crypto/aegis128.c - third_party/linux - Git at Google

 /*
  * The AEGIS-128 Authenticated-Encryption Algorithm
  *
  * Copyright (c) 2017-2018 Ondrej Mosnacek <omosnacek@gmail.com>
  * Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
  *
  * 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 of the License, or (at your option)
  * any later version.
  */

 #include <crypto/algapi.h>
 #include <crypto/internal/aead.h>
 #include <crypto/internal/skcipher.h>
 #include <crypto/scatterwalk.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/scatterlist.h>

 #include "aegis.h"

 #define AEGIS128_NONCE_SIZE 16
 #define AEGIS128_STATE_BLOCKS 5
 #define AEGIS128_KEY_SIZE 16
 #define AEGIS128_MIN_AUTH_SIZE 8
 #define AEGIS128_MAX_AUTH_SIZE 16

 struct aegis_state {
 	union aegis_block blocks[AEGIS128_STATE_BLOCKS];
 };

 struct aegis_ctx {
 	union aegis_block key;
 };

 struct aegis128_ops {
 	int (*skcipher_walk_init)(struct skcipher_walk *walk,
 				  struct aead_request *req, bool atomic);

 	void (*crypt_chunk)(struct aegis_state *state, u8 *dst,
 			    const u8 *src, unsigned int size);
 };

 static void crypto_aegis128_update(struct aegis_state *state)
 {
 	union aegis_block tmp;
 	unsigned int i;

 	tmp = state->blocks[AEGIS128_STATE_BLOCKS - 1];
 	for (i = AEGIS128_STATE_BLOCKS - 1; i > 0; i--)
 		crypto_aegis_aesenc(&state->blocks[i], &state->blocks[i - 1],
 				    &state->blocks[i]);
 	crypto_aegis_aesenc(&state->blocks[0], &tmp, &state->blocks[0]);
 }

 static void crypto_aegis128_update_a(struct aegis_state *state,
 				     const union aegis_block *msg)
 {
 	crypto_aegis128_update(state);
 	crypto_aegis_block_xor(&state->blocks[0], msg);
 }

 static void crypto_aegis128_update_u(struct aegis_state *state, const void *msg)
 {
 	crypto_aegis128_update(state);
 	crypto_xor(state->blocks[0].bytes, msg, AEGIS_BLOCK_SIZE);
 }

 static void crypto_aegis128_init(struct aegis_state *state,
 				 const union aegis_block *key,
 				 const u8 *iv)
 {
 	union aegis_block key_iv;
 	unsigned int i;

 	key_iv = *key;
 	crypto_xor(key_iv.bytes, iv, AEGIS_BLOCK_SIZE);

 	state->blocks[0] = key_iv;
 	state->blocks[1] = crypto_aegis_const[1];
 	state->blocks[2] = crypto_aegis_const[0];
 	state->blocks[3] = *key;
 	state->blocks[4] = *key;

 	crypto_aegis_block_xor(&state->blocks[3], &crypto_aegis_const[0]);
 	crypto_aegis_block_xor(&state->blocks[4], &crypto_aegis_const[1]);

 	for (i = 0; i < 5; i++) {
 		crypto_aegis128_update_a(state, key);
 		crypto_aegis128_update_a(state, &key_iv);
 	}
 }

 static void crypto_aegis128_ad(struct aegis_state *state,
 			       const u8 *src, unsigned int size)
 {
 	if (AEGIS_ALIGNED(src)) {
 		const union aegis_block *src_blk =
 				(const union aegis_block *)src;

 		while (size >= AEGIS_BLOCK_SIZE) {
 			crypto_aegis128_update_a(state, src_blk);

 			size -= AEGIS_BLOCK_SIZE;
 			src_blk++;
 		}
 	} else {
 		while (size >= AEGIS_BLOCK_SIZE) {
 			crypto_aegis128_update_u(state, src);

 			size -= AEGIS_BLOCK_SIZE;
 			src += AEGIS_BLOCK_SIZE;
 		}
 	}
 }

 static void crypto_aegis128_encrypt_chunk(struct aegis_state *state, u8 *dst,
 					  const u8 *src, unsigned int size)
 {
 	union aegis_block tmp;

 	if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
 		while (size >= AEGIS_BLOCK_SIZE) {
 			union aegis_block *dst_blk =
 					(union aegis_block *)dst;
 			const union aegis_block *src_blk =
 					(const union aegis_block *)src;

 			tmp = state->blocks[2];
 			crypto_aegis_block_and(&tmp, &state->blocks[3]);
 			crypto_aegis_block_xor(&tmp, &state->blocks[4]);
 			crypto_aegis_block_xor(&tmp, &state->blocks[1]);
 			crypto_aegis_block_xor(&tmp, src_blk);

 			crypto_aegis128_update_a(state, src_blk);

