GENERATING A UNIQUE CLIENT ID

Uniquely identifying an installation is obviously crucial in terms of device based licensing. There are three ways to uniquely identify an (on-premise) installation.

HARDWARE ID

In order to adequately protect your system (i.e., make sure a license key is not used on multiple machines), your software has to generate a unique device ID. This is usually a combination of:

UUID
Processor ID
Motherboard ID
Machine ID
(Virtual) MAC Address
Other custom ID

As a vendor you (not SLASCONE) have to decide what suits more to your application, in other words how restrictive you want to be. In any case, this ID is not being saved in your application, but generated every time its value is needed.

It should be noted though, that there is a trade-off between security and customer convenience. Increasing the number of identifiers (e.g., MAC + Processor ID), increases the probability of a new unique identifier upon hardware change.

WINDOWS

The simplest way to generate a unique device ID on Windows is to use the “wmic” command:

wmic csproduct get UUID

LINUX

On Linux installations, the convention is to read /etc/machine-id

The /etc/machine-id file contains the unique machine ID of the local system that is set during installation or boot. The machine ID is a single newline-terminated, hexadecimal, 32-character, lowercase ID. When decoded from hexadecimal, this corresponds to a 16-byte/128-bit value. This ID may not be all zeros.

.NET CORE

If your application runs in .NET Core, the official SLASCONE NuGet package returns a unique device id for both Windows and Linux, without you having to implement it.

Particularly for Linux environments, the NuGet package provides rich functionality, such as providing multiple hardware ids (e.g., machine ID, host ID, MAC ID) and functions helping you to identify a docker environment.

ENVIRONMENT ID

With the proliferation of cloud and virtualized systems, relying on a hardware ID is not always feasible. The same applies if your application is a plugin or an extension of some platform.

In such cases, there is usually a unique environment identifier you can refer to. This might be a subscription or a customer identifier, or even a username or email. Please refer to the respective documentation.

AWS & AZURE Virtual Machines

if your software runs on an AWS or Azure virtual machine, it is much safer to use an ID identifying the virtual machine.

AWS: Instance ID
Azure: VM ID

Using this is highly recommended since it prevents any potential issues arising from VM cloning.

If your application runs in .NET Core, the official SLASCONE NuGet package identifies if the application runs in AWS or Azure and returns the respective ID. The mechanism is the same for any operating system.

RANDOM ID

An alternative option to a hardware ID, is to generate a random ID during the installation. Contrary to a hardware ID, this ID needs to be saved in your application (in a file or in a database), using some sort of encryption in order to avoid easy manipulation.