Subject: RE: PKIX: String representation of GeneralName

From: "Manger, James" <[email-masked]>
Date: Thu, 4 Nov 1999 12:00:20 +1100

Amit,

There is already a standardized string representation of GeneralName values.
It is ASN.1 value notation.  As stated in the X.680 summary, ASN.1 provides
"a notation .. for specifying values of these [ASN.1] types".  Almost all
specifications defining ASN.1 types also use value notation to define some
values, e.g. object identifier values, version values, default values,
algorithm identifier values etc.

Below are the examples from your draft in value notation:

	rfc822Name:"[email-masked]"

	dNSName:"gandalf.trustpoint.com"

	uniformResourceIdentifier:"http://www.trustpoint.com/"

	iPAddress:'C0A8000A'H

	registeredId:{ 1 2 3 4 5 6 }

Value notation looks very similar to the notation in draft-generalname.txt
for most general name choices.  The major exception is directory name.  A
directory name has such a rich syntax (an ordered collection of levels, each
with 1 or more values, each value with an arbitrary type) that it is always
going to be awkward to devise a human-friendly notation for all possible
values.  So it is probably reasonable to use RFC 1779 [DN] for this choice:

	directoryName:CN=Amit Kapoor, O=Trustpoint, L=Mountain View,
ST=California, C=US

Your labels (e.g. "mail", "ip") may seem easier than the value notation
labels (e.g. "rfc822Name", "iPAddress") but the later match precisely &
obviously to fields in the type definition.  You get value notation for free
whenever a new ASN.1 type is defined.  Value notation offers a notation for
all the GeneralName choices (e.g. otherName), not just the 6 your draft
lists.  Value notation offers a notation for all possible values (e.g.
values with unusual or unprintable characters).  It is likely that anyone
wanting a text representation for GeneralName values today will want a text
representation for values of another ASN.1 type tomorrow so value notation,
which works for all ASN.1 types, is preferable.

> ----------
> From: 	Amit Kapoor[SMTP:[email-masked]]
> Sent: 	Tuesday, 2 November 1999 9:34
> To: 	PKIX
> Subject: 	String representation of GeneralName
> 
> a draft to document a string representation of GeneralName
> 
> 	http://www.trustpoint.com/draft-generalname.txt
>

---

From: Paul Koning <[email-masked]>
Date: Fri, 5 Nov 1999 16:05:34 -0500

>>>>> "Manger" == Manger, James <[email-masked]> writes:

 Manger> Amit, There is already a standardized string representation
 Manger> of GeneralName values.  It is ASN.1 value notation.  As
 Manger> stated in the X.680 summary, ASN.1 provides "a notation
 Manger> .. for specifying values of these [ASN.1] types".  Almost
 Manger> all specifications defining ASN.1 types also use value
 Manger> notation to define some values, e.g. object identifier
 Manger> values, version values, default values, algorithm identifier
 Manger> values etc.

 Manger> Below are the examples from your draft in value notation:
 Manger> ...
 Manger> iPAddress:'C0A8000A'H

I think Amit is right to submit a spec of his own if this is the
alternative.  Any document that attempts to propose a "standard"
notation for IPv4 addresses as 8-digit hex strings is clearly broken.

An alternative would be to have that document repaired so it shows the
correct representation for IP addresses.  If that is done, the need
for Amit's draft may disappear.

	paul