Category: Tips on Using our Service

Introducing reseller portal for software licensing

Since the end of last year, we have made the reseller portal generally available for all users. We would like to thank all our beta customers for their feedback during the development process.

Idea

The goal behind the reseller portal is to allow you to delegate license issuance rights to other users. This can be your resellers/distributors, IT-admins of your customers or your employees. In other words, “reseller” can be any user that should only be able to create specific amount of new licenses based on a pre-defined template.

The reseller portal also introduces new logging capabilities. All events related to new licenses, customers, etc, are stored in the object log. Thanks to this log, you can, for instance, bill your resellers or customers only when they have successfully created a new license.

Getting started

Once you have created a new account, the reseller portal will be available in the top menu. If you are an existing customer, you can enable it on the billing page. As the next step, we recommend to check out the wiki page for more information.

Please let us know if you have any questions šŸ™‚

Autodesk Revit plugin software licensing

AutodeskĀ® Revit is a powerful building information software, which allows developers to extend its functionality through plug-ins that can be written in either Python or .NET. In order to monetize your plugin, we need to implement a license verification mechanism and a way to accept payments from prospective customers.

License verification

Python plugins

If your plugin is written in Python, you can use the Python2 version of our Python client. A simple license verification can be performed with the code below (your specific parameters can be found here):

from cryptolens_python2 import *
HelperMethods.ironpython2730_legacy = True

pubKey = "<RSAKeyValue><Modulus>sGbvxwdlDbqFXOMlVUnAF5ew0t0WpPW7rFpI5jHQOFkht/326dvh7t74RYeMpjy357NljouhpTLA3a6idnn4j6c3jmPWBkjZndGsPL4Bqm+fwE48nKpGPjkj4q/yzT4tHXBTyvaBjA8bVoCTnu+LiC4XEaLZRThGzIn5KQXKCigg6tQRy0GXE13XYFVz/x1mjFbT9/7dS8p85n8BuwlY5JvuBIQkKhuCNFfrUxBWyu87CFnXWjIupCD2VO/GbxaCvzrRjLZjAngLCMtZbYBALksqGPgTUN7ZM24XbPWyLtKPaXF2i4XRR9u6eTj5BfnLbKAU5PIVfjIS+vNYYogteQ==</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>"

res = Key.activate(token="WyIyNTU1IiwiRjdZZTB4RmtuTVcrQlNqcSszbmFMMHB3aWFJTlBsWW1Mbm9raVFyRyJd",\
                   rsa_pub_key=pubKey,\
                   product_id=3349, key="ICVLD-VVSZR-ZTICT-YKGXL", \
                   machine_code=Helpers.GetMachineCode())

if res[0] == None or not Helpers.IsOnRightMachine(res[0]):
    print("An error occurred: {0}".format(res[1]))
else:
    print("Success")
    
    license_key = res[0]
    print("Feature 1: " + str(license_key.f1))
    print("License expires: " + str(license_key.expires))

C# or VB.NET

If your plugin is either written in C# or VB.NET, you can use our .NET library instead. To add it to your project in Visual Studio:

  1. Right click on your project in the Solution Explorer and click on Manage NuGet Packages.
  2. Search for Cryptolens.Licensing and install it.
  3. Add the code-snippet form this page in the code where the plugin loads for the first time.

Accepting payments

One way to sell an Autodesk Revit plug-ins is by publishing them in theĀ Autodesk App Store, where a basic licensing mechanism is already provided. The problem with this approach is that the licensing models available are quite limited (eg. you can only charge your customers once for the plug-in and they will be able to use it in perpetuity). For instance, selling your plug-in as a service (subscription model) is not supported.

A better approach is to still publish your plug-in in the Autodesk App Store and set it to be a free app. You can then ask your customers to get a separate license key to be able to unlock all features.

You can read more about various ways of selling your software in our help pages. I would also recommend to check out the available licensing models.

If you have any questions, please feel free to reach out!

Tips on monetizing Python applications

Python can be used to develop a variety of applications, either as plugins (eg. for Discord, AutoCAD, Autodesk Maya, etc) or standalone applications. In this post we will focus on how to monetize a standalone Python application.

Let’s say you have developed a Python application that classifies images (eg. using tensorflow or pytorch). To start selling it, there are just three things we need in place:

  • Code obfuscation – to ensure that no one can reverse engineer the application.
  • License verification – to ensure that customers need a license key before they can use the application (eg. so that you can restrict which features they can use and how long the license is valid).
  • Webshop – so that customers can obtain a license key to unlock functionality.

Code obfuscation

To obfuscate your application, multiple tools can be used. You can either use packages such as pyarmor that are made to obfuscate Python code or open source tools such as pyinstaller in combination with cpython (for most sensitive code).

