[Kde-kiosk] kmail

[Ask Holme]

[i know i should followup from the post last night, but i deleted that
one] 
Verner Kjærsgaard <vk at os-academy.dk> wrote:
> Lørdag den 26. juni 2004 22:52 skrev Alexander Schunk:
> 
> Now, could one imagine that the mail received (by any user) was actually owned 
> by root,- who would then only give reading access to group and world? The 
> pattern 744 root.any_group would do the trick? The question is now, how to 
> make root the owner of all incoming mail to all users...
Yes, and thats the reason i said the solution would be an action
restriction. (i will not comment nor apology for what else i said). 

Why:
Generaly we can all agree that on unix the permissions to delete files
lies in having permissions to write to the directory the file resides in
or having permissions to write to the file itself. 
So for the filebased permission approach to work all dires containing
email would need to be 755 and owned by root and all files would be 644
also owned by root. The problems now start when we will have new mail
put into our structure. This mail can come via several ways:
	POP3: the users can fetch it themself (imap doesn't apply who
don't have the mail in that case). However then the permissions based
approach becomes impossible because the user would require write access
to the dirs containing mail when fetching mail from the pop3 server,
however giving write access to the dir is the same as giving permission
to delete files. 
	Local MTA: a mail daemon running on the system can dump the mail
at a given location, depending on the mta this can give more or less
problems - if we as an example take qmail then it would be default
refuse to deliver mail when the dir isn't owned and only readable by the
user the mail belongs to. I dunno how postfix takes cases like this, but
i'm fairly certain that postfix makes the receiving users the owner of
any mail files before ending the delivery process. Sendmail usually puts
the mail in /var/spool/mail/username and actually you might just be able
to make the mail undeleteable with sendmail in this way. I won't comment
on exim as i never used it. 

Anyway, theres another problem left with the filebased aprooach, the
question was how to avoid users deleting mail - however non said that
the users shouldn't be able to move mail into other folders than inbox. 

A kde action restriction on delete, combined with a correct URL
restriction on konqueror (i'm asuming no shell access is set). would
make it pretty hard to delete any mails at all. I'm not anywhere near a
KDE environment right now, so i can't try and figure out the right
action restriction to use, but i will try when i get near one.
	
--
Ask Holme
  "<+lisa`> well, sometimes, when the moon is right i like to print out 
   the source code to the Linux kernel, scatter them on the floor, lube
   myself up and roll around in the printed code."