Background...
It was decided a long time ago that a CLI "root" user could accomplish import using: cp <import_file> /etc/pki/entitlement

However, the design has changed so that an entitlement cert from rhsm-web can now have a key appended (see bug 712980).  As such a CLI import function makes sense to handle splitting the contents of the import file..

fixed in master at eeb90f106bc8fe32baf797ae33bdfc48608738f2.

verified using following steps 


[root@dhcp201-207 ~]# rpm -qa | grep subscription
subscription-manager-firstboot-0.96.8-1.git.18.770d58e.el6.x86_64
subscription-manager-gnome-0.96.8-1.git.18.770d58e.el6.x86_64
subscription-manager-0.96.8-1.git.18.770d58e.el6.x86_64
[root@dhcp201-207 ~]# subscription-manager list --avail
Error: You need to register this system by running `register` command before using this option.
[root@dhcp201-207 ~]# subscription-manager import --certificate /tmp/4177067579706068544.pem 
Successfully imported certificate 4177067579706068544.pem
[root@dhcp201-207 ~]# ls /etc/pki/entitlement/
4177067579706068544-key.pem  4177067579706068544.pem
[root@dhcp201-207 ~]# 

successfully imported entitlement cert via cli 

Working fine moving defect status from ON_QA to verified

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2011-1695.html