### Using Google Authenticator This section explains how to use Google Authenticator as a second-level authentication solution in Parallels RAS. To configure Google Authenticator: In the Parallels RAS Console, navigate to Connection / Multi-factor authentication. In the Provider drop-down list, select Google Authenticator. Click the Settings button. In the Google Authenticator Properties dialog that opens, specify the following options: Type Name: The default name here is Google Authenticator. The name will appear on the registration dialog in Parallels Client in the following sentence, "Install Google Authenticator app on your iOS or Android device". If you change the name, the sentence will contain the name you specify, such as "Install <new-name> app on your iOS or Android device". Technically, you can use any authenticator app (hence the ability to change the name), but at the time of this writing only the Google Authenticator app is officially supported. The User enrollment section allows you to limit user enrollment via Google Authenticator if needed. You can allow all users to enroll without limitations (the Allow option), allow enrollment until the specified date and time (Allow until), or completely disable enrollment (the Do not allow option). If enrollment is disabled due to expired time frame or because the Do not allow option is selected, a user trying to log in will see an error message saying that enrollment is disabled and advising the user to contact the system administrator. When you restrict or disable enrollment, Google authenticator or other TOTP provider can still be used, but with added security which would not allow further user enrollment. This is a security measure to mitigate users with compromised credentials to enroll in MFA. The Authentication section allows you to configure TOTP tolerance. When using Time-based One-Time Password (TOTP), it is required to have the time synchronized between the RAS Publishing Agent and client devices. The synchronization must be performed against a global NTP server (e.g. time.goole.com). Using the TOTP tolerance drop-down box, you can select a time difference that should be tolerated while performing authentication. Expand the drop-down box and select one of the predefined values (number of seconds). Note that changing time tolerance should be used with caution as it has security implications since the time validity of a security token can be increased, thus a wider time window for potential misuse. Note: When using Time-based One-time Passwords (TOTP) providers, it is required to have both Publishing Agents and client devices time synchronized with a global NTP server (e.g. time.google.com). Adding TOTP tolerance increases the one-time password validity, which might have security implications. The Reset User(s) field in the User management section is used to reset the token that a user receives when they log in to Parallels RAS for the first time using Google Authenticator. If you reset a user, they'll have to go through the registration procedure again (see Using Google Authenticator in Parallels Client below). You can search for specific users, reset all users, or import the list of users from a CSV file. Click OK when done. Please also note that the TOTP available time is calculated as the default 30 seconds + x amount of seconds in the past + x amount of second in the future. Using Google Authenticator in Parallels Client Important: To use Google Authenticator or other TOTP provider, the time on a user device must be in sync with the time set on the RAS Publishing Agent server. Otherwise, Google authentication will fail. Google Authenticator is supported in Parallels Client running on all supported platforms, including mobile, desktop, HTML5. To use Google Authenticator, a user needs to install the Authenticator app on their iOS or Android device. Simply visit Google Play or App Store and install the app. Once the Authenticator app is installed, the user is ready to connect to Parallels RAS using two-factor authentication. To connect to Parallels RAS: The user opens Parallels Client or HTML5 Client and logs in using his/her credentials. The multi-factor authentication dialog opens displaying a barcode (also known as QR code) and a secret key. The user opens the Google Authenticator app on their mobile device: If this is the first time they use it, they tap Begin and then tap Scan a barcode. If a user already has another account in Google Authenticator, they tap the plus-sign icon and choose Scan a barcode. The user then scans the barcode displayed in the Parallels Client login dialog. If scanning doesn't work for any reason, the user goes back in the app, chooses Enter a provided key and then enters the account name and the key displayed in the Parallels Client login dialog. The user then taps Add account in the app, which will create an account and display a one time password. The user goes back to Parallels Client, clicks Next and enters the one time password in the OTP field. On every subsequent logon, the user will only have to type their credentials (or nothing at all if the Save password options was selected) and enter a one time password obtained from the Google Authenticator app (the app will continually generate a new password). If the RAS administrator resets a user (see the Reset Users(s) field description at the beginning of this section), the user will have to repeat the registration procedure described above.