From: iceman1001 Date: Fri, 12 Feb 2016 11:34:54 +0000 (+0100) Subject: CHG: extracted a #define for the crc16 poly X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/commitdiff_plain/6b6815bccb7b11cf7847a353f8c9cf588ab0d342 CHG: extracted a #define for the crc16 poly --- diff --git a/common/crc16.c b/common/crc16.c index 07090fc6..c90eeb55 100644 --- a/common/crc16.c +++ b/common/crc16.c @@ -7,7 +7,8 @@ //----------------------------------------------------------------------------- #include "crc16.h" -#define CRC16_MASK_CCITT 0x1021 +#define CRC16_POLY_CCITT 0x1021 +#define CRC16_POLY 0x8408 unsigned short update_crc16( unsigned short crc, unsigned char c ) { @@ -15,11 +16,11 @@ unsigned short update_crc16( unsigned short crc, unsigned char c ) v = (crc ^ c) & 0xff; for (i = 0; i < 8; i++) { - tcrc = ( (tcrc ^ v) & 1 ) ? ( tcrc >> 1 ) ^ 0x8408 : tcrc >> 1; + tcrc = ( (tcrc ^ v) & 1 ) ? ( tcrc >> 1 ) ^ CRC16_POLY : tcrc >> 1; v >>= 1; } - return ((crc >> 8) ^ tcrc)&0xffff; + return ((crc >> 8) ^ tcrc) & 0xffff; } uint16_t crc16(uint8_t const *message, int length, uint16_t remainder, uint16_t polynomial) { @@ -41,11 +42,11 @@ uint16_t crc16(uint8_t const *message, int length, uint16_t remainder, uint16_t } uint16_t crc16_ccitt(uint8_t const *message, int length) { - return crc16(message, length, 0xffff, CRC16_MASK_CCITT); + return crc16(message, length, 0xffff, CRC16_POLY_CCITT); } uint16_t crc16_ccitt_kermit(uint8_t const *message, int length) { - return bit_reverse_uint16(crc16(message, length, 0x0000, CRC16_MASK_CCITT)); + return bit_reverse_uint16(crc16(message, length, 0x0000, CRC16_POLY_CCITT)); } uint16_t bit_reverse_uint16 (uint16_t value) { const uint16_t mask0 = 0x5555; diff --git a/common/lfdemod.c b/common/lfdemod.c index 4c0f3ad9..23b9c8b5 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -135,8 +135,7 @@ uint32_t bytebits_to_byte(uint8_t *src, size_t numbits) uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits) { uint32_t num = 0; - for(int i = 0 ; i < numbits ; i++) - { + for(int i = 0 ; i < numbits ; i++) { num = (num << 1) | *(src + (numbits-(i+1))); } return num;