License verification

A license key can be easily verified using the code below. You can find more information about the parametersĀ here.

from licensing.helpers import Helpers
from licensing.models import Response, RSAPublicKey
from licensing.methods import Key

pubKey = "<RSAKeyValue><Modulus>sGbvxwdlDbqFXOMlVUnAF5ew0t0WpPW7rFpI5jHQOFkht/326dvh7t74RYeMpjy357NljouhpTLA3a6idnn4j6c3jmPWBkjZndGsPL4Bqm+fwE48nKpGPjkj4q/yzT4tHXBTyvaBjA8bVoCTnu+LiC4XEaLZRThGzIn5KQXKCigg6tQRy0GXE13XYFVz/x1mjFbT9/7dS8p85n8BuwlY5JvuBIQkKhuCNFfrUxBWyu87CFnXWjIupCD2VO/GbxaCvzrRjLZjAngLCMtZbYBALksqGPgTUN7ZM24XbPWyLtKPaXF2i4XRR9u6eTj5BfnLbKAU5PIVfjIS+vNYYogteQ==</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>"

res = Key.activate(token="WyIyNTU1IiwiRjdZZTB4RmtuTVcrQlNqcSszbmFMMHB3aWFJTlBsWW1Mbm9raVFyRyJd",\
                   rsa_pub_key=pubKey,\
                   product_id=3349, key="ICVLD-VVSZR-ZTICT-YKGXL", machine_code="test")

if res[0] == None:
    print("An error occured: {0}".format(res[1]))
else:
    print("Success")

Webshop

When you have obfuscation and license verification in place, we need a way for customers to be able to order a license key. If you already have Stripe, you can use the recurring billing module, which acts like an interface for plans defined in your Stripe account. In other cases, you can either use payment forms or a different platform (please read more here).

Questions? Please reach out to us at support@cryptolens.io šŸ™‚

Sign up customers automatically for the customer portal

A recent addition to the platform is the ability to sign up customers automatically to the customer portal. Instead of creating a customer manually or through the API, you can publish a generic link that will automatically register a customer with your account. This link can be found on the customer page.

In addition to allowing your customers to see their current licenses, the customer portal gives them the option to order new licenses as well as use their login credentials instead of the license key when unlocking your software. We will cover each case below.

Why customer portal?

Listing licenses

When you assign licenses to a customer account, your customers will be able to see all their licenses and their properties, such as the set of features they are entitled to and when they expire.

Recurring payments

If you have set up Stripe with your account, you can allow your customers to sign up for a plan in the customer portal and get instant access to a valid license key. They can also easily manage their subscriptions. You can read more about how you can get started here.

User account authentication

Instead of using a license key, you can allow your customers to authenticate using their login credentials. Cryptolens has developed a state-of-the-art protocol that preserves the privacy of your customers (more information about the protocol can be found here). You can read more on how to get started here.

Managing app settings in software licensing

When developing apps, you will likely need to store some metadata. This can either be specific to a certain user or be shared among all users.

Data objects offer an easy way of managing metadata either on the product, license key or machine code level. They are quite useful since it’s easy to change them as your application evolves and user-specific data will stay the same across all devices.

In this article, we will cover data objects associated with a product.

Editing metadata

To add or edit data objects on the product level, you can click on the Data Objects link as shown below:

On the next page, you can either add or edit existing data objects. The names are case-sensitive and duplicates are not allowed.

Retrieving metadata on app start

Let’s assume our application needs to obtain the currently supported DOTNET_RUNTIME (which we defined in the previous step). This can be accomplished with the code below (the project files are available here).

To get it up and running, we need to specify an access token and modify the ReferencerId. The access token needs to have the “ListDataObjects” permission checked and we also strongly recommend to specify the product it should work with. The ReferencerId should be the Id of the product.

 var systemSettings = Data.ListDataObjects("access token", new ListDataObjectsModel
 {
     ReferencerType = DataObjectType.Product,
     ReferencerId = 3349,  // <- the product id
 });
 
 if(!Helpers.IsSuccessful(systemSettings) || systemSettings.DataObjects == null)
 {
     Console.WriteLine("Could not retrieve the settings.");
 }

 var settings = systemSettings.DataObjects.ToDictionary(x=> x.Name, x => x);

 if(settings.ContainsKey("DOTNET_RUNTIME"))
     Console.WriteLine(settings["DOTNET_RUNTIME"].StringValue);

What’s next?

In the future tutorials we will describe how you can store user specific information. In meantime, let us know if you have any questions šŸ‘

Autodesk Maya plugin software licensing

In the beginning of the year, we looked at licensing for Autodesk AutoCAD. Today, we are announcing support for another Autodesk product, Maya. Similar to AutoCAD, Maya allows you to develop plug-ins, and in this post we are going to cover how licensing works if you plan to sell them.

