- From: Henry S. Thompson <ht@inf.ed.ac.uk>
- Date: Fri, 18 Dec 2009 19:19:43 +0000
- To: ietf-http-wg@w3.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 During its telcon of 2009-12-17 [1], the TAG agreed to request that the following paragraphs be added at the end of section 3.2.1 of Part 3 of HTTP bis [2]: If the Content-Type header field _is_ present, a receipient which interprets the underlying data in a way inconsistent with the specified media type risks drawing incorrect conclusions. In practice, however, currently-deployed servers sometime provide a Content-Type header which does not correctly identify the content sent, with the result that some classes of recipients have adopted a policy of examining the content and overriding the specified type. Such 'sniffing' SHOULD NOT be done unless there is evidence that the specified media type is in error (for example, because it is 'text/plain' but there are bytes in the data which are not legal for the specified or defaulted charset). In any case recipients SHOULD NOT override the specified type if the change would significantly increase the security exposure ('privilege escalation'). Deploying any heuristic for detecting mistaken Content-Types risks overriding user intentions and misrepresenting data---accordingly recipients SHOULD provide for users to disable sniffing in general and/or in particular cases. Thank you, ht, by and on behalf of the TAG [1] http://tools.ietf.org/html/draft-ietf-httpbis-p3-payload-08#section-3.2.1 [2] http://www.w3.org/2001/tag/2009/12/17-minutes.html#item05 - -- Henry S. Thompson, School of Informatics, University of Edinburgh Half-time member of W3C Team 10 Crichton Street, Edinburgh EH8 9AB, SCOTLAND -- (44) 131 650-4440 Fax: (44) 131 651-1426, e-mail: ht@inf.ed.ac.uk URL: http://www.ltg.ed.ac.uk/~ht/ [mail really from me _always_ has this .sig -- mail without it is forged spam] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (GNU/Linux) iD8DBQFLK9XPkjnJixAXWBoRAudxAJ9YZg70dC0piSh+34ftR5+X4n/y9wCdEHnw rWL3bWKkuX4nqIHyKmBQ4wI= =sZXk -----END PGP SIGNATURE-----
Received on Friday, 18 December 2009 19:20:12 UTC