dependencies {
     // You must install or update the Google Repository through the SDK manager to use this dependency.
     // The Google Repository (separate from the corresponding library) can be found in the Extras category.
     // implementation 'com.google.android.gms:play-services:4.2.42'
-    implementation project(path: ':ownCloud-Account-Importer', configuration: 'default')
+    implementation "com.github.nextcloud:android-SingleSignOn:sso-SNAPSHOT"
     implementation "com.android.support:support-v4:${SUPPORT_VERSION}"
     implementation "com.android.support:support-compat:${SUPPORT_VERSION}"
     implementation "com.android.support:appcompat-v7:${SUPPORT_VERSION}"
@@ -113,6 +115,7 @@ dependencies {
     implementation 'com.nostra13.universalimageloader:universal-image-loader:1.9.4'
     implementation 'com.google.code.gson:gson:2.8.0'
     implementation 'com.jakewharton:butterknife:8.8.1'
+    implementation 'com.android.support:multidex:1.0.3'
     annotationProcessor 'com.jakewharton:butterknife-compiler:8.8.1'
 
     compileOnly 'com.google.auto.value:auto-value:1.5.2'
diff --git a/News-Android-App/src/main/AndroidManifest.xml b/News-Android-App/src/main/AndroidManifest.xml
index 3bc1a936..f6394e9a 100644
--- a/News-Android-App/src/main/AndroidManifest.xml
+++ b/News-Android-App/src/main/AndroidManifest.xml
@@ -20,6 +20,7 @@
     <uses-permission android:name="android.permission.USE_CREDENTIALS" />
     <uses-permission android:name="android.permission.MEDIA_CONTENT_CONTROL" />
 
+    <uses-permission android:name="com.owncloud.android.sso"/>
     <!--
     <uses-permission android:name="android.permission.DOWNLOAD_WITHOUT_NOTIFICATION" />
     -->
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/LoginDialogFragment.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/LoginDialogFragment.java
index 35c07cd9..c4b08055 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/LoginDialogFragment.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/LoginDialogFragment.java
@@ -21,14 +21,20 @@
 
 package de.luhmer.owncloudnewsreader;
 
+import android.Manifest;
+import android.accounts.Account;
+import android.accounts.AccountManager;
 import android.app.Activity;
 import android.app.Dialog;
 import android.app.ProgressDialog;
 import android.content.DialogInterface;
+import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.SharedPreferences.Editor;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
+import android.support.design.widget.TextInputLayout;
+import android.support.v4.app.ActivityCompat;
 import android.support.v4.app.DialogFragment;
 import android.support.v7.app.AlertDialog;
 import android.text.Editable;
@@ -48,7 +54,9 @@ import android.widget.CompoundButton;
 import android.widget.CompoundButton.OnCheckedChangeListener;
 import android.widget.EditText;
 import android.widget.ImageView;
+import android.widget.Switch;
 import android.widget.TextView;
+import android.widget.Toast;
 
 import java.net.MalformedURLException;
 import java.net.URL;
@@ -57,9 +65,9 @@ import javax.inject.Inject;
 
 import butterknife.BindView;
 import butterknife.ButterKnife;
-import de.luhmer.owncloud.accountimporter.ImportAccountsDialogFragment;
 import de.luhmer.owncloud.accountimporter.helper.AccountImporter;
-import de.luhmer.owncloud.accountimporter.helper.OwnCloudAccount;
+import de.luhmer.owncloud.accountimporter.helper.NextcloudAPI;
+import de.luhmer.owncloud.accountimporter.helper.SingleSignOnAccount;
 import de.luhmer.owncloud.accountimporter.interfaces.IAccountImport;
 import de.luhmer.owncloudnewsreader.authentication.AuthenticatorActivity;
 import de.luhmer.owncloudnewsreader.database.DatabaseConnectionOrm;
@@ -72,12 +80,18 @@ import io.reactivex.annotations.NonNull;
 import io.reactivex.disposables.Disposable;
 import io.reactivex.schedulers.Schedulers;
 
+import static android.app.Activity.RESULT_OK;
+
 /**
  * Activity which displays a login screen to the user, offering registration as
  * well.
  */
 public class LoginDialogFragment extends DialogFragment implements IAccountImport {
 
+    final String TAG = LoginDialogFragment.class.getCanonicalName();
+    final int CHOOSE_ACCOUNT = 12;
+
+
     static LoginDialogFragment instance;
     public static LoginDialogFragment getInstance() {
         if(instance == null)
@@ -104,23 +118,39 @@ public class LoginDialogFragment extends DialogFragment implements IAccountImpor
 	// UI references.
 	@BindView(R.id.username) EditText mUsernameView;
 	@BindView(R.id.password) EditText mPasswordView;
+	@BindView(R.id.password_container) TextInputLayout mPasswordContainerView;
 	@BindView(R.id.edt_owncloudRootPath) EditText mOc_root_path_View;
 	@BindView(R.id.cb_AllowAllSSLCertificates) CheckBox mCbDisableHostnameVerificationView;
     @BindView(R.id.imgView_ShowPassword) ImageView mImageViewShowPwd;
+    @BindView(R.id.swSingleSignOn) Switch mSwSingleSignOn;
 
-    boolean mPasswordVisible = false;
+	private Account importedAccount = null;
+    private boolean mPasswordVisible = false;
+    private LoginSuccessfulListener listener;
 
-    @Override
-    public void accountAccessGranted(OwnCloudAccount account) {
-        mUsernameView.setText(account.getUsername());
-        mPasswordView.setText(account.getPassword());
-        mOc_root_path_View.setText(account.getUrl());
-    }
+	@Override
+	public void accountAccessGranted(final Account account) {
+		try {
+			SingleSignOnAccount singleAccount = AccountImporter.BlockingGetAuthToken(getActivity(), account);
+			mUsernameView.setText(singleAccount.username);
+            mPasswordView.setText("");
+            mOc_root_path_View.setText(singleAccount.url);
+
+			mPasswordContainerView.setVisibility(View.GONE);
+            mImageViewShowPwd.setVisibility(View.GONE);
+            mCbDisableHostnameVerificationView.setVisibility(View.GONE);
 
-    public interface LoginSuccessfullListener {
+			this.importedAccount = account;
+		} catch (Exception e) {
+			e.printStackTrace();
+			Toast.makeText(getActivity(), e.getMessage(), Toast.LENGTH_SHORT).show();
+		}
+	}
+
+	public interface LoginSuccessfulListener {
 		void LoginSucceeded();
 	}
-	LoginSuccessfullListener listener;
+
 
 
 	public LoginDialogFragment() {
@@ -134,7 +164,7 @@ public class LoginDialogFragment extends DialogFragment implements IAccountImpor
 	/**
 	 * @param listener the listener to set
 	 */
-	public void setListener(LoginSuccessfullListener listener) {
+	public void setListener(LoginSuccessfulListener listener) {
 		this.listener = listener;
 	}
 
