> Date: Wed, 23 Jun 93 9:22:27 EDT
> From: "Charles W. Gardiner" <gardiner(_at_)BBN(_dot_)COM>
>
> I thought there was supposed to be a sequence of zero length.
>
> The ASN.1 says that it is optional. That probably means that it doesn't
> need to be present. However I agree with you, if present it should probably
> be a null sequence (the code I have will accept a null sequence).
>
> -Jeff
Jeff,
After looking into it further, I too believe that it is incorrect
to represent a null constructed quantity (sequence or set) with
a primitive null. However, I also think that null quantities within
well-defined structures (i.e. the signed portion of a crl) should
be designated null and not just omitted. In the case of crls
the revoked certificate list is the last object within the tobesigned
object. This may not be true in general, so omission has the potential
to introduce ambiguity (e.g. two adjacent sequences, either of which
may be null).
Paul
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