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// -*-c++-*-
/* $Id: ocb.h,v 1.2 2003/01/07 22:12:21 dm Exp $ */
/*
*
* Copyright (C) 2002 David Mazieres (dm@uun.org)
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*
*/
#ifndef _CRYPT_OCB_H_
#define _CRYPT_OCB_H_ 1
#include "aes.h"
class ocb {
public:
struct blk {
enum { nc = 16, nl = nc / sizeof (long) };
union {
signed char c[nc];
long l[nl];
};
void get (const void *s) { memcpy (c, s, nc); }
void put (void *d) { memcpy (d, c, nc); }
};
static void blkclear (blk *d)
{ for (int i = 0; i < blk::nl; i++) d->l[i] = 0; }
static void blkxor (blk *d, const blk &s1, const blk &s2)
{ for (int i = 0; i < blk::nl; i++) d->l[i] = s1.l[i] ^ s2.l[i]; }
static void blkxor (blk *d, const blk &s)
{ for (int i = 0; i < blk::nl; i++) d->l[i] ^= s.l[i]; }
static void lshift (blk *d, const blk &s);
static void lshift (blk *d) { lshift (d, *d); }
static void rshift (blk *d, const blk &s);
static void rshift (blk *d) { rshift (d, *d); }
private:
const size_t maxmsg_size;
const u_int l_size;
aes k;
blk *l;
public:
ocb (size_t max_msg_size);
~ocb ();
void setkey (const void *key, u_int keylen);
void encrypt (void *ctext, blk *tag, u_int64_t nonce,
const void *ptext, size_t len) const;
bool decrypt (void *ptext, u_int64_t nonce, const void *ctext,
const blk *tag, size_t len) const;
};
#endif /* !_CRYPT_OCB_H_ */
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