Re: [kitten] The Hashed-Token SASL Mechanism (SASL-HT)

Alexey Melnikov <alexey.melnikov@isode.com> Tue, 17 October 2017 16:57 UTC

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To: Sam Whited <sam@samwhited.com>, kitten@ietf.org
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From: Alexey Melnikov <alexey.melnikov@isode.com>
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Date: Tue, 17 Oct 2017 17:57:00 +0100
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Subject: Re: [kitten] The Hashed-Token SASL Mechanism (SASL-HT)
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Hi Sam,

On 17/10/2017 15:08, Sam Whited wrote:

> On Fri, Sep 29, 2017, at 04:08, Florian Schmaus wrote:
>> I would like to note the existence of draft-schmaus-kitten-sasl-ht-01:
>>
>> https://tools.ietf.org/html/draft-schmaus-kitten-sasl-ht-01
> After a quick read through of the latest draft, the only thing I found
> which I wasn't sure about was the following:
>
>> Before sending the authentication identity string the initiator SHOULD
>> prepare the data with the UsernameCaseMapped profile of [RFC7613].
> This limits the SASL mechanisms usefulness to Unicode encodings.
I think use of Unicode, in particular UTF-8 is the right thing. Other 
character sets can be mapped to UTF-8.

Normalization to disallow problematic characters is a good thing, so I 
think a SHOULD level requirement is appropriate. But I am not sure that 
case-mapped version of UserName profile is the right thing here.
>   I'd
> suggest that normalizing the username is something the application
> protocol should do, it should not be required by the authentication
> framework (as far as SASL is concerned these should just be bytes).
>
> —Sam
>
> P.S. Also note that 7613 was recently replaced by RFC 8265, if this
> reference is kept it may be good to update it.
+1.