On Wed, Sep 28, 2011 at 5:32 AM, Gervase Markham <[email protected]> wrote:
> On 27/09/11 18:10, Phillip Hallam-Baker wrote:
>> On the digest front the objective would be to make it possible to use
>> the URI format with any digest at all in theory but strongly encourage
>> people to only use the digests IETF is confident in. Use of OIDs as
>> the identifier has the nice property that anyone can get an identifier
>> to distinguish their algorithm from other people's but getting an OID
>> does not produce any paper trail that can be used to imply an IETF
>> endorsement.
>
> But it also makes the identifiers less human readable and much longer
> than they could otherwise be.

It is a message digest, how readable would you like it to be?

We can easily put some of the packing in ascii:

DIGEST:SHA-256:text/plain:eiwoeiwoiejfoiwejfiojefiojweoifj==

You are still going to end up with an unreadable blob at some point.


> Why does it take so many bytes to determine between a very small number
> of options?

Because of the vanity crypto problem.


> Worrying about clashes in the text-based identifiers people use seems
> somewhat unnecessary. How many hash algorithms with the same name (or
> without an obvious canonical name) are there? If this was really a
> problem, we could have a microformats-like wiki registry:
> http://microformats.org/wiki/existing-rel-values

We have an IANA registry already.


>> For all applications that make sense it is
>> going to be perfectly OK to simply generate the prefix for the
>> identifier part as a static array of octets and append / verify it as
>> such whenever it is needed. I do not see any need to write ASN.1
>> handling code for these apps :-)
>
> Then why use ASN.1 at all?

Because the crypto APIs use ASN.1 as the identifier that they key off.
So if you introduce a text based identifier they have to track two
different registries.


> Counter-proposal: how about:
>
> digest:SHA1,<base64 string of digest>

It still needs to at least have an option for specifying the content
type, this could be made optional though.




-- 
Website: http://hallambaker.com/
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