XSF Discussion - 2022-09-27

Example 26 in https://xmpp.org/extensions/xep-0178.html#example-26 shows an empty response being represented by a '=' character, "as shown in RFC 6120. I'm seeing the same example in RFC 6120 9.2.2 (https://www.rfc-editor.org/rfc/rfc6120#section-9.2.2), but where is that defined? Isn't the base64 encoding of an empty string an empty string?

Guus, I think it is, but the designers of the rfc probably wanted to be able to distinguish between an initial repsonse of the empty string and no intial response ✏

Guus, I think it is, but the designers of the rfc probably wanted to be able to distinguish between an initial repsonse being the empty string and no intial response ✏

Guus, see rfc6120 § 6.4.2

ah, ace.

thanks

So <auth></auth> and <auth/> means no value and <auth>=</auth> means empty string. ✏

Interestingly SASL2 does it differently (empty element vs absent element)

which seems to be a saner design ✏

Zash, I'd think that <auth/></auth> is forbidden by 6.4.2?

How?

I would hope that we consider <element></element> and <element/> equal everywhere

not using '=' ,I mean

6.4.2 seems to state that 'zero-length' response MUST be represented with an '=' ?

zero-length response on the sasl layer

not on the XMPP layer

as in base64("") → "="

but base64(null) → "", sorta

aka <auth/>

correct

I get how this is confusing, but I believe <auth></auth> (and <auth/>) means "no initial data on the sasl layer", and <auth>=</auth> means "initial data on the sasl layer that is the empty string" ✏

ok, thanks

I get how this is confusing, but I believe <auth></auth> (and <auth/>) means "no initial data on the sasl layer", and <auth>=</auth> means "initial data on the sasl layer with a length of 0" ✏