allowing users to run crontab

[Mike Bethune]

Hello,

I would like to use sudo to allow crontab usage for some users as below:
Cmnd_Alias USER1CRON = /usr/bin/crontab -u user1 /home/user1/crontab, /usr/bin/crontab -u user1 -r, /usr/bin/crontab -u user1 -l

but I realize that user1 could simply create a link from his /home/user1/crontab to say /var/spool/crontab/root (or any other file), and so end up reading this file with root privileges.  If the file he sym links to isn't a valid crontab then he'll see an error that quotes a (small?) part of the file that isn't in valid crontab format.

Can someone tell me how I could fix this (without allowing them to run crontab directly :).
Thanks,

Mike