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Posted to users@tomcat.apache.org by Peter Brandt-Erichsen <pb...@adsl.intergate.ca> on 2001/07/25 09:51:24 UTC

request for suggestions on how to secure a web application....

This posting is a request for suggestions on how best to 
secure a web application.

First my setup:

NT 4.0
Apache 1.3.12
Tomcat 3.2.1 (running behind Apache)
servlets 
jsp pages
static html pages
jdk1.3


Web-app directory structure:

webapps/my_context/
    /jsp/jsp_pages
    /web-inf/classes/my_servlets
    /web-inf/classes/beans/my_java_beans

My static html files reside under the apache 
document root.

For servlet access I am using session cookies, as specified in
the Java Servlet Spec, to authorize users. This works very 
well for my purposes.

My concern is protecting sensitive jsp and static
html pages.

How do I stop an unauthorized user from accessing a 
jsp or html resource directly?  ie: a back-door attack.  

For example, I am protecting my site with a login page, 
but if a user simply sidesteps the login and types
    
        http://my_domain/my_context/jsp/any_jsp_page

into his browser, he will get access to any jsp page 
that resides in the specified context. 

I have experimented with some different approaches:

1.  hide the jsp directory directly under the /web-inf 
directory and let Tomcat restrict access.

So I would have:

        /web-inf/classes/servlets
        /web-inf/jsp/jsp_pages

Then provide access to jsp pages only through a 
verification servlet, which can verify the user and
then forward the request to the correct resource. 

However, this is causing problems when I utilize a 
RequestDispatcher(path).forward(req, res)  or 
RequestDispatcher(path).include(req, res) 
instruction.

The path needs to start with a "/" and be relative to 
the context root, per the Java Servlet API docs, which makes 
it impossible(?) to provide a correct path, since my 
verification servlet, and hence the execution thread, 
is in /web-inf/classes. When I issue the forward or inlude, 
I need to provide a path that looks something like:

        /../jsp/jsp_page 

which is correctly making the JVM puke.


2. Utilize the apache rewrite module and have apache
rewrite all requests for http://my_domain/my_context/jsp/*.jsp
to my verification servlet. The verification servlet can then
do its thing and forward valid requests to the appropriate 
request. 

A hornet's nest of complexity here! and my nose tells
me this is the wrong path to take.


3. Thought a lot about utilizing the Tomcat API.

ie: RequestInterceptor, Virtual Host, Valves etc.

I found rudimentary information about what these
constructs are, but very little on how to use them.

So, I am kinda stumped :-(

I guess the next step would be to explore Basic or
Digest Authorization, but I was hoping there would be
a simpler way, that uses the power of servlets....

I would greatly welcome any and all suggestions....

Thank you, and keep up the great work.
The Tomcat effort rocks!

Peter


BTW, I anticipate that the Tomcat docs will improve greatly 
in the future, and I was greatly encouraged to see the 
effort being put into making a book, and the template forming
around v4.0

I would like to suggest a section on real world examples, 
using and programming the Tomcat API and the xml config 
files, like server.xml. 

For an example of what I mean, the documentation 
for the Apache mod_rewrite, written by Ralf S. Engelschall, 
has a section on practical solutions. 

http://httpd.apache.org/docs/mod/mod_rewrite.html

That's kinda what I mean.













Re: request for suggestions on how to secure a web application....

Posted by Lars Nielsen Lind <mo...@worldonline.dk>.
You can try this:

When the user logs on to the system - you place his/hers username and password in Session variables.

Then you create an include file - for instance: validateusersec.jsp, which purpose is to control if the Session variables that holds the username and password is not empty or is valid data (exists in database, XML ..).

This file includes at the top of each of your secure pages.

If the include file finds empty or non-valid Session variables then it redirects the user back to start or logon page. If the data is correct the rest of the page is shown to the user.

But remember: when users are sending data with port 80 (standard http) then it is possible to 'sniff' the users data. Therefor it might be a good idea to use SSL with your solution - so that it is not possible to sniff the datas.

Lars Nielsen Lind



----- Original Message ----- 
From: "Peter Brandt-Erichsen" <pb...@adsl.intergate.ca>
To: <to...@jakarta.apache.org>
Sent: Wednesday, July 25, 2001 9:51 AM
Subject: request for suggestions on how to secure a web application....


