File: [local] / src / usr.bin / ssh / cipher-chachapoly.h (download)
Revision 1.1, Thu Nov 21 00:45:44 2013 UTC (10 years, 6 months ago) by djm
Branch: MAIN
CVS Tags: OPENBSD_5_5_BASE, OPENBSD_5_5
Add a new protocol 2 transport cipher "chacha20-poly1305@openssh.com"
that combines Daniel Bernstein's ChaCha20 stream cipher and Poly1305 MAC
to build an authenticated encryption mode.
Inspired by and similar to Adam Langley's proposal for TLS:
http://tools.ietf.org/html/draft-agl-tls-chacha20poly1305-03
but differs in layout used for the MAC calculation and the use of a
second ChaCha20 instance to separately encrypt packet lengths.
Details are in the PROTOCOL.chacha20poly1305 file.
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/* $OpenBSD: cipher-chachapoly.h,v 1.1 2013/11/21 00:45:44 djm Exp $ */
/*
* Copyright (c) Damien Miller 2013 <djm@mindrot.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef CHACHA_POLY_AEAD_H
#define CHACHA_POLY_AEAD_H
#include <sys/types.h>
#include "chacha.h"
#include "poly1305.h"
#define CHACHA_KEYLEN 32 /* Only 256 bit keys used here */
struct chachapoly_ctx {
struct chacha_ctx main_ctx, header_ctx;
};
void chachapoly_init(struct chachapoly_ctx *cpctx,
const u_char *key, u_int keylen)
__attribute__((__bounded__(__buffer__, 2, 3)));
int chachapoly_crypt(struct chachapoly_ctx *cpctx, u_int seqnr,
u_char *dest, const u_char *src, u_int len, u_int aadlen, u_int authlen,
int do_encrypt);
int chachapoly_get_length(struct chachapoly_ctx *cpctx,
u_int *plenp, u_int seqnr, const u_char *cp, u_int len)
__attribute__((__bounded__(__buffer__, 4, 5)));
#endif /* CHACHA_POLY_AEAD_H */