Re: [http-state] non-ASCII cookie values (was Re: Closing Ticket 3: Public Suffixes)

[Maciej Stachowiak <[e-mail]>]

On Feb 1, 2010, at 10:14 AM, Adam Barth wrote:

> On Sun, Jan 31, 2010 at 2:37 PM, eric bianchetti
> <[e-mail]> wrote:
>> That part does not please :
>> 
>> The cookie-value is opaque to the user agent and MAY be anything the
>>    origin server chooses to send, possibly in a server-selected
>>    printable ASCII encoding.
>> 
>> Livng and working in a non ASCII country, I tend to think we shall prepare for the coming of the other languages (Thai, Chines, Korean ....), IF a person get a cookie from a Thai server , can we securely suppose that person(computer) went to a thai site, and that person is using Thai on a daily basis? (Replace Thai by any multi bytes languages).
> 
> The part of that sentence after the "possibly" doesn't haven any
> normative force (it's just advice that the server can take or leave).
> I can remove the reference to ASCII here if you like.  Julian please
> correct me if I'm wrong, but I believe that HTTP headers typically
> contain only ASCII characters.

We do have to define what happens if there are non-ASCII characters in a header value. Presumably, if such bytes are set via Set-Cookie, then the Cookie header just echoes them back, so we can treat them as opaque. (That's assuming there is no requirement to reject non-ASCII cookie values.) But there are two ways in which it matters:

1) A header with non-ASCII bytes get set via Set-Cookie, then read through a JS API such as document.cookie. document.cookie gives a UTF-16 encoded string, so at this point the server has to decide how to interpret non-ASCII bytes in the cookie value.

2) If you set a cookie via document.cookie and include non-ASCII characters in the value, what bytes get sent?

Regards,
Maciej