X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/68d9d60a4d5a4696faf3e36a9a8a7f10ed5bdd22..1b6cc9746e25e93b9c8d76e193af4796c942b167:/common/crc.c diff --git a/common/crc.c b/common/crc.c index 817272eb..f9a15234 100644 --- a/common/crc.c +++ b/common/crc.c @@ -1,24 +1,62 @@ -/* - * crc.c - * - * Generic CRC calculation code. - * - */ - +//----------------------------------------------------------------------------- +// This code is licensed to you under the terms of the GNU GPL, version 2 or, +// at your option, any later version. See the LICENSE.txt file for the text of +// the license. +//----------------------------------------------------------------------------- +// Generic CRC calculation code. +//----------------------------------------------------------------------------- +// the Check value below in the comments is CRC of the string '123456789' +// #include "crc.h" -void crc_init(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, uint32_t final_xor) -{ +void crc_init_ref(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, uint32_t final_xor, bool refin, bool refout) { + crc_init(crc, order, polynom, initial_value, final_xor); + crc->refin = refin; + crc->refout = refout; + crc_clear(crc); +} + +void crc_init(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, uint32_t final_xor) { crc->order = order; + crc->topbit = BITMASK( order-1 ); crc->polynom = polynom; crc->initial_value = initial_value; crc->final_xor = final_xor; crc->mask = (1L<refin = FALSE; + crc->refout = FALSE; crc_clear(crc); } +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_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 ^= data << (crc->order - data_width); + + for( uint8_t bit = data_width; bit > 0; --bit) { + + if (crc->state & crc->topbit) + crc->state = (crc->state << 1) ^ crc->polynom; + else + crc->state = (crc->state << 1); + } +} + 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; @@ -30,12 +68,103 @@ void crc_update(crc_t *crc, uint32_t data, int data_width) } } -void crc_clear(crc_t *crc) -{ - crc->state = crc->initial_value & crc->mask; +uint32_t crc_finish(crc_t *crc) { + uint32_t val = crc->state; + if (crc->refout) val = reflect(val, crc->order); + return ( val ^ crc->final_xor ) & crc->mask; } -uint32_t crc_finish(crc_t *crc) -{ - return ( crc->state ^ crc->final_xor ) & crc->mask; +/* +static void print_crc(crc_t *crc) { + printf(" Order %d\n Poly %x\n Init %x\n Final %x\n Mask %x\n topbit %x\n RefIn %s\n RefOut %s\n State %x\n", + crc->order, + crc->polynom, + crc->initial_value, + crc->final_xor, + crc->mask, + crc->topbit, + (crc->refin) ? "TRUE":"FALSE", + (crc->refout) ? "TRUE":"FALSE", + crc->state + ); +} +*/ + +// width=8 poly=0x31 init=0x00 refin=true refout=true xorout=0x00 check=0xA1 name="CRC-8/MAXIM" +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_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_update2(&crc, buff[i], 8); + 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 + 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 reflect(crc_finish(&crc), 16); +} + +//w=16 poly=0x3d65 init=0x0000 refin=true refout=true xorout=0xffff check=0xea82 name="CRC-16/DNP" +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_update2(&crc, buff[i], 8); + + return BSWAP_16(crc_finish(&crc)); +} + +//width=16 poly=0x1021 init=0x1d0f refin=false refout=false xorout=0x0000 check=0xe5cc name="CRC-16/AUG-CCITT" +uint32_t CRC16_CCITT(uint8_t *buff, size_t size) { + crc_t crc; + crc_init(&crc, 16, 0x1021, 0x1d0f, 0); + 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