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cds333

Contributor

Registered: 2019-04-06

Posts: 18

Removing timeout on dump command?

Essentially I want to use the RDV4 as a reader, that will wait indefinitely until a tag is presented, at which time it will run "hf mfu dump" and capture the user memory.

I cannot seem to find a way to remove the timeout on the dump command, so it fails after less than a second with "[!] iso14443a card select failed".

Thanks!

mwalker

Moderator

Registered: 2019-05-11

Posts: 318

Re: Removing timeout on dump command?

I believe the timeout is there to stop the rdv4 from getting too hot.  it will heat up when the field is energized, and could damage it.

Edit: I was wrong about the heat issue.  Thanks for the correction guys.

Last edited by mwalker (2019-07-25 21:12:01)

iceman

Administrator

Registered: 2013-04-25

Posts: 9,537

Website

Re: Removing timeout on dump command?

act as a reader,  no problem.   dumping on the go?   I see where this is going...   You know you will need all keys for the specific card that enters the reader field before you can "dump" the card memory.

iceman

Administrator

Registered: 2013-04-25

Posts: 9,537

Website

Re: Removing timeout on dump command?

And no,  the timeout has nothing to do with RDV4.  It was there long before, to ensure that the device doesn't hang.

piwi

Contributor

Registered: 2013-06-04

Posts: 704

Re: Removing timeout on dump command?

Changing the timeout would not help. If there is no card in vicinity when the wakeup is sent, there will be no response anymore. You would need to repeat the selection (or at least a wakeup) until a card responds. Assuming that you have all the keys, you can then dump the contents.

cds333

Contributor

Registered: 2019-04-06

Posts: 18

Re: Removing timeout on dump command?

The arduino MFRC522 reader I built, running the DumpInfo.ino example sketch can do the exact thing I want to do with the RDV4. Once powered on, it will wait indefinitely for a tag and then dump the memory contents using default keys.

In my application it is a standard Ultralight with no security, fyi. If anything, it would be all 0xFF

I had thought about writing a script that constantly runs the dump command, then parses the output file until it contains the proper strings indicating that it contains the correct number of pages comprising a full memory dump.

Unless anyone has any better ideas?

Last edited by cds333 (2019-07-25 03:05:41)

Mackwa

Contributor

Registered: 2016-06-10

Posts: 51

Re: Removing timeout on dump command?

I like the idea of piwi, using a script / standalone mode, which does:
-  a select / wake-up loop, until successfully selected a card,
- afterwards "hf mfu dump k FFFFFFFF" for Ultralight with default key