Cookie Domain

[Adam]

Not really a perl question so much as it is a CGI question:

Is there a way to give a cookie two domains? In other words, two sites working coopertively to read and write a cookie, but no other sites should read it? Thanks.

[Ovid]

In theory, this is not possible. You can read about RFC2109 to get the technical specifications on what cookies can and cannot do.

The best you can do is set the cookie domain name as something like Domain=.mysite.com. This will allow www.mysite.com or abc.mysite.com to retrieve the cookie. Note that in both cases the domain name must be the same (which I assume that you do not want).

You can also use an IP address for a domain name. If different domains share the same IP address, you should be able to use the IP address as the domain on the cookie.

But then what happens if you need to move a site to a different IP address or change your IP address? Probably not a good solution.

[chromatic]

Only if the two sites share the same domain. (Or if you're using Internet Explorer, though that doesn't fulfill the second part of your question. It's a security hole.)

You can set domain=.myserver.com and it should be accessible to foo.myserver.com and bar.myserver.com, at least according to Cookie Central.

[httptech]

Well, I can think of one kludgy way it could be done theoretically... Say on mysite.com you have a page with an image loaded from myothersite.com. Only the image coming from myothersite.com is actually a CGI script that reads the cookie for myothersite.com, and with some clever backend communication, sends the cookie data to mysite.com. Of course, this wouldn't work if the person enabled the "Accept only cookies that get sent back to the originating server" option in Netscape. So considering it may not be very reliable to do it this way, I would just find a non-cookie solution for whatever you are doing.

[JanneVee]

How about using a session id in the get string. The two server needs just share the session id afterwards.

[BigJoe]

Well if your users are using IE 5 you can read any cookie from any site. If that helps. But other than that I don't think that can happen.

--BigJoe

[Anonymous Monk]

No, they'd need to share a domain. You might be able to work some magic with your banner server which you'd place in the shared domain and have it duplicate the contents of one domain's cookie into the the other domain's cookie, but you'd have to make sure that the page that *referenced* the banner server didn't need an up to date cookie.

[Adam]

Thanks guys. Your answers confirmed my fears.

And yes I meant two different domains, like MySite.com and MyOtherSite.com, oh well. Thanks again.

[Anonymous Monk]

you could try doing this, though its kinda clunky. use two cookies. identical except for the domain name. either domain will be able to read one of the cookies. and whenever you write the cookie, write both cookies, updating both of them. i think it'll work.

[Anonymous Monk]

nope