website logo
⌘K
Getting Started
Introduction
Basic Concepts
Opening an Account
Creating & Configuring Products
Integrating SDK and Configuring License Fulfillment
Activate a Key-Based License
Vendor Platform
Issuing New Licenses
License Detail View
Order Detail View
Customer Detail View
Metadata
Analytics
Settings
Product Configuration
Product Features
Product Custom Fields
Product Versioning
License Policies
Product Bundles
License Entitlements
License Types
Activations & Device Transfers
Features
Custom Fields
License Start Date
License Note
Maintenance Period
Trial Licenses
Floating Licenses
License Activation Types
Portals
End-User Portal
Offline Portal
Air-Gapped Portal
License API
License API Authorization
License Activation/Deactivation
License Check
Consumption
Floating
Trial Key
Product Details
Device Variables
Changing Password
Management API
Making API Requests
Management API Authorization
Customer
Product
Order
License
Device
Analytics
SDKs
Tutorials
.NET/C# SDK
.NET/C# Management SDK
C++ SDK
Java SDK
Python SDK
Go SDK
Delphi SDK
Swift/Objective-C SDK
Android SDK
Unity SDK
Errors and Response Codes
Floating Server
API Reference
Deployment
Configuration
Floating Server UI
Securing the Server
Whitelabeling
FAQ
Floating Server Changelog
Integrations
Salesforce
FastSpring
Stripe
Shopify
Common Scenarios
Single Sign On (SSO)
Glossary
General
SDK Glossary
Vendor Platform
Product Configuration Glossary
License Configuration
Postman Collections
Frequently Asked Questions
Changelog
License API changelog
Platform changelog
Docs powered by
Archbee
SDKs
...
Getting Started
C++

C-Interface

12min

The C interface of LicenseSpring's C++ SDK allows using SDK features in C applications. This tutorial will explain how to implement licensing in a C application using the LicenseSpring SDK.

In this article we will look at activating, checking, and deactivating licenses. This functionality can be implemented using the LSLicenseHandler struct. It is a wrapper of C++ LicenseHandler class and is similar in use. 

SDK Configuration

To initialize the SDK you will need to fill in your application name and version, LicenseSpring API key, shared key and product code. For more information about getting these values see: Getting API key and shared key

When you have the necessary values, create the LSConfiguration object.

C
|
const char* AppName = "My LicenseSpring Application";
const char* AppVersion = "1.0.0";
const char* ApiKey = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx";
const char* SharedKey = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
const char* ProductCode = "XX";

LSExtendedOptions* options = CreateLSExtendedOptions();
LSConfiguration* configuration = CreateLSConfiguration( ApiKey, SharedKey, ProductCode, AppName, AppVersion, options );
FreeLSExtendedOptions( options );


You have to create a LSExtendedOptions object even if you don’t intend to change its values. It is necessary to copy the default values to the LSConfiguration. Then you can delete the options object.

Now you can create and initialize LSLicenseHandler using this configuration.

C
|
LSLicenseHandler* lh = CreateLSLicenseHandler( configuration );


License Activation

To activate a license, you need its key or user email and password. For information about getting license keys see: Key-based license activation

For information about user based licenses see: Adding user to a license

Using these values, create a LSLicenseID and call activation method.

C
|
LSLicenseID licenseId = CreateLicenseIDfromKey( "XXXX-XXXX-XXXX-XXXX" ); 
lh->activateLicense( lh, licenseId );


Local License

Make sure that you check if a license exists on the device before a new activation. For more information see: C++ SDK Configuration and Usage

C
|
if( !lh->isLicenseExists( lh ) )
  //activate a new license


License Check

It is recommended to perform a local license check at application start to confirm that the local license file belongs to the current device, has not been tampered with and is still valid. 

Online license check refreshes the local license with the data from LicenseSpring backend.

C
|
lh->checkLicenseLocal( lh );//local check

LSInstallationFile* pInstallFile = lh->checkLicense( lh );//online check
        if( pInstallFile )
            FreeLSInstallationFile( pInstallFile );


This method also returns the most recent LSInstallationFile available for the license which can be useful for managing software updates. [TODO: insert link to the article about handling versions]

You can also check for active, valid, enabled, and expired licenses using isLicenseActive, isLicenseValid, isLicenseEnabled, and isLicenseExpired methods respectively.

Full Code Sample

Below you can find a code sample that initializes the SDK, retrieves a local license or activates a new one, and performs the necessary checks.

C
|
const char* AppName = "My LicenseSpring Application";
const char* AppVersion = "1.0.0";
const char* ApiKey = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx";
const char* SharedKey = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
const char* ProductCode = "XX";

LSExtendedOptions* options = CreateLSExtendedOptions();
LSConfiguration* configuration = CreateLSConfiguration( ApiKey, SharedKey, ProductCode, AppName, AppVersion, options );
FreeLSExtendedOptions( options );

LSLicenseHandler* lh = CreateLSLicenseHandler( configuration );

if( !lh->isLicenseExists( lh ) )
{
    LSLicenseID licenseId = CreateLicenseIDfromKey( "XXXX-XXXX-XXXX-XXXX" ); 
    lh->activateLicense( lh, licenseId );
    if( lh->wasError( lh ) )
   	{
        const char* error = lh->getLastErrorMsg( lh );
        enum LSErrorCode code = lh->getLastError( lh );
        printf( "Error occurred. Message: %s Code: %d\n\n", error, code );
   	}
}

lh->checkLicenseLocal( lh );
if( lh->wasError( lh ) )
{
    const char* error = lh->getLastErrorMsg( lh );
   	enum LSErrorCode code = lh->getLastError( lh );
   	printf( "Error occurred. Message: %s Code: %d\n\n", error, code );
}

LSInstallationFile* pInstallFile = lh->checkLicense( lh );
if( pInstallFile )
    FreeLSInstallationFile( pInstallFile );

if( lh->wasError( lh ) )
{
    const char* error = lh->getLastErrorMsg( lh );
   	enum LSErrorCode code = lh->getLastError( lh );
   	printf( "Error occurred. Message: %s Code: %d\n\n", error, code );
}


License Deactivation

Deactivating a license unbinds the device from the license, and decrements the number of total activations. Deactivating is done using the following method:

C
|
if( lh->deactivateLicense( lh ) )
    printf( "License deactivated successfully.\n" );


Common Errors

The license checks can produce the following errors:

Error

Definition

eLicenseDisabled

eLicenseInactive

eLicenseExpired

License is in invalid state (disabled, epired or inactive)

eProductMismatchError

License does not belong to configured product

eDeviceError

License does not belong to current device

eDeviceBlacklisted

The device has been blacklisted

eClockTamperedError

Detected cheating with system clock

eNoInternetError

eNetworkTimeoutError

eSreverError

Connection-related errors: if there's no Internet or an internal server error occured



Updated 15 Sep 2023
Did this page help you?
PREVIOUS
C++ SDK Configuration and Usage
NEXT
.NET/C#
Docs powered by
Archbee
TABLE OF CONTENTS
SDK Configuration
License Activation
Local License
License Check
Full Code Sample
License Deactivation
Common Errors
Docs powered by
Archbee