Develop Reference

Inter domain cookies in Tomcat 7 via XML config

I've been tasked with modifying an application, of which I have access to the XML configuration of it in what appears to be Tomcat 7.
I need a cookie (called oname to be specific) shared to another domain (example.com). That is to say that, an iframe on the application to example.com can share the cookies from the application.
First of all, is this possible? Second of all, if it is (which I hope it is! :)) how can I do it via XML and XML only (referring to the configuration files found in the base of the application).
I've done some research on cookies, and I determined I need to modify the domain section on all cookies. If I need to change change all cookies globally (e.g. adding an XML element within the configuration to add domain = example.com to all cookies then that's acceptable!
I've pretty much have 2 options:
Find a specific XML element to change all cookies globally to add my desired domain
Have a JavaScript shim on the client side (I have access to the HTML also) wrap around the normal method to set cookies, while also adding example.com to the domain bit on the cookies.
Thanks for any help!

If your application is running on www.example.com, it can set a cookie for .example.com, but not if it's running on any other domain than example.com. If it would be possible to set cookies for unrelated domains, Anybody could easily set a cookie for any other random site, and as cookie names are typically well predictable, interfere with those sites (e.g. setting jsessionid or other session- and identification cookies in a rogue way).
Your only option is if the other site cooperates and provides a URL that you can redirect to which sets the cookie itself. Beware: Without checking the validity of the request, anybody can redirect to that site and set a cookie through the same measures - you can easily introduce a security issue.

Losing sessions between two servlets localhost

I am having a little problem here. We are a group of 3 guys developing a web application.. When I'm doing post to one servlet handling the login, and afterwards do a post to another servlet where I'm trying to use the attribute we've stored in the session in the Login, it's like it is using another session. I don't think there is a problem in the code, since the other guys can do this without any problems..
I'm using fiddler2 as my restclient, where the others are using Cocoa as their clients. When I'm inspecting the headers the two different posts is having two different session id's.
I've been trying to figure this out most of the day, but haven't found out of anything yet. I will be thankfull for any advise.

Fiddler's Composer does not attempt to maintain any sort of cookie jar for you. If you want to send a cookie on a request using the Composer, you must add it yourself. You will find the value in the Set-Cookie response header on a previous response.

Same JSESSIONID but different Session Object

I have an Java Http Servlet and trying to store things into the session. I have checked the request header and the same JSESSIONID is being sent each request.
However, every time, the session object (id) is different AND it contains none of the properties that we set in the last request.
More details: This works fine with just Tomcat7, but when I try to use nginx as a frontloader, the cookie is still sent, but the session object is still different.
Looks like the request URL is a fully-qualified domain.
Any ideas on what would be causing this or how to debug?
Thanks!

How do I keep Struts2 from appending jsessionid to the URL (on redirects)?

I want to keep the jsessionid parameter out of the URLs generated by Struts, but can't seem to find a configuration parameter or similar. To be honest, I don't even know exactly at which level this is handled.
Specifically, Struts (or the servlet engine) puts a sessionid in the URL when it's redirecting with a 302 and the session has not been established before (i. e. the redirect is in response to a request that sent no Cookie header). The response also contains a Set-Cookie header.
Generally, I just don't want the session id in the URL, ever. No cookies, no session.

You can try to check what's your servlet container offers to solve this problem. Alternatively you can write a filter to get rid of jsessionid. Hae a look here for details: http://seamframework.org/Documentation/RemovingJSESSIONIDFromYourURLsAndFixingScache

Best way for allowing subdomain session cookies using Tomcat

By default tomcat will create a session cookie for the current domain.
If you are on www.example.com, your cookie will be created for www.example.com (will only work on www.example.com). Whereas for example.com it will be created for .example.com (desired behaviour, will work on any subdomain of example.com as well as example.com itself).
I've seen a few Tomcat valves which seem to intercept the creation of session cookies and create a replacement cookie with the correct .example.com domain, however none of them seem to work flawlessly and they all appear to leave the existing cookie and just create a new one. This means that two JSESSIONID cookies are being sent with each request.
I was wondering if anybody has a definitive solution to this problem.

