TOOLS: Use file descriptor to avoid races when creating a home directory
    
    When creating a home directory, the destination tree can be modified in
    various ways while it is being constructed because directory
    permissions
    are set before populating the directory. This can lead to file creation
    and permission changes outside the target directory tree, using hard
    links.
    
    This security problem was assigned CVE-2013-0219
    
    https://fedorahosted.org/sssd/ticket/1782