In the custom cloud you place the certificate in the .ssh directory and adjusted the m2ee.yaml file in the .m2ee directory. In the yaml file you add in the 'The following options can only be set here' part (last part of the yaml file) the following lines:
CACertificates:
"/home/environmentname/.ssh/somecertificate.cer"
Make sure you change the path to the certificate according to your environment in the cloud.
Regards,
Ronald