 			*dst_blk = tmp;

 			size -= AEGIS_BLOCK_SIZE;
 			src += AEGIS_BLOCK_SIZE;
 			dst += AEGIS_BLOCK_SIZE;
 		}
 	} else {
 		while (size >= AEGIS_BLOCK_SIZE) {
 			tmp = state->blocks[2];
 			crypto_aegis_block_and(&tmp, &state->blocks[3]);
 			crypto_aegis_block_xor(&tmp, &state->blocks[4]);
 			crypto_aegis_block_xor(&tmp, &state->blocks[1]);
 			crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);

 			crypto_aegis128_update_u(state, src);

 			memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);

 			size -= AEGIS_BLOCK_SIZE;
 			src += AEGIS_BLOCK_SIZE;
 			dst += AEGIS_BLOCK_SIZE;
 		}
 	}

 	if (size > 0) {
 		union aegis_block msg = {};
 		memcpy(msg.bytes, src, size);

 		tmp = state->blocks[2];
 		crypto_aegis_block_and(&tmp, &state->blocks[3]);
 		crypto_aegis_block_xor(&tmp, &state->blocks[4]);
 		crypto_aegis_block_xor(&tmp, &state->blocks[1]);

 		crypto_aegis128_update_a(state, &msg);

 		crypto_aegis_block_xor(&msg, &tmp);

 		memcpy(dst, msg.bytes, size);
 	}
 }

 static void crypto_aegis128_decrypt_chunk(struct aegis_state *state, u8 *dst,
 					  const u8 *src, unsigned int size)
 {
 	union aegis_block tmp;

 	if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
 		while (size >= AEGIS_BLOCK_SIZE) {
 			union aegis_block *dst_blk =
 					(union aegis_block *)dst;
 			const union aegis_block *src_blk =
 					(const union aegis_block *)src;

 			tmp = state->blocks[2];
 			crypto_aegis_block_and(&tmp, &state->blocks[3]);
 			crypto_aegis_block_xor(&tmp, &state->blocks[4]);
 			crypto_aegis_block_xor(&tmp, &state->blocks[1]);
 			crypto_aegis_block_xor(&tmp, src_blk);

 			crypto_aegis128_update_a(state, &tmp);

 			*dst_blk = tmp;

 			size -= AEGIS_BLOCK_SIZE;
 			src += AEGIS_BLOCK_SIZE;
 			dst += AEGIS_BLOCK_SIZE;
 		}
 	} else {
 		while (size >= AEGIS_BLOCK_SIZE) {
 			tmp = state->blocks[2];
 			crypto_aegis_block_and(&tmp, &state->blocks[3]);
 			crypto_aegis_block_xor(&tmp, &state->blocks[4]);
 			crypto_aegis_block_xor(&tmp, &state->blocks[1]);
 			crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);

 			crypto_aegis128_update_a(state, &tmp);

 			memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);

 			size -= AEGIS_BLOCK_SIZE;
 			src += AEGIS_BLOCK_SIZE;
 			dst += AEGIS_BLOCK_SIZE;
 		}
 	}

 	if (size > 0) {
 		union aegis_block msg = {};
 		memcpy(msg.bytes, src, size);

 		tmp = state->blocks[2];
 		crypto_aegis_block_and(&tmp, &state->blocks[3]);
 		crypto_aegis_block_xor(&tmp, &state->blocks[4]);
 		crypto_aegis_block_xor(&tmp, &state->blocks[1]);
 		crypto_aegis_block_xor(&msg, &tmp);

 		memset(msg.bytes + size, 0, AEGIS_BLOCK_SIZE - size);

 		crypto_aegis128_update_a(state, &msg);

 		memcpy(dst, msg.bytes, size);
 	}
 }

 static void crypto_aegis128_process_ad(struct aegis_state *state,
 				       struct scatterlist *sg_src,
 				       unsigned int assoclen)
 {
 	struct scatter_walk walk;
 	union aegis_block buf;
 	unsigned int pos = 0;

