出現：Public key for xxxxxx.rpm is not installed

[root@desktop ~]# rpm --import http://apt.sw.be/RPM-GPG-KEY.dag.txt
[root@desktop ~]# rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY*

參考：
http://wiki.centos.org/AdditionalResources/Repositories/RPMForge#head-f0c3ecee3dbb407e4eed79a56ec0ae92d1398e01
http://www.fedorafaq.org/#gpgsig