@@ -153,7 +183,11 @@ public class LoginDialogFragment extends DialogFragment implements IAccountImpor
 
     @Override
     public Dialog onCreateDialog(Bundle savedInstanceState) {
-		showImportAccountButton = AccountImporter.findAccounts(getActivity()).size() > 0;
+        ActivityCompat.requestPermissions(getActivity(),
+                new String[]{Manifest.permission.GET_ACCOUNTS}, 0);
+
+        //accountImporter = new AccountImporter();
+		showImportAccountButton = AccountImporter.AccountsToImportAvailable(getActivity());
 
 		//setRetainInstance(true);
 
@@ -179,6 +213,7 @@ public class LoginDialogFragment extends DialogFragment implements IAccountImpor
         mUsername = mPrefs.getString(SettingsActivity.EDT_USERNAME_STRING, "");
         mPassword = mPrefs.getString(SettingsActivity.EDT_PASSWORD_STRING, "");
         mOc_root_path = mPrefs.getString(SettingsActivity.EDT_OWNCLOUDROOTPATH_STRING, "");
+        boolean useSSO = mPrefs.getBoolean(SettingsActivity.SW_USE_SINGLE_SIGN_ON, false);
         mCbDisableHostnameVerification = mPrefs.getBoolean(SettingsActivity.CB_DISABLE_HOSTNAME_VERIFICATION_STRING, false);
 
 		if(!mPassword.isEmpty()) {
@@ -201,11 +236,52 @@ public class LoginDialogFragment extends DialogFragment implements IAccountImpor
 			}
 		});
 
+        if(useSSO) {
+            mSwSingleSignOn.setChecked(true);
+            syncUiElementState();
+        }
+
+        mSwSingleSignOn.setOnCheckedChangeListener(new OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+                syncUiElementState();
+
+                mUsernameView.setText("");
+                mPasswordView.setText("");
+                mOc_root_path_View.setText("");
+                mCbDisableHostnameVerificationView.setChecked(false);
+
+                mPasswordContainerView.setVisibility(View.VISIBLE);
+                mImageViewShowPwd.setVisibility(View.VISIBLE);
+                mCbDisableHostnameVerificationView.setVisibility(View.VISIBLE);
+
+                if(isChecked) {
+                    Intent intent = AccountManager.newChooseAccountIntent(null, null, new String[] {"nextcloud"},
+                            true, null, null, null, null);
+                    startActivityForResult(intent, CHOOSE_ACCOUNT);
+                } else {
+                    importedAccount = null;
+                }
+            }
+        });
+
+
+
 		AlertDialog dialog = builder.create();
 		// Set dialog to resize when soft keyboard pops up
 		dialog.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE);
 
-        return dialog;
+
+
+		return dialog;
+    }
+
+    private void syncUiElementState() {
+        boolean useSSO = mSwSingleSignOn.isChecked();
+        mUsernameView.setEnabled(!useSSO);
+        mPasswordView.setEnabled(!useSSO);
+        mOc_root_path_View.setEnabled(!useSSO);
+        mCbDisableHostnameVerificationView.setEnabled(!useSSO);
     }
 
 	@Override
@@ -219,7 +295,9 @@ public class LoginDialogFragment extends DialogFragment implements IAccountImpor
 				neutralButton.setOnClickListener(new View.OnClickListener() {
 					@Override
 					public void onClick(View v) {
-						ImportAccountsDialogFragment.show(getActivity(), LoginDialogFragment.this);
+                        mSwSingleSignOn.setChecked(false);
+                        mSwSingleSignOn.setChecked(true);
+						//ImportAccountsDialogFragment.show(getActivity(), LoginDialogFragment.this);
 					}
 				});
 				// Limit button width to not push positive button out of view
@@ -235,6 +313,7 @@ public class LoginDialogFragment extends DialogFragment implements IAccountImpor
 		}
 	}
 
+
 	@Override
 	public void onCancel(DialogInterface dialog) {
 		super.onCancel(dialog);
@@ -304,36 +383,39 @@ public class LoginDialogFragment extends DialogFragment implements IAccountImpor
 		boolean cancel = false;
 		View focusView = null;
 
-		// Check for a valid password.
-		if (TextUtils.isEmpty(mPassword)) {
-			mPasswordView.setError(getString(R.string.error_field_required));
-			focusView = mPasswordView;
-			cancel = true;
-		}
-		// Check for a valid email address.
-		if (TextUtils.isEmpty(mUsername)) {
-			mUsernameView.setError(getString(R.string.error_field_required));
-			focusView = mUsernameView;
-			cancel = true;
-		}
+        // Only run checks if we don't use sso
+        if(!mSwSingleSignOn.isChecked()) {
+            // Check for a valid password.
+            if (TextUtils.isEmpty(mPassword)) {
+                mPasswordView.setError(getString(R.string.error_field_required));
+                focusView = mPasswordView;
+                cancel = true;
+            }
+            // Check for a valid email address.
+            if (TextUtils.isEmpty(mUsername)) {
+                mUsernameView.setError(getString(R.string.error_field_required));
+                focusView = mUsernameView;
+                cancel = true;
+            }
 
-		if (TextUtils.isEmpty(mOc_root_path)) {
-			mOc_root_path_View.setError(getString(R.string.error_field_required));
-			focusView = mOc_root_path_View;
-			cancel = true;
-		} else {
-			try {
-				URL url = new URL(mOc_root_path);
-				if(!url.getProtocol().equals("https"))
-					ShowAlertDialog(getString(R.string.login_dialog_title_security_warning),
-							getString(R.string.login_dialog_text_security_warning), getActivity());
-			} catch (MalformedURLException e) {
-				mOc_root_path_View.setError(getString(R.string.error_invalid_url));
-				focusView = mOc_root_path_View;
-				cancel = true;
-				//e.printStackTrace();
-			}
-		}
+            if (TextUtils.isEmpty(mOc_root_path)) {
+                mOc_root_path_View.setError(getString(R.string.error_field_required));
+                focusView = mOc_root_path_View;
+                cancel = true;
+            } else {
+                try {
+                    URL url = new URL(mOc_root_path);
+                    if (!url.getProtocol().equals("https"))
+                        ShowAlertDialog(getString(R.string.login_dialog_title_security_warning),
+                                getString(R.string.login_dialog_text_security_warning), getActivity());
+                } catch (MalformedURLException e) {
+                    mOc_root_path_View.setError(getString(R.string.error_invalid_url));
+                    focusView = mOc_root_path_View;
+                    cancel = true;
+                    //e.printStackTrace();
+                }
+            }
+        }
 
 		if (cancel) {
 			// There was an error; don't attempt login and focus the first
@@ -345,74 +427,87 @@ public class LoginDialogFragment extends DialogFragment implements IAccountImpor
             editor.putString(SettingsActivity.EDT_OWNCLOUDROOTPATH_STRING, mOc_root_path);
             editor.putString(SettingsActivity.EDT_PASSWORD_STRING, mPassword);
             editor.putString(SettingsActivity.EDT_USERNAME_STRING, mUsername);
+            editor.putBoolean(SettingsActivity.SW_USE_SINGLE_SIGN_ON, importedAccount != null);
             editor.commit();
 
