Reviews

Review: Desaware Licensing System 1.1

• By Mike Gunderloy
• October 11, 2004

Desaware Licensing System 1.1
starting at $495
Desaware, Inc.
Campbell, California
(408) 377-4770
www.desaware.com

The folks over at Desaware have revised their Licensing System software, which I looked at about a year ago. The goal of this software is simple: to make it harder for other people to steal your hard work. There's a constant arms race between crackers and licensers on this one, but for most purposes this system should be plenty good enough.

The user experience is fairly simple: there's a 26-character alphanumeric key. Enter it and the software authenticates to a server across the Internet (there's also provision for shipping authentication via diskette or other removeable media for disconnected machines). Keys can be full or demo (with timeouts), and can allow only a single installation or multiple installs. Installs are tied to a particular computer, so you can't just use the same key willy-nilly on multiple machines.

From the developer standpoint, there are two pieces of software to set up. First is the license server, an ASP.NET application that validates keys over the Internet. An internal management interface lets you create new applications and keys. The other piece you need to set up is the License Manager, which lets you interact with the server as a developer. This will pull out the necessary crytographic information for your application and put it in a RESX file for easy inclusion. Samples in the manual show where to go from there; you can implement anything from extremely restrictive licensing (single install, must activate before you can do anything) to more relaxed schemes that include grace periods and background activation. Desaware provides controls that you can drop into your Windows forms applications to handle license entry and license validation.

The system is also extensible in key areas. For example, you can implement your own algorithm for identifying systems (this lets you create per-user licenses, if you like), or extend the licensing server to perform notifications or other actions when a license is activated.

1.1 includes some additional utilities, diagnostics, and advice on making your code more secure. One nice touch is the inclusion of Desaware's QND Obfuscator to make it harder for an attacker to browser through client code looking for ways to disable the licensing checks. There's also a utility to help generate code to check at runtime that your own application hasn't been altered. Finally, the price point to get started with this software has been considerably lowered: you can buy DLS for use with a single application for $495. This edition doesn't have the extensibility features, but it will work fine for the small vendor and can be upgraded to the full version (which still costs $1495).