Login to WAS Admin Console
Login into WAS Admin Console: https://<WAS_ADMIN_HOST>:<WAS_ADMIN_PORT>/ibm/console
Navigate to certificate configuration section
Go to Security (Left Nav) -> SSL certificate and key management and under Related Items section, click on Key stores and certificates link.
Click on NodeDefaultTrustStore
Start addition of certificate
Under Additional Properties, Click on Signer Certificates
Add new signer certificate
Click on Add button
Provide certificate details
Provide details for the certificate to be added. Then click on Apply.
Make sure the .crt file is already copied to WAS machine, for e.g. /opt/IBM/WebSphere/Profiles/DefaultAppSrv01/etc/xxxssl.crt
Check the certificate details
The certificate details can be seen as below. Click on Save.
SSL certificate is successfully added
! Note that a server restart is not required for these changes to take effect.