revert field on/off in hf 14a reader

[proxmark3-svn] / common / crc.c

diff --git a/common/crc.c b/common/crc.c
index 817272eb7a438a06220be72ca2775d717de70683..0c73474fa75888bf40878f4b41d6269e7f74510c 100644 (file)
--- a/common/crc.c
+++ b/common/crc.c
@@ -1,11 +1,13 @@
-/*
- * 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.
+//-----------------------------------------------------------------------------
 #include "crc.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)
 {
@@ -39,3 +41,16 @@ 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);
+}