James Seng wrote: >Therefore, a UTF-8 string which was somehow squeeze into the DNS packet has >no meaning right now. > >IDNA do not ignore the possibility of using UTF-8 in DNS Packet. But the use >is yet to be defined. Until it is defined, it is useless to discuss that >possibility. > > > Your argument stands only in DNS on-the-wire context. IN all other protocol/display contexts, utf8 labels are legitimate domain labels. That is why zone admins may input their labels in utf8 into their zone files and end users recoginze them as domain names.
Moreover, I didn't limit my question into DNS and its protocols (just 'protocol', DNS is not the 'all') Rather, that may span into all application protocols that use domain names, like future ESMTP. There will be many application protocols (IETF's or home-made) that may exchange utf8-form labels as protocols elements (not for human eyes) according to IDNA section 6.1-3. IDNA draft granted such use of utf8 labels as legitimate one. Length restriction should be clarified before IDN deployments. Currently valid IDN label should not be invalidated in the future due to today's misspecifications. To avoid buffer overflow errors and security breaches, label length issues are practically important to implementors who want to estimate enough buffer spaces for IDN labels. Soobok Lee
