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#1 2012-09-17 17:46:20

asper
Contributor
Registered: 2008-08-24
Posts: 1,409

Mifare Access Condition Calculator

A little ?useful? utility to encode/decode the sector trailer (block 3) bytes 6-7-8 (starting form 0; they are called "Access Bits"); those bits set the access conditions (read/write/value) of the 4 blocks of a specific sector. Software is also able to give an error message for impossible bits condition.

screenshot:
41703872.png

link (windows-only): http://www.sendspace.com/file/o3frc9 (pass: mifcalc10)

Software built using MF1 IC S50 Functional Specification datasheet M001052.pdf directly form NXP (expacially pages 12-13-14) [link: http://www.thaieasyelec.net/archives/Manual/M001052.pdf].

Last edited by asper (2013-05-22 06:44:21)

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#2 2012-09-17 18:01:10

RadioWar
Contributor
From: China
Registered: 2012-09-15
Posts: 96

Re: Mifare Access Condition Calculator

where is the screenshot?not working for me?

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#3 2012-09-17 18:08:03

asper
Contributor
Registered: 2008-08-24
Posts: 1,409

Re: Mifare Access Condition Calculator

Sometimes imageshack does not work, try to reload ! Anyway here is the direct link: http://imageshack.us/a/img706/1418/imghq.png

Last edited by asper (2012-09-17 18:08:29)

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#4 2012-09-17 18:13:53

RadioWar
Contributor
From: China
Registered: 2012-09-15
Posts: 96

Re: Mifare Access Condition Calculator

asper wrote:

Sometimes imageshack does not work, try to reload ! Anyway here is the direct link: http://imageshack.us/a/img706/1418/imghq.png

God!!!we have a great wall~so i cant see it in china ~fuck that GFW~~~

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#5 2012-09-17 18:16:01

asper
Contributor
Registered: 2008-08-24
Posts: 1,409

Re: Mifare Access Condition Calculator

So try the software wink

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#6 2012-09-17 18:25:09

RadioWar
Contributor
From: China
Registered: 2012-09-15
Posts: 96

Re: Mifare Access Condition Calculator

asper wrote:

So try the software wink

anyway,watch my post about Chinese Magic Card on NFC-WAR

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#7 2013-03-20 20:13:43

b0ngokarl
Contributor
Registered: 2013-01-17
Posts: 16

Re: Mifare Access Condition Calculator

And I love you for the tool! smile

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#8 2013-09-19 10:11:32

ikarus
Contributor
Registered: 2012-09-20
Posts: 249
Website

Re: Mifare Access Condition Calculator

I used this tool a lot but never said thank you...
So: Thank you, asper smile

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#9 2013-10-30 22:48:04

asper
Contributor
Registered: 2008-08-24
Posts: 1,409

Re: Mifare Access Condition Calculator

Thank you all guys wink

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#10 2013-11-07 12:31:37

sboudjem
Member
Registered: 2013-11-07
Posts: 2

Re: Mifare Access Condition Calculator

Hi everyone,
I have a problem: I discovered yesterday how to write on a myfare card, and I tried some operations.
But I think I set the 0x03 sector to an invalid access condition (and i don't remember which one, maybe FFFFFF).
Now I can find all the 32 keys with the nested command, however when I try a dump, I have a read block error (#db# Cmd Error: 04) on the first block, and on the 4 first sectors.
I tried to change the access conditions to FF 07 80 with the commands hf mf wrbl 0x03 A FFFFFFFFFFFF FFFFFFFFFFFFFF078069FFFFFFFFFFFF or
hf mf wrbl 0x03 B FFFFFFFFFFFF FFFFFFFFFFFFFF078069FFFFFFFFFFFF but with both commands, the proxmark3 client returns a Cmd Error 04.
Moreover, I could see 16 blocks on the dumpdata file before, but now in the new file there are only 15 blocks.
It seems like the first block has disappeared.
Please, could someone help me?
Thanks.

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#11 2013-11-07 13:05:04

asper
Contributor
Registered: 2008-08-24
Posts: 1,409

Re: Mifare Access Condition Calculator

Probably you permalocked access condition write capabilities so you cannot change it anymore but you can always read it using KeyA so use KeyA to read a sector trailer (block3 of a sector) and read acutal access coditions: if you obtain all FF so you probably permalocked it (FFFFFF is not a valid value but you can always write it on the card and I don't know how a mifare card process this value).
If you cannot read blocks either with KeyA or KeyB you seems also to have permanently disabled reading using KeyA and KeyB and if access conditions are permalocked you cannot unfortunately read them anymore.

Please create a new topic because this thread is related to the software only.

EDIT
Directly form mifare dasheets (ex. page 12 of this):

Remark: With each memory access the internal logic verifies the format of the access
conditions. If it detects a format violation the whole sector is irreversible blocked.

Probably "FFFFFF" is considered an "access violation".

Last edited by asper (2013-11-09 12:51:04)

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#12 2016-04-18 18:54:47

osys
Contributor
From: Nearby
Registered: 2016-03-28
Posts: 62

Re: Mifare Access Condition Calculator

Nice user-friendly, thanks a lot!

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