--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtomcrypt/src/encauth/ocb3/ocb3_int_xor_blocks.c	Fri Feb 09 21:44:05 2018 +0800
@@ -0,0 +1,40 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+
+/**
+   @file ocb3_int_xor_blocks.c
+   OCB implementation, INTERNAL ONLY helper, by Karel Miko
+*/
+#include "tomcrypt.h"
+
+#ifdef LTC_OCB3_MODE
+
+/**
+   Compute xor for two blocks of bytes 'out = block_a XOR block_b' (internal function)
+   @param out        The block of bytes (output)
+   @param block_a    The block of bytes (input)
+   @param block_b    The block of bytes (input)
+   @param block_len  The size of block_a, block_b, out
+*/
+void ocb3_int_xor_blocks(unsigned char *out, const unsigned char *block_a, const unsigned char *block_b, unsigned long block_len)
+{
+   int x;
+   if (out == block_a) {
+     for (x = 0; x < (int)block_len; x++) out[x] ^= block_b[x];
+   }
+   else {
+     for (x = 0; x < (int)block_len; x++) out[x] = block_a[x] ^ block_b[x];
+   }
+}
+
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */