Subject: The definition of OTHER-NAME

From: "Tom Biskupic" <[email-masked]>
Date: Tue, 7 Dec 1999 12:02:36 -0000

Hello,

I'm sure this must have been discussed previously, but not having found an
answer in the first 12Mb archive of this mailing list I thought I'd float it
anyhow.

There seems to be a discrepancy in the definition of Othername in RFC2459
and X509V3

The definition of OtherName in RFC2459 is as follows :-

     OtherName ::= SEQUENCE {
           type-id    OBJECT IDENTIFIER,
           value      [0] EXPLICIT ANY DEFINED BY type-id }

where as X509.V3 defines it as

OTHER-NAME ::= TYPE-IDENTIFIER

Which does not have the [0] tag on the value (see X.681 Annex A)

The draft-ietf-pkix-new-part1-00.txt even says
	-- AnotherName replaces OTHER-NAME ::= TYPE-IDENTIFIER, as
	-- TYPE-IDENTIFIER is not supported in the '88 ASN.1 syntax

But then goes on to define AnotherName to include the [0] tag.

Why is the [0] tag there? I don't see any ambiguity in the encoding that
would require a context specific tag.

Thanks,

Tom Biskupic,
Software Engineer
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From: Magnus Nystrom <[email-masked]>
Date: Tue, 7 Dec 1999 13:12:55 +0100 (W. Europe Standard Time)

Hi Tom,

Note that the 'otherName' choice in the definition of 'GeneralName' in
X.509:1997 is:

otherName INSTANCE OF OTHER-NAME,

and 'INSTANCE OF' is defined in Annex C of X.681 as precisely the
'OtherName' type defined in RFC 2459.

Hope this helps,
-- Magnus
Magnus Nystrom		Email: [email-masked]
RSA Laboratories