ADD: first try to implement crc-16 for Legic Advant *not working yet* Can't verify it.

[proxmark3-svn] / common / crc.c

diff --git a/common/crc.c b/common/crc.c
index 90d57afab6a56c90bdfbc4b8840b718ffea247cf..8e9f39962a3b0b415b17b8ffbd49d878a037704c 100644 (file)
--- a/common/crc.c
+++ b/common/crc.c
@@ -5,8 +5,10 @@
 //-----------------------------------------------------------------------------
 // Generic CRC calculation code.
 //-----------------------------------------------------------------------------
-
 #include "crc.h"
+#include "util.h"
+#include <stdint.h>
+#include <stddef.h>
 
 void crc_init(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, uint32_t final_xor)
 {
@@ -20,8 +22,7 @@ void crc_init(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, u
 
 void crc_update(crc_t *crc, uint32_t data, int data_width)
 {
-       int i;
-       for(i=0; i<data_width; i++) {
+       for( int i=0; i < data_width; i++) {
                int oldstate = crc->state;
                crc->state = crc->state >> 1;
                if( (oldstate^data) & 1 ) {
@@ -40,3 +41,29 @@ uint32_t crc_finish(crc_t *crc)
 {
        return ( crc->state ^ crc->final_xor ) & crc->mask;
 }
+
+//credits to iceman
+uint32_t CRC8Maxim(uint8_t *buff, size_t size) {
+       crc_t crc;
+       crc_init(&crc, 9, 0x8c, 0x00, 0x00);
+       crc_clear(&crc);
+
+       for (size_t i=0; i < size; ++i)
+               crc_update(&crc, buff[i], 8);
+
+       return crc_finish(&crc);
+}
+
+uint32_t CRC8Legic(uint8_t *buff, size_t size) {
+
+       // Poly 0x63,   reversed poly 0xC6,  Init 0x55,  Final 0x00
+       crc_t crc;
+       crc_init(&crc, 8, 0xC6, 0x55, 0);
+       crc_clear(&crc);
+       
+       for ( int i = 0; i < size; ++i)
+               crc_update(&crc, buff[i], 8);
+       return SwapBits(crc_finish(&crc), 8);
+}
+
+