[linux.git] / crypto / aegis256.c

/*
 * The AEGIS-256 Authenticated-Encryption Algorithm
 *
 * Copyright (c) 2017-2018 Ondrej Mosnacek <[email protected]>
 * 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 AEGIS256_NONCE_SIZE 32
#define AEGIS256_STATE_BLOCKS 6
#define AEGIS256_KEY_SIZE 32
#define AEGIS256_MIN_AUTH_SIZE 8
#define AEGIS256_MAX_AUTH_SIZE 16

struct aegis_state {
	union aegis_block blocks[AEGIS256_STATE_BLOCKS];
};

struct aegis_ctx {
	union aegis_block key[AEGIS256_KEY_SIZE / AEGIS_BLOCK_SIZE];
};

struct aegis256_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_aegis256_update(struct aegis_state *state)
{
	union aegis_block tmp;
	unsigned int i;

	tmp = state->blocks[AEGIS256_STATE_BLOCKS - 1];
	for (i = AEGIS256_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_aegis256_update_a(struct aegis_state *state,
				     const union aegis_block *msg)
{
	crypto_aegis256_update(state);
	crypto_aegis_block_xor(&state->blocks[0], msg);
}

static void crypto_aegis256_update_u(struct aegis_state *state, const void *msg)
{
	crypto_aegis256_update(state);
	crypto_xor(state->blocks[0].bytes, msg, AEGIS_BLOCK_SIZE);
}

static void crypto_aegis256_init(struct aegis_state *state,
				 const union aegis_block *key,
				 const u8 *iv)
{
	union aegis_block key_iv[2];
	unsigned int i;

	key_iv[0] = key[0];
	key_iv[1] = key[1];
	crypto_xor(key_iv[0].bytes, iv + 0 * AEGIS_BLOCK_SIZE,
			AEGIS_BLOCK_SIZE);
	crypto_xor(key_iv[1].bytes, iv + 1 * AEGIS_BLOCK_SIZE,
			AEGIS_BLOCK_SIZE);

	state->blocks[0] = key_iv[0];
	state->blocks[1] = key_iv[1];
	state->blocks[2] = crypto_aegis_const[1];
	state->blocks[3] = crypto_aegis_const[0];
	state->blocks[4] = key[0];
	state->blocks[5] = key[1];

	crypto_aegis_block_xor(&state->blocks[4], &crypto_aegis_const[0]);
	crypto_aegis_block_xor(&state->blocks[5], &crypto_aegis_const[1]);

	for (i = 0; i < 4; i++) {
		crypto_aegis256_update_a(state, &key[0]);
		crypto_aegis256_update_a(state, &key[1]);
		crypto_aegis256_update_a(state, &key_iv[0]);
		crypto_aegis256_update_a(state, &key_iv[1]);
	}
}

static void crypto_aegis256_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_aegis256_update_a(state, src_blk);

			size -= AEGIS_BLOCK_SIZE;
			src_blk++;
		}
	} else {
		while (size >= AEGIS_BLOCK_SIZE) {
			crypto_aegis256_update_u(state, src);

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

static void crypto_aegis256_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[5]);
			crypto_aegis_block_xor(&tmp, &state->blocks[4]);
			crypto_aegis_block_xor(&tmp, &state->blocks[1]);
			crypto_aegis_block_xor(&tmp, src_blk);

			crypto_aegis256_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[5]);
			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_aegis256_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[5]);
		crypto_aegis_block_xor(&tmp, &state->blocks[4]);
		crypto_aegis_block_xor(&tmp, &state->blocks[1]);

		crypto_aegis256_update_a(state, &msg);

		crypto_aegis_block_xor(&msg, &tmp);

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

static void crypto_aegis256_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[5]);
			crypto_aegis_block_xor(&tmp, &state->blocks[4]);
			crypto_aegis_block_xor(&tmp, &state->blocks[1]);
			crypto_aegis_block_xor(&tmp, src_blk);

			crypto_aegis256_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[5]);
			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_aegis256_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[5]);
		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_aegis256_update_a(state, &msg);

