Work around pkisilent bugs.
    
    Check directory manager password and certificate subject base for
    invalid characters.
    (https://bugzilla.redhat.com/show_bug.cgi?id=658641)
    
    Shell-escape pkisilent command-line arguments.
    (https://bugzilla.redhat.com/show_bug.cgi?id=741180)
    
    ticket 1636