[EXIM] Force root?

How can I force a file lookup in a directory to be done with root
permissions? I'm looking data up in a file in a users home directory, and
there is no guarantee that the home dir will be world readable (or
readable by the exim user).


Here is what I am working with:

virtualdfl:
           driver = smartuser
           domains = lsearch;/admin/exim/virtual.domains
           condition = "${if exists {${extract{6}{:}{${lookup{${domain_data}}nis{passwd.byname}{$va
           new_address = $domain_data@OUR_LOCAL_DOMAIN.COM
           headers_add = "X-Virtual: dfl: $local_part\@$domain"

virtualmap:
           driver = aliasfile
           domains = lsearch;/admin/exim/virtual.domains
           require_files = ${extract{6}{:}{${lookup{${domain_data}}nis{passwd.byname}{$value}fail}}
           file = ${extract{6}{:}{${lookup{${domain_data}}nis{passwd.byname}{$value}fail}}}/${lc:${
           search_type = lsearch*
           headers_add = "X-Virtual: map: $local_part\@$domain"
           more = false

I want to force the exists check in the condition in virtualdfl, and the
require_files and the aliasfile lsearch in virtualmap, to be done with
root permission to prevent a non-world-readable home dir from mucking it
up.



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