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

static void crypto_aegis256_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_aegis256_update_a(state, &buf);
				pos = 0;
				left -= fill;
				src += fill;
			}

			crypto_aegis256_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_aegis256_update_a(state, &buf);
	}
}

static void crypto_aegis256_process_crypt(struct aegis_state *state,
					  struct aead_request *req,
					  const struct aegis256_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_aegis256_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_aegis256_update_a(state, &tmp);

	for (i = 0; i < AEGIS256_STATE_BLOCKS; i++)
		crypto_aegis_block_xor(tag_xor, &state->blocks[i]);
}

static int crypto_aegis256_setkey(struct crypto_aead *aead, const u8 *key,
				  unsigned int keylen)
{
	struct aegis_ctx *ctx = crypto_aead_ctx(aead);

	if (keylen != AEGIS256_KEY_SIZE) {
		crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
		return -EINVAL;
	}

	memcpy(ctx->key[0].bytes, key, AEGIS_BLOCK_SIZE);
	memcpy(ctx->key[1].bytes, key + AEGIS_BLOCK_SIZE,
			AEGIS_BLOCK_SIZE);
	return 0;
}

static int crypto_aegis256_setauthsize(struct crypto_aead *tfm,
				       unsigned int authsize)
{
	if (authsize > AEGIS256_MAX_AUTH_SIZE)
		return -EINVAL;
	if (authsize < AEGIS256_MIN_AUTH_SIZE)
		return -EINVAL;
	return 0;
}

static void crypto_aegis256_crypt(struct aead_request *req,
				  union aegis_block *tag_xor,
				  unsigned int cryptlen,
				  const struct aegis256_ops *ops)
{
	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
	struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
	struct aegis_state state;

	crypto_aegis256_init(&state, ctx->key, req->iv);
	crypto_aegis256_process_ad(&state, req->src, req->assoclen);
	crypto_aegis256_process_crypt(&state, req, ops);
	crypto_aegis256_final(&state, tag_xor, req->assoclen, cryptlen);
}

static int crypto_aegis256_encrypt(struct aead_request *req)
{
	static const struct aegis256_ops ops = {
		.skcipher_walk_init = skcipher_walk_aead_encrypt,
		.crypt_chunk = crypto_aegis256_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_aegis256_crypt(req, &tag, cryptlen, &ops);

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

static int crypto_aegis256_decrypt(struct aead_request *req)
{
	static const struct aegis256_ops ops = {
		.skcipher_walk_init = skcipher_walk_aead_decrypt,
		.crypt_chunk = crypto_aegis256_decrypt_chunk,
	};
	static const u8 zeros[AEGIS256_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_aegis256_crypt(req, &tag, cryptlen, &ops);

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

static int crypto_aegis256_init_tfm(struct crypto_aead *tfm)
{
	return 0;
}

static void crypto_aegis256_exit_tfm(struct crypto_aead *tfm)
{
}

static struct aead_alg crypto_aegis256_alg = {
	.setkey = crypto_aegis256_setkey,
	.setauthsize = crypto_aegis256_setauthsize,
	.encrypt = crypto_aegis256_encrypt,
	.decrypt = crypto_aegis256_decrypt,
	.init = crypto_aegis256_init_tfm,
	.exit = crypto_aegis256_exit_tfm,

	.ivsize = AEGIS256_NONCE_SIZE,
	.maxauthsize = AEGIS256_MAX_AUTH_SIZE,
	.chunksize = AEGIS_BLOCK_SIZE,

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

		.cra_priority = 100,

		.cra_name = "aegis256",
		.cra_driver_name = "aegis256-generic",

		.cra_module = THIS_MODULE,
	}
};

static int __init crypto_aegis256_module_init(void)
{
	return crypto_register_aead(&crypto_aegis256_alg);
}

static void __exit crypto_aegis256_module_exit(void)
{
	crypto_unregister_aead(&crypto_aegis256_alg);
}