 	scatterwalk_start(&walk, sg_src);
 	while (assoclen != 0) {
 		unsigned int size = scatterwalk_clamp(&walk, assoclen);
 		unsigned int left = size;
 		void *mapped = scatterwalk_map(&walk);
 		const u8 *src = (const u8 *)mapped;

 		if (pos + size >= AEGIS_BLOCK_SIZE) {
 			if (pos > 0) {
 				unsigned int fill = AEGIS_BLOCK_SIZE - pos;
 				memcpy(buf.bytes + pos, src, fill);
 				crypto_aegis128_update_a(state, &buf);
 				pos = 0;
 				left -= fill;
 				src += fill;
 			}

 			crypto_aegis128_ad(state, src, left);
 			src += left & ~(AEGIS_BLOCK_SIZE - 1);
 			left &= AEGIS_BLOCK_SIZE - 1;
 		}

 		memcpy(buf.bytes + pos, src, left);

 		pos += left;
 		assoclen -= size;
 		scatterwalk_unmap(mapped);
 		scatterwalk_advance(&walk, size);
 		scatterwalk_done(&walk, 0, assoclen);
 	}

 	if (pos > 0) {
 		memset(buf.bytes + pos, 0, AEGIS_BLOCK_SIZE - pos);
 		crypto_aegis128_update_a(state, &buf);
 	}
 }

 static void crypto_aegis128_process_crypt(struct aegis_state *state,
 					  struct aead_request *req,
 					  const struct aegis128_ops *ops)
 {
 	struct skcipher_walk walk;
 	u8 *src, *dst;
 	unsigned int chunksize;

 	ops->skcipher_walk_init(&walk, req, false);

 	while (walk.nbytes) {
 		src = walk.src.virt.addr;
 		dst = walk.dst.virt.addr;
 		chunksize = walk.nbytes;

 		ops->crypt_chunk(state, dst, src, chunksize);

 		skcipher_walk_done(&walk, 0);
 	}
 }

 static void crypto_aegis128_final(struct aegis_state *state,
 				  union aegis_block *tag_xor,
 				  u64 assoclen, u64 cryptlen)
 {
 	u64 assocbits = assoclen * 8;
 	u64 cryptbits = cryptlen * 8;

 	union aegis_block tmp;
 	unsigned int i;

 	tmp.words64[0] = cpu_to_le64(assocbits);
 	tmp.words64[1] = cpu_to_le64(cryptbits);

 	crypto_aegis_block_xor(&tmp, &state->blocks[3]);

 	for (i = 0; i < 7; i++)
 		crypto_aegis128_update_a(state, &tmp);

 	for (i = 0; i < AEGIS128_STATE_BLOCKS; i++)
 		crypto_aegis_block_xor(tag_xor, &state->blocks[i]);
 }

 static int crypto_aegis128_setkey(struct crypto_aead *aead, const u8 *key,
 				  unsigned int keylen)
 {
 	struct aegis_ctx *ctx = crypto_aead_ctx(aead);

 	if (keylen != AEGIS128_KEY_SIZE) {
 		crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
 		return -EINVAL;
 	}

 	memcpy(ctx->key.bytes, key, AEGIS128_KEY_SIZE);
 	return 0;
 }

 static int crypto_aegis128_setauthsize(struct crypto_aead *tfm,
 				       unsigned int authsize)
 {
 	if (authsize > AEGIS128_MAX_AUTH_SIZE)
 		return -EINVAL;
 	if (authsize < AEGIS128_MIN_AUTH_SIZE)
 		return -EINVAL;
 	return 0;
 }

 static void crypto_aegis128_crypt(struct aead_request *req,
 				  union aegis_block *tag_xor,
 				  unsigned int cryptlen,
 				  const struct aegis128_ops *ops)
 {
 	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 	struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
 	struct aegis_state state;

 	crypto_aegis128_init(&state, &ctx->key, req->iv);
 	crypto_aegis128_process_ad(&state, req->src, req->assoclen);
 	crypto_aegis128_process_crypt(&state, req, ops);
 	crypto_aegis128_final(&state, tag_xor, req->assoclen, cryptlen);
 }

 static int crypto_aegis128_encrypt(struct aead_request *req)
 {
 	static const struct aegis128_ops ops = {
 		.skcipher_walk_init = skcipher_walk_aead_encrypt,
 		.crypt_chunk = crypto_aegis128_encrypt_chunk,
 	};

