Can anyone share any insight into a STORE_DATA for DGI 8000 for a VIS applet please?

[marknimbuspay]

I am struggling to get a DGI 8000 for DES (as it happens) keys happily stored onto a VIS applet.

DGI 8000 is a Fixed format, so I think has no need for a length byte.

I am forgoing the encryption of the key payload for now, but can only get a store data with a length to give me a '9000'.

Can anyone here guide me on this at all and perhaps also specifically...

• DGI 8000 - a length byte or no?
• As I understand it, this DGI does not need padding, but would like to try and confirm.
• does anyone have a test STORE_DATA example apdu they could share - payload obscured of course.

Any guidance would be appreciated.

[marknimbuspay]

Sometimes posting a question in a public forum acts as a small 'rubber duck debugging' session.

After thinking on this post overnight, of course the length is needed - as my result was telling me! It is the TLV structure that the 'Fixed form' doesn't have, since the alternative would be to TLV' where V' = ENC(K)[V] which in turn could lead to other issues.

Sorry for be a self answerer again, I went round in loops with my bad presumption on length byte presense; but if 'rubber duck debugging' is new to you then at least this exchange wasn't a complete waste of time - just mostly.

[no-usernames-left]

There's no shame in it!