Peter Saint-Andre wrote:
OK, we have had a long long discussion thread about JID Escaping and nodeprep and allowable characters in JIDs etc. Here I summarize the discussion and draw some conclusions for those of you who have checked out. :)1. Support for XEP-0106: JID Escaping (i.e., mapping of ' to \27 etc.) is needed only in certain specialized deployment situations -- mainly when an organization wants to reuse existing userids (e.g., email addresses) or gateway to other messaging systems. 2. We needed to define JID escaping because version 1 of nodeprep (see RFC 3920) prohibits including the characters SP " & ' / : < > @ in XMPP node identifiers. (See also XEP-0029.) 3. IIRC we prohibited some of those characters because very early Jabber clients didn't properly escape things like " & ' < > in XMPP 'to' and 'from' addresses. 4. One solution would be to define version 2 of nodeprep in rfc3920bis. As far as I can see, nodeprep2 would allow " & ' < > since those can be escaped in XML (e.g., XMPP 'to' address) as the predefined entities " & ' < >. I'm not sure why : was prohibited in the first place so that would be allowed. I suppose / was prohibited because it's used later in a full JID to differentiate the resource identifier, but in a node identifier I don't think it would be confusing so thatwould be allowed.
user/[EMAIL PROTECTED] and domain/[EMAIL PROTECTED] cant be differentiated if / is allowed.
Btw, changing nodeprep now will cause quite a lot of problem with existing deployments - since the contact jid's are part of the user data - and would pretty much mean we cant adopt bis spec.
The number of deployments with these usecases are not as specialized as it might seem.
- Mridul
Clearly we can't allow @ because we use that character
as a separator between the node identifier and the domain identifier. So
nodeprep2 would be the same as nodepre1 except that it would disallow
only the at-sign ("@"). (Naturally we can discuss this further...) As to
how it is discovered that a server supports nodeprep2, I will post a
separate message about that.
Peter
