- From: C. M. Sperberg-McQueen <cmsmcq@blackmesatech.com>
- Date: Sat, 11 Sep 2010 09:06:18 -0600
- To: www-forms@w3.org
- Cc: "C. M. Sperberg-McQueen" <cmsmcq@blackmesatech.com>
When a submission resource is protected by HTTP Basic Authentication, some existing XForms implementations (or, quite possibly, the browsers they are running in) prompt the user for a userid and password and use them to supply an appropriate HTTP Authorization header. For other implementations, this does not happen and a form author may need or wish to supply the header field using the xf:header element. The value needed takes the form of the string 'Basic ', concatenated with the base64 encoding of the concatenation of the username, a colon, and the user's password. Unless I'm missing something, however, neither the XPath Functions and Operators nor XForms provide a function that can perform the required base64 encoding. All XForms processors already possess the required functionality if they implement the digest() function, since the result of the MD5 or SHA-n hashing must be base64 encoded, but there is no way (that I've seen) to obtain base64 encoding on a simple Unicode or ASCII string. It's easy enough to implement a base64 encoding routine in any environment supporting user extensions, but it seems to this user that it would be convenient to be able to do this without relying on a non-standard extension function. Would it be a good idea to provide a suitable new keyword for the second argument of digest()? I assume the process to be described by that new keyword is almost, but not quite, an identity function, since the characters in the XForms document will be ISO 10646 / Unicode UCS characters, and I assume that the HTTP specs all work in ASCII (or rather, in octets, but in any case not in UCS code points), and the process defined by the new keyword will need to do whatever the HTTP specs (and existing users and browsers and servers) expect when non-ASCII characters appear in a username or password. If there is another way to address this problem, I'll be happy to learn about it. -- **************************************************************** * C. M. Sperberg-McQueen, Black Mesa Technologies LLC * http://www.blackmesatech.com * http://cmsmcq.com/mib * http://balisage.net ****************************************************************
Received on Saturday, 11 September 2010 15:03:46 UTC