Subject: A minor issue with hash function name IANA registry defined by RFC 4572

From: Alexey Melnikov <[email-masked]>
Date: Sun, 09 Nov 2008 18:43:34 +0000

RFC 4572 established an IANA registry for hash function names:
<http://www.iana.org/assignments/hash-function-text-names/hash-function-text-names.xhtml>. 
All function names defined so far are in lowercase. SASL mechanism names 
only allow for uppercase letters.
I think the registry need to be updated to restrict which US-ASCII 
characters are allowed in textual representations of a hash function 
name. It might also be a good idea to say that hash function names are 
case insensitive.

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From: Alexey Melnikov <[email-masked]>
Date: Sun, 09 Nov 2008 19:05:00 +0000

Alexey Melnikov wrote:

> All function names defined so far are in lowercase. SASL mechanism 
> names only allow for uppercase letters.

Actually, RFC 4572 has ABNF for the hash function name, but it is not 
mentioned in the IANA registration. The document is referencing <token> 
from RFC 4566, which is defined:

   token-char =          %x21 / %x23-27 / %x2A-2B / %x2D-2E / %x30-39
                         / %x41-5A / %x5E-7E

   token =               1*(token-char)

This is still too permissive for SASL mechanism names, which only allow 
uppercase letters, digits, "-" and "_".