 	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 	union aegis_block tag = {};
 	unsigned int authsize = crypto_aead_authsize(tfm);
 	unsigned int cryptlen = req->cryptlen;

 	crypto_aegis128_crypt(req, &tag, cryptlen, &ops);

 	scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen,
 				 authsize, 1);
 	return 0;
 }

 static int crypto_aegis128_decrypt(struct aead_request *req)
 {
 	static const struct aegis128_ops ops = {
 		.skcipher_walk_init = skcipher_walk_aead_decrypt,
 		.crypt_chunk = crypto_aegis128_decrypt_chunk,
 	};
 	static const u8 zeros[AEGIS128_MAX_AUTH_SIZE] = {};

 	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 	union aegis_block tag;
 	unsigned int authsize = crypto_aead_authsize(tfm);
 	unsigned int cryptlen = req->cryptlen - authsize;

 	scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen,
 				 authsize, 0);

 	crypto_aegis128_crypt(req, &tag, cryptlen, &ops);

 	return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0;
 }

 static int crypto_aegis128_init_tfm(struct crypto_aead *tfm)
 {
 	return 0;
 }

 static void crypto_aegis128_exit_tfm(struct crypto_aead *tfm)
 {
 }

 static struct aead_alg crypto_aegis128_alg = {
 	.setkey = crypto_aegis128_setkey,
 	.setauthsize = crypto_aegis128_setauthsize,
 	.encrypt = crypto_aegis128_encrypt,
 	.decrypt = crypto_aegis128_decrypt,
 	.init = crypto_aegis128_init_tfm,
 	.exit = crypto_aegis128_exit_tfm,

 	.ivsize = AEGIS128_NONCE_SIZE,
 	.maxauthsize = AEGIS128_MAX_AUTH_SIZE,
 	.chunksize = AEGIS_BLOCK_SIZE,

 	.base = {
 		.cra_flags = CRYPTO_ALG_TYPE_AEAD,
 		.cra_blocksize = 1,
 		.cra_ctxsize = sizeof(struct aegis_ctx),
 		.cra_alignmask = 0,

 		.cra_priority = 100,

 		.cra_name = "aegis128",
 		.cra_driver_name = "aegis128-generic",

 		.cra_module = THIS_MODULE,
 	}
 };

 static int __init crypto_aegis128_module_init(void)
 {
 	return crypto_register_aead(&crypto_aegis128_alg);
 }

 static void __exit crypto_aegis128_module_exit(void)
 {
 	crypto_unregister_aead(&crypto_aegis128_alg);
 }

 module_init(crypto_aegis128_module_init);
 module_exit(crypto_aegis128_module_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
 MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm");
 MODULE_ALIAS_CRYPTO("aegis128");
 MODULE_ALIAS_CRYPTO("aegis128-generic");
	/*
	* The AEGIS-128 Authenticated-Encryption Algorithm
	*
	* Copyright (c) 2017-2018 Ondrej Mosnacek <omosnacek@gmail.com>
	* Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
	*
	* 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 of the License, or (at your option)
	* any later version.
	*/

	#include <crypto/algapi.h>
	#include <crypto/internal/aead.h>
	#include <crypto/internal/skcipher.h>
	#include <crypto/scatterwalk.h>
	#include <linux/err.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/scatterlist.h>

	#include "aegis.h"

	#define AEGIS128_NONCE_SIZE 16
	#define AEGIS128_STATE_BLOCKS 5
	#define AEGIS128_KEY_SIZE 16
	#define AEGIS128_MIN_AUTH_SIZE 8
	#define AEGIS128_MAX_AUTH_SIZE 16

	struct aegis_state {
	union aegis_block blocks[AEGIS128_STATE_BLOCKS];
	};

	struct aegis_ctx {
	union aegis_block key;
	};

	struct aegis128_ops {
	int (skcipher_walk_init)(struct skcipher_walk walk,
	struct aead_request *req, bool atomic);

	void (crypt_chunk)(struct aegis_state state, u8 *dst,
	const u8 *src, unsigned int size);
	};

	static void crypto_aegis128_update(struct aegis_state *state)
	{
	union aegis_block tmp;
	unsigned int i;

