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pacemaker

Member

Registered: 2009-10-02

Posts: 2

Changing (i.e. decreasing) DCF value on a LEGIC Prime blank card

I list,

I'm trying to clone a card from a blank LEGIC prime card. It is clear that the UID and the CRC cannot be rewritten, but what about the DCF (decremented counter)? Indeed most LEGIC prime blank cards have a DCF = 0xff 0xff (GAM) and I want to transform the card into a SAM.

in armsrc/legicrf.c we have:

 
int legic_write_byte(int byte, int addr, int addr_sz) {
    //do not write UID, CRC, DCF                                                                
                                                                  
  if(addr <= 0x06) {
    return 0;
  }

I naively replaced

 addr <= 0x06 

 
with

 addr <= 0x04

to rewrite the DCF but it's not working. Some of you have an idea to rewrite the DCF value ? Maybe there is a free tool to do that with an official LEGIC reader ?

AntiCat

Contributor

Registered: 2010-01-01

Posts: 22

Re: Changing (i.e. decreasing) DCF value on a LEGIC Prime blank card

.

Last edited by AntiCat (2018-09-23 10:13:24)

AntiCat

Contributor

Registered: 2010-01-01

Posts: 22

Re: Changing (i.e. decreasing) DCF value on a LEGIC Prime blank card

.

Last edited by AntiCat (2018-09-23 10:12:27)