Change recorded stream files permissions from server side

Yes, look for this config in Server.xml of your FMS

<!-- This key controls who has read/write access to the shared object   -->
        <!-- files and stream files in the server. The Mask is used by umask    -->
        <!-- to set file creation mask.  By default, the mask is set to 017     -->
        <!-- and the files are created with permission 0666.                    -->
        <!-- 0666 & ~017 = 0660 = r w - r w - - - -, that means the owner of    -->
        <!-- the server and all the users belonging to the same group as the    -->
        <!-- owner will have read/write access to the files. This mask must be  -->
        <!-- a 3 digit octal format                                             -->
        <!-- This config node is for unix only.                                 -->
        <Mask>017</Mask>

Asa