X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/c062856a74bee13df6d41181dee8c920d405f409..fdcc61d3189f7e91db27a865c25d923849ec47d5:/common/iso14443crc.c diff --git a/common/iso14443crc.c b/common/iso14443crc.c index 250a4ee5..f91b3ce1 100644 --- a/common/iso14443crc.c +++ b/common/iso14443crc.c @@ -1,31 +1,31 @@ -#include "iso14443crc.h" - -static unsigned short UpdateCrc14443(unsigned char ch, unsigned short *lpwCrc) -{ - ch = (ch ^ (unsigned char) ((*lpwCrc) & 0x00FF)); - ch = (ch ^ (ch << 4)); - *lpwCrc = (*lpwCrc >> 8) ^ ((unsigned short) ch << 8) ^ - ((unsigned short) ch << 3) ^ ((unsigned short) ch >> 4); - return (*lpwCrc); -} - -void ComputeCrc14443(int CrcType, - unsigned char *Data, int Length, - unsigned char *TransmitFirst, - unsigned char *TransmitSecond) -{ - unsigned char chBlock; - unsigned short wCrc=CrcType; - - do { - chBlock = *Data++; - UpdateCrc14443(chBlock, &wCrc); - } while (--Length); - - if (CrcType == CRC_14443_B) - wCrc = ~wCrc; /* ISO/IEC 13239 (formerly ISO/IEC 3309) */ - - *TransmitFirst = (unsigned char) (wCrc & 0xFF); - *TransmitSecond = (unsigned char) ((wCrc >> 8) & 0xFF); - return; -} +#include "iso14443crc.h" + +static unsigned short UpdateCrc14443(unsigned char ch, unsigned short *lpwCrc) +{ + ch = (ch ^ (unsigned char) ((*lpwCrc) & 0x00FF)); + ch = (ch ^ (ch << 4)); + *lpwCrc = (*lpwCrc >> 8) ^ ((unsigned short) ch << 8) ^ + ((unsigned short) ch << 3) ^ ((unsigned short) ch >> 4); + return (*lpwCrc); +} + +void ComputeCrc14443(int CrcType, + unsigned char *Data, int Length, + unsigned char *TransmitFirst, + unsigned char *TransmitSecond) +{ + unsigned char chBlock; + unsigned short wCrc=CrcType; + + do { + chBlock = *Data++; + UpdateCrc14443(chBlock, &wCrc); + } while (--Length); + + if (CrcType == CRC_14443_B) + wCrc = ~wCrc; /* ISO/IEC 13239 (formerly ISO/IEC 3309) */ + + *TransmitFirst = (unsigned char) (wCrc & 0xFF); + *TransmitSecond = (unsigned char) ((wCrc >> 8) & 0xFF); + return; +}