Unable to send RESTful requests with client certificate in Katalon Studio

When trying to send RESTful requests using a client certificate, you may encounter the following error:

Could not initialize class org.apache.commons.ssl.KeyMaterial

The root cause of the issue is related to the outdated yet-commons-ssl-0.3.11 library, which is used to parse the certificate file in Katalon Studio. This library does not support Java versions 9 and later.

Since Katalon Studio version 9.x, the embedded JRE has been upgraded to JRE 17, which is incompatible with this library. As a result, the system searches for the JKS keystore format, even when the certificate is in PKCS12 format.

You need to update the keystore format from PKCS12 to JKS. Follow these steps:

1. Locate the security folder inside the JRE used by Katalon Studio: <path to your Katalon Studio product>\jre\conf\.
2. Open the file named java.security in a text editor.
3. Change the keystore type.
   Find the line: keystore.type=pkcs12

   Change it to: keystore.type=jks

4. Save the changes, close the file, and restart Katalon Studio to apply the updated configuration.