Trying to install an extra package Endian , to add some interesting application , due to the operating system Endian be well optimized , it does not have many libraries and dependency.
1- Run the command to enable the packages executions without error checking and validation key.
smart config –set rpm-check-signatures=False
2- Install the package directly from the repository you set, below is an example for installing package nano.
smart install http://vault.centos.org/4.9/os/i386/CentOS/RPMS/nano-1.2.4-1.i386.rpm
Note : I recommend using repositories versions CentOS 4.9 , 5 or RedHat 5, if you try to install a package to a newer version , errors can occur with libraries and modules, as Endian is optimized it just has the essential and customized versions and not I recommend updating the libraries or modules , as this may result in severe damage to the system.