/*

 * Copyright (C) 2011-2012 Free Software Foundation, Inc.

 * Copyright (C) 2018 Red Hat, Inc.

 *

 * Author: Nikos Mavrogiannopoulos

 *

 * This file is part of GnuTLS.

 *

 * The GnuTLS is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public License

 * as published by the Free Software Foundation; either version 2.1 of

 * the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>

 *

 */

/*

 * The following code is an implementation of the AES-128-CBC cipher

 * using intel's AES instruction set. 

 */

#include "errors.h"

#include "gnutls_int.h"

#include <gnutls/crypto.h>

#include "errors.h"

#include <aes-x86.h>

#include <sha-x86.h>

#include <x86-common.h>

struct aes_ctx {

	AES_KEY expanded_key;

	uint8_t iv[16];

	int enc;

};

static int

aes_cipher_init(gnutls_cipher_algorithm_t algorithm, void **_ctx, int enc)

{

	/* we use key size to distinguish */

	if (algorithm != GNUTLS_CIPHER_AES_128_CBC

	    && algorithm != GNUTLS_CIPHER_AES_192_CBC

	    && algorithm != GNUTLS_CIPHER_AES_256_CBC)

		return GNUTLS_E_INVALID_REQUEST;

	*_ctx = gnutls_calloc(1, sizeof(struct aes_ctx));

	if (*_ctx == NULL) {

		gnutls_assert();

		return GNUTLS_E_MEMORY_ERROR;

	}

	((struct aes_ctx *) (*_ctx))->enc = enc;

	return 0;

}

static int

aes_ssse3_cipher_setkey(void *_ctx, const void *userkey, size_t keysize)

{

	struct aes_ctx *ctx = _ctx;

	int ret;

	CHECK_AES_KEYSIZE(keysize);

	if (ctx->enc)

		ret =

		    vpaes_set_encrypt_key(userkey, keysize * 8,

					  ALIGN16(&ctx->expanded_key));

	else

		ret =

		    vpaes_set_decrypt_key(userkey, keysize * 8,

					  ALIGN16(&ctx->expanded_key));

	if (ret != 0)

		return gnutls_assert_val(GNUTLS_E_ENCRYPTION_FAILED);

	return 0;

}

static int

aes_ssse3_encrypt(void *_ctx, const void *src, size_t src_size,

	    void *dst, size_t dst_size)

{

	struct aes_ctx *ctx = _ctx;

	if (unlikely(src_size % 16 != 0))

		return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

	vpaes_cbc_encrypt(src, dst, src_size, ALIGN16(&ctx->expanded_key),

			  ctx->iv, 1);

	return 0;

}

static int

aes_ssse3_decrypt(void *_ctx, const void *src, size_t src_size,

	    void *dst, size_t dst_size)

{

	struct aes_ctx *ctx = _ctx;

	if (unlikely(src_size % 16 != 0))

		return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

	vpaes_cbc_encrypt(src, dst, src_size, ALIGN16(&ctx->expanded_key),

			  ctx->iv, 0);

	return 0;

}

static int aes_setiv(void *_ctx, const void *iv, size_t iv_size)

{

	struct aes_ctx *ctx = _ctx;

	if (iv_size != 16)

		return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

	memcpy(ctx->iv, iv, 16);

	return 0;

}

static void aes_deinit(void *_ctx)

{

	struct aes_ctx *ctx = _ctx;

	zeroize_temp_key(ctx, sizeof(*ctx));

	gnutls_free(ctx);

}

const gnutls_crypto_cipher_st _gnutls_aes_ssse3 = {

	.init = aes_cipher_init,

	.setkey = aes_ssse3_cipher_setkey,

	.setiv = aes_setiv,

	.encrypt = aes_ssse3_encrypt,

	.decrypt = aes_ssse3_decrypt,

	.deinit = aes_deinit,

};