-            // Re-init API
-            mApi.initApi();
-
-            //((NewsReaderApplication) getActivity().getApplication()).initDaggerAppComponent();
-            //((NewsReaderApplication) getActivity().getApplication()).getAppComponent().injectFragment(this);
-
-
-			final String TAG = LoginDialogFragment.class.getCanonicalName();
-            final ProgressDialog mDialogLogin = BuildPendingDialogWhileLoggingIn();
-            mDialogLogin.show();
-
-
-			mApi.getAPI().version()
-					.subscribeOn(Schedulers.newThread())
-					.observeOn(AndroidSchedulers.mainThread())
-					.subscribe(new Observer<NextcloudNewsVersion>() {
-                                boolean loginSuccessful = false;
-
-								   @Override
-								   public void onSubscribe(@NonNull Disposable d) {
-									   Log.v(TAG, "onSubscribe() called with: d = [" + d + "]");
-								   }
+            final ProgressDialog dialogLogin = BuildPendingDialogWhileLoggingIn();
+            dialogLogin.show();
 
-								   @Override
-								   public void onNext(@NonNull NextcloudNewsVersion version) {
-									   Log.v(TAG, "onNext() called with: status = [" + version + "]");
-
-                                       loginSuccessful = true;
-                                       mPrefs.edit().putString(Constants.NEWS_WEB_VERSION_NUMBER_STRING, version.version).apply();
-
-                                       if(version.version.equals("0")) {
-                                           ShowAlertDialog(getString(R.string.login_dialog_title_error), getString(R.string.login_dialog_text_zero_version_code), getActivity());
-                                           loginSuccessful = false;
-                                       }
-								   }
-
-								   @Override
-								   public void onError(@NonNull Throwable e) {
-                                       mDialogLogin.dismiss();
-									   Log.v(TAG, "onError() called with: e = [" + e + "]");
-
-                                       Throwable t = OkHttpSSLClient.HandleExceptions(e);
-                                       ShowAlertDialog(getString(R.string.login_dialog_title_error), t.getMessage(), getActivity());
-								   }
-
-								   @Override
-								   public void onComplete() {
-                                       mDialogLogin.dismiss();
+			if(mSwSingleSignOn.isChecked()) {
+				AccountImporter.SetCurrentAccount(getActivity(), importedAccount);
+			}
 
-									   Log.v(TAG, "onComplete() called");
 
-                                       if(loginSuccessful) {
-                                           //Reset Database
-                                           DatabaseConnectionOrm dbConn = new DatabaseConnectionOrm(getActivity());
-                                           dbConn.resetDatabase();
+			mApi.initApi(new NextcloudAPI.ApiConnectedListener() {
+                @Override
+                public void onConnected() {
+                    Log.d(TAG, "onConnected() called");
+                    finishLogin(dialogLogin);
+                }
 
-                                           listener.LoginSucceeded();
-                                           LoginDialogFragment.this.getDialog().cancel();
-                                           if(mActivity instanceof AuthenticatorActivity)
-                                               mActivity.finish();
-                                       }
-                                   }
-							   });
+                @Override
+                public void onError(Exception ex) {
+                    Log.d(TAG, "onError() called with: ex = [" + ex + "]");
+                    ShowAlertDialog(getString(R.string.login_dialog_title_error), ex.getMessage(), getActivity());
+                }
+            });
 		}
 	}
 
+	private void finishLogin(final ProgressDialog dialogLogin) {
+        mApi.getAPI().version()
+                .subscribeOn(Schedulers.newThread())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(new Observer<NextcloudNewsVersion>() {
+                    boolean loginSuccessful = false;
+
+                    @Override
+                    public void onSubscribe(@NonNull Disposable d) {
+                        Log.v(TAG, "onSubscribe() called with: d = [" + d + "]");
+                    }
+
+                    @Override
+                    public void onNext(@NonNull NextcloudNewsVersion version) {
+                        Log.v(TAG, "onNext() called with: status = [" + version + "]");
+
+                        loginSuccessful = true;
+                        mPrefs.edit().putString(Constants.NEWS_WEB_VERSION_NUMBER_STRING, version.version).apply();
+
+                        if(version.version.equals("0")) {
+                            ShowAlertDialog(getString(R.string.login_dialog_title_error), getString(R.string.login_dialog_text_zero_version_code), getActivity());
+                            loginSuccessful = false;
+                        }
+                    }
+
+                    @Override
+                    public void onError(@NonNull Throwable e) {
+                        dialogLogin.dismiss();
+                        Log.v(TAG, "onError() called with: e = [" + e + "]");
+
+                        Throwable t = OkHttpSSLClient.HandleExceptions(e);
+                        ShowAlertDialog(getString(R.string.login_dialog_title_error), t.getMessage(), getActivity());
+                    }
+
+                    @Override
+                    public void onComplete() {
+                        dialogLogin.dismiss();
+
+                        Log.v(TAG, "onComplete() called");
+
+                        if(loginSuccessful) {
+                            //Reset Database
+                            DatabaseConnectionOrm dbConn = new DatabaseConnectionOrm(getActivity());
+                            dbConn.resetDatabase();
+
+                            listener.LoginSucceeded();
+                            LoginDialogFragment.this.getDialog().cancel();
+                            if(mActivity instanceof AuthenticatorActivity)
+                                mActivity.finish();
+                        }
+                    }
+                });
+    }
+
 	public static void ShowAlertDialog(String title, String text, Activity activity)
 	{
 		// Linkify the message
@@ -429,4 +524,21 @@ public class LoginDialogFragment extends DialogFragment implements IAccountImpor
 		// Make the textview clickable. Must be called after show()
 		((TextView)aDialog.findViewById(android.R.id.message)).setMovementMethod(LinkMovementMethod.getInstance());
 	}
+
+    @Override
+    public void onActivityResult(int requestCode, int resultCode, Intent data) {
+        super.onActivityResult(requestCode, resultCode, data);
+
+        if (resultCode == RESULT_OK) {
+            if (requestCode == CHOOSE_ACCOUNT) {
+                importedAccount = null;
+                String accountName = data.getStringExtra(AccountManager.KEY_ACCOUNT_NAME);
+
+                Account account = AccountImporter.GetAccountForName(getActivity(), accountName);
+                if(account != null) {
+                    accountAccessGranted(account);
+                }
+            }
+        }
+    }
 }
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListActivity.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListActivity.java
index 2ada5c97..3c0a38dd 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListActivity.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListActivity.java
@@ -69,8 +69,9 @@ import java.util.List;
 
 import butterknife.BindView;
 import butterknife.ButterKnife;
+import de.luhmer.owncloud.accountimporter.helper.NextcloudAPI;
 import de.luhmer.owncloudnewsreader.ListView.SubscriptionExpandableListAdapter;
-import de.luhmer.owncloudnewsreader.LoginDialogFragment.LoginSuccessfullListener;
+import de.luhmer.owncloudnewsreader.LoginDialogFragment.LoginSuccessfulListener;
 import de.luhmer.owncloudnewsreader.adapter.NewsListRecyclerAdapter;
 import de.luhmer.owncloudnewsreader.adapter.RecyclerItemClickListener;
 import de.luhmer.owncloudnewsreader.adapter.ViewHolder;
@@ -824,7 +825,9 @@ public class NewsReaderListActivity extends PodcastFragmentActivity implements
 	}
 
