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Hem

Contributor

Registered: 2019-12-12

Posts: 3

Cracked keys via hardnested but still can't dump Mifare Classic

Hey all, new to proxmark here and just experimenting with a bunch of random cards I have laying around. I've read a bunch of blogs and have a decent idea how it works, but I'm having an interesting issue dumping a card directly.

So with one of the cards I ran hardnested and cracked a key successfully, such that the chk command returns:

|---|----------------|----------------|
|sec|key A           |key B           |
|---|----------------|----------------|
|000|  a2a3cca2a3cc  |  ffffffffffff  |
|001|        ?       |  ffffffffffff  |
|002|  ffffffffffff  |  ffffffffffff  |
|003|  a2a3cca2a3cc  |  ffffffffffff  |
|004|  a2a3cca2a3cc  |  ffffffffffff  |
|005|  a2a3cca2a3cc  |  ffffffffffff  |
|006|  a2a3cca2a3cc  |  ffffffffffff  |
|007|  a2a3cca2a3cc  |  ffffffffffff  |
|008|  a2a3cca2a3cc  |  ffffffffffff  |
|009|  a2a3cca2a3cc  |  ffffffffffff  |
|010|  a2a3cca2a3cc  |  ffffffffffff  |
|011|  a2a3cca2a3cc  |  ffffffffffff  |
|012|  a2a3cca2a3cc  |  ffffffffffff  |
|013|  a2a3cca2a3cc  |  ffffffffffff  |
|014|  a2a3cca2a3cc  |  ffffffffffff  |
|015|  a2a3cca2a3cc  |  ffffffffffff  |
|---|----------------|----------------|
31 keys(s) found have been transferred to the emulator memory

For some reason there is a `?` in sector 001 and `ffffffffffff` in sector 002, however running hardnested on those blocks just returns the same key for both. That is confirmed by the fact that I can run `hf mf rdbl 1 A a2a3cca2a3cc` and `hf mf rdbl 2 A a2a3cca2a3cc` and successfully read the data.

I have tried positioning the card in a million different ways but no matter what I do I can't populate those two sectors. This problem exists on another card as well, except instead of a `?` there is a random key that gets populated in sector 1.

Running `hf mf ekeyprn` returns:

|---|----------------|----------------|
|sec|key A           |key B           |
|---|----------------|----------------|
|000|  a2a3cca2a3cc  |  ffffffffffff  |
|001|  ffffffffffff  |  ffffffffffff  |
|002|  ffffffffffff  |  ffffffffffff  |
|003|  a2a3cca2a3cc  |  ffffffffffff  |
|004|  a2a3cca2a3cc  |  ffffffffffff  |
|005|  a2a3cca2a3cc  |  ffffffffffff  |
|006|  a2a3cca2a3cc  |  ffffffffffff  |
|007|  a2a3cca2a3cc  |  ffffffffffff  |
|008|  a2a3cca2a3cc  |  ffffffffffff  |
|009|  a2a3cca2a3cc  |  ffffffffffff  |
|010|  a2a3cca2a3cc  |  ffffffffffff  |
|011|  a2a3cca2a3cc  |  ffffffffffff  |
|012|  a2a3cca2a3cc  |  ffffffffffff  |
|013|  a2a3cca2a3cc  |  ffffffffffff  |
|014|  a2a3cca2a3cc  |  ffffffffffff  |
|015|  a2a3cca2a3cc  |  ffffffffffff  |
|---|----------------|----------------|

Trying to dump the card doesn't work, I assume that's because those two sectors don't have the correct key in them. Is there a way to manually set those values?

Output of `hf mf dump 1`:

|-----------------------------------------|
|------ Reading sector access bits...-----|
|-----------------------------------------|
#db# READ BLOCK FINISHED
#db# Authentication failed. Card timeout.
#db# Auth error
#db# READ BLOCK FINISHED
#db# Authentication failed. Card timeout.
#db# Auth error
#db# READ BLOCK FINISHED
#db# Authentication failed. Card timeout.
#db# Auth error
#db# READ BLOCK FINISHED
Could not get access rights for sector  1. Trying
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
#db# READ BLOCK FINISHED
|-----------------------------------------|
|----- Dumping all blocks to file... -----|
|-----------------------------------------|
#db# READ BLOCK FINISHED
Successfully read block  0 of sector  0.
#db# READ BLOCK FINISHED
Successfully read block  1 of sector  0.
#db# READ BLOCK FINISHED
Successfully read block  2 of sector  0.
#db# READ BLOCK FINISHED
Successfully read block  3 of sector  0.
#db# Authentication failed. Card timeout.
#db# Auth error
#db# READ BLOCK FINISHED
#db# Authentication failed. Card timeout.
#db# Auth error
#db# READ BLOCK FINISHED
#db# Authentication failed. Card timeout.
#db# Auth error
#db# READ BLOCK FINISHED
Could not read block  0 of sector  1

hw version

Prox/RFID mark3 RFID instrument
bootrom: /-suspect 2019-12-09 04:30:11
os: /-suspect 2019-12-09 04:30:15
fpga_lf.bit built for 2s30vq100 on 2019/11/21 at 09:02:37
fpga_hf.bit built for 2s30vq100 on 2019/11/13 at 14:52:19
SmartCard Slot: available

uC: AT91SAM7S512 Rev B
Embedded Processor: ARM7TDMI
Nonvolatile Program Memory Size: 512K bytes. Used: 207736 bytes (40%). Free: 31 552 bytes (60%).
Second Nonvolatile Program Memory Size: None
Internal SRAM Size: 64K bytes
Architecture Identifier: AT91SAM7Sxx Series
Nonvolatile Program Memory Type: Embedded Flash Memory

Any ideas?

Thanks!

Last edited by Hem (2019-12-12 11:34:31)

iceman

Administrator

Registered: 2013-04-25

Posts: 9,537

Website

Re: Cracked keys via hardnested but still can't dump Mifare Classic

.... the good old blocks is not sectors...

Hem

Contributor

Registered: 2019-12-12

Posts: 3

Re: Cracked keys via hardnested but still can't dump Mifare Classic

Ah right, got it working. I had to run hardnested on block 4 to crack sector 1 and it worked as expected