1) Modify /etc/pam.d/sshd
From suse:
cat /etc/pam.d/sshd
Change the auth include common-auth try_first_pass in the below
#%PAM-1.0
auth requisite pam_nologin.so
auth include common-auth try_first_pass
account include common-account
password include common-password
session required pam_loginuid.so
session include common-session
TO:
#%PAM-1.0
auth requisite pam_nologin.so
auth requisite pam_vas3.so create_homedir get_nonvas_pass store_creds try_first_pass
account include common-account
password include common-password
session required pam_loginuid.so
session include common-session
From common-auth.
The above is from suse machine, RedHat is similiar except it is system-auth instead of common-auth.