Stunnel for self-check

Setting up Stunnel for self-check

The following steps are required to set up Stunnel for self-check:  
  1. Select a server or workstation and install Stunnel
  2. Obtain the Alma certificate
  3. Update the configuration file
  4. Configure the self-service machines
  5. Test

We tend to recommend using an stunnel instance for a group of self-check machines which have something in common. Installing stunnel on the self-check machine, when allowed by the vendor, also has the benefit of having less network traffic since the self-check machine will be configured to communicate with localhost (

Obtaining an Alma Certificate

An Alma certificate can be obtained by the Ex Libris implementation engineer assigned to the project. Optionally, you can download the certificate from the Alma interface. Download the certificate file from Alma by clicking the Download Certificate button in the self-check profile’s Actions tab:
Note: Each self-check profile (external interface) has its own certificate. One profile’s certificate cannot be used for another profile. Save the certificate for use while configuring Stunnel.

Configure Stunnel as described in Configuring Stunnel.
Alma address for self-check communication:<alma domain>

Configuring the Self-Service Machine to Communicate with Stunnel

Configure the self-service machine to send traffic to the IP address of the workstation on which Stunnel is running and configure the port to the value configured in the Stunnel configuration file. For example, for 3M self-service machines, update the following two parameters under the self-service machine administration:
  • Integrated Library System (ILS) Host IP Address – Enter the IP address of the workstation that is running Stunnel.
  • ILS TCP Port Number – Enter the port that you specified during Stunnel configuration (such as 5001).
The self-service machines are configured to communicate with the Stunnel workstation and not directly with the library management system (the ILS).
We recommend setting a timeout of 15 seconds: usually responses from Alma via Stunnel will take much faster,  but it should be given slack for complex circumstances.