	tmp = state->blocks[AEGIS128_STATE_BLOCKS - 1];
	for (i = AEGIS128_STATE_BLOCKS - 1; i > 0; i--)
	crypto_aegis_aesenc(&state->blocks[i], &state->blocks[i - 1],
	&state->blocks[i]);
	crypto_aegis_aesenc(&state->blocks[0], &tmp, &state->blocks[0]);
	}

	static void crypto_aegis128_update_a(struct aegis_state *state,
	const union aegis_block *msg)
	{
	crypto_aegis128_update(state);
	crypto_aegis_block_xor(&state->blocks[0], msg);
	}

	static void crypto_aegis128_update_u(struct aegis_state state, const void msg)
	{
	crypto_aegis128_update(state);
	crypto_xor(state->blocks[0].bytes, msg, AEGIS_BLOCK_SIZE);
	}

	static void crypto_aegis128_init(struct aegis_state *state,
	const union aegis_block *key,
	const u8 *iv)
	{
	union aegis_block key_iv;
	unsigned int i;

	key_iv = *key;
	crypto_xor(key_iv.bytes, iv, AEGIS_BLOCK_SIZE);

	state->blocks[0] = key_iv;
	state->blocks[1] = crypto_aegis_const[1];
	state->blocks[2] = crypto_aegis_const[0];
	state->blocks[3] = *key;
	state->blocks[4] = *key;

	crypto_aegis_block_xor(&state->blocks[3], &crypto_aegis_const[0]);
	crypto_aegis_block_xor(&state->blocks[4], &crypto_aegis_const[1]);

	for (i = 0; i < 5; i++) {
	crypto_aegis128_update_a(state, key);
	crypto_aegis128_update_a(state, &key_iv);
	}
	}

	static void crypto_aegis128_ad(struct aegis_state *state,
	const u8 *src, unsigned int size)
	{
	if (AEGIS_ALIGNED(src)) {
	const union aegis_block *src_blk =
	(const union aegis_block *)src;

	while (size >= AEGIS_BLOCK_SIZE) {
	crypto_aegis128_update_a(state, src_blk);

	size -= AEGIS_BLOCK_SIZE;
	src_blk++;
	}
	} else {
	while (size >= AEGIS_BLOCK_SIZE) {
	crypto_aegis128_update_u(state, src);

	size -= AEGIS_BLOCK_SIZE;
	src += AEGIS_BLOCK_SIZE;
	}
	}
	}

	static void crypto_aegis128_encrypt_chunk(struct aegis_state state, u8 dst,
	const u8 *src, unsigned int size)
	{
	union aegis_block tmp;

	if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
	while (size >= AEGIS_BLOCK_SIZE) {
	union aegis_block *dst_blk =
	(union aegis_block *)dst;
	const union aegis_block *src_blk =
	(const union aegis_block *)src;

	tmp = state->blocks[2];
	crypto_aegis_block_and(&tmp, &state->blocks[3]);
	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
	crypto_aegis_block_xor(&tmp, src_blk);

	crypto_aegis128_update_a(state, src_blk);

	*dst_blk = tmp;

	size -= AEGIS_BLOCK_SIZE;
	src += AEGIS_BLOCK_SIZE;
	dst += AEGIS_BLOCK_SIZE;
	}
	} else {
	while (size >= AEGIS_BLOCK_SIZE) {
	tmp = state->blocks[2];
	crypto_aegis_block_and(&tmp, &state->blocks[3]);
	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
	crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);

	crypto_aegis128_update_u(state, src);

	memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);

	size -= AEGIS_BLOCK_SIZE;
	src += AEGIS_BLOCK_SIZE;
	dst += AEGIS_BLOCK_SIZE;
	}
	}

	if (size > 0) {
	union aegis_block msg = {};
	memcpy(msg.bytes, src, size);

	tmp = state->blocks[2];
	crypto_aegis_block_and(&tmp, &state->blocks[3]);
	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
	crypto_aegis_block_xor(&tmp, &state->blocks[1]);

	crypto_aegis128_update_a(state, &msg);

	crypto_aegis_block_xor(&msg, &tmp);

	memcpy(dst, msg.bytes, size);
	}
	}

	static void crypto_aegis128_decrypt_chunk(struct aegis_state state, u8 dst,
	const u8 *src, unsigned int size)
	{
	union aegis_block tmp;

	if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
	while (size >= AEGIS_BLOCK_SIZE) {
	union aegis_block *dst_blk =
	(union aegis_block *)dst;
	const union aegis_block *src_blk =
	(const union aegis_block *)src;

	tmp = state->blocks[2];
	crypto_aegis_block_and(&tmp, &state->blocks[3]);
	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
	crypto_aegis_block_xor(&tmp, src_blk);

	crypto_aegis128_update_a(state, &tmp);

