rdSaltFile</code> directive configures a file which contains
salt data.  This salt will be added to the digest, along with the password
sent by the client.  Note that the salt will be used for all users.

<p>
Since many editors will automatically add a newline when writing a file,
the <code>mod_sql_passwd</code> file will automatically trim the last newline
in the salt data, if there is one.  This means that if your salt <b>must</b>
end in a newline character, then your <code>SQLPasswordSaltFile</code> must