e_chacha.c revision 1.3 
1/* $OpenBSD: e_chacha.c,v 1.3 2014/06/12 15:49:29 deraadt Exp $ */
2/*
3 * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#ifndef OPENSSL_NO_CHACHA
19
20#include <openssl/chacha.h>
21#include <openssl/evp.h>
22#include <openssl/objects.h>
23
24#include "evp_locl.h"
25
26static int chacha_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
27    const unsigned char *in, size_t len);
28static int chacha_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
29    const unsigned char *iv, int enc);
30
31static const EVP_CIPHER chacha20_cipher = {
32	.nid = NID_chacha20,
33	.block_size = 1,
34	.key_len = 32,
35	.iv_len = 8,
36	.flags = EVP_CIPH_STREAM_CIPHER,
37	.init = chacha_init,
38	.do_cipher = chacha_cipher,
39	.ctx_size = sizeof(ChaCha_ctx)
40};
41
42const EVP_CIPHER *
43EVP_chacha20(void)
44{
45	return (&chacha20_cipher);
46}
47
48static int
49chacha_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
50    const unsigned char *iv, int enc)
51{
52	ChaCha_set_key((ChaCha_ctx *)ctx->cipher_data, key,
53	    EVP_CIPHER_CTX_key_length(ctx) * 8);
54	ChaCha_set_iv((ChaCha_ctx *)ctx->cipher_data, iv, NULL);
55	return 1;
56}
57
58static int
59chacha_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in,
60    size_t len)
61{
62	ChaCha((ChaCha_ctx *)ctx->cipher_data, out, in, len);
63	return 1;
64}
65
66#endif
67