     @Override
-    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+    protected void onActivityResult(int requestCode, int resultCode, final Intent data) {
+	    super.onActivityResult(requestCode, resultCode, data);
+
 		if(resultCode == RESULT_OK) {
 			UpdateListView();
 			getSlidingListFragment().ListViewNotifyDataSetChanged();
@@ -833,17 +836,26 @@ public class NewsReaderListActivity extends PodcastFragmentActivity implements
         if(requestCode == RESULT_SETTINGS)
         {
             //Update settings of image Loader
-            mApi.initApi();
-
-			String oldLayout = data.getStringExtra(SettingsActivity.SP_FEED_LIST_LAYOUT);
-			String newLayout = PreferenceManager.getDefaultSharedPreferences(this).getString(SettingsActivity.SP_FEED_LIST_LAYOUT,"0");
+            mApi.initApi(new NextcloudAPI.ApiConnectedListener() {
+                @Override
+                public void onConnected() {
+                    String oldLayout = data.getStringExtra(SettingsActivity.SP_FEED_LIST_LAYOUT);
+                    String newLayout = PreferenceManager.getDefaultSharedPreferences(NewsReaderListActivity.this).getString(SettingsActivity.SP_FEED_LIST_LAYOUT,"0");
+
+                    if(ThemeChooser.getInstance(NewsReaderListActivity.this).themeRequiresRestartOfUI(NewsReaderListActivity.this) || !newLayout.equals(oldLayout)) {
+                        finish();
+                        startActivity(getIntent());
+                    } else if(data.hasExtra(SettingsActivity.CACHE_CLEARED) && ownCloudSyncService != null) {
+                        resetUiAndStartSync();
+                    }
+                }
+
+                @Override
+                public void onError(Exception ex) {
+                    ex.printStackTrace();
+                }
+            });
 
-            if(ThemeChooser.getInstance(this).themeRequiresRestartOfUI(this) || !newLayout.equals(oldLayout)) {
-                finish();
-                startActivity(getIntent());
-            } else if(data.hasExtra(SettingsActivity.CACHE_CLEARED) && ownCloudSyncService != null) {
-                resetUiAndStartSync();
-            }
         } else if(requestCode == RESULT_ADD_NEW_FEED) {
             if(data != null) {
                 boolean val = data.getBooleanExtra(NewFeedActivity.ADD_NEW_SUCCESS, false);
@@ -867,7 +879,7 @@ public class NewsReaderListActivity extends PodcastFragmentActivity implements
     {
 	   	LoginDialogFragment dialog = LoginDialogFragment.getInstance();
 	   	dialog.setActivity(activity);
-	   	dialog.setListener(new LoginSuccessfullListener() {
+	   	dialog.setListener(new LoginSuccessfulListener() {
             @Override
             public void LoginSucceeded() {
                 ((NewsReaderListActivity) activity).resetUiAndStartSync();
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SettingsActivity.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SettingsActivity.java
index 20e31b65..8e5b8ebf 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SettingsActivity.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SettingsActivity.java
@@ -90,6 +90,7 @@ public class SettingsActivity extends AppCompatPreferenceActivity {
 	public static final String EDT_USERNAME_STRING = "edt_username";
 	public static final String EDT_PASSWORD_STRING = "edt_password";
 	public static final String EDT_OWNCLOUDROOTPATH_STRING = "edt_owncloudRootPath";
+	public static final String SW_USE_SINGLE_SIGN_ON = "sw_use_single_sign_on";
 	public static final String EDT_CLEAR_CACHE = "edt_clearCache";
 
     //public static final String CB_ALLOWALLSSLCERTIFICATES_STRING = "cb_AllowAllSSLCertificates";
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/di/ApiProvider.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/di/ApiProvider.java
index a008cdc9..da24281a 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/di/ApiProvider.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/di/ApiProvider.java
@@ -1,36 +1,24 @@
 package de.luhmer.owncloudnewsreader.di;
 
+import android.accounts.Account;
 import android.content.Context;
 import android.content.SharedPreferences;
-import android.graphics.BitmapFactory;
-import android.util.Base64;
+import android.support.annotation.NonNull;
 import android.util.Log;
 
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonDeserializationContext;
-import com.google.gson.JsonDeserializer;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
-import com.google.gson.JsonParseException;
-import com.google.gson.reflect.TypeToken;
 import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
 import com.nostra13.universalimageloader.core.DisplayImageOptions;
 import com.nostra13.universalimageloader.core.ImageLoader;
 import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
 
-import java.lang.reflect.Type;
-import java.util.List;
-
+import de.luhmer.owncloud.accountimporter.helper.AccountImporter;
+import de.luhmer.owncloud.accountimporter.helper.NextcloudAPI;
+import de.luhmer.owncloud.accountimporter.helper.SingleSignOnAccount;
 import de.luhmer.owncloudnewsreader.SettingsActivity;
-import de.luhmer.owncloudnewsreader.database.model.Feed;
-import de.luhmer.owncloudnewsreader.database.model.Folder;
-import de.luhmer.owncloudnewsreader.database.model.RssItem;
-import de.luhmer.owncloudnewsreader.model.UserInfo;
+import de.luhmer.owncloudnewsreader.helper.GsonConfig;
 import de.luhmer.owncloudnewsreader.reader.OkHttpImageDownloader;
 import de.luhmer.owncloudnewsreader.reader.nextcloud.API;
-import de.luhmer.owncloudnewsreader.reader.nextcloud.NextcloudDeserializer;
-import de.luhmer.owncloudnewsreader.reader.nextcloud.Types;
+import de.luhmer.owncloudnewsreader.reader.nextcloud.API_SSO;
 import de.luhmer.owncloudnewsreader.ssl.MemorizingTrustManager;
 import de.luhmer.owncloudnewsreader.ssl.OkHttpSSLClient;
 import okhttp3.HttpUrl;
@@ -45,74 +33,71 @@ import retrofit2.converter.gson.GsonConverterFactory;
 
 public class ApiProvider {
 
+    private static final String TAG = ApiProvider.class.getCanonicalName();
     private final MemorizingTrustManager mMemorizingTrustManager;
     private final SharedPreferences mPrefs;
     private API mApi;
     private Context context;
 
