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+/* memxor.h -- perform binary exclusive OR operation on memory blocks.
+   Copyright (C) 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Simon Josefsson.  The interface was inspired by memxor
+   in Niels Möller's Nettle. */
+
+#ifndef MEMXOR_H
+# define MEMXOR_H
+
+#include <stddef.h>
+
+/* Compute binary exclusive OR of memory areas DEST and SRC, putting
+   the result in DEST, of length N bytes.  Returns a pointer to
+   DEST. */
+void *memxor (void *restrict dest, const void *restrict src, size_t n);
+
+#endif /* MEMXOR_H */