Merge pull request #158 from marshmellow42/master

[proxmark3-svn] / client / util.c

diff --git a/client/util.c b/client/util.c
index 32c06e910a31480c2443fb1edfaa70f9b33a35fb..c4f7d200f61bb096949c2e5939c9c48349da7431 100644 (file)
--- a/client/util.c
+++ b/client/util.c
@@ -497,3 +497,13 @@ void xor(unsigned char *dst, unsigned char *src, size_t len) {
 int32_t le24toh (uint8_t data[3]) {
     return (data[2] << 16) | (data[1] << 8) | data[0];
 }
+
+// RotateLeft - Ultralight, Desfire, works on byte level
+// 00-01-02  >> 01-02-00
+void rol(uint8_t *data, const size_t len){
+    uint8_t first = data[0];
+    for (size_t i = 0; i < len-1; i++) {
+        data[i] = data[i+1];
+    }
+    data[len-1] = first;
+}