X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/3e134b4c20a5528b8264cd87d3fdebd0b2df6fd9..fada2feaf782ec47909886e86219ad49818e603a:/common/crc.c diff --git a/common/crc.c b/common/crc.c index 451282bf..2f11f5f4 100644 --- a/common/crc.c +++ b/common/crc.c @@ -43,6 +43,8 @@ void crc_update(crc_t *crc, uint32_t indata, int data_width){ crc->state ^= indata << (crc->order - data_width); for( uint8_t bit = data_width; bit > 0; --bit) { + + // Try to divide the current data bit. if (crc->state & crc->topbit) crc->state = (crc->state << 1) ^ crc->polynom; @@ -51,6 +53,22 @@ void crc_update(crc_t *crc, uint32_t indata, int data_width){ } } +void crc_update2(crc_t *crc, uint32_t data, int data_width) +{ + if (crc->refin) data = reflect(data, data_width); + + int i; + for(i=0; istate; + 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); @@ -82,8 +100,15 @@ uint32_t CRC8Maxim(uint8_t *buff, size_t size) { 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) { @@ -94,24 +119,13 @@ uint32_t CRC8Legic(uint8_t *buff, size_t size) { 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); @@ -137,4 +151,21 @@ uint32_t CRC16_CCITT(uint8_t *buff, size_t size) { 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