Adding software licensing library

Maya supports Python 2 for plugin development. To add license verification, only two things are necessary:

  1. Download and place cryptolens_python2.py into your plugin folder.
  2. Add the correct namespaces and the key verification logic, as described here.

If you want to read more about plug-in development in Maya, please check out this tutorial.

The next step is to sell your plugin, which we covered in the AutoCAD article. As always, let us know if you have any questions šŸ™‚

License templates for frequently used license configurations

To make it easier to create licenses of a common type, we have introduced a new feature called license template. In short, it’s a way to save license configurations (eg. features, set time, maximum number of machines) so that they can be re-used later.

It’s quite easy to get started. To save a license configuration, you can click on Save as Template button on the key creation page. This will re-direct you to a new page where you can provide a name for that configuration. Next time you want to generate a license from this configuration you can select it in the drop down list and click on Create button next to it.

We are always happy to hear your feedback or help you in case you have any questions šŸ™‚

Unity Software Licensing

Unity is a powerful cross-platform game engine. Since it uses C# as the scripting language, we can easily integrate it with Cryptolens client library. In this post, we explain how you can add license key verification into a Unity game and briefly cover payment integration.

Adding software licensing

  1. Download the binaries (please pick those without “System.Management”).
  2. Place these binaries into “Assets” folder.
  3. Add code from the key verification tutorial.

A sample Unity project can be found here.

Adding payments

Once licensing is in place, the next step is to add payment integration. Since Cryptolens is cloud-based, you can easily integrate it with your own billing system or use our existing integrations with popular platforms such as Stripe and PayPal. You can read more about how this can be accomplished here.

Please feel free to reach out should you have any questions!

Automating offline activations

Many times your customers may have either restricted internet access or no internet access at all. Although Cryptolens is a cloud-based licensing solution, you can still use it to protect offline devices. In this post, we cover three ways internet access can be restricted and how license key verification can be performed.

Periodic internet access

If your users are connected to the internet on a regular basis, we can cache the response from the “Activate” method each time we are able to contact the server. If, at some point, internet connection would not be present, we would fallback on a cached version of the license object.

When using this approach, it’s important to define how long time your users can be offline. There is a field called “SignDate” in the license key object, which is the time when the response was signed by the server (i.e. the last time you successfully called Activate). So, if you only want to allow your users to be offline for 30 days, you can compare the current date with the “SignDate”.

License server (re-routing)

If your users have certain devices that have no direct internet access, one option is to use a license server, which will re-route all requests through a server hosted by the user. Only the server has internet access.

There is currently a Windows version of the server, freely available on GitHub.

Air gap (no internet)

If the devices have no internet access at all, we can use a similar idea that was described in periodicĀ internetĀ access, with the only difference that we always fallback on the license file.

In Cryptolens, there are three ways you can create such a file:

In the dashboard

Next to each license key, there is a yellow button which can be used to create license files:

UsingĀ activationĀ forms

Activation forms allow your customers to download activation files themselves.

UsingĀ theĀ API

If you want to automate license file creation, you can either call the Activate method using one of our client APIs or call the Web API directly (eg. using curl).

Floating licenses in Java

Floating licenses makes it easier for your customers to switch between machines that actively run your software, without having to deactivate them first. For instance, you can constrain the number of concurrent users to 10, but still allow the software to be installed on eg. 100 computers.

In Cryptolens, floating licensing works by letting your app to regularly poll the server to check if the number of concurrent users has been exceeded, which can be accomplished with the code snippet below:

import io.cryptolens.methods.*;
import io.cryptolens.models.*;

public static void main(String args[]) {
    String RSAPubKey = "RSA Public Key";
    String auth = "Access token";

    LicenseKey license = Key.Activate(auth, RSAPubKey, new ActivateModel(3349, "MTMPW-VZERP-JZVNZ-SCPZM", Helpers.GetMachineCode(), 300, 1));
    if (license == null || !Helpers.IsOnRightMachine(license, true, true)) {
        System.out.println("The license does not work.");
    } else {
        System.out.println("The license is valid!");
        System.out.println("It will expire: " + license.Expires);
    }
}

Normally, if the app stops polling the server, that user will be automatically deactivated within the specified period of time. However, if you want to deactivate it instantly, you can use the code below:

import io.cryptolens.methods.*;
import io.cryptolens.models.*;

public static void main(String args[]) {
    String auth = "";

    boolean result = Key.Deactivate(auth, new DeactivateModel(3349, "MTMPW-VZERP-JZVNZ-SCPZM", Helpers.GetMachineCode(), true));
    if (result == true) {
        System.out.println("Deactivation successful.");
    } else {
        System.out.println("Deactivation failed.");
    }
}

To see all the required parameters, please check out the GitHub repo of the Java client. Should you have any questions, please feel free to reach out.