Date: Thu, 02 Oct 2003 12:42:26 -0700 
From: Harald Tveit Alvestrand <harald@alvestrand.no> 
To: iab@ietf.org 
Cc: iesg@ietf.org 
Subject: Architectural question: Checking data for validity before usage in protocol

IAB,

1. The IESG has determined that it wants to ask the following question of the Internet Architecture Board, following the procedures agreed upon and documented at http://www.ietf.org/IESG/architectural-iab.html:

Document draft-klensin-name-filters-03.txt
has been sent to the RFC editor for publication and referred to the IESG for review as an Informational RFC. The draft raises an issue related to protocol processing which seems fairly important, which can be summarized as:

“What issues should be considered when deciding when and how to apply validity checks for protocol processing not conducted by the application applying the validity check?”

To steal a concrete example, what might be the issues in an application pre-checking the syntactical validity of a DNS name prior to passing it to the DNS?

2. Type of response expected

The IESG expects two things in response:

• a review of the Klensin draft and
• a short document describing the issues.

Note that this is not asking IAB to re-write the Klensin draft, which explicitly does not take on this task:

“this document takes no position on whether or not the testing is desirable. It only identifies the correct tests to be made if tests are to be applied.”

3. Response expected by: November 7, 2003.

4. Specific IAB people the IESG considers to have the best background are: Leslie Daigle, Rob Austein, Patrik Falstrom