X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/514ddaa2ff936ded76554a2ad97f6fe978c6f86e..5381b6fed52da1b7d1d3d07bb176555e02903029:/common/crc.c?ds=inline diff --git a/common/crc.c b/common/crc.c index 0425a4fd..f9a15234 100644 --- a/common/crc.c +++ b/common/crc.c @@ -29,21 +29,22 @@ void crc_init(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, u } 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 @@ -51,6 +52,22 @@ void crc_update(crc_t *crc, uint32_t indata, int data_width){ } } +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; 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); @@ -78,19 +95,26 @@ uint32_t CRC8Maxim(uint8_t *buff, size_t size) { crc_t crc; crc_init_ref(&crc, 8, 0x31, 0, 0, TRUE, TRUE); for ( int i=0; i < size; ++i) - crc_update(&crc, buff[i], 8); + crc_update2(&crc, buff[i], 8); 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); } @@ -114,7 +138,7 @@ uint32_t CRC16_DNP(uint8_t *buff, size_t size) { crc_t crc; crc_init_ref(&crc, 16, 0x3d65, 0, 0xffff, TRUE, TRUE); for ( int i=0; i < size; ++i) - crc_update(&crc, buff[i], 8); + crc_update2(&crc, buff[i], 8); return BSWAP_16(crc_finish(&crc)); } @@ -126,4 +150,21 @@ 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