Re: [http-state] Ticket 6: host-only cookies

CFNetwork used to treat domain attributes starting without a dot literally, but I think we've gone back to prepending the dot due to compatibility issues.

On Feb 2, 2010, at 11:35 AM, Adam Barth wrote:

> On Tue, Feb 2, 2010 at 11:14 AM, Dave Kristol
> <dmk-http-state@kristol.org> wrote:
>> Adam Barth wrote:
>>> Do you mean that
>>> 
>>> Set-Cookie: foo=bar; Domain=example.com
>>> 
>>> and
>>> 
>>> Set-Cookie: foo=bar; Domain=.example.com
>>> 
>>> are treated differently by user agents?  That might be true according
>>> to 2109 (I'd have to check), but I don't think that's how user agents
>>> work in practice.  They appear to ignore the leading dot.  If you have
>>> a test case that show a difference, I'd be very interested in seeing
>>> it.
>> 
>> That is what I meant, and I do not have a test case.  That is what 2109
>> said, and I believe (though it's been many years now... ugh!) I adopted that
>> from Netscape's spec.  Generally speaking, the idea was that, in the absence
>> of Domain=, the cookie should be returned only to the server that sent it.
> 
> I believe this is the line of code in Firefox that causes the leading
> dot in the domain attribute to be ignored.
> 
> http://mxr.mozilla.org/mozilla-central/source/netwerk/cookie/src/nsCookieService.cpp#2159
> 
> There's a similar line of code in Chrome in the GetCookieDomainKey
> function in this file:
> 
> http://src.chromium.org/viewvc/chrome/trunk/src/net/base/cookie_monster.cc?view=markup
> 
> Here's the comment:
> 
>  // Get the normalized domain specified in cookie line.
>  // Note: The RFC says we can reject a cookie if the domain
>  // attribute does not start with a dot. IE/FF/Safari however, allow a cookie
>  // of the form domain=my.domain.com, treating it the same as
>  // domain=.my.domain.com -- for compatibility we do the same here.  Firefox
>  // also treats domain=.....my.domain.com like domain=.my.domain.com, but
>  // neither IE nor Safari do this, and we don't either.
> 
> Note that Firefox now acts like IE/Chrome/Safari in regards to
> Domain=.....my.domain.com
> 
> Adam
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