This is apparently supported via a configuration setting in 6.0.27 and onwards:
Configuration is done by editing
META-INF/context.xml
<Context
sessionCookiePath="/something"
sessionCookieDomain=".domain.tld" />
https://issues.apache.org/bugzilla/show_bug.cgi?id=48379

I have just gone through all of this looking for a simple solution. I started looking at it from the tomcat perspective first.
Tomcat does not give direct access to configuring the domain cookie for the session, and I definitely did not want to custom patch tomcat to fix that problem as shown in some other posts.
Valves in tomcat also seems to be a problem solution due to the limitations on accessing headers & cookies built into the Servlet specification. They also fail completely if the http response is commited before it gets passed to your valve.
Since we proxy our requests through Apache, I then moved onto how to use apache to fix the problem instead.
I first tried the mod_proxy directive ProxyPassReverseCookieDomain, but it does not work for JSESSIONID cookies because tomcat does not set the domain attribute and ProxyPassReverseCookieDomain cannot work without some sort of domain being part of the cookie.
I also came across a hack using ProxyPassReverseCookiePath where they were rewriting the path to add a domain attribute to the cookie, but that felt way to messy for a production site.
I finally got it to work by rewriting the response headers using the mod_headers module in apache as mentioned by Dave above.
I have added the following line inside the virtual host definition:
Header edit Set-Cookie "(JSESSIONID\s?=[^;,]+?)((?:;\s?(?:(?i)Comment|Max-Age|Path|Version|Secure)[^;,]*?)*)(;\s?(?:(?i)Domain\s?=)[^;,]+?)?((?:;\s?(?:(?i)Comment|Max-Age|Path|Version|Secure)[^;,]*?)*)(,|$)" "$1$2; Domain=.example.com$4$5"
The above should all be a single line in the config. It will replace any JSESSIONID cookies domain attribute with ".example.com". If a JSESSIONID cookie does not contain a domain attribute, then the pattern will add one with a value of ".example.com". As a bonus, this solution does not suffer from the double JSESSION cookies problem of the valves.
The pattern should work with multiple cookies in the Set-Cookie header without affecting the other cookies in the header. It should also be modifiable to work with other cookies by changing JSESSIONID in the first part of the pattern to what ever cookie name you desire.
I am not reg-ex power user, so I am sure there are a couple of optimisations that could be made to the pattern, but it seems to be working for us so far.
I will update this post if I find any bugs with the pattern. Hopefully this will stop a few of you from having to go through the last couple of days worth of frustrations as I did.

As a session (and its Id) is basically considered of value only for the issueing application, you may rather look for setting an additional cookie. Have a look at Tomcats SingleSignOnValve, providing the extra-Cookie JSESSIONIDSSO (note the ...SSO) for the server path "/" instead of "/applicationName" (as JSESSIONID cookies are usually set).
With such a Valve you may implement any interprocess communication you need in order to synchronize any state between different servers, virtual hosts or webapps on any number of tomcats/webservers/whatever.
Another reason why you cannot use tomcats session cookie for your own purposes is, that multiple webapps on the same host have different session ids. E.g. there are different cookies for "/webapp1" and "/webapp2". If you provide "/webapp1"'s cookie to "/webapp2", this wouldn't find the session you referenced, invalidate your session+cookie and set its own new one. You'd have to rewrite all of tomcats session handling to accept external session id values (bad idea securitywise) or to share a certain state among applications.
Session handling should be considered the containers (tomcats) business. Whatever else you need you should add without interfering with what the container believes is necessary to do.

I've run into this at $DAYJOB. In my case I wanted to implement SSL signon then redirect to a non SSL page. The core problem in tomcat is the method (from memory) SessionManager.configureSessionCookie which hard codes all the variables you would like to get access to.
I came up with a few ideas, including a particularly egregious hack using mod_headers in apache to rewrite the cookie based on regex substitution.
The definative way to solve this would be to submit a patch to the tomcat developers that adds configurable parameters to the SessionManager class.

The valve techniques do not seem to be 100% perfect. If you dare to modify Tomcat itself:
catalina.jar contains the following class: org.apache.catalina.connector.Request
The Request has a method:
configureSessionCookie(Cookie cookie)
For our environment it was best to just hardcode it, but you could do more fancy logic:
cookie.setDomain(".xyz.com");
Seems to work perfectly. Would be nice if this was configurable in tomcat.