	*dst_blk = tmp;

	size -= AEGIS_BLOCK_SIZE;
	src += AEGIS_BLOCK_SIZE;
	dst += AEGIS_BLOCK_SIZE;
	}
	} else {
	while (size >= AEGIS_BLOCK_SIZE) {
	tmp = state->blocks[2];
	crypto_aegis_block_and(&tmp, &state->blocks[3]);
	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
	crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);

	crypto_aegis128_update_a(state, &tmp);

	memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);

	size -= AEGIS_BLOCK_SIZE;
	src += AEGIS_BLOCK_SIZE;
	dst += AEGIS_BLOCK_SIZE;
	}
	}

	if (size > 0) {
	union aegis_block msg = {};
	memcpy(msg.bytes, src, size);

	tmp = state->blocks[2];
	crypto_aegis_block_and(&tmp, &state->blocks[3]);
	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
	crypto_aegis_block_xor(&msg, &tmp);

	memset(msg.bytes + size, 0, AEGIS_BLOCK_SIZE - size);

	crypto_aegis128_update_a(state, &msg);

	memcpy(dst, msg.bytes, size);
	}
	}

	static void crypto_aegis128_process_ad(struct aegis_state *state,
	struct scatterlist *sg_src,
	unsigned int assoclen)
	{
	struct scatter_walk walk;
	union aegis_block buf;
	unsigned int pos = 0;

	scatterwalk_start(&walk, sg_src);
	while (assoclen != 0) {
	unsigned int size = scatterwalk_clamp(&walk, assoclen);
	unsigned int left = size;
	void *mapped = scatterwalk_map(&walk);
	const u8 src = (const u8 )mapped;

	if (pos + size >= AEGIS_BLOCK_SIZE) {
	if (pos > 0) {
	unsigned int fill = AEGIS_BLOCK_SIZE - pos;
	memcpy(buf.bytes + pos, src, fill);
	crypto_aegis128_update_a(state, &buf);
	pos = 0;
	left -= fill;
	src += fill;
	}

	crypto_aegis128_ad(state, src, left);
	src += left & ~(AEGIS_BLOCK_SIZE - 1);
	left &= AEGIS_BLOCK_SIZE - 1;
	}

	memcpy(buf.bytes + pos, src, left);

	pos += left;
	assoclen -= size;
	scatterwalk_unmap(mapped);
	scatterwalk_advance(&walk, size);
	scatterwalk_done(&walk, 0, assoclen);
	}

	if (pos > 0) {
	memset(buf.bytes + pos, 0, AEGIS_BLOCK_SIZE - pos);
	crypto_aegis128_update_a(state, &buf);
	}
	}

	static void crypto_aegis128_process_crypt(struct aegis_state *state,
	struct aead_request *req,
	const struct aegis128_ops *ops)
	{
	struct skcipher_walk walk;
	u8 src, dst;
	unsigned int chunksize;

	ops->skcipher_walk_init(&walk, req, false);

	while (walk.nbytes) {
	src = walk.src.virt.addr;
	dst = walk.dst.virt.addr;
	chunksize = walk.nbytes;

	ops->crypt_chunk(state, dst, src, chunksize);

	skcipher_walk_done(&walk, 0);
	}
	}

	static void crypto_aegis128_final(struct aegis_state *state,
	union aegis_block *tag_xor,
	u64 assoclen, u64 cryptlen)
	{
	u64 assocbits = assoclen * 8;
	u64 cryptbits = cryptlen * 8;

	union aegis_block tmp;
	unsigned int i;

	tmp.words64[0] = cpu_to_le64(assocbits);
	tmp.words64[1] = cpu_to_le64(cryptbits);

	crypto_aegis_block_xor(&tmp, &state->blocks[3]);

	for (i = 0; i < 7; i++)
	crypto_aegis128_update_a(state, &tmp);

