Re: Authentication - based on request parameters
Morten,
HttpServletRequest is simply an interface. If you wanted to subclass it,
you would have to implement every member of the interface. However, you
could do this easily enough by passing every method that you didn't want to
implement to the original request object, for example:
public class MySpecialHttpServletRequest implements HttpServletRequest
{
private HttpServletRequest origRequest;
public MySpecialHttpServletRequest(HttpServletRequest origRequest)
{
this.origRequest = origRequest;
}
public String getAuthType()
{
return origRequest.getAuthType();
}
etc.
public boolean isUserInRole(String role)
{
// Do your own stuff
}
}
And then in your JSP you would have something like
%
request = new MySpecialHttpServletRequest(request);
%
However, if I were thinking of implementing an entire J2EE interface simply
to handle a single method, I'd be questioning whether I was going in the
right direction. If you have something that is working, you may want to
consider keeping it. Alternatively, why not try to use Tomcat's role-based
security architecture rather than overriding it?
Something else that occurs to me is that your security model appears to
depend on a GET parameter in the request (?site=MySite). A client could
easily change this value to circumvent your security. A better model is
that your logon page sets a value in the Session object to identify the
user. Then the security depends on a very long, random session ID and it is
vanishingly unlikely that a client will be able to change this ID (either in
a URL or a cookie) and, by chance, hit on a valid session ID belonging to
another user.
-
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Re: Authentication - based on request parameters
hi morten You can very well take the power of tomcat which helps you to authenticate in basic JDBC Realm or memory Reams or Userdatabase Realm. and you can use the request object's method called getremoteuser() to get the user name used for authentication by the user.Ensure the user name is unique for this purpose. regards sat - Original Message - From: Morten Andersen [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, September 26, 2003 5:01 PM Subject: Authentication - based on request parameters I've developed a authentication mechanism on my own because I could not figure out how to make authentication based on some request - parameters. This is what I've implemented: Whenever the user makes a request, the site parameter plus the path is used to figure out whether the user has the rights to access the path on that site. If not I sent him to a login - page, and after that back to the initially requested page. For instance: 1) The user requests: myTomcat:8080/MyApp/saveEditedPage.action?site=MySite 2) I figure out whether saveEditedPage needs login. If it does, then I check whether the user has previously logged in. If not the user is sent to the login page. 3) When the user has logged in. The rights for the user for the site=MySite is checked. If the user may enter he is sent the request is carried out. I have finally got it to work, but then it stroke me that I maybe could use the built in security - mechanism in tomcat. Here is my idea: I make a subclass of - or wraps HttpServletRequest, with my own class that overwrites the isUserInRole(String) method. So that the isUserInRole method could use some of the parameters from the request to make the finegrained access-control. (That is to use the site parameter). Does that sound possible or can't HttpServletRequest be subclassed like that? Or am I just plain stupid and could have saved me from a lot of hours of work by using a built in mechanism? Ragards Morten Andersen Master of applied mathematics and computer science Amanuensis (in e-learning) The Maersk Institute of Production technology at Southern Danish University www.mip.sdu.dk Campusvej 55 DK-5230 Odense M Denmark +45 6550-3654 +45 6171-1103 Jabber id: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Authentication - based on request parameters
Why is that a security-issue? I wan't the user to enter the site by cliking on a link or whatever, so that the user enters the site using that request. It should be OK, that the user tryes to go to a restricted page by writing blabla:8080/MyApp/restrictedRequest.action?site=JustAGuess But if that is done and the user has not got rights to do it, then he is being rejected... Regards Morten Andersen PS: I did consider the role-based model form tomcat, but that is coarse-grained, in the sense that it is based on 1 role for one web-app, and that is not suficient. Something else that occurs to me is that your security model appears to depend on a GET parameter in the request (?site=MySite). A client could easily change this value to circumvent your security. A better model is that your logon page sets a value in the Session object to identify the user. Then the security depends on a very long, random session ID and it is vanishingly unlikely that a client will be able to change this ID (either in a URL or a cookie) and, by chance, hit on a valid session ID belonging to another user. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Morten Andersen Master of applied mathematics and computer science Amanuensis (in e-learning) The Maersk Institute of Production technology at Southern Danish University www.mip.sdu.dk Campusvej 55 DK-5230 Odense M Denmark +45 6550-3654 +45 6171-1103 Jabber id: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Authentication - based on request parameters
The problem is that your model does not seem to be based on a secret and
site names don't have a lot of entropy. I don't know enough about your
model to give you examples of possible attacks, but it seems to be similar
to an access control model where you ask to people to enter their user ID
but no password. Saying Oh, the client has to know a valid user name to
get in would not be enough to make this a secure model. If you store the
remote site information in the Session, this information is stored-server
side and a client never even gets the chance to have a go at circumventing
it.
The role model can be made to work. You have a list of clients, or sites,
and you assign them roles. You create a table of role-to-permissions or
simply declare the required roles in your JSP. Then in your pages make the
following access check:
// This gives MyApp/saveEditedPage.action in your original example; you
may also use
// getServletPath() to give you saveEditedPage.action
String requestURI = request.getRequestURI();
// Implement this method yourself
String[] permittedRoles = getPermittedRoles(requestURI);
boolean accessAllowed = false;
for (int i = 0; i permittedRoles.length; i++)
{
if (request.isUserInRole(permittedRoles[i]))
{
accessAllowed = true;
break;
}
}
This is simply an example, of course, and I don't know whether such a scheme
would work for you.
- Original Message -
From: Morten Andersen [EMAIL PROTECTED]
To: Tomcat Users List [EMAIL PROTECTED]
Sent: Friday, September 26, 2003 10:33 AM
Subject: Re: Authentication - based on request parameters
Why is that a security-issue?
I wan't the user to enter the site by cliking on a link or whatever, so
that the user enters the site using that request. It should be OK, that
the
user tryes to go to a restricted page by writing
blabla:8080/MyApp/restrictedRequest.action?site=JustAGuess
But if that is done and the user has not got rights to do it, then he is
being rejected...
Regards
Morten Andersen
PS: I did consider the role-based model form tomcat, but that is
coarse-grained, in the sense that it is based on 1 role for one web-app,
and that is not suficient.
Something else that occurs to me is that your security model appears to
depend on a GET parameter in the request (?site=MySite). A client
could
easily change this value to circumvent your security. A better model is
that your logon page sets a value in the Session object to identify the
user. Then the security depends on a very long, random session ID and it
is
vanishingly unlikely that a client will be able to change this ID (either
in
a URL or a cookie) and, by chance, hit on a valid session ID belonging to
another user.
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Morten Andersen
Master of applied mathematics and computer science
Amanuensis (in e-learning)
The Maersk Institute of Production technology at Southern Danish
University
www.mip.sdu.dk
Campusvej 55
DK-5230 Odense M
Denmark
+45 6550-3654
+45 6171-1103
Jabber id: [EMAIL PROTECTED]
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Re: Authentication - based on request parameters
Here is my requirements for the security mechanism:
The whole thing is about making secured rooms for groups of user.
1) It should be possible to make new sites / groups while the application
is running.
2) The sites has members, and only these should be allowed to do some of
the restricted requests.
3) Some sites may be totally open, so that everyone can do anything without
logging in.
4) All of this is decided while the application is running.
5) One user may be administrator of 1 group and not allowed to do anything
in another.
So for instance
the request:
TomcatServer:8080/MyApp/restrictedRequest.action?site=closedSite
would result in that the user is required to login using a login-screen,
because closedSite is defined as closed.
while the request:
TomcatServer:8080/MyApp/restrictedRequest.action?site=openSite
Would not result in that the user has to login, because the openSite is
defined as total open.
At 11:06 26-09-2003 +0100, you wrote:
The problem is that your model does not seem to be based on a secret and
site names don't have a lot of entropy. I don't know enough about your
model to give you examples of possible attacks, but it seems to be similar
to an access control model where you ask to people to enter their user ID
but no password. Saying Oh, the client has to know a valid user name to
get in would not be enough to make this a secure model.
Why? knowing my hotmail address doesn't make it possible for other than me
to login to my hotmail account.
If you store the
remote site information in the Session, this information is stored-server
side and a client never even gets the chance to have a go at circumventing
it.
The role model can be made to work. You have a list of clients, or sites,
and you assign them roles. You create a table of role-to-permissions or
simply declare the required roles in your JSP. Then in your pages make the
following access check:
// This gives MyApp/saveEditedPage.action in your original example; you
may also use
// getServletPath() to give you saveEditedPage.action
String requestURI = request.getRequestURI();
// Implement this method yourself
String[] permittedRoles = getPermittedRoles(requestURI);
boolean accessAllowed = false;
for (int i = 0; i permittedRoles.length; i++)
{
if (request.isUserInRole(permittedRoles[i]))
{
accessAllowed = true;
break;
}
}
This is simply an example, of course, and I don't know whether such a scheme
would work for you.
- Original Message -
From: Morten Andersen [EMAIL PROTECTED]
To: Tomcat Users List [EMAIL PROTECTED]
Sent: Friday, September 26, 2003 10:33 AM
Subject: Re: Authentication - based on request parameters
Why is that a security-issue?
I wan't the user to enter the site by cliking on a link or whatever, so
that the user enters the site using that request. It should be OK, that
the
user tryes to go to a restricted page by writing
blabla:8080/MyApp/restrictedRequest.action?site=JustAGuess
But if that is done and the user has not got rights to do it, then he is
being rejected...
Regards
Morten Andersen
PS: I did consider the role-based model form tomcat, but that is
coarse-grained, in the sense that it is based on 1 role for one web-app,
and that is not suficient.
Something else that occurs to me is that your security model appears to
depend on a GET parameter in the request (?site=MySite). A client
could
easily change this value to circumvent your security. A better model is
that your logon page sets a value in the Session object to identify the
user. Then the security depends on a very long, random session ID and it
is
vanishingly unlikely that a client will be able to change this ID (either
in
a URL or a cookie) and, by chance, hit on a valid session ID belonging to
another user.
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Morten Andersen
Master of applied mathematics and computer science
Amanuensis (in e-learning)
The Maersk Institute of Production technology at Southern Danish
University
www.mip.sdu.dk
Campusvej 55
DK-5230 Odense M
Denmark
+45 6550-3654
+45 6171-1103
Jabber id: [EMAIL PROTECTED]
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Morten Andersen
Master of applied mathematics and computer science
Amanuensis (in e-learning)
The Maersk Institute of Production technology at Southern Danish University
www.mip.sdu.dk
Campusvej 55
DK-5230 Odense M
Denmark
+45 6550-3654
+45 6171-1103
Jabber id: [EMAIL PROTECTED]
RE: Authentication - based on request parameters
Morten,
I missed the orginal post but noticed in a later message you rejected the
Tomcat role-based model as too coarse grained. If you use a JDBC based
security model you can assign more than one role to a user. I have used
this to good effect with the following header code in controlled pages:
%@ page import=java.sql.* %
%@ taglib uri=http://jakarta.apache.org/taglibs/request-1.0; prefix=req
%
%@ taglib uri=http://jakarta.apache.org/taglibs/response-1.0; prefix=rsp
%
% Class.forName(org.gjt.mm.mysql.Driver); %
req:request id=rq/
%
boolean validRole = false;
%
req:isUserInRole role=leader
%
validRole = true;
%
/req:isUserInRole
%
if (!validRole)
{
System.out.println(access is not allowed);
%
rsp:sendError error=SC_FORBIDDEN reset=true/
rsp:skipPage/
%
}
%
HTML
insert the rest of your page here. This page is restricted to users
who have been assigned both the member and the leader roles.
The requirement for assignment to the member role comes from your web app's
web.xml file thus
security-constraint
web-resource-collection
web-resource-nameScoutGroup-Secure/web-resource-name
url-pattern/members/*/url-pattern
/web-resource-collection
auth-constraint
role-namemember/role-name
/auth-constraint
user-data-constraint
transport-guaranteeCONFIDENTIAL/transport-guarantee
/user-data-constraint
/security-constraint
It is necessary for every user to have a member role assigned in order to
reach the members' section (that is one role per web app to allow access in
the first place) but, having been permitted to access the members' pages,
you can further control access to pages within that area by performing your
own role checks within each page.
Murray
-Original Message-
From: Morten Andersen [mailto:[EMAIL PROTECTED]
Sent: Friday, 26 September 2003 20:33
To: Tomcat Users List
Subject: Re: Authentication - based on request parameters
Here is my requirements for the security mechanism:
The whole thing is about making secured rooms for groups of user.
1) It should be possible to make new sites / groups while the application
is running.
2) The sites has members, and only these should be allowed to do some of
the restricted requests.
3) Some sites may be totally open, so that everyone can do anything without
logging in.
4) All of this is decided while the application is running.
5) One user may be administrator of 1 group and not allowed to do anything
in another.
So for instance
the request:
TomcatServer:8080/MyApp/restrictedRequest.action?site=closedSite
would result in that the user is required to login using a login-screen,
because closedSite is defined as closed.
while the request:
TomcatServer:8080/MyApp/restrictedRequest.action?site=openSite
Would not result in that the user has to login, because the openSite is
defined as total open.
At 11:06 26-09-2003 +0100, you wrote:
The problem is that your model does not seem to be based on a secret and
site names don't have a lot of entropy. I don't know enough about your
model to give you examples of possible attacks, but it seems to be similar
to an access control model where you ask to people to enter their user ID
but no password. Saying Oh, the client has to know a valid user name to
get in would not be enough to make this a secure model.
Why? knowing my hotmail address doesn't make it possible for other than me
to login to my hotmail account.
If you store the
remote site information in the Session, this information is stored-server
side and a client never even gets the chance to have a go at circumventing
it.
The role model can be made to work. You have a list of clients, or sites,
and you assign them roles. You create a table of role-to-permissions or
simply declare the required roles in your JSP. Then in your pages make the
following access check:
// This gives MyApp/saveEditedPage.action in your original example; you
may also use
// getServletPath() to give you saveEditedPage.action
String requestURI = request.getRequestURI();
// Implement this method yourself
String[] permittedRoles = getPermittedRoles(requestURI);
boolean accessAllowed = false;
for (int i = 0; i permittedRoles.length; i++)
{
if (request.isUserInRole(permittedRoles[i]))
{
accessAllowed = true;
break;
}
}
This is simply an example, of course, and I don't know whether such a
scheme
would work for you.
- Original Message -
From: Morten Andersen [EMAIL PROTECTED]
To: Tomcat Users List [EMAIL PROTECTED]
Sent: Friday, September 26, 2003 10:33 AM
Subject: Re: Authentication - based on request parameters
Why is that a security-issue?
I wan't the user to enter the site by cliking on a link or whatever, so
that the user enters the site using that request. It should be OK, that
the
user tryes to go to a restricted page by writing
blabla:8080/MyApp/restrictedRequest.action?site=JustAGuess
But if that is done and the user has not got
Re: Authentication - based on request parameters
do it like list below,then the client could only submit his request by the POST method security-constraint display-nameExample Security Constraint/display-name web-resource-collection web-resource-nameProtected Area/web-resource-name url-patternyourProtectedDir/*.jsp/url-pattern http-methodDELETE/http-method http-methodGET/http-method !-- http-methodPOST/http-method -- http-methodPUT/http-method /web-resource-collection _ MSN Messenger: http://messenger.msn.com/cn - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
