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[zpackage] / libtomcrypt / src / encauth / ocb / ocb_shift_xor.c
diff --git a/libtomcrypt/src/encauth/ocb/ocb_shift_xor.c b/libtomcrypt/src/encauth/ocb/ocb_shift_xor.c
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+/* 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 ocb_shift_xor.c
+   OCB implementation, internal function, by Tom St Denis
+*/
+#include "tomcrypt.h"
+
+#ifdef LTC_OCB_MODE
+
+/**
+   Compute the shift/xor for OCB (internal function)
+   @param ocb  The OCB state
+   @param Z    The destination of the shift
+*/
+void ocb_shift_xor(ocb_state *ocb, unsigned char *Z)
+{
+   int x, y;
+   y = ocb_ntz(ocb->block_index++);
+   for (x = 0; x < ocb->block_len; x++) {
+       ocb->Li[x] ^= ocb->Ls[y][x];
+       Z[x]        = ocb->Li[x] ^ ocb->R[x];
+   }
+}
+
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */