}
void crc_clear(crc_t *crc) {
+
crc->state = crc->initial_value & crc->mask;
if (crc->refin)
crc->state = reflect(crc->state, crc->order);
}
-void crc_update(crc_t *crc, uint32_t indata, int data_width){
-
- //reflected
- if (crc->refin) indata = reflect(indata, data_width);
+void crc_update2(crc_t *crc, uint32_t data, int data_width){
+
+ if (crc->refin)
+ data = reflect(data, data_width);
// Bring the next byte into the remainder.
- crc->state ^= indata << (crc->order - data_width);
+ crc->state ^= data << (crc->order - data_width);
- for( uint8_t bit = data_width; bit > 0; --bit) {
- // Try to divide the current data bit.
+ for( uint8_t bit = data_width; bit > 0; --bit) {
+
if (crc->state & crc->topbit)
crc->state = (crc->state << 1) ^ crc->polynom;
else
}
}
+void crc_update(crc_t *crc, uint32_t data, int data_width)
+{
+ if (crc->refin)
+ data = reflect(data, data_width);
+
+ int i;
+ for(i=0; i<data_width; i++) {
+ int oldstate = crc->state;
+ crc->state = crc->state >> 1;
+ if( (oldstate^data) & 1 ) {
+ crc->state ^= crc->polynom;
+ }
+ data >>= 1;
+ }
+}
+
+
uint32_t crc_finish(crc_t *crc) {
uint32_t val = crc->state;
if (crc->refout) val = reflect(val, crc->order);
return crc_finish(&crc);
}
-
// width=4 poly=0xC, reversed poly=0x7 init=0x5 refin=true refout=true xorout=0x0000 check= name="CRC-4/LEGIC"
+uint32_t CRC4Legic(uint8_t *cmd, size_t size) {
+ crc_t crc;
+ crc_init_ref(&crc, 4, 0x19 >> 1, 0x5, 0, TRUE, TRUE);
+ crc_update2(&crc, 1, 1); /* CMD_READ */
+ crc_update2(&crc, cmd[0], 8);
+ crc_update2(&crc, cmd[1], 8);
+ return reflect(crc_finish(&crc), 4);
+}
// width=8 poly=0x63, reversed poly=0x8D init=0x55 refin=true refout=true xorout=0x0000 check=0xC6 name="CRC-8/LEGIC"
// the CRC needs to be reversed before returned.
uint32_t CRC8Legic(uint8_t *buff, size_t size) {
crc_t crc;
crc_init_ref(&crc, 8, 0x63, 0x55, 0, TRUE, TRUE);
for ( int i = 0; i < size; ++i)
- crc_update(&crc, buff[i], 8);
+ crc_update2(&crc, buff[i], 8);
return reflect(crc_finish(&crc), 8);
}
-// credits to marshmellow
-// width=8 poly=0xA3, reversed poly=0x8B, init=0xB0 refin=true refout=true xorout=0x00 check=0x28 name="CRC-8/JA"
-uint32_t CRC8ja(uint8_t *buff, size_t size) {
- crc_t crc;
- crc_init_ref(&crc, 8, 0xA3, 0x42, 0x00, TRUE, TRUE);
- for ( int i=0; i < size; ++i)
- crc_update(&crc, buff[i], 8);
- return crc_finish(&crc);
- //return reflect(crc_finish(&crc), 8);
-}
-
// This CRC-16 is used in Legic Advant systems.
// width=8 poly=0xB400, reversed poly=0x init=depends refin=true refout=true xorout=0x0000 check= name="CRC-16/LEGIC"
uint32_t CRC16Legic(uint8_t *buff, size_t size, uint8_t uidcrc) {
#define CRC16_POLY_LEGIC 0xB400
- //uint8_t initial = reflect(uidcrc, 8);
- uint16_t initial = uidcrc;
+ uint16_t initial = reflect(uidcrc, 8);
+ //uint16_t initial = uidcrc;
initial |= initial << 8;
crc_t crc;
crc_init_ref(&crc, 16, CRC16_POLY_LEGIC, initial, 0, TRUE, TRUE);
for ( int i=0; i < size; ++i)
crc_update(&crc, buff[i], 8);
return crc_finish(&crc);
+}
+//width=16 poly=0x8408 init=0xffff refin=false refout=true xorout=0xffff check=0xF0B8 name="CRC-16/ISO/IEC 13239"
+uint32_t CRC16_Iso15693(uint8_t *buff, size_t size) {
+ crc_t crc;
+ crc_init_ref(&crc, 16, 0x8408, 0xFFFF, 0xFFFF, true, false);
+ for ( int i=0; i < size; ++i)
+ crc_update(&crc, buff[i], 8);
+ return reflect(crc_finish(&crc), 16);
+}
+//width=16 poly=0x8408 init=0xffff refin=true refout=true xorout=0x0BC3 check=0xF0B8 name="CRC-16/ICLASS"
+uint32_t CRC16_ICLASS(uint8_t *buff, size_t size) {
+
+ crc_t crc;
+ crc_init_ref(&crc, 16, 0x8408, 0xFFFF, 0x0BC3, false, false);
+ for ( int i=0; i < size; ++i)
+ crc_update(&crc, buff[i], 8);
+ return crc_finish(&crc);
}
\ No newline at end of file