OPUS Bus Card for Montreal Quebec System

Hey I got the flipper in large part to replace a few of my Access cards, but unfortunately, it cannot support my 2 bus cards (the Montreal system is stupid)

the cards use NFC-B and I know they aren’t currently supported but I think it would be awesome to have them!

Now I don’t know much about NFC in general but here’s what I do know about the cards:
they seem to be based on the ATMEL 8820 series controller and the NFC TagInfo app identifies the OPUS card as ISO 14443-B type.

according to an online user, OPUS cards use OTP bits and so any attempt to scan a card with initial content in RW area (pages 4-15) with non-zero OTP area results in ERROR 200 and the card gets locked with all lock bits (becomes entirely read-only).

I personally don’t need to rewrite these cards, just need to emulate them for the readers but hey, figured I would add my findings.

Hoping this will get added eventually as it would help reduce the number of cards I need to carry on my person, Thanks!

(do let me know if you need more info or anything of the like)

Transport cards should have a picture and a name of the user so that you can’t use the BUS system with the card of someone else. If a security/employee of the BUS/Train/Metro whatever transport system asks you to show you the card you can’t show them the flipper and expect them to be happy. Same goes if you use the flipper to change the original cards to charge them without paying. You can go to jail.

Thanks for the response!
Fear not however, I am very aware of all this.

I also know the STM system quite well and know that there are a few different kinds of OPUS cards.

There are the subscription passes which indeed require a photo, then there are the refillable cards (like the one I use) and finally the one time use cards (which are not opus cards and use NFC-A and can already be used with the flipper)

The two actual opus cards are actually quite simple devices, they only hold an ID number and everything else is held on the STM servers. So worry not about my going to jail as I cannot just add new bus passes myself!

As I said I don’t need to rewrite them, all I need is to emulate the tag I already have in my pocket just to save me some trouble trying to pull cards out of my wallet since my flipper is already attached to my bag and quick to access (I already use it as a few RFID tags)

So let me know if you have further concerns, I assure you I will not be going to jail over this. (Also it’s a flipper if I wanted jail time the device is already more than capable enough to assist me)

Even with STM server you ight attempt to “guess” a valid UID/Card to allow you access ! :sweat_smile:

indeed, that would be pretty bad,
nevertheless, NFC is not the only tool that has this exploit and NFC-B is helpful for many other things than just Opus cards.

I just want to coerce my surplus of various access cards and passes into one clean device, but that is just for me, for the rest of the Flipper userbase I doubt that I am the only one who needs NFC-B for something

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Agree !