Proxmark3 community

shinechou

Contributor

Registered: 2008-10-20

Posts: 35

how to decrypt the mifare-log with "crapto1" tool

hi all,

I'm confused how to decrypt the mifare-log with "crapto1" tool (the newest version 1.0), I can use it to recovery the Key.

for example, in the post http://www.proxmark.org/forum/viewtopic.php?id=71, after the authentication the reader will read the blocks of Mifare-Tag, so how to decrypt the ciphertext "[Block(00)]: c7! 84! b5! 92! a4! 16! 82  fe  eb! 0b! ac  22! ed! 89  e1! 6d  1e  6e!" to get the plaintext "Block(00): 00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  37  49"?

would be "ks4^ciphertext"? and the next block would be "ks5^ciphertext"?

thx in advance!

Last edited by shinechou (2009-02-19 11:51:37)

rule

Member

Registered: 2008-05-21

Posts: 417

Re: how to decrypt the mifare-log with "crapto1" tool

Please post your messages only once

ks4(4 bytes long) is xor'ed against the read command from the reader.
ks5(18 bytes long) is xor'ed to the 16 bytes data + 2 bytes crc from the tag

I hope this helps, cheers,

  roel

shinechou

Contributor

Registered: 2008-10-20

Posts: 35

Re: how to decrypt the mifare-log with "crapto1" tool

thx! I'll try to decrypt the block as u said!

sorry, I'll post only once from now!