+
     public ApiProvider(MemorizingTrustManager mtm, SharedPreferences sp, Context context) {
         this.mMemorizingTrustManager = mtm;
         this.mPrefs = sp;
         this.context = context;
-        initApi();
+        initApi(new NextcloudAPI.ApiConnectedListener() {
+            @Override
+            public void onConnected() {
+
+            }
+
+            @Override
+            public void onError(Exception ex) {
+
+            }
+        });
     }
 
-    public void initApi() {
+    public void initApi(@NonNull NextcloudAPI.ApiConnectedListener apiConnectedListener) {
         String username   = mPrefs.getString(SettingsActivity.EDT_USERNAME_STRING, "");
         String password   = mPrefs.getString(SettingsActivity.EDT_PASSWORD_STRING, "");
         String baseUrlStr = mPrefs.getString(SettingsActivity.EDT_OWNCLOUDROOTPATH_STRING, "https://luhmer.de"); // We need to provide some sort of default URL here..
+        Boolean useSSO    = mPrefs.getBoolean(SettingsActivity.SW_USE_SINGLE_SIGN_ON, false);
         HttpUrl baseUrl = HttpUrl.parse(baseUrlStr).newBuilder()
                 .addPathSegments("index.php/apps/news/api/v1-2/")
                 .build();
-
         Log.d("ApiModule", "HttpUrl: " + baseUrl.toString());
+        OkHttpClient client = OkHttpSSLClient.GetSslClient(baseUrl, username, password, mPrefs, mMemorizingTrustManager);
+        initImageLoader(mPrefs, client, context);
 
-        Type feedList = new TypeToken<List<Feed>>() {}.getType();
-        Type folderList = new TypeToken<List<Folder>>() {}.getType();
-        Type rssItemsList = new TypeToken<List<RssItem>>() {}.getType();
-
-        // Info: RssItems are handled as a stream (to be more memory efficient - see @OwnCloudSyncService and @RssItemObservable)
-        Gson gson = new GsonBuilder()
-                .setLenient()
-                .registerTypeAdapter(folderList,   new NextcloudDeserializer<>(Types.FOLDERS.toString(), Folder.class))
-                .registerTypeAdapter(feedList,     new NextcloudDeserializer<>(Types.FEEDS.toString(), Feed.class))
-                .registerTypeAdapter(rssItemsList, new NextcloudDeserializer<>(Types.ITEMS.toString(), RssItem.class))
-                .registerTypeAdapter(UserInfo.class, new JsonDeserializer<UserInfo>() {
-                    @Override
-                    public UserInfo deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
-                        try {
-                            JsonObject jObj = json.getAsJsonObject();
-                            JsonElement avatar = jObj.get("avatar");
-                            byte[] decodedString = {};
-                            if (!avatar.isJsonNull()) {
-                                decodedString = Base64.decode(avatar.getAsJsonObject().get("data").getAsString(), Base64.DEFAULT);
-                            }
-                            return new UserInfo.Builder()
-                                    .setDisplayName(jObj.get("displayName").getAsString())
-                                    .setUserId(jObj.get("userId").getAsString())
-                                    .setAvatar(BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length))
-                                    .setLastLoginTimestamp(jObj.get("lastLoginTimestamp").getAsLong())
-                                    .build();
-                        } catch(IllegalStateException ex) {
-                            throw OkHttpSSLClient.HandleExceptions(ex);
-                        }
-                    }
-                })
-                .create();
+        if(useSSO) {
+            Account account = AccountImporter.GetCurrentAccount(context);
+            initSsoApi(account, apiConnectedListener);
+        } else {
+            initRetrofitApi(baseUrl, client);
+            apiConnectedListener.onConnected();
+        }
+    }
 
-        OkHttpClient client = OkHttpSSLClient.GetSslClient(baseUrl, username, password, mPrefs, mMemorizingTrustManager);
+    private void initRetrofitApi(HttpUrl baseUrl, OkHttpClient client) {
         Retrofit retrofit = new Retrofit.Builder()
-                .addConverterFactory(GsonConverterFactory.create(gson))
+                .addConverterFactory(GsonConverterFactory.create(GsonConfig.GetGson()))
                 .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                 .baseUrl(baseUrl)
                 .client(client)
                 .build();
 
-        initImageLoader(mPrefs, client, context);
-
         mApi = retrofit.create(API.class);
     }
 
