Subject: [AAA-WG]: Issue 357: Inappropriate UTF-8 encoding

From: Bernard Aboba <[email-masked]>
Date: Tue, 10 Sep 2002 05:40:39 -0700 (PDT)

Issue 357: Inappropriate UTF-8 encoding
Submitter: Bernard Aboba
Submitter email address: [email-masked]
Date first submitted: September 9, 2002
Reference:
Document: BASE-12
Comment type: T
Priority: S
Section: 4.3
Rationale/Explanation of issue:
The DiameterIdentity type is defined to use the UTF-8 charset
and is indicated to carry a Fully Qualified Domain Name (FQDN).

Unfortunately, FQDNs are to be encoded as specified by the
Internationalized Domain Name (IDN) specification, not UTF-8.
For example, see:

http://www.ietf.org/internet-drafts/draft-ietf-idn-idna-11.txt

To fix this, the DiameterIdentity type should be defined to
use the ASCII character set, not UTF-8, and references
to UTF-8 in FQDNs should instead refer to the DiameterIdentity
type.

AVPs that use UTF8String instead of DiameterIdentity include:

Origin-Realm AVP (6.4)
Destination-Realm AVP (6.6)

Note that there are other questionable uses of UTF-8 within
the specification. For example, why does IPFilterRule or
QoSFilterRule use UTF-8 instead of ASCII?