Solaris X Window System Developer's Guide

Authorization Protocols

The OpenWindows environment supports two different authorization protocols: MIT-MAGIC-COOKIE-1 and SUN-DES-1. While they differ in the authorization data used, they are similar in the access control mechanism used.

The MIT-MAGIC-COOKIE-1 protocol, using the user-based mechanism, is the OpenWindows environment default.


The MIT-MAGIC-COOKIE-1 authorization protocol was developed by the Massachusetts Institute of Technology (MIT). A magic cookie is a long, randomly generated binary password. At server startup, the magic cookie is created for the server and the user who started the system. On every connection attempt, the user's client sends the magic cookie to the server as part of the connection packet. This magic cookie is compared with the server's magic cookie. The connection is allowed if the magic cookies match, or denied if they do not match.


The SUN-DES-1 authorization protocol was developed by Sun Microsystems. It is based on Secure Remote Procedure Call (RPC) and requires Data Encryption Software (DES) support. The authorization data is the machine-independent netname, or network name, of a user. This data is encrypted and sent to the server as part of the connection packet. The server decrypts the data, and, if the netname is known, allows the connection.

The SUN-DES-1 authorization protocol provides a higher level of security than the MIT-MAGIC-COOKIE-1 protocol. There is no way for another user to use your machine-independent netname to access a server, but it is possible for another user to use the magic cookie to access a server.

This protocol is available only in libraries in the OpenWindows Version 3 and later environments. Any applications built with static libraries, in particular Xlib, in environments prior to OpenWindows Version 3 cannot use this authorization protocol.

Allowing Access When Using SUN-DES-1describes how to allow another user access to your server by adding their netname to your server's access list.

Changing the Default Authorization Protocol

The default authorization protocol, MIT-MAGIC-COOKIE-1, can be changed to another supported authorization protocol or to no user-based access mechanism at all. The default is changed by supplying options with the openwin command. See the openwin(1) man page for more information.

For example, to change the default from MIT-MAGIC-COOKIE-1 to SUN-DES-1, start the OpenWindows environment as follows:


openwin -auth


If you must run OpenWindows without the user-based access mechanism, use the -noauth command line option.


openwin -noauth

Caution – Caution –

Using -noauth weakens security. It is equivalent to running OpenWindows with only the host-based access control mechanism; the server inactivates the user-based access control mechanism. Anyone who can run applications on your local machine will be allowed access to your server.