module_init(crypto_aegis256_module_init);
module_exit(crypto_aegis256_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ondrej Mosnacek <[email protected]>");
MODULE_DESCRIPTION("AEGIS-256 AEAD algorithm");
MODULE_ALIAS_CRYPTO("aegis256");
MODULE_ALIAS_CRYPTO("aegis256-generic");
Commit	Line	Data
f606a88e OM	1	/*
	2	* The AEGIS-256 Authenticated-Encryption Algorithm
	3	*
	4	* Copyright (c) 2017-2018 Ondrej Mosnacek <[email protected]>
	5	* Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
	6	*
	7	* This program is free software; you can redistribute it and/or modify it
	8	* under the terms of the GNU General Public License as published by the Free
	9	* Software Foundation; either version 2 of the License, or (at your option)
	10	* any later version.
	11	*/
	12
	13	#include <crypto/algapi.h>
	14	#include <crypto/internal/aead.h>
	15	#include <crypto/internal/skcipher.h>
	16	#include <crypto/scatterwalk.h>
	17	#include <linux/err.h>
	18	#include <linux/init.h>
	19	#include <linux/kernel.h>
	20	#include <linux/module.h>
	21	#include <linux/scatterlist.h>
	22
	23	#include "aegis.h"
	24
	25	#define AEGIS256_NONCE_SIZE 32
	26	#define AEGIS256_STATE_BLOCKS 6
	27	#define AEGIS256_KEY_SIZE 32
	28	#define AEGIS256_MIN_AUTH_SIZE 8
	29	#define AEGIS256_MAX_AUTH_SIZE 16
	30
	31	struct aegis_state {
	32	union aegis_block blocks[AEGIS256_STATE_BLOCKS];
	33	};
	34
	35	struct aegis_ctx {
	36	union aegis_block key[AEGIS256_KEY_SIZE / AEGIS_BLOCK_SIZE];
	37	};
	38
	39	struct aegis256_ops {
	40	int (skcipher_walk_init)(struct skcipher_walk walk,
	41	struct aead_request *req, bool atomic);
	42
	43	void (crypt_chunk)(struct aegis_state state, u8 *dst,
	44	const u8 *src, unsigned int size);
	45	};
	46
	47	static void crypto_aegis256_update(struct aegis_state *state)
	48	{
	49	union aegis_block tmp;
	50	unsigned int i;
	51
	52	tmp = state->blocks[AEGIS256_STATE_BLOCKS - 1];
	53	for (i = AEGIS256_STATE_BLOCKS - 1; i > 0; i--)
	54	crypto_aegis_aesenc(&state->blocks[i], &state->blocks[i - 1],
	55	&state->blocks[i]);
	56	crypto_aegis_aesenc(&state->blocks[0], &tmp, &state->blocks[0]);
	57	}
	58
	59	static void crypto_aegis256_update_a(struct aegis_state *state,
	60	const union aegis_block *msg)
	61	{
	62	crypto_aegis256_update(state);
	63	crypto_aegis_block_xor(&state->blocks[0], msg);
	64	}
65
66	static void crypto_aegis256_update_u(struct aegis_state state, const void msg)
67	{
68	crypto_aegis256_update(state);
69	crypto_xor(state->blocks[0].bytes, msg, AEGIS_BLOCK_SIZE);
70	}
71
72	static void crypto_aegis256_init(struct aegis_state *state,
73	const union aegis_block *key,
74	const u8 *iv)
75	{
76	union aegis_block key_iv[2];
77	unsigned int i;
78
79	key_iv[0] = key[0];
80	key_iv[1] = key[1];
81	crypto_xor(key_iv[0].bytes, iv + 0 * AEGIS_BLOCK_SIZE,
82	AEGIS_BLOCK_SIZE);
83	crypto_xor(key_iv[1].bytes, iv + 1 * AEGIS_BLOCK_SIZE,
84	AEGIS_BLOCK_SIZE);
85
86	state->blocks[0] = key_iv[0];
87	state->blocks[1] = key_iv[1];
88	state->blocks[2] = crypto_aegis_const[1];
89	state->blocks[3] = crypto_aegis_const[0];
90	state->blocks[4] = key[0];
91	state->blocks[5] = key[1];
92
93	crypto_aegis_block_xor(&state->blocks[4], &crypto_aegis_const[0]);
94	crypto_aegis_block_xor(&state->blocks[5], &crypto_aegis_const[1]);
95
96	for (i = 0; i < 4; i++) {
97	crypto_aegis256_update_a(state, &key[0]);
98	crypto_aegis256_update_a(state, &key[1]);
99	crypto_aegis256_update_a(state, &key_iv[0]);
100	crypto_aegis256_update_a(state, &key_iv[1]);
101	}
102	}
103
104	static void crypto_aegis256_ad(struct aegis_state *state,