+    private void initSsoApi(final Account account, final NextcloudAPI.ApiConnectedListener callback) {
+        SingleSignOnAccount ssoAccount = AccountImporter.GetAuthTokenInSeparateThread(context, account);
+        NextcloudAPI nextcloudAPI = new NextcloudAPI(ssoAccount, GsonConfig.GetGson());
+        nextcloudAPI.start(context, callback);
+        mApi = new API_SSO(nextcloudAPI);
+    }
+
+
+
     private void initImageLoader(SharedPreferences mPrefs, OkHttpClient okHttpClient, Context context) {
         int diskCacheSize = Integer.parseInt(mPrefs.getString(SettingsActivity.SP_MAX_CACHE_SIZE,"500"))*1024*1024;
         if(ImageLoader.getInstance().isInited()) {
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/GsonConfig.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/GsonConfig.java
new file mode 100644
index 00000000..12e533bd
--- /dev/null
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/GsonConfig.java
@@ -0,0 +1,67 @@
+package de.luhmer.owncloudnewsreader.helper;
+
+import android.graphics.BitmapFactory;
+import android.util.Base64;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonDeserializationContext;
+import com.google.gson.JsonDeserializer;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import com.google.gson.reflect.TypeToken;
+
+import java.lang.reflect.Type;
+import java.util.List;
+
+import de.luhmer.owncloudnewsreader.database.model.Feed;
+import de.luhmer.owncloudnewsreader.database.model.Folder;
+import de.luhmer.owncloudnewsreader.database.model.RssItem;
+import de.luhmer.owncloudnewsreader.model.UserInfo;
+import de.luhmer.owncloudnewsreader.reader.nextcloud.NextcloudDeserializer;
+import de.luhmer.owncloudnewsreader.reader.nextcloud.Types;
+import de.luhmer.owncloudnewsreader.ssl.OkHttpSSLClient;
+
+/**
+ * Created by david on 27.06.17.
+ */
+
+public class GsonConfig {
+
+    public static Gson GetGson() {
+        Type feedList = new TypeToken<List<Feed>>() {}.getType();
+        Type folderList = new TypeToken<List<Folder>>() {}.getType();
+        Type rssItemsList = new TypeToken<List<RssItem>>() {}.getType();
+
+        // Info: RssItems are handled as a stream (to be more memory efficient - see @OwnCloudSyncService and @RssItemObservable)
+        return new GsonBuilder()
+                .setLenient()
+                .registerTypeAdapter(folderList,   new NextcloudDeserializer<>(Types.FOLDERS.toString(), Folder.class))
+                .registerTypeAdapter(feedList,     new NextcloudDeserializer<>(Types.FEEDS.toString(), Feed.class))
+                .registerTypeAdapter(rssItemsList, new NextcloudDeserializer<>(Types.ITEMS.toString(), RssItem.class))
+                .registerTypeAdapter(UserInfo.class, new JsonDeserializer<UserInfo>() {
+                    @Override
+                    public UserInfo deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
+                        try {
+                            JsonObject jObj = json.getAsJsonObject();
+                            JsonElement avatar = jObj.get("avatar");
+                            byte[] decodedString = {};
+                            if (!avatar.isJsonNull()) {
+                                decodedString = Base64.decode(avatar.getAsJsonObject().get("data").getAsString(), Base64.DEFAULT);
+                            }
+                            return new UserInfo.Builder()
+                                    .setDisplayName(jObj.get("displayName").getAsString())
+                                    .setUserId(jObj.get("userId").getAsString())
+                                    .setAvatar(BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length))
+                                    .setLastLoginTimestamp(jObj.get("lastLoginTimestamp").getAsLong())
+                                    .build();
+                        } catch(IllegalStateException ex) {
+                            throw OkHttpSSLClient.HandleExceptions(ex);
+                        }
+                    }
+                })
+                .create();
+    }
+
+}
\ No newline at end of file
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/API_SSO.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/API_SSO.java
new file mode 100644
index 00000000..373fa275
--- /dev/null
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/API_SSO.java
@@ -0,0 +1,216 @@
+package de.luhmer.owncloudnewsreader.reader.nextcloud;
+
+import com.google.gson.reflect.TypeToken;
+
+import java.lang.reflect.Type;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import de.luhmer.owncloud.accountimporter.helper.NextcloudAPI;
+import de.luhmer.owncloud.accountimporter.helper.NextcloudRequest;
+import de.luhmer.owncloudnewsreader.database.model.Feed;
+import de.luhmer.owncloudnewsreader.database.model.Folder;
+import de.luhmer.owncloudnewsreader.database.model.RssItem;
+import de.luhmer.owncloudnewsreader.helper.GsonConfig;
+import de.luhmer.owncloudnewsreader.model.NextcloudNewsVersion;
+import de.luhmer.owncloudnewsreader.model.NextcloudStatus;
+import de.luhmer.owncloudnewsreader.model.UserInfo;
+import io.reactivex.Completable;
+import io.reactivex.Observable;
+import okhttp3.ResponseBody;
+import retrofit2.Call;
+
+
+public class API_SSO implements API {
+
+    private static final String mApiEndpoint = "/index.php/apps/news/api/v1-2/";
+    private NextcloudAPI nextcloudAPI;
+
+    public API_SSO(NextcloudAPI nextcloudAPI) {
+        this.nextcloudAPI = nextcloudAPI;
+    }
+
+    public NextcloudAPI getNextcloudAPI() {
+        return nextcloudAPI;
+    }
+
+
+
+
+    @Override
+    public Observable<UserInfo> user() {
+        final Type type = UserInfo.class;
+        NextcloudRequest request = new NextcloudRequest.Builder()
+                .setMethod("GET")
+                .setUrl(mApiEndpoint + "user")
+                .build();
+        return nextcloudAPI.performRequestObservable(type, request);
+    }
+
+    @Override
+    public Observable<NextcloudStatus> status() {
+        Type type = NextcloudStatus.class;
+        NextcloudRequest request = new NextcloudRequest.Builder()
+                .setMethod("GET")
+                .setUrl(mApiEndpoint + "status")
+                .build();
+        return nextcloudAPI.performRequestObservable(type, request);
+    }
+
+    @Override
+    public Observable<NextcloudNewsVersion> version() {
+        Type type = NextcloudNewsVersion.class;
+        NextcloudRequest request = new NextcloudRequest.Builder()
+                .setMethod("GET")
+                .setUrl(mApiEndpoint + "version")
+                .build();
+        return nextcloudAPI.performRequestObservable(type, request);
+    }
+
+    @Override
+    public Observable<List<Folder>> folders() {
+        Type type = new TypeToken<List<Folder>>() {}.getType();
+        NextcloudRequest request = new NextcloudRequest.Builder()
+                .setMethod("GET")
+                .setUrl(mApiEndpoint + "folders")
+                .build();
+        return nextcloudAPI.performRequestObservable(type, request);
+    }
+
+    @Override
+    public Observable<List<Feed>> feeds() {
+        Type type = new TypeToken<List<Feed>>() {}.getType();
+        NextcloudRequest request = new NextcloudRequest.Builder()
+                .setMethod("GET")
+                .setUrl(mApiEndpoint + "feeds")
+                .build();
+
+        return nextcloudAPI.performRequestObservable(type, request);
+    }
+
+    @Override
+    public Call<List<Folder>> createFolder(Map<String, Object> folderMap) {
+        String body = GsonConfig.GetGson().toJson(folderMap);
+        NextcloudRequest request = new NextcloudRequest.Builder()
+                .setMethod("POST")
+                .setUrl(mApiEndpoint + "folders")
+                .setRequestBody(body)
+                .build();
+        return API_SSO_Helper.WrapInCall(nextcloudAPI, request, Folder.class);
+    }
+
+
+    @Override
+    public Call<List<Feed>> createFeed(Map<String, Object> feedMap) {
+        Type feedListType = new TypeToken<List<Feed>>() {}.getType();
+        String body = GsonConfig.GetGson().toJson(feedMap);
+        NextcloudRequest request = new NextcloudRequest.Builder()
+                .setMethod("POST")
+                .setUrl(mApiEndpoint + "feeds")
+                .setRequestBody(body)
+                .build();
+        return API_SSO_Helper.WrapInCall(nextcloudAPI, request, feedListType);
+    }
+
+    @Override
+    public Completable renameFeed(long feedId, Map<String, String> feedTitleMap) {
+        String body = GsonConfig.GetGson().toJson(feedTitleMap);
+        final NextcloudRequest request = new NextcloudRequest.Builder()
+                .setMethod("PUT")
+                .setUrl(mApiEndpoint + "feeds/" + feedId + "/rename")
+                .setRequestBody(body)
+                .build();
+        return API_SSO_Helper.WrapInCompletable(nextcloudAPI, request);
+    }
+
+    @Override
+    public Completable deleteFeed(long feedId) {
+        final NextcloudRequest request = new NextcloudRequest.Builder()
+                .setMethod("DELETE")
+                .setUrl(mApiEndpoint + "feeds/" + feedId)
+                .build();
+        return API_SSO_Helper.WrapInCompletable(nextcloudAPI, request);
+    }
+
+
+    @Override
+    public Call<List<RssItem>> items(long batchSize, long offset, int type, long id, boolean getRead, boolean oldestFirst) {
+        HashMap<String, String> parameters = new HashMap<>();
+        parameters.put("batchSize", String.valueOf(batchSize));
+        parameters.put("offset", String.valueOf(offset));
+        parameters.put("type", String.valueOf(type));
+        parameters.put("id", String.valueOf(id));
+        parameters.put("getRead", String.valueOf(getRead));
+        parameters.put("oldestFirst", String.valueOf(oldestFirst));
+
+        Type resType = new TypeToken<List<RssItem>>() {}.getType();
+        NextcloudRequest request = new NextcloudRequest.Builder()
+                .setParameter(parameters)
+                .setMethod("GET")
+                .setUrl(mApiEndpoint + "items")
+                .build();
+
+        return API_SSO_Helper.WrapInCall(nextcloudAPI, request, resType);
+    }
+
+    @Override
+    public Observable<ResponseBody> updatedItems(long lastModified, int type, long id) {
+        HashMap<String, String> parameters = new HashMap<>();
+        parameters.put("lastModified", String.valueOf(lastModified));
+        parameters.put("type", String.valueOf(type));
+        parameters.put("id", String.valueOf(id));
+
+        final NextcloudRequest request = new NextcloudRequest.Builder()
+                .setMethod("GET")
+                .setUrl(mApiEndpoint + "items/updated")
+                .setParameter(parameters)
+                .build();
+        return Observable.just(API_SSO_Helper.getResponseBodyFromRequest(nextcloudAPI, request));
+    }
+
+    // https://github.com/owncloud/news/wiki/Items-1.2#mark-multiple-items-as-read
+    @Override
+    public Call<Void> markItemsRead(ItemIds items) {
+        String body = GsonConfig.GetGson().toJson(items);
+        return markItems("items/read/multiple", body);
+    }
+
+    // https://github.com/owncloud/news/wiki/Items-1.2#mark-multiple-items-as-read
+    @Override
+    public Call<Void> markItemsUnread(ItemIds items) {
+        String body = GsonConfig.GetGson().toJson(items);
+        return markItems("items/unread/multiple", body);
+    }
+
+    // https://github.com/owncloud/news/wiki/Items-1.2#mark-multiple-items-as-read
+    @Override
+    public Call<Void> markItemsStarred(ItemMap itemMap) {
+        String body = GsonConfig.GetGson().toJson(itemMap);
+        return markItems("items/star/multiple", body);
+    }
+
+    // https://github.com/owncloud/news/wiki/Items-1.2#mark-multiple-items-as-read
