# Types of License Managers

Several types of License Managers may by available to a protected application, depending on the platform used. The protected application selects the License Manager to use depending on various circumstances.

>Integrated License Manager (Windows, Linux Intel, Linux ARM, Android)

The Integrated License Manager (Integrated LM) is included in the Sentinel LDK Licensing API and in applications that were protected using Sentinel LDK Envelope. A given instance of the Integrated LM is dedicated to the protected application in which it is included.

The Integrated LM is able to directly handle local SL UserMode keys, local Sentinel HL (Driverless configuration) keys. Admin rights are not required to install the Integrated LM.

The Integrated LM has no user interface. Sessions for protection keys that are handled directly by the Integrated LM are not visible in Admin Control Center. However, the Integrated LM can be configured. For more information, see the Sentinel Admin API C Reference.

The Integrated LM can be upgraded by upgrading the Licensing API or by re-protecting the application with the latest version of Sentinel LDK Envelope.

>External License Manager (Windows)

The External License Manager (External LM) is contained in a standalone file: hasp_rt.exe. The hasp_rt.exe file must be placed in the same directory as the protected application. A given instance of the External LM is dedicated to the protected application whose directory contains the hasp_rt.exe file.

The External LM can directly handle local SL UserMode keys and local Sentinel HL (Driverless configuration) keys. It can also serve the consumption of SL AdminMode keys, see the table below for details. To handle SL UserMode protection keys, place your customized Vendor library in the same directory as the protected application.

NOTE Using hasp_rt.exe is strongly recommended, especially when Envelope protection is applied. For more details, see Sentinel LDK Software Protection and Licensing Guide

The External LM has no user interface. However, the External LM can be managed with Sentinel Admin API.

Admin rights are not required to deploy the External LM. The External LM can be upgraded by simply replacing the hasp_rt.exe file with a later version of the file.

NOTE For applications that were protected with versions of Sentinel LDK earlier than v.7.0, you must replace the Licensing API DLL or LIB file in order to make the External LM available.

>Admin License Manager (Windows, Mac, Linux Intel, Linux ARM)

The Admin License Manager (Admin LM) is included as part of the Run-time Environment. The Run-time Environment also includes device drivers, data file encryption drivers, and Sentinel Admin Control Center, which is the user interface for the Admin LM.

The Admin LM can manage Sentinel HL keys, SL Legacy keys, and SL AdminMode keys. Under Windows, the Admin LM can also manage SL UserMode keys.

Sessions for protection keys that are handled by the Admin LM are visible in Admin Control Center. Sessions for SL UserMode keys are not visible.

The Admin License Manager must be present on machines where remote protection keys are located.

The Sentinel LDK License Manager Service must be active at all times on the machine where the Admin LM is used. This service is started automatically when the machine is started.

Installation of the Run-time Environment on a computer requires admin rights. No special rights are required after the installation.

The following table compares the capabilities and platform support of the available License Managers.

Licensing Capability | Admin License Manager | External License Manager | Integrated License Manager
--- | --- | --- | ---
Installation and Platforms
Supported platforms for installation | Windows Mac Linux Intel/ARM | Windows | Windows Linux Intel/ARM Android
Requires admin rights for installation | Yes | No | No
License Serving and Consumption
Serve concurrent licenses (server-side) | Yes | No | No
Consume remote concurrent licenses (client-side) NOTE The Sentinel LDK Licensing REST API allows remote license consumption from any operating system that supports REST communication. In this scenario, a License Manager is not required on the client machine. | Windows Mac Linux Intel/ARM | Windows | Windows Linux Intel/ARM Android
Supports Sentinel HL (HASP configuration) key and HASP HL key for local license consumption | Yes | No | No
Supports Sentinel HL (HASP configuration) key and HASP HL key for remote concurrent license consumption (client-side) | Yes | Yes | Yes
Supports SL AdminMode key for remote consumption including cloud licenses (client-side) | Yes | Yes | Yes
Deployment
Requires rebuilding the application to upgrade the License Manager | No | No | Yes2
Hardware Key Support
Supports Sentinel HL (Driverless configuration) key | Yes | Yes | Yes
Software Key Support
SL AdminMode key | Yes (mandatory) | No | No
SL UserMode key | Yes (with limited support)1 | Yes | Yes
SL Legacy key | Yes (mandatory) | No | No
Legend: 1 - For more information, see the Sentinel LDK Software Protection and Licensing Guide. 2 - Rebuilding is required only when the application integrates static libraries. Applications using dynamic libraries do not require rebuilding.

### Differences between the External LM and the Integrated LM in the Licensing API

The functionality of the External LM is nearly identical to that of the Integrated LM. This includes backward compatibility with Licensing API, the server search process, Sentinel SL UserMode license support, Sentinel HL (Driverless configuration) key support and configuration options.

The following are the differences between the External LM and the Integrated LM in the Licensing API:

External License Manager | Integrated License Manager
--- | ---
The Licensing API runs in a separate process. In the Task Manager, two processes are listed: The protected application and the External License Manager module | There is no separate process for the License Manager.
If, for any reason, the License Manager fails, only the hasp_rt.exe process will crash. The protected application continues to run. The error HASP_LOCAL_COMM_ERR (33) is returned for any subsequent calls to the Licensing API. | If the License Manager fails, the protected application also fails.
If the protected application fails for any reason, the hasp_rt.exe module automatically exits, but only after closing all the login sessions left open by the protected application | Login sessions are kept alive for three minutes. The licenses that were in use by the protected application are not available during this time.
When debugging a protected application (and thus stopping all the background threads of the application) login sessions do not time out after three minutes, because the License Manager keeps the sessions alive. | Login sessions time out after three minutes. After they time out, the protected application cannot use calls to the Licensing API.

## Related Topics

Sentinel License Managers - Overview

Selection of License Manager Under Windows