	for (i = 0; i < AEGIS128_STATE_BLOCKS; i++)
	crypto_aegis_block_xor(tag_xor, &state->blocks[i]);
	}

	static int crypto_aegis128_setkey(struct crypto_aead aead, const u8 key,
	unsigned int keylen)
	{
	struct aegis_ctx *ctx = crypto_aead_ctx(aead);

	if (keylen != AEGIS128_KEY_SIZE) {
	crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
	return -EINVAL;
	}

	memcpy(ctx->key.bytes, key, AEGIS128_KEY_SIZE);
	return 0;
	}

	static int crypto_aegis128_setauthsize(struct crypto_aead *tfm,
	unsigned int authsize)
	{
	if (authsize > AEGIS128_MAX_AUTH_SIZE)
	return -EINVAL;
	if (authsize < AEGIS128_MIN_AUTH_SIZE)
	return -EINVAL;
	return 0;
	}

	static void crypto_aegis128_crypt(struct aead_request *req,
	union aegis_block *tag_xor,
	unsigned int cryptlen,
	const struct aegis128_ops *ops)
	{
	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
	struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
	struct aegis_state state;

	crypto_aegis128_init(&state, &ctx->key, req->iv);
	crypto_aegis128_process_ad(&state, req->src, req->assoclen);
	crypto_aegis128_process_crypt(&state, req, ops);
	crypto_aegis128_final(&state, tag_xor, req->assoclen, cryptlen);
	}

	static int crypto_aegis128_encrypt(struct aead_request *req)
	{
	static const struct aegis128_ops ops = {
	.skcipher_walk_init = skcipher_walk_aead_encrypt,
	.crypt_chunk = crypto_aegis128_encrypt_chunk,
	};

	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
	union aegis_block tag = {};
	unsigned int authsize = crypto_aead_authsize(tfm);
	unsigned int cryptlen = req->cryptlen;

	crypto_aegis128_crypt(req, &tag, cryptlen, &ops);

	scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen,
	authsize, 1);
	return 0;
	}

	static int crypto_aegis128_decrypt(struct aead_request *req)
	{
	static const struct aegis128_ops ops = {
	.skcipher_walk_init = skcipher_walk_aead_decrypt,
	.crypt_chunk = crypto_aegis128_decrypt_chunk,
	};
	static const u8 zeros[AEGIS128_MAX_AUTH_SIZE] = {};

	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
	union aegis_block tag;
	unsigned int authsize = crypto_aead_authsize(tfm);
	unsigned int cryptlen = req->cryptlen - authsize;

	scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen,
	authsize, 0);

	crypto_aegis128_crypt(req, &tag, cryptlen, &ops);

	return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0;
	}

	static int crypto_aegis128_init_tfm(struct crypto_aead *tfm)
	{
	return 0;
	}

	static void crypto_aegis128_exit_tfm(struct crypto_aead *tfm)
	{
	}

	static struct aead_alg crypto_aegis128_alg = {
	.setkey = crypto_aegis128_setkey,
	.setauthsize = crypto_aegis128_setauthsize,
	.encrypt = crypto_aegis128_encrypt,
	.decrypt = crypto_aegis128_decrypt,
	.init = crypto_aegis128_init_tfm,
	.exit = crypto_aegis128_exit_tfm,

	.ivsize = AEGIS128_NONCE_SIZE,
	.maxauthsize = AEGIS128_MAX_AUTH_SIZE,
	.chunksize = AEGIS_BLOCK_SIZE,

	.base = {
	.cra_flags = CRYPTO_ALG_TYPE_AEAD,
	.cra_blocksize = 1,
	.cra_ctxsize = sizeof(struct aegis_ctx),
	.cra_alignmask = 0,

	.cra_priority = 100,

	.cra_name = "aegis128",
	.cra_driver_name = "aegis128-generic",

	.cra_module = THIS_MODULE,
	}
	};

	static int __init crypto_aegis128_module_init(void)
	{
	return crypto_register_aead(&crypto_aegis128_alg);
	}

	static void __exit crypto_aegis128_module_exit(void)
	{
	crypto_unregister_aead(&crypto_aegis128_alg);
	}

	module_init(crypto_aegis128_module_init);
	module_exit(crypto_aegis128_module_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
	MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm");
	MODULE_ALIAS_CRYPTO("aegis128");
	MODULE_ALIAS_CRYPTO("aegis128-generic");