VNC^® Enterprise Edition User Guide

Relaxing the authentication rules

By default, VNC Server specifies platform-native authentication, which means that a user must supply the credentials of a host computer user in order to connect to VNC Server. For more information, see Authenticating connections to VNC Server.

You can relax the authentication rules by choosing an alternative authentication mechanism. Depending on your choice, this may speed up the connection process, prevent ‘password fatigue’, or forgo the need to distribute host computer user credentials. Note that some mechanisms allocate VNC permissions in ways that cannot be customized.

To change the authentication mechanism, open the VNC Server Properties dialog. For more information on this dialog, see Using the VNC Server Properties dialog. On the Connections tab, select an alternative to the default Windows password option from the Authentication dropdown:

(Windows XP)

Note: Under UNIX or Linux, Windows password is called UNIX password. Under Mac OS X, it is called Mac password.

For more information on the alternative authentication mechanisms, read the appropriate section below.

Single sign on

The Single sign-on authentication mechanism extends platform-native authentication to automatically authenticate a VNC Viewer user to any instance of VNC Server on any host computer using the credentials used to log on to the client computer. For this to work, all host computers must be on a domain, and all instances of VNC Server must have Single sign-on specified. Note that this feature is not available for VNC Viewer for Java; web browser users must always supply a user name and password in order to connect.

VNC permissions are granted in the same way as for platform-native authentication, and can be customized. For more information, see the appropriate platform-specific section in Authenticating connections to VNC Server.

VNC password

The VNC password authentication mechanism disassociates VNC Server from the credentialing system of the host computer. Instead, a user must supply a password of your choice in order to connect to VNC Server. You can specify three types of password, each of which grants a different set of VNC permissions to connected users.

Note: VNC password is the default authentication mechanism in VNC Personal Edition.

To do this, select VNC password from the Authentication dropdown, and click the Configure button. The VNC Server Password dialog opens:

(Windows XP)

To grant connected users a Default set of VNC permissions, enter and confirm a generic password, and click the OK button.

To grant connected users either a Full or a View Only set of VNC permissions, click the Extended Configuration button. The VNC Extended Authentication dialog opens:

(Windows XP)

To grant to connected users:

•  A Full set of VNC permissions, turn on Enable “Admin” user, and click the adjacent Set password button to enter and confirm a password.

•  A View Only set of VNC permissions, turn on Enable “ViewOnly” user and click the adjacent Set password button to enter and confirm a password.

When connecting to VNC Server, a user is presented with the VNC Authentication dialog:

(Windows XP)

If the user enters:

•  The generic password in the Password field, leaving the Username field empty (if it is enabled at all), a Default set of VNC permissions is granted.

•  Admin in the Username field, and the appropriate password in the Password field, a Full set of VNC permissions is granted.

•  ViewOnly in the Username field, and the appropriate password in the Password field, a View Only set of VNC permissions is granted.

For more information on VNC permissions, see Restricting functionality for particular connected users. Note you cannot customize VNC permissions under this authentication mechanism.

None

The None authentication mechanism enables a user to connect to VNC Server without supplying a password. You should only choose this option if you are sure all potential users are trustworthy. Note you can allow just particular users to connect without supplying a password; see Bypassing the authentication rules for more information.

Note: The None option is only available in the Authentication dropdown when the VNC Server Properties dialog is in Advanced mode. For more information, see Using the VNC Server Properties dialog.

A Default set of VNC permissions is granted to each connected user. For more information, see Restricting functionality for particular connected users. Note you cannot customize VNC permissions under this authentication mechanism.