From the forums;

I found that the hardcoded keystore type “jks” is used in xmppserver\src\main\webapp\security-certificate-store-management.jsp, which means the type “jks” will be used even if a different type is specified in the system property xmpp.socket.ssl.storeType.

line 138 -139:
final CertificateStoreConfiguration configKey = new CertificateStoreConfiguration( “jks”, new File( locKey ), pwdKey.toCharArray(), backupKey );
final CertificateStoreConfiguration configTrust = new CertificateStoreConfiguration( “jks”, new File( locTrust ), pwdTrust.toCharArray(), backupTrust );