Jay Paulson wrote:
I also found that in the /etc/httpd/conf/httpd.conf file you can
change the group apache runs as from apache to www (or whatever group
you want). Then start up /etc/init.d/httpd as root for it to take
effect (at least that what it says in the httpd.conf file).
My question now is which is the better way?
I'll have to try both ways. :)
The two things are completely different.
Changing the group in /etc/httpd/conf/httpd.conf just changes group
that apache runs as. It will not affect the permission bits of files
created by the web server in any way, only the GID of those files (if
you're using the SGID bit on a directory, the GID of newly-created
files will be the same as the directory, otherwise, the GID of the
running process).
Be careful about the UID/GID you run httpd as, and the
UID/GID/permissions of the files on your system. Security-wise, the
httpd should run with just enough permissions to be able to function
correctly, i.e. it should not be able to write to most files, just
read the files it's serving and write to files/directories that you
want to be able to upload to.
Changing the umask to 002 will mean that newly-created files will have
write permissions set for the UID and GID of the file.
Paul.
Thanks for the explanation it makes perfect sense to me and the security
issue you bring up is very serious.
The reason why I need apache to have write permissions set for the UID
and the GID is that I have other users who log in locally and will need
access to modify those files that are uploaded via apache. Hence the
reason why my local users and apache are all in the 'www' group. This,
as you pointed out, isn't best for security, which really does concern me.
Is there a more secure way of setting this up so that files that are
created by apache are writable by the group and the local users without
compromising the security of the rest of the files on the web root
through apache?
Try this:
- create a new group specifically to cover the area that httpd and your
local users should be able to write to, and add user apache and your
local users to that group.
- change the GID of that directory and everything underneath it to the
new group.
- set the SGID bit on that directory and all directories underneath it
so that new files created there have the correct group ID.
- change httpd.conf back to the default of running as user and group apache.
- make sure that your web root is not owned by user apache so that it
cannot write to it.
- start httpd with a umask of 002 so that it sets the group write bit on
any files it creates.
Paul.
