15 ms·

Ya, looks like the iPhone is tinkering with the NDEF message itself. If my Android phone wasn't dead, I'd love to compare an iPhone's write against the Android

Ya, looks like the iPhone is tinkering with the NDEF message itself. If my Android phone wasn't dead, I'd love to compare an iPhone's write against the Android NFC Tools app's write. If anyone else has an iPhone, an Android phone, and a Proxmark, I'd be interested in seeing a three-way diff between them all. EDIT: I'm going to try to cross-post to the DT forum to see if anyone has ideas.

stavros 2y ago
I've got both phones next to me, what do you want me to do exactly?
- ewpratten 2y ago
  Wipe the card. Make a dump after doing "hf mf ndefformat". Then make a dump after writing a payload from an iPhone. (since iPhone seems to want ndefformat anyways) Then wipe again and make a dump after writing from Android.
  - stavros 2y ago
    Here you go: https://www.pastery.net/xajezk+gbkqqz+aqwygg+ukrdad/ https://www.pastery.net/xajezk+gbkqqz+aqwygg+ukrdad/
    - ewpratten 2y ago
      Thank you very much! Something's clearly up there. You can see that even IOS and Android disagree with each other on what NDEF should look like by a few bytes. Very interesting.
      - stavros 2y ago
        Yep, 89 EC A9 7F 8C 2A 00 00 on iOS versus FF FF FF FF FF FF on Android. Interesting how the number of bytes is different, I should play with them a bit.
        ewpratten 2y ago
        There's lots of info about the NDEF "packet" format online. I used this page as reference when I was putting together the "magic bytes" in the final section of the blog post: https://www.oreilly.com/library/view/beginning-nfc/9781449324094/ch04.html https://www.oreilly.com/library/view/beginning-nfc/978144932...
        stavros 2y ago
        This is fantastic, thanks! Also, one thing that might be of interest: Even after a wipe and an ndefformat, my Android-written tag can be read by my iPhone 15. NFC tools will only read it in compatibility mode, though.
        ewpratten 2y ago
        Are you sure? The NFC app for iPhone can always read tags. Its specifically getting phones without the app to read them. Try wiping, then writing a URL from Android. Then just tap to the iPhone and see if Safari opens or not. It shouldn't
        stavros 2y ago
        Yes: https://imgz.org/i9ZqL6Ax.png https://imgz.org/i9ZqL6Ax.png I don't know if it's Vivaldi doing that, but I can't imagine they would have added NFC tag reading capability to the browser specifically. Feel free to email me if you want, btw, as this thread is getting a bit too deep.
        fragmede 2y ago
        If a URL is written using NFCTools on iPhone, iOS will open it in the default browser without using NFCTools, or in the related app (eg Instagram) if there is one.
        MichaelBosworth 2y ago
        I find this only to be true when used on the same iPhone where NFCTools was used. If you try to have another iPhone detect the badge, it appears not to work - unless you use NFCTools on that iPhone, too. I don't have conclusive proof but that's what the evidence seems to indicate. Are you seeing something different?

stavros 2y ago

I've got both phones next to me, what do you want me to do exactly?

ewpratten 2y ago
Wipe the card. Make a dump after doing "hf mf ndefformat". Then make a dump after writing a payload from an iPhone. (since iPhone seems to want ndefformat anyways) Then wipe again and make a dump after writing from Android.
- stavros 2y ago
  Here you go: https://www.pastery.net/xajezk+gbkqqz+aqwygg+ukrdad/ https://www.pastery.net/xajezk+gbkqqz+aqwygg+ukrdad/
  - ewpratten 2y ago
    Thank you very much! Something's clearly up there. You can see that even IOS and Android disagree with each other on what NDEF should look like by a few bytes. Very interesting.
    - stavros 2y ago
      Yep, 89 EC A9 7F 8C 2A 00 00 on iOS versus FF FF FF FF FF FF on Android. Interesting how the number of bytes is different, I should play with them a bit.
      - ewpratten 2y ago
        There's lots of info about the NDEF "packet" format online. I used this page as reference when I was putting together the "magic bytes" in the final section of the blog post: https://www.oreilly.com/library/view/beginning-nfc/9781449324094/ch04.html https://www.oreilly.com/library/view/beginning-nfc/978144932...
        stavros 2y ago
        This is fantastic, thanks! Also, one thing that might be of interest: Even after a wipe and an ndefformat, my Android-written tag can be read by my iPhone 15. NFC tools will only read it in compatibility mode, though.
        ewpratten 2y ago
        Are you sure? The NFC app for iPhone can always read tags. Its specifically getting phones without the app to read them. Try wiping, then writing a URL from Android. Then just tap to the iPhone and see if Safari opens or not. It shouldn't
        stavros 2y ago
        Yes: https://imgz.org/i9ZqL6Ax.png https://imgz.org/i9ZqL6Ax.png I don't know if it's Vivaldi doing that, but I can't imagine they would have added NFC tag reading capability to the browser specifically. Feel free to email me if you want, btw, as this thread is getting a bit too deep.
        fragmede 2y ago
        If a URL is written using NFCTools on iPhone, iOS will open it in the default browser without using NFCTools, or in the related app (eg Instagram) if there is one.
        MichaelBosworth 2y ago
        I find this only to be true when used on the same iPhone where NFCTools was used. If you try to have another iPhone detect the badge, it appears not to work - unless you use NFCTools on that iPhone, too. I don't have conclusive proof but that's what the evidence seems to indicate. Are you seeing something different?