I've heard a couple of ideas, but so far nothing very different from what I'm
planning. Has anyone done anything really different out there?
Kevin, I like your idea for quickly protecting several pages. The difference
here is that I need to be able to turn on any combination of access for users.
By using Levels, it doesn't give me quite the granularity of permissions for
this particular project.
Come on, let's see some creative solutions! I know there's some pretty dang
smart people out there, and this isn't a new problem. I'm also starting to
dissect some existing open source projects that have multiple users and
permissions to get (hopefully) some other ideas.
Thanks for any thoughts!
Jason
ATTACHMENT part 9 message/rfc822
From: Kevin Stone [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Date: Wed, 5 Jun 2002 14:14:11 -0600
Subject: Re: [PHP-DB] permissions system
Very simply I protect whole pages on my member's website by include()'ing a
script called auth.php into the top of each page. Rather than using a
binary string to turn functions 'on' and 'off', I do things a bit more
general than that. I have defined levels of access (ie, L1, L2, L3, etc..)
stored in the member's table in the database. At the top of each page I
wish to protect I write ($min_access = 'L2') to define a minimum level of
access. If the user has L2 access or greater they'll fall right through the
auth.php and end up on the page. Otherwise one of the conditionals will
catch them like a net and dump them into the logout() function which kills
the session and displays the login screen with a lovely ACCESS DENIED (or
other appropriate text) message. In this way I can protect any number and
type of webpage (so long as I rename it .php) without registering the
filename. And all of my staff and admin scripts can remain public instead
of behind some .htaccess file.
As for the complexity of auth.php. It's hardly complex but I'm fairly
thurough in my check. The auth.php script is actually about 150 lines of
code and does timeout, tracks the member's movement and more... but it
could be as simple as a single db query. This is the best continuous
pervasive authentication scheme I have devised. It's probably not as good
as other systems out there but it does the job in the limited scope of
protecting my member's site. :)
-Keivn
- Original Message -
From: Jason Markantes [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Tuesday, June 04, 2002 10:43 PM
Subject: [PHP-DB] permissions system
Howdy All-
I've poked around the net for some snippets, and have done my own in the
past,
but wanted to get some more ideas on how you do a permissions system.
This
means, in your application, how do you control and enforce different
permissions for different users?
Simple example: An image repository. You have users who can download
images
and/or upload images. And certain users can only search for images within
a
certain criteria.
What I've done in the past is created a permission_flag column for each
user.
Zero or One determines whether or not the user can do that function, and
the
various functions are indicated by position (or index). So if you had
upload
and download functions, you can have:
01 = can download, but can't upload
11 = can download and upload.
If I add a new function, I have to add another digit (and potentially
increase
the column size if things grow faster than planned).
To enforce this, as a user attempts each function, I simply check the
function
index and see if it's one or zero.
With me so far?
Now, for restricting database access:
What I've done is created a user_where column for each user. In this
column I
add a where clause that's appended to each and every search the user
attempts
(with the usual input safety checks for common db exploits).
For example, if a user can only see Approved images (in my pretend
application
example here), the user_where value might be category = 'Approved'. For
multiple values, it could be category IN ('Approved', 'Pending').
Does this make sense? How are other people doing things? I've given a
little
bit of thought to it, but not enough. With all the applications out there
everyone at some point has to come up with their own system.
Ideas?
Thanks,
Jason
=
Just Another Fu@#in' Adventure
http://markantes.com/jason
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