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Re: WG Charter

1997-01-23 15:13:23

At 11:48 PM 1/21/97 +0100, Dave Crocker wrote: 
At 8:24 PM +0100 1/20/97, Housley, Russ wrote:
The use of "SEQUENCE OF" is necessary when order is important, but it can 
also be used when order is not important.  And, it has much less overhead 

Just to see whether my interpretation of your statement is accurate: 

Your view is that it is ok to impose a required order in all cases?

No.  Just because the use of "SEQUENCE OF" will preserve the order chosen 
by the sender does not mean that there is any semantic meaning to the 

I object to the use of "SET OF" with the Distinguished Encoding Rules (DER) 
because it imposes an order.  The "SET OF" encoding must place the 
membership in sorted order.

When one of these constructs is digitally signed, the validator must 
compute the hash (a.k.a. digest) over the same sequence of bits.  In either 
case, the cheapest processing to achieve this is to use the order presented 
by the originator.  In the "SEQUENCE OF" case, there is no laternative.  In 
the "SET OF" case, the recipient could re-sort the members, but there is no 
need to do this if the order used bu the originator is preserved by the 
ASN.1 software .


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