Subject: [Sidrops] Alignment of ASAP to RFC 3779

From: Russ Housley <[email-masked]>
Date: Tue, 9 Nov 2021 15:08:59 -0500

I was looking at RFC 3779 for something else, and I realized two small differences in the ASN.1.  I doubt that these differences would break anything, but I'd like them to be the same unless there is a reason.

DIFFERENCE 1: AS Identifier

RFC 3779 uses:

	ASId ::= INTEGER

ASPA uses:

	ASID ::= INTEGER

DIFFERENCE 2: Address Family Identifier

RFC 3779 uses:

	OCTET STRING (SIZE (2..3))

ASPA uses:

	OCTET STRING (SIZE (2))

Is there any reason for these to be different?

Russ

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From: Ben Maddison <[email-masked]>
Date: Tue, 9 Nov 2021 22:23:22 +0200

Hi Russ,

> DIFFERENCE 1: AS Identifier
Not that I can see. ASPA should probably use ASId for consistency
(although, since the "ID" is an acronym, the capitals are probably more
appropriate).
> 	OCTET STRING (SIZE (2..3))
Yes, the SAFI byte is not used in ASPA.

The same is true in a ROA, but RFC 6482 uses SIZE(2..3) despite
explicitly mandating only two 2-octet values in the text:

   Within the ROAIPAddressFamily structure, addressFamily contains the
   Address Family Identifier (AFI) of an IP address family.  This
   specification only supports IPv4 and IPv6.  Therefore, addressFamily
   MUST be either 0001 or 0002.

... which I find weird, and slightly contradictory.

It would be nice to have an enumeration defined somewhere, that can
simply be IMPORTed, but I don't think that you can enumerate OCTET
STRINGs like you can for INTEGERs, can you?

Cheers,

Ben