105	const u8 *src, unsigned int size)
106	{
107	if (AEGIS_ALIGNED(src)) {
108	const union aegis_block *src_blk =
109	(const union aegis_block *)src;
110
111	while (size >= AEGIS_BLOCK_SIZE) {
112	crypto_aegis256_update_a(state, src_blk);
113
114	size -= AEGIS_BLOCK_SIZE;
115	src_blk++;
116	}
117	} else {
118	while (size >= AEGIS_BLOCK_SIZE) {
119	crypto_aegis256_update_u(state, src);
120
121	size -= AEGIS_BLOCK_SIZE;
122	src += AEGIS_BLOCK_SIZE;
123	}
124	}
125	}
126
127	static void crypto_aegis256_encrypt_chunk(struct aegis_state state, u8 dst,
128	const u8 *src, unsigned int size)
129	{
130	union aegis_block tmp;
131
132	if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
133	while (size >= AEGIS_BLOCK_SIZE) {
134	union aegis_block *dst_blk =
135	(union aegis_block *)dst;
136	const union aegis_block *src_blk =
137	(const union aegis_block *)src;
138
139	tmp = state->blocks[2];
140	crypto_aegis_block_and(&tmp, &state->blocks[3]);
141	crypto_aegis_block_xor(&tmp, &state->blocks[5]);
142	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
143	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
144	crypto_aegis_block_xor(&tmp, src_blk);
145
146	crypto_aegis256_update_a(state, src_blk);
147
148	*dst_blk = tmp;
149
150	size -= AEGIS_BLOCK_SIZE;
151	src += AEGIS_BLOCK_SIZE;
152	dst += AEGIS_BLOCK_SIZE;
153	}
154	} else {
155	while (size >= AEGIS_BLOCK_SIZE) {
156	tmp = state->blocks[2];
157	crypto_aegis_block_and(&tmp, &state->blocks[3]);
158	crypto_aegis_block_xor(&tmp, &state->blocks[5]);
159	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
160	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
161	crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
162
163	crypto_aegis256_update_u(state, src);
164
165	memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
166
167	size -= AEGIS_BLOCK_SIZE;
168	src += AEGIS_BLOCK_SIZE;
169	dst += AEGIS_BLOCK_SIZE;
170	}
171	}
172
173	if (size > 0) {
174	union aegis_block msg = {};
175	memcpy(msg.bytes, src, size);
176
177	tmp = state->blocks[2];
178	crypto_aegis_block_and(&tmp, &state->blocks[3]);
179	crypto_aegis_block_xor(&tmp, &state->blocks[5]);
180	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
181	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
182
183	crypto_aegis256_update_a(state, &msg);
184
185	crypto_aegis_block_xor(&msg, &tmp);
186
187	memcpy(dst, msg.bytes, size);
188	}
189	}
190
191	static void crypto_aegis256_decrypt_chunk(struct aegis_state state, u8 dst,
192	const u8 *src, unsigned int size)
193	{
194	union aegis_block tmp;
195
196	if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
197	while (size >= AEGIS_BLOCK_SIZE) {
198	union aegis_block *dst_blk =
199	(union aegis_block *)dst;
200	const union aegis_block *src_blk =
201	(const union aegis_block *)src;
202
203	tmp = state->blocks[2];
204	crypto_aegis_block_and(&tmp, &state->blocks[3]);
205	crypto_aegis_block_xor(&tmp, &state->blocks[5]);
206	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
207	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
208	crypto_aegis_block_xor(&tmp, src_blk);
209
210	crypto_aegis256_update_a(state, &tmp);
211
212	*dst_blk = tmp;
213
214	size -= AEGIS_BLOCK_SIZE;
215	src += AEGIS_BLOCK_SIZE;
216	dst += AEGIS_BLOCK_SIZE;
217	}
218	} else {
219	while (size >= AEGIS_BLOCK_SIZE) {
220	tmp = state->blocks[2];
221	crypto_aegis_block_and(&tmp, &state->blocks[3]);
222	crypto_aegis_block_xor(&tmp, &state->blocks[5]);
223	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
224	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
