Can unfused cards advance into OP_READY and later lifecycle states?

[rlaneth]

Hey everyone!

I've been looking at Java Cards for use with open source applets such as FIDO2Applet, and I'm wondering how secure this type of usage really is.

First of all, it's unclear to me whether unfused cards can be set to OP_READY and later states. The lifecycle state and fuse state are two different properties, but as far as I can tell, no operations can be performed by GlobalPlatformPro on an unfused card, and once the card has been fused, there's no way to go back to the pre-initialization state—is that assumption correct?

My specific concern is about whether a rogue card vendor would theoretically be able to sell cards in OP_READY and provide the regular keys (ENC, MAC and DEK) while still keeping a Transport Key (TK) as a backdoor that would be able to reset the card into a previous state in the lifecycle and change its keys.

I'd love any information about this!

Thanks in advance.

[martinpaljak]

This is a very vendor-specific issue. Do analyze the product documentation to figure out if the pre-personalization integrity satisfies your requirements, and choose a vendor (and a product) without any backdoors. Generally speaking: a rogue vendor is like a rogue maid - not only can they claim to be world record holder in speed-cleaning when they are not, they can also steal everything AND (theoretically) can also hit you with an axe. What decisions you make based on this knowledge, is up to your own judgement.

[martinpaljak]

Generally speaking, whatever happens before OP_READY is not part of global platform specs. How a well-behaving global platform device should behave, is described in the global platform specification (mostly, in general terms at least). If you're paranoid about rogue vendors and backdoors, nothing in the global platform specification can help you anyway.

[rlaneth]

Thanks for your answer!

Sure, before posting here, I reached out to the vendor through the proper support channels, yet they refused an answer and told me to ask the distributor—which can argue NDA and is exactly the party that I'm concerned about in the first place. 🫠

I've decided to post in case anyone had information or tips they could share. But, in the end, I guess we all are indeed left mostly blind and guessing, selecting vendors that look trustworthy and just hoping for the best.