> This posting is a request for suggestions on how best to 
> secure a web application.
> 
> First my setup:
> 
> NT 4.0
> Apache 1.3.12
> Tomcat 3.2.1 (running behind Apache)
> servlets 
> jsp pages
> static html pages
> jdk1.3
> 
> 
> Web-app directory structure:
> 
> webapps/my_context/
>     /jsp/jsp_pages
>     /web-inf/classes/my_servlets
>     /web-inf/classes/beans/my_java_beans
> 
> My static html files reside under the apache 
> document root.
> 
> For servlet access I am using session cookies, as specified in
> the Java Servlet Spec, to authorize users. This works very 
> well for my purposes.
> 
> My concern is protecting sensitive jsp and static
> html pages.
> 
> How do I stop an unauthorized user from accessing a 
> jsp or html resource directly?  ie: a back-door attack.  
> 
> For example, I am protecting my site with a login page, 
> but if a user simply sidesteps the login and types
>     
>         http://my_domain/my_context/jsp/any_jsp_page
> 
> into his browser, he will get access to any jsp page 
> that resides in the specified context. 
> 
> I have experimented with some different approaches:
> 
> 1.  hide the jsp directory directly under the /web-inf 
> directory and let Tomcat restrict access.
> 
> So I would have:
> 
>         /web-inf/classes/servlets
>         /web-inf/jsp/jsp_pages
> 
> Then provide access to jsp pages only through a 
> verification servlet, which can verify the user and
> then forward the request to the correct resource. 
> 
> However, this is causing problems when I utilize a 
> RequestDispatcher(path).forward(req, res)  or 
> RequestDispatcher(path).include(req, res) 
> instruction.
> 
> The path needs to start with a "/" and be relative to 
> the context root, per the Java Servlet API docs, which makes 
> it impossible(?) to provide a correct path, since my 
> verification servlet, and hence the execution thread, 
> is in /web-inf/classes. When I issue the forward or inlude, 
> I need to provide a path that looks something like:
> 
>         /../jsp/jsp_page 
> 
> which is correctly making the JVM puke.
> 
> 
> 2. Utilize the apache rewrite module and have apache
> rewrite all requests for http://my_domain/my_context/jsp/*.jsp
> to my verification servlet. The verification servlet can then
> do its thing and forward valid requests to the appropriate 
> request. 
> 
> A hornet's nest of complexity here! and my nose tells
> me this is the wrong path to take.
> 
> 
> 3. Thought a lot about utilizing the Tomcat API.
> 
> ie: RequestInterceptor, Virtual Host, Valves etc.
> 
> I found rudimentary information about what these
> constructs are, but very little on how to use them.
> 
> So, I am kinda stumped :-(
> 
> I guess the next step would be to explore Basic or
> Digest Authorization, but I was hoping there would be
> a simpler way, that uses the power of servlets....
> 
> I would greatly welcome any and all suggestions....
> 
> Thank you, and keep up the great work.
> The Tomcat effort rocks!
> 
> Peter
> 
> 
> BTW, I anticipate that the Tomcat docs will improve greatly 
> in the future, and I was greatly encouraged to see the 
> effort being put into making a book, and the template forming
> around v4.0
> 
> I would like to suggest a section on real world examples, 
> using and programming the Tomcat API and the xml config 
> files, like server.xml. 
> 
> For an example of what I mean, the documentation 
> for the Apache mod_rewrite, written by Ralf S. Engelschall, 
> has a section on practical solutions. 
> 
> http://httpd.apache.org/docs/mod/mod_rewrite.html
> 
> That's kinda what I mean.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 


AW: request for suggestions on how to secure a web application....

Posted by Reto Badertscher <rb...@i-netsystems.com>.
Your JSP can check if there's a valid login before processing. In our
application we use a login object with user information for authenticated
users and store it in the user session.
(BTW we use a servlet as a controller and Velocity to handle the view - so
it's impossible to access directly a page without passing the controller)

Reto

-----Ursprüngliche Nachricht-----
Von: Peter Brandt-Erichsen [mailto:pbe@adsl.intergate.ca]
Gesendet: Mittwoch, 25. Juli 2001 09:51
An: tomcat-user@jakarta.apache.org
Betreff: request for suggestions on how to secure a web application....


This posting is a request for suggestions on how best to
secure a web application.

First my setup:

NT 4.0
Apache 1.3.12
Tomcat 3.2.1 (running behind Apache)
servlets
jsp pages
static html pages
jdk1.3


Web-app directory structure:

webapps/my_context/
    /jsp/jsp_pages
    /web-inf/classes/my_servlets
    /web-inf/classes/beans/my_java_beans

My static html files reside under the apache
document root.

For servlet access I am using session cookies, as specified in
the Java Servlet Spec, to authorize users. This works very
well for my purposes.

My concern is protecting sensitive jsp and static
html pages.

How do I stop an unauthorized user from accessing a
jsp or html resource directly?  ie: a back-door attack.

For example, I am protecting my site with a login page,
but if a user simply sidesteps the login and types

        http://my_domain/my_context/jsp/any_jsp_page

into his browser, he will get access to any jsp page
that resides in the specified context.

I have experimented with some different approaches:

1.  hide the jsp directory directly under the /web-inf
directory and let Tomcat restrict access.

So I would have:

        /web-inf/classes/servlets
        /web-inf/jsp/jsp_pages

Then provide access to jsp pages only through a
verification servlet, which can verify the user and
then forward the request to the correct resource.

However, this is causing problems when I utilize a
RequestDispatcher(path).forward(req, res)  or
RequestDispatcher(path).include(req, res)
instruction.

The path needs to start with a "/" and be relative to
the context root, per the Java Servlet API docs, which makes
it impossible(?) to provide a correct path, since my
verification servlet, and hence the execution thread,
is in /web-inf/classes. When I issue the forward or inlude,
I need to provide a path that looks something like:

        /../jsp/jsp_page

which is correctly making the JVM puke.


2. Utilize the apache rewrite module and have apache
rewrite all requests for http://my_domain/my_context/jsp/*.jsp
to my verification servlet. The verification servlet can then
do its thing and forward valid requests to the appropriate
request.

A hornet's nest of complexity here! and my nose tells
me this is the wrong path to take.


3. Thought a lot about utilizing the Tomcat API.

ie: RequestInterceptor, Virtual Host, Valves etc.

I found rudimentary information about what these
constructs are, but very little on how to use them.

So, I am kinda stumped :-(

I guess the next step would be to explore Basic or
Digest Authorization, but I was hoping there would be
a simpler way, that uses the power of servlets....

I would greatly welcome any and all suggestions....

Thank you, and keep up the great work.
The Tomcat effort rocks!

Peter


BTW, I anticipate that the Tomcat docs will improve greatly
in the future, and I was greatly encouraged to see the
effort being put into making a book, and the template forming
around v4.0

I would like to suggest a section on real world examples,
using and programming the Tomcat API and the xml config
files, like server.xml.

For an example of what I mean, the documentation
for the Apache mod_rewrite, written by Ralf S. Engelschall,
has a section on practical solutions.

http://httpd.apache.org/docs/mod/mod_rewrite.html

That's kinda what I mean.