eap Mailing List: Null character in EAP Identity

[Artur Hecker (hecker]

hello


i'm not sure this issue has already been resolved and it is perhaps just 
my own misunderstanding. however, your kind clarification on this matter 
would be greatly appreciated.

in the latest draft version (draft-ietf-eap-rfc2284bis-09.txt) in 
"Appendix A. Changes from RFC 2284" section it is explicitly stated that:

   o  The null character is forbidden in the Type-Data field of an
      Identity Response message, as it is in RFC 2284.  <...>


Now, reading the original RFC2284 in section 3.1 Identity/Type-Data it 
merely states that:

      <...> The field
      MUST NOT be null terminated.  The length of this field is derived
      from the Length field of the Request/Response packet and hence a
      null is not required.

So, I understand it as following: if a typical NAS implementation 
follows this section of the original RFC2284, it should be capable of 
dealing with arbitrary Identity payloads i.e. also with ones consisting 
of several Null bytes, since it would be blindly copying the whole 
<Length field value> characters.

The Identity string just MUST NOT be null _terminated_. I don't see 
where the original RFC generally prohibits the Null byte in the Identity 
payload, e.g. in the middle of it. Actually for me the explicit 
obligation to use the Length field means that Identity can carry 
arbitrary characters.

Would you kindly provide clarification on this matter?


Regards,
artur