Explain filename/filetype please

[Julian Field]

On 25 May 2006, at 14:40, Steve Campbell wrote:

> I had always figured I had a handle on the two filename/filetype  
> rules conf files, but apparently, I don't.

And I have further muddied the waters by adding an alternative much  
simpler system you can use as well or instead. See the comments in  
MailScanner.conf just above the "Allow Filenames" setting.

Just to keep you on your toes of course :-)

You can do most things with the new settings and they are a hell of a  
lot easier to understand for most people.

> I need to block movie files, but they aren't being done as I  
> thought they would. I see in 4.50, these were defaulted to 'allow'  
> in the filetype rule, but I have modified that conf file back to  
> before 4.50 (actually never implemented the rpmnew file).
>
> I need an explaination of the following please from the Changelog  
> for 4.50:
>
> Disabled movie format "deny" rules in filetype.rules.conf

I commented out the movie format rules I supply in my  
filetype.rules.conf file.

> and have enabled
>  filetype checking by default.

You can enable and disable the whole filetype checking system by not  
telling it where to find the "file" command. I used to supply the  
MailScanner.conf file with the location of the "file" command  
commented out, so that the whole system was switched off. I have now  
removed the comment character # from the line, so that the whole  
system is switched on in the MailScanner.conf file I supply.

> Am I correct in my way of thinking that "filename"  uses a RegExp  
> type match

Correct.

> and that "filetype" uses the result from the 'file' command?

Correct.

> Should I add extensions in the filename file for these as they are  
> not, by default, there, just to cover all bases? Recommendations of  
> filetype extensions would be appreciated here!

You can disable them by filename as well as by filetype to be doubly  
sure you get them. For the "filetype" rule text to put in, use the  
"file" command on a few of the files and put in filetype.rules.conf  
the important bits of the text you get back from the "file" command.  
You probably don't want to put all of it in, as they often contain  
information on the block encoding, data rate, etc of the movie file,  
and you just want to block these movie files in general.

Then just make sure your MailScanner.conf file has the setting  
telling it where to find the "file" command and away you go.

> Thanks for any help in making the clouds disappear over my brain.

I hope stuff above helps!

-- 
Julian Field
www.MailScanner.info
Buy the MailScanner book at www.MailScanner.info/store
PGP footprint: EE81 D763 3DB0 0BFD E1DC 7222 11F6 5947 1415 B654


-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.
MailScanner thanks transtec Computers for their support.