225	crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
226
227	crypto_aegis256_update_a(state, &tmp);
228
229	memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
230
231	size -= AEGIS_BLOCK_SIZE;
232	src += AEGIS_BLOCK_SIZE;
233	dst += AEGIS_BLOCK_SIZE;
234	}
235	}
236
237	if (size > 0) {
238	union aegis_block msg = {};
239	memcpy(msg.bytes, src, size);
240
241	tmp = state->blocks[2];
242	crypto_aegis_block_and(&tmp, &state->blocks[3]);
243	crypto_aegis_block_xor(&tmp, &state->blocks[5]);
244	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
245	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
246	crypto_aegis_block_xor(&msg, &tmp);
247
248	memset(msg.bytes + size, 0, AEGIS_BLOCK_SIZE - size);
249
250	crypto_aegis256_update_a(state, &msg);
251
252	memcpy(dst, msg.bytes, size);
253	}
254	}
255
256	static void crypto_aegis256_process_ad(struct aegis_state *state,
257	struct scatterlist *sg_src,
258	unsigned int assoclen)
259	{
260	struct scatter_walk walk;
261	union aegis_block buf;
262	unsigned int pos = 0;
263
264	scatterwalk_start(&walk, sg_src);
265	while (assoclen != 0) {
266	unsigned int size = scatterwalk_clamp(&walk, assoclen);
267	unsigned int left = size;
268	void *mapped = scatterwalk_map(&walk);
269	const u8 src = (const u8 )mapped;
270
271	if (pos + size >= AEGIS_BLOCK_SIZE) {
272	if (pos > 0) {
273	unsigned int fill = AEGIS_BLOCK_SIZE - pos;
274	memcpy(buf.bytes + pos, src, fill);
275	crypto_aegis256_update_a(state, &buf);
276	pos = 0;
277	left -= fill;
278	src += fill;
279	}
280
281	crypto_aegis256_ad(state, src, left);
282	src += left & ~(AEGIS_BLOCK_SIZE - 1);
283	left &= AEGIS_BLOCK_SIZE - 1;
284	}
285
286	memcpy(buf.bytes + pos, src, left);
287
288	pos += left;
289	assoclen -= size;
290	scatterwalk_unmap(mapped);
291	scatterwalk_advance(&walk, size);
292	scatterwalk_done(&walk, 0, assoclen);
293	}
294
295	if (pos > 0) {
296	memset(buf.bytes + pos, 0, AEGIS_BLOCK_SIZE - pos);
297	crypto_aegis256_update_a(state, &buf);
298	}
299	}
300
301	static void crypto_aegis256_process_crypt(struct aegis_state *state,
302	struct aead_request *req,
303	const struct aegis256_ops *ops)
304	{
305	struct skcipher_walk walk;
306	u8 src, dst;
307	unsigned int chunksize;
308
309	ops->skcipher_walk_init(&walk, req, false);
310
311	while (walk.nbytes) {
312	src = walk.src.virt.addr;
313	dst = walk.dst.virt.addr;
314	chunksize = walk.nbytes;
315
316	ops->crypt_chunk(state, dst, src, chunksize);
317
318	skcipher_walk_done(&walk, 0);
319	}
320	}
321
322	static void crypto_aegis256_final(struct aegis_state *state,
323	union aegis_block *tag_xor,
324	u64 assoclen, u64 cryptlen)
325	{
326	u64 assocbits = assoclen * 8;
327	u64 cryptbits = cryptlen * 8;
328
329	union aegis_block tmp;
330	unsigned int i;
331
332	tmp.words64[0] = cpu_to_le64(assocbits);
333	tmp.words64[1] = cpu_to_le64(cryptbits);
334
335	crypto_aegis_block_xor(&tmp, &state->blocks[3]);
336
337	for (i = 0; i < 7; i++)
338	crypto_aegis256_update_a(state, &tmp);
339
340	for (i = 0; i < AEGIS256_STATE_BLOCKS; i++)
341	crypto_aegis_block_xor(tag_xor, &state->blocks[i]);
342	}
343
344	static int crypto_aegis256_setkey(struct crypto_aead aead, const u8 key,
345	unsigned int keylen)
346	{
347	struct aegis_ctx *ctx = crypto_aead_ctx(aead);
348
349	if (keylen != AEGIS256_KEY_SIZE) {
350	crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
351	return -EINVAL;
352	}
353
354	memcpy(ctx->key[0].bytes, key, AEGIS_BLOCK_SIZE);
355	memcpy(ctx->key[1].bytes, key + AEGIS_BLOCK_SIZE,
356	AEGIS_BLOCK_SIZE);
357	return 0;
358	}
359