+    @Override
+    public Call<Void> markItemsUnstarred(ItemMap itemMap) {
+        String body = GsonConfig.GetGson().toJson(itemMap);
+        return markItems("items/unstar/multiple", body);
+    }
+
+
+    private Call<Void> markItems(String endpoint, String body) {
+        NextcloudRequest request = new NextcloudRequest.Builder()
+                .setMethod("PUT")
+                .setUrl(mApiEndpoint + endpoint)
+                .setRequestBody(body)
+                .build();
+        try {
+            nextcloudAPI.performRequest(Void.class, request);
+            return API_SSO_Helper.WrapVoidCall(true);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return API_SSO_Helper.WrapVoidCall(false);
+    }
+}
+
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/API_SSO_Helper.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/API_SSO_Helper.java
new file mode 100644
index 00000000..db3a2fbf
--- /dev/null
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/API_SSO_Helper.java
@@ -0,0 +1,138 @@
+package de.luhmer.owncloudnewsreader.reader.nextcloud;
+
+import android.os.ParcelFileDescriptor;
+import android.os.RemoteException;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.reflect.Type;
+
+import de.luhmer.owncloud.accountimporter.helper.NextcloudAPI;
+import de.luhmer.owncloud.accountimporter.helper.NextcloudRequest;
+import io.reactivex.Completable;
+import io.reactivex.functions.Action;
+import okhttp3.Request;
+import okhttp3.ResponseBody;
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+
+public class API_SSO_Helper {
+
+    public static ResponseBody getResponseBodyFromRequest(NextcloudAPI nextcloudAPI, NextcloudRequest request) {
+        try {
+            InputStream os = nextcloudAPI.performNetworkRequest(request);
+            return ResponseBody.create(null, 0, new BufferedSourceSSO(os));
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return ResponseBody.create(null, "");
+    }
+
+    public static Completable WrapInCompletable(final NextcloudAPI nextcloudAPI, final NextcloudRequest request) {
+        return Completable.fromAction(new Action() {
+            @Override
+            public void run() throws Exception {
+                nextcloudAPI.performRequest(Void.class, request);
+            }
+        });
+    }
+
+    public static <T> Call<T> WrapInCall(final NextcloudAPI nextcloudAPI, final NextcloudRequest nextcloudRequest, final Type resType) {
+        return new Call<T>() {
+            @Override
+            public Response<T> execute() throws IOException {
+                try {
+                    T body = nextcloudAPI.performRequest(resType, nextcloudRequest);
+                    return Response.success(body);
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+                return null;
+            }
+
+            @Override
+            public void enqueue(Callback<T> callback) {
+                try {
+                    T body = nextcloudAPI.performRequest(resType, nextcloudRequest);
+                    callback.onResponse(null, Response.success(body));
+                } catch (Exception e) {
+                    callback.onResponse(null, Response.<T>error(520, ResponseBody.create(null, e.toString())));
+                }
+            }
+
+            @Override
+            public boolean isExecuted() {
+                return false;
+            }
+
+            @Override
+            public void cancel() {
+
+            }
+
+            @Override
+            public boolean isCanceled() {
+                return false;
+            }
+
+            @Override
+            public Call<T> clone() {
+                return null;
+            }
+
+            @Override
+            public Request request() {
+                return null;
+            }
+        };
+    }
+
+    public static Call<Void> WrapVoidCall(final boolean success) {
+        return new Call<Void>() {
+            @Override
+            public Response<Void> execute() {
+                if(success) {
+                    return Response.success(null);
+                } else {
+                    return Response.error(520, null);
+                }
+            }
+
+            @Override
+            public void enqueue(Callback callback) {
+                if(success) {
+                    callback.onResponse(null, Response.success(null));
+                } else {
+                    callback.onResponse(null, Response.error(520, null));
+                }
+            }
+
+            @Override
+            public boolean isExecuted() {
+                return false;
+            }
+
+            @Override
+            public void cancel() {
+
+            }
+
+            @Override
+            public boolean isCanceled() {
+                return false;
+            }
+
+            @Override
+            public Call<Void> clone() {
+                return null;
+            }
+
+            @Override
+            public Request request() {
+                return null;
+            }
+        };
+
+    }
+}
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/BufferedSourceSSO.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/BufferedSourceSSO.java
new file mode 100644
index 00000000..4ab782bf
--- /dev/null
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/BufferedSourceSSO.java
@@ -0,0 +1,249 @@
+package de.luhmer.owncloudnewsreader.reader.nextcloud;
+
+import android.support.annotation.Nullable;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.Charset;
+
+import okio.Buffer;
+import okio.BufferedSource;
+import okio.ByteString;
+import okio.Options;
+import okio.Sink;
+import okio.Timeout;
+
+public class BufferedSourceSSO implements BufferedSource {
+
+    private InputStream mInputStream;
+
+    public BufferedSourceSSO(InputStream inputStream) {
+        this.mInputStream = inputStream;
+    }
+
+    @Override
+    public Buffer buffer() {
+        return null;
+    }
+
+    @Override
+    public boolean exhausted() throws IOException {
+        return false;
+    }
+
+    @Override
+    public void require(long byteCount) throws IOException {
+
+    }
+
+    @Override
+    public boolean request(long byteCount) throws IOException {
+        return false;
+    }
+
+    @Override
+    public byte readByte() throws IOException {
+        return 0;
+    }
+
+    @Override
+    public short readShort() throws IOException {
+        return 0;
+    }
+
+    @Override
+    public short readShortLe() throws IOException {
+        return 0;
+    }
+
+    @Override
+    public int readInt() throws IOException {
+        return 0;
+    }
+
+    @Override
+    public int readIntLe() throws IOException {
+        return 0;
+    }
+
+    @Override
+    public long readLong() throws IOException {
+        return 0;
+    }
+
+    @Override
+    public long readLongLe() throws IOException {
+        return 0;
+    }
+
+    @Override
+    public long readDecimalLong() throws IOException {
+        return 0;
+    }
+
+    @Override
+    public long readHexadecimalUnsignedLong() throws IOException {
+        return 0;
+    }
+
+    @Override
+    public void skip(long byteCount) throws IOException {
+
+    }
+
+    @Override
+    public ByteString readByteString() throws IOException {
+        return null;
+    }
+
+    @Override
+    public ByteString readByteString(long byteCount) throws IOException {
+        return null;
+    }
+
+    @Override
+    public int select(Options options) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public byte[] readByteArray() throws IOException {
+        return new byte[0];
+    }
+
+    @Override
+    public byte[] readByteArray(long byteCount) throws IOException {
+        return new byte[0];
+    }
+
+    @Override
+    public int read(byte[] sink) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public void readFully(byte[] sink) throws IOException {
+
+    }
+
+    @Override
+    public int read(byte[] sink, int offset, int byteCount) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public void readFully(Buffer sink, long byteCount) throws IOException {
+
+    }
+
+    @Override
+    public long readAll(Sink sink) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public String readUtf8() throws IOException {
+        return null;
+    }
+
+    @Override
+    public String readUtf8(long byteCount) throws IOException {
+        return null;
+    }
+
+    @Nullable
+    @Override
+    public String readUtf8Line() throws IOException {
+        return null;
+    }
+
+    @Override
+    public String readUtf8LineStrict() throws IOException {
+        return null;
+    }
+
+    @Override
+    public String readUtf8LineStrict(long limit) throws IOException {
+        return null;
+    }
+
+    @Override
+    public int readUtf8CodePoint() throws IOException {
+        return 0;
+    }
+
+    @Override
+    public String readString(Charset charset) throws IOException {
+        return null;
+    }
+
+    @Override
+    public String readString(long byteCount, Charset charset) throws IOException {
+        return null;
+    }
+
+    @Override
+    public long indexOf(byte b) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public long indexOf(byte b, long fromIndex) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public long indexOf(byte b, long fromIndex, long toIndex) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public long indexOf(ByteString bytes) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public long indexOf(ByteString bytes, long fromIndex) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public long indexOfElement(ByteString targetBytes) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public long indexOfElement(ByteString targetBytes, long fromIndex) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public boolean rangeEquals(long offset, ByteString bytes) throws IOException {
+        return false;
+    }
+
+    @Override
+    public boolean rangeEquals(long offset, ByteString bytes, int bytesOffset, int byteCount) throws IOException {
+        return false;
+    }
+
+    @Override
+    public InputStream inputStream() {
+        return mInputStream;
+    }
+
+    @Override
+    public long read(Buffer sink, long byteCount) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public Timeout timeout() {
+        return null;
+    }
+
+    @Override
+    public void close() throws IOException {
+
+    }
+}
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/RssItemObservable.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/RssItemObservable.java
index 67602f8e..259ac15f 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/RssItemObservable.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/RssItemObservable.java
@@ -51,7 +51,6 @@ public class RssItemObservable implements Publisher<Integer> {
     @Override
     public void subscribe(Subscriber<? super Integer> s) {
         try {
-            //throw new RuntimeException("");
             sync(s);
             s.onComplete();
         } catch (Exception ex) {
diff --git a/News-Android-App/src/main/res/layout/dialog_signin.xml b/News-Android-App/src/main/res/layout/dialog_signin.xml
index f061a621..e3d66280 100644
--- a/News-Android-App/src/main/res/layout/dialog_signin.xml
+++ b/News-Android-App/src/main/res/layout/dialog_signin.xml
@@ -1,11 +1,10 @@
 <ScrollView
     xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools"
-    tools:context=".LoginActivity"
     android:id="@+id/login_form"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
+
     <RelativeLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
@@ -13,11 +12,20 @@
         android:paddingRight="@dimen/abc_dialog_padding_material"
         android:paddingTop="@dimen/abc_dialog_padding_material">
 
