This API serves as a layer that simplifies communication with Serial Key Manager Web API 2 and 3 (https://app.cryptolens.io/docs/api).

You can access the documentation of the library at https://help.cryptolens.io/api/dotnet/.

In Visual Studio package manager

PM> Install-Package Cryptolens.Licensing

Using dotnet CLI

dotnet add package Cryptolens.Licensing

• Key verification
• Offline verification

To get access to all of the featues in the library, .NET Framework 4.6 or above has to be used. We have summarized the functionality that is included in each framework. Note, .NET Standard means the library can run on multiple platforms (eg. .NET Core), based on the following document.

• .NET Framework 4.0 - Verifying metadata signatures is not supported.
• .NET Framework 4.6 - All features supported.
• .NET Standard 2.0 - Computing machine codes is not supported. You can still use the available hash functions to compute a machine code, assuming you can collect machine specific information.
• Unity/Linux/Mac - You need to use the packages in the "Without System.Management" folder on the release page. You can find more info here.

Cryptolens.Licensing library does also work on Mono (eg. when running on Linux or Unity), however you need to use the version of the library that is compiled without System.Management. You can find pre-compiled binaries here or compile it yourself by following the instructions below.

If you plan to use Cryptolens.Licensing on Linux, you need to use a version of the library that does not include System.Management. By excluding System.Management, calculating device fingerprints will not work (i.e. any method that depends on SKM.getMachineCode). You can still use the available hash functions and helper methods, as long as SKM.getMachineCode is not invoked.

To compile without System.Management, open Cryptolens.Licensing.csproj and remove the <DefineConstants>SYSTEM_MANAGEMENT</DefineConstants> below inside the <PropertyGroup> tag, i.e.

<PropertyGroup>
    ...

    <DefineConstants>SYSTEM_MANAGEMENT</DefineConstants>   <-- remove this
</PropertyGroup>

Make sure there are no other DefineConstants definitions later in the file, as these will override the value.

In order to make sure that the local time (date and time) wasn't changed by the user, the following code can be used.

public void HasLocalTimeChanged()
{
    bool hasChanged = SKGL.SKM.TimeCheck();

    if(hasChanged)
    {
        Debug.WriteLine("The local time was changed by the user. Validation fails.");
    }
    else
    {
        Debug.WriteLine("The local time hasn't been changed. Continue validation.");
    }
}

Machine code can be calculated with the function below. Any other hash algorithm will do, as long as it only contains letters and digits only.

public void TestingHashes()
{
    //eg. "61843235" (getEightDigitsLongHash)
    //eg. "D38F13CAB8938AC3C393BC111E1A85BB4BA2CCC9" (getSHA1)
    string machineID1 = SKGL.SKM.getMachineCode(SKGL.SKM.getEightDigitsLongHash);
    string machineID2 = SKGL.SKM.getMachineCode(SKGL.SKM.getSHA1);
}