Solved

Redirect and relative URL

Posted on 2004-04-07
12
534 Views
Last Modified: 2007-12-19
Here is my problem scenario:

In my servlet I am able to successfully bypass
authentication using Base64Encoding when accessing a
password protected page.
This page can be successfully displayed as well in the
browser, if I just stream the URL content from my
servlet to the client.However if this page had
relative links in its source, these
relative links do not work at all.

To overcome this, I tried using
response.sendRedirect()
from within my Servlet after setting
response.setHeader("Authorization", "Basic " +
encodedString);
(I have also tried
response.setHeader("WWW-Authenticate", "Basic " +
encodedString)
Either way with redirect, now I cannot bypass
authentication, because the browser keeps asking me
for credentials.

Basically I am looking to bypass authentication and
have the password protected page work correctly even
if it has relative links. Is this possible?

Let me clarify my scenario, hopefully this will make
it more clear

a) Client requests a password protected page from my
servlet.
b) servlet asks for username and password *once*.
c) Now my servlet has the user credentials in Base64
format.
d) I use these credentials to access the protected URL
from the servlet.  I get the contents fine to display
on the client. However if this URL content has
*relative* URL links it does not work since the
relative link is relative to the URL page and not the
ServletContext, which has made the request.
e) So I tried using response.sendRedirect which only
takes a String (which would be my password protected
URL string). So I tried using
response.setHeader("Authorization", "Basic " +
encodedString);
(I have also tried
response.setHeader("WWW-Authenticate", "Basic " +
encodedString)
to set the credentials and it still does not work.
   
I must mention that the password protected page is not
serviced by a servlet.
In fact these pages could be are cgi scripts. I want
to ask the credentials just once and use these
credentials from then on when visiting any password
protected page *even* with relative links.

                  Any ideas?
0
Comment
Question by:jkini
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 5
  • 5
12 Comments
 
LVL 92

Expert Comment

by:objects
ID: 10779243
i think you're going to need to parse html and modify the link before returning it to client.
0
 
LVL 1

Author Comment

by:jkini
ID: 10779314
But this is not possible since I would not even know where or which is the relative
entity (URL or gif) and which is not. Since the page could be any password protected page of the intranet whose content I have no control over or predefined knowledge of.

I am looking for some thing I can either set in the HttpServletResponse or
HttpServletRequest which I can then use to bypass authentication and achieve
what the sendRedirect would do.
0
 
LVL 92

Expert Comment

by:objects
ID: 10779356
The request is being sent by the browser so you have no control.
That is why you have to modify all the links in the page to make all requests go thru your servlet so that headers can be modified.
0
Online Training Solution

Drastically shorten your training time with WalkMe's advanced online training solution that Guides your trainees to action. Forget about retraining and skyrocket knowledge retention rates.

 
LVL 92

Expert Comment

by:objects
ID: 10779395
you could t5ry doing a forward instead of a redirect and see how that goes.
0
 
LVL 1

Author Comment

by:jkini
ID: 10779411
Is there a way I can ask my browser my credentials s that is does not ask me? Generally when I visit
a password protected page the browser would ask me for credentials once. Then the second time
I revisit the page it does not ask me for credentials, since I guess it would
have cached it.  So there should be some way to tell the browser just that, is it not?

If there is no other way then can you give me some code  that will generically modify the relative URLs
of the page programmatically, as I am reading the content and sending to the client?
 

 
0
 
LVL 1

Author Comment

by:jkini
ID: 10779430
I tried a forward. But the requestDispatcher needs  a location within the current ServletContext. The location that I am trying to access is not within the current ServletContext. It is just a cgi .pl script
that is not even serviced by a Servlet. So forward is not getting me anywhere :(
0
 
LVL 92

Accepted Solution

by:
objects earned 100 total points
ID: 10779449
> So there should be some way to tell the browser just that, is it not?

The browser is storing the authentication details, but it is authenticating with your servlet and not the actaul server.
That is why you need to change all links to instead go thru your servlet.
0
 
LVL 1

Author Comment

by:jkini
ID: 10795071
I appreciate the comments made above, however the above proposal does not seem to be a feasible solution to my problem, since I still see no way of how I can determine which are the link I need to change to bypass authentication and which are the links which are simply relative resources. Recreating the entire HTML content, just does not seem like an appropriate
solution.

If anyone can send me some **code**  that is a feasible solution that I can **use**
then I can award the points to that person. If not I will just have to request to delete my question.
0
 
LVL 92

Expert Comment

by:objects
ID: 10795088
There is no other solution that I am aware of for the reasons I have mentioned above.
Just because you do not like the required solution does not make it invalid.
0
 
LVL 1

Author Comment

by:jkini
ID: 10795277
Probably. But if the solution is not feasible for the reasons I mentioned it is not worth
the 100 points that I assigned to the question, since I have received no code. I expect a workable
code if this happens to be a solution to assign points. So far I have requested code 3 times
and none has been provided.
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

INTRODUCTION Working with files is a moderately common task in Java.  For most projects hard coding the file names, using parameters in configuration files, or using command-line arguments is sufficient.   However, when your application has vi…
For beginner Java programmers or at least those new to the Eclipse IDE, the following tutorial will show some (four) ways in which you can import your Java projects to your Eclipse workbench. Introduction While learning Java can be done with…
Viewers learn about the “for” loop and how it works in Java. By comparing it to the while loop learned before, viewers can make the transition easily. You will learn about the formatting of the for loop as we write a program that prints even numbers…
Viewers learn about the scanner class in this video and are introduced to receiving user input for their programs. Additionally, objects, conditional statements, and loops are used to help reinforce the concepts. Introduce Scanner class: Importing…
Suggested Courses

739 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question