Proxmark3 community

lohcm88

Contributor

Registered: 2016-02-05

Posts: 59

Using PM3 iclass WRITEBLK command

Hello all, can anyone provide insight on how to write to BLK 03 using writeblk command?

When I tried to writing on other blocks, it was successful:

proxmark3> hf iclass writeblk b 07 xxxxxxxxxxxxxxxx k xxxxxxxxxxxxxxxx
CSN: xx xx xx xx  xx xx xx xx
Authing with diversified key: xxxxxxxxxxxx
#db# Write block [07] successful

But when I tried writing on blk 03, it failed:

proxmark3> hf iclass writeblk b 03 xxxxxxxxxxxxxxxx k xxxxxxxxxxxxxxxx
CSN: xx xx xx xx xx xx xx xx
Authing with diversified key: xxxxxxxxxxxx
#db# Write block [03] failed
Write Block Failed

After that, it bricked my card and I no longer able to dump my card.

I tried editing blk 03 using hex editor and use the clone command instead, but it prompt me "You cannot write key blocks this way. yet... make your start block > 4"

Any suggestions? Thank you.

marshmellow

Contributor

From: US

Registered: 2013-06-10

Posts: 2,302

Re: Using PM3 iclass WRITEBLK command

Blocks 3 and 4 are special and cannot be read back so
I believe it will always say it failed, even though it wrote that block.  But writing to those block's is also special and you better understand how to build the data to properly make a key before attempting to write the keys or you will brick your tag.  Find and read up all info on Pico pass key blocks.

lohcm88

Contributor

Registered: 2016-02-05

Posts: 59

Re: Using PM3 iclass WRITEBLK command

Thx Marsh...  I will try to get a copy of Pico pass key blocks.

Last edited by lohcm88 (2018-06-22 00:15:16)