360	static int crypto_aegis256_setauthsize(struct crypto_aead *tfm,
361	unsigned int authsize)
362	{
363	if (authsize > AEGIS256_MAX_AUTH_SIZE)
364	return -EINVAL;
365	if (authsize < AEGIS256_MIN_AUTH_SIZE)
366	return -EINVAL;
367	return 0;
368	}
369
370	static void crypto_aegis256_crypt(struct aead_request *req,
371	union aegis_block *tag_xor,
372	unsigned int cryptlen,
373	const struct aegis256_ops *ops)
374	{
375	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
376	struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
377	struct aegis_state state;
378
379	crypto_aegis256_init(&state, ctx->key, req->iv);
380	crypto_aegis256_process_ad(&state, req->src, req->assoclen);
381	crypto_aegis256_process_crypt(&state, req, ops);
382	crypto_aegis256_final(&state, tag_xor, req->assoclen, cryptlen);
383	}
384
385	static int crypto_aegis256_encrypt(struct aead_request *req)
386	{
387	static const struct aegis256_ops ops = {
388	.skcipher_walk_init = skcipher_walk_aead_encrypt,
389	.crypt_chunk = crypto_aegis256_encrypt_chunk,
390	};
391
392	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
393	union aegis_block tag = {};
394	unsigned int authsize = crypto_aead_authsize(tfm);
395	unsigned int cryptlen = req->cryptlen;
396
397	crypto_aegis256_crypt(req, &tag, cryptlen, &ops);
398
399	scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen,
400	authsize, 1);
401	return 0;
402	}
403
404	static int crypto_aegis256_decrypt(struct aead_request *req)
405	{
406	static const struct aegis256_ops ops = {
407	.skcipher_walk_init = skcipher_walk_aead_decrypt,
408	.crypt_chunk = crypto_aegis256_decrypt_chunk,
409	};
410	static const u8 zeros[AEGIS256_MAX_AUTH_SIZE] = {};
411
412	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
413	union aegis_block tag;
414	unsigned int authsize = crypto_aead_authsize(tfm);
415	unsigned int cryptlen = req->cryptlen - authsize;
416
417	scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen,
418	authsize, 0);
419
420	crypto_aegis256_crypt(req, &tag, cryptlen, &ops);
421
422	return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0;
423	}
424
425	static int crypto_aegis256_init_tfm(struct crypto_aead *tfm)
426	{
427	return 0;
428	}
429
430	static void crypto_aegis256_exit_tfm(struct crypto_aead *tfm)
431	{
432	}
433
434	static struct aead_alg crypto_aegis256_alg = {
435	.setkey = crypto_aegis256_setkey,
436	.setauthsize = crypto_aegis256_setauthsize,
437	.encrypt = crypto_aegis256_encrypt,
438	.decrypt = crypto_aegis256_decrypt,
439	.init = crypto_aegis256_init_tfm,
440	.exit = crypto_aegis256_exit_tfm,
441
442	.ivsize = AEGIS256_NONCE_SIZE,
443	.maxauthsize = AEGIS256_MAX_AUTH_SIZE,
444	.chunksize = AEGIS_BLOCK_SIZE,
445
446	.base = {
f606a88e OM	447	.cra_blocksize = 1,
	448	.cra_ctxsize = sizeof(struct aegis_ctx),
	449	.cra_alignmask = 0,
	450
	451	.cra_priority = 100,
	452
	453	.cra_name = "aegis256",
	454	.cra_driver_name = "aegis256-generic",
	455
	456	.cra_module = THIS_MODULE,
	457	}
	458	};
	459
	460	static int __init crypto_aegis256_module_init(void)
	461	{
	462	return crypto_register_aead(&crypto_aegis256_alg);
	463	}
	464
	465	static void __exit crypto_aegis256_module_exit(void)
	466	{
	467	crypto_unregister_aead(&crypto_aegis256_alg);
	468	}
	469
	470	module_init(crypto_aegis256_module_init);
	471	module_exit(crypto_aegis256_module_exit);
	472
	473	MODULE_LICENSE("GPL");
	474	MODULE_AUTHOR("Ondrej Mosnacek <[email protected]>");
	475	MODULE_DESCRIPTION("AEGIS-256 AEAD algorithm");
	476	MODULE_ALIAS_CRYPTO("aegis256");
	477	MODULE_ALIAS_CRYPTO("aegis256-generic");