RfidResearchGroup/proxmark3
1
1
Fork 0
mirror of https://github.com/RfidResearchGroup/proxmark3.git synced 2024-09-21 15:56:21 +08:00
Code Issues Packages Projects Releases Wiki Activity

FIX: @marshmellow found out that the CRC-8/Maxim was not always giving the right checksum. Change POLY from 0x31 -> 0x8C

Browse source
This commit is contained in:
iceman1001 2015-03-12 20:33:36 +01:00
parent 118bfa1b1f
commit a8cd503dd5
2 changed files with 5 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
common/crc.c
View file

@ -42,13 +42,11 @@ uint32_t crc_finish(crc_t *crc)
return ( crc->state ^ crc->final_xor ) & crc->mask;
}
int CRC8Maxim(uint8_t *buff, size_t size ) {
uint32_t CRC8Maxim(uint8_t *buff, size_t size) {
crc_t crc;
crc_init(&crc, 8, 0x31, 0x00, 0x00);
crc_clear(&crc);
for ( int i=0; i < size; ++i){
crc_init(&crc, 9, 0x8c, 0x00, 0x00);
for ( uint8_t i = 0; i < size; ++i){
crc_update(&crc, buff[i], 8);
}
return crc_finish(&crc);

2
common/crc.h
View file

@ -38,7 +38,7 @@ extern void crc_clear(crc_t *crc);
extern uint32_t crc_finish(crc_t *crc);
// Calculate CRC-8/Maxim checksum
int CRC8Maxim(uint8_t *buff, size_t size );
uint32_t CRC8Maxim(uint8_t *buff, size_t size );
/* Static initialization of a crc structure */
#define CRC_INITIALIZER(_order, _polynom, _initial_value, _final_xor) { \