[Cryptography Team] ASN1WrapperConstructedType and ASN1ExplicitContextValue use

[rabbit]

Hi Ron,

I see that originally when you had introduce ASN1 to our library, you 
defined the classes ASN1WrapperConstructedType and 
ASN1ExplicitContextValue. I tried to implement decode and encode to 
ASN1WrapperConstructedType, but only partially. I used your 
ASN1ExplicitContextValue but have not completed it. Now I have the need 
to implement, as I attempt to switch the PromisesRemote to using ASN1 
encoding, rather than STON.

In looking at Object>>#asn1Tag we construct a tag with

    Object>>#asn1Tag

         ^ (ASN1MappedSequenceType new asn1Tag "48"
                 bitOr: 2r11000000) "Application"
                 bitOr: 2r00100000 "Constructed"

So we are an application class and constructed. In 
ASN1OutputStream>>#typeForTag: tag, the tag is broken down into the 
numericTag, the tagClass (application) and whether it is constructed. 
This is called from decode: anObject with the call:

    ^ self encode: anObject with Type: (self typeForTag: anObject asn1Tag)

So Object>>#asn1Tag is called. So with a ASN1 non-registered object, we 
end up with a ASN1WrapperConstructedType.

I am totally unsure about how the ASN1ExplicitContextValue should be 
used with the ASN1WrapperConstructedType, nor how it builds the context 
from the ivars of the provided anonymous object.

My related concern is whether all of the crypto objects with ASN1 
definitions ought to be of the application tagClass.

Any guidance you could provide me for this would be very welcome! If it 
is not too far back in history! Heh!

Thanks!

-- 
Have a good one; keep it, light.
Kindly,
rabbit
. .. … ‘…^,^

Sent from Callisto House :: decentralized mobile homeless solutions
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