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freebsd/sys/opencrypto/xform_chacha20_poly1305.c
John Baldwin ab91fb6c21 crypto: Refactor software support for AEAD ciphers.
Extend struct enc_xform to add new members to handle auth operations
for AEAD ciphers.  In particular, AEAD operations in cryptosoft no
longer use a struct auth_hash.  Instead, the setkey and reinit methods
of struct enc_xform are responsible for initializing both the cipher
and auth state.

Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D33196
2021-12-09 11:52:42 -08:00

147 lines
4.5 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 Netflix Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <opencrypto/xform_auth.h>
#include <opencrypto/xform_enc.h>
#include <sodium/crypto_onetimeauth_poly1305.h>
#include <sodium/crypto_stream_chacha20.h>
struct chacha20_poly1305_ctx {
struct crypto_onetimeauth_poly1305_state auth;
const void *key;
uint32_t ic;
bool ietf;
char nonce[CHACHA20_POLY1305_IV_LEN];
};
static int
chacha20_poly1305_setkey(void *vctx, const uint8_t *key, int len)
{
struct chacha20_poly1305_ctx *ctx = vctx;
if (len != CHACHA20_POLY1305_KEY)
return (EINVAL);
ctx->key = key;
return (0);
}
static void
chacha20_poly1305_reinit(void *vctx, const uint8_t *iv, size_t ivlen)
{
struct chacha20_poly1305_ctx *ctx = vctx;
char block[CHACHA20_NATIVE_BLOCK_LEN];
KASSERT(ivlen == 8 || ivlen == sizeof(ctx->nonce),
("%s: invalid nonce length", __func__));
memcpy(ctx->nonce, iv, ivlen);
ctx->ietf = (ivlen == CHACHA20_POLY1305_IV_LEN);
/* Block 0 is used for the poly1305 key. */
if (ctx->ietf)
crypto_stream_chacha20_ietf(block, sizeof(block), iv, ctx->key);
else
crypto_stream_chacha20(block, sizeof(block), iv, ctx->key);
crypto_onetimeauth_poly1305_init(&ctx->auth, block);
explicit_bzero(block, sizeof(block));
/* Start with block 1 for ciphertext. */
ctx->ic = 1;
}
static void
chacha20_poly1305_crypt(void *vctx, const uint8_t *in, uint8_t *out)
{
struct chacha20_poly1305_ctx *ctx = vctx;
int error __diagused;
if (ctx->ietf)
error = crypto_stream_chacha20_ietf_xor_ic(out, in,
CHACHA20_NATIVE_BLOCK_LEN, ctx->nonce, ctx->ic, ctx->key);
else
error = crypto_stream_chacha20_xor_ic(out, in,
CHACHA20_NATIVE_BLOCK_LEN, ctx->nonce, ctx->ic, ctx->key);
KASSERT(error == 0, ("%s failed: %d", __func__, error));
ctx->ic++;
}
static void
chacha20_poly1305_crypt_last(void *vctx, const uint8_t *in, uint8_t *out,
size_t len)
{
struct chacha20_poly1305_ctx *ctx = vctx;
int error __diagused;
if (ctx->ietf)
error = crypto_stream_chacha20_ietf_xor_ic(out, in, len,
ctx->nonce, ctx->ic, ctx->key);
else
error = crypto_stream_chacha20_xor_ic(out, in, len, ctx->nonce,
ctx->ic, ctx->key);
KASSERT(error == 0, ("%s failed: %d", __func__, error));
}
static int
chacha20_poly1305_update(void *vctx, const void *data, u_int len)
{
struct chacha20_poly1305_ctx *ctx = vctx;
crypto_onetimeauth_poly1305_update(&ctx->auth, data, len);
return (0);
}
static void
chacha20_poly1305_final(uint8_t *digest, void *vctx)
{
struct chacha20_poly1305_ctx *ctx = vctx;
crypto_onetimeauth_poly1305_final(&ctx->auth, digest);
}
const struct enc_xform enc_xform_chacha20_poly1305 = {
.type = CRYPTO_CHACHA20_POLY1305,
.name = "ChaCha20-Poly1305",
.ctxsize = sizeof(struct chacha20_poly1305_ctx),
.blocksize = 1,
.native_blocksize = CHACHA20_NATIVE_BLOCK_LEN,
.ivsize = CHACHA20_POLY1305_IV_LEN,
.minkey = CHACHA20_POLY1305_KEY,
.maxkey = CHACHA20_POLY1305_KEY,
.macsize = POLY1305_HASH_LEN,
.encrypt = chacha20_poly1305_crypt,
.decrypt = chacha20_poly1305_crypt,
.setkey = chacha20_poly1305_setkey,
.reinit = chacha20_poly1305_reinit,
.encrypt_last = chacha20_poly1305_crypt_last,
.decrypt_last = chacha20_poly1305_crypt_last,
.update = chacha20_poly1305_update,
.final = chacha20_poly1305_final,
};