+        <Switch
+            android:id="@+id/swSingleSignOn"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginStart="4dp"
+            android:text="Use single sign on" />
+
+
         <android.support.design.widget.TextInputLayout
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:layout_alignParentTop="true"
-            android:id="@+id/username_container">
+            android:id="@+id/username_container"
+            android:layout_marginTop="8dp"
+            android:layout_below="@id/swSingleSignOn">
 
             <EditText
                 android:id="@+id/username"
@@ -34,7 +42,6 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_below="@+id/username_container"
-            android:layout_alignParentLeft="true"
             android:layout_alignParentStart="true"
             android:id="@+id/password_container">
 
@@ -56,7 +63,6 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_below="@+id/password_container"
-            android:layout_alignParentLeft="true"
             android:layout_alignParentStart="true">
 
             <EditText
@@ -84,7 +90,6 @@
             android:src="@drawable/ic_action_visibility"
             android:layout_alignTop="@+id/password_container"
             android:layout_alignBottom="@+id/password_container"
-            android:layout_alignRight="@+id/password_container"
             android:layout_alignEnd="@+id/password_container"
             android:contentDescription="@string/content_desc_show_password"/>
 
@@ -93,9 +98,7 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:text="@string/pref_title_DisableHostnameVerification"
-            android:layout_below="@+id/url_container"
-            android:layout_alignRight="@+id/imgView_ShowPassword"
-            android:layout_alignEnd="@+id/imgView_ShowPassword" />
+            android:layout_below="@+id/url_container" />
 
     </RelativeLayout>