[linux.git] / crypto / aegis128.c

/*
 * The AEGIS-128 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 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_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 <[email protected]>");
MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm");
MODULE_ALIAS_CRYPTO("aegis128");
MODULE_ALIAS_CRYPTO("aegis128-generic");
Commit	Line	Data
f606a88e OM	1	/*
	2	* The AEGIS-128 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 AEGIS128_NONCE_SIZE 16
	26	#define AEGIS128_STATE_BLOCKS 5
	27	#define AEGIS128_KEY_SIZE 16
	28	#define AEGIS128_MIN_AUTH_SIZE 8
	29	#define AEGIS128_MAX_AUTH_SIZE 16
	30
	31	struct aegis_state {
	32	union aegis_block blocks[AEGIS128_STATE_BLOCKS];
	33	};
	34
	35	struct aegis_ctx {
	36	union aegis_block key;
	37	};
	38
	39	struct aegis128_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_aegis128_update(struct aegis_state *state)
	48	{
	49	union aegis_block tmp;
	50	unsigned int i;
	51
	52	tmp = state->blocks[AEGIS128_STATE_BLOCKS - 1];
	53	for (i = AEGIS128_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_aegis128_update_a(struct aegis_state *state,
	60	const union aegis_block *msg)
	61	{
	62	crypto_aegis128_update(state);
	63	crypto_aegis_block_xor(&state->blocks[0], msg);
	64	}
65
66	static void crypto_aegis128_update_u(struct aegis_state state, const void msg)
67	{
68	crypto_aegis128_update(state);
69	crypto_xor(state->blocks[0].bytes, msg, AEGIS_BLOCK_SIZE);
70	}
71
72	static void crypto_aegis128_init(struct aegis_state *state,
73	const union aegis_block *key,
74	const u8 *iv)
75	{
76	union aegis_block key_iv;
77	unsigned int i;
78
79	key_iv = *key;
80	crypto_xor(key_iv.bytes, iv, AEGIS_BLOCK_SIZE);
81
82	state->blocks[0] = key_iv;
83	state->blocks[1] = crypto_aegis_const[1];
84	state->blocks[2] = crypto_aegis_const[0];
85	state->blocks[3] = *key;
86	state->blocks[4] = *key;
87
88	crypto_aegis_block_xor(&state->blocks[3], &crypto_aegis_const[0]);
89	crypto_aegis_block_xor(&state->blocks[4], &crypto_aegis_const[1]);
90
91	for (i = 0; i < 5; i++) {
92	crypto_aegis128_update_a(state, key);
93	crypto_aegis128_update_a(state, &key_iv);
94	}
95	}
96
97	static void crypto_aegis128_ad(struct aegis_state *state,
98	const u8 *src, unsigned int size)
99	{
100	if (AEGIS_ALIGNED(src)) {
101	const union aegis_block *src_blk =
102	(const union aegis_block *)src;
103
104	while (size >= AEGIS_BLOCK_SIZE) {
105	crypto_aegis128_update_a(state, src_blk);
106
107	size -= AEGIS_BLOCK_SIZE;
108	src_blk++;
109	}
110	} else {
111	while (size >= AEGIS_BLOCK_SIZE) {
112	crypto_aegis128_update_u(state, src);
113
114	size -= AEGIS_BLOCK_SIZE;
115	src += AEGIS_BLOCK_SIZE;
116	}
117	}
118	}
119
120	static void crypto_aegis128_encrypt_chunk(struct aegis_state state, u8 dst,
121	const u8 *src, unsigned int size)
122	{
123	union aegis_block tmp;
124
125	if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
126	while (size >= AEGIS_BLOCK_SIZE) {
127	union aegis_block *dst_blk =
128	(union aegis_block *)dst;
129	const union aegis_block *src_blk =
130	(const union aegis_block *)src;
131
132	tmp = state->blocks[2];
133	crypto_aegis_block_and(&tmp, &state->blocks[3]);
134	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
135	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
136	crypto_aegis_block_xor(&tmp, src_blk);
137
138	crypto_aegis128_update_a(state, src_blk);
139
140	*dst_blk = tmp;
141
142	size -= AEGIS_BLOCK_SIZE;
143	src += AEGIS_BLOCK_SIZE;
144	dst += AEGIS_BLOCK_SIZE;
145	}
146	} else {
147	while (size >= AEGIS_BLOCK_SIZE) {
148	tmp = state->blocks[2];
149	crypto_aegis_block_and(&tmp, &state->blocks[3]);
150	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
151	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
152	crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
153
154	crypto_aegis128_update_u(state, src);
155
156	memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
157
158	size -= AEGIS_BLOCK_SIZE;
159	src += AEGIS_BLOCK_SIZE;
160	dst += AEGIS_BLOCK_SIZE;
161	}
162	}
163
164	if (size > 0) {
165	union aegis_block msg = {};
166	memcpy(msg.bytes, src, size);
167
168	tmp = state->blocks[2];
169	crypto_aegis_block_and(&tmp, &state->blocks[3]);
170	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
171	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
172
173	crypto_aegis128_update_a(state, &msg);
174
175	crypto_aegis_block_xor(&msg, &tmp);
176
177	memcpy(dst, msg.bytes, size);
178	}
179	}
180
181	static void crypto_aegis128_decrypt_chunk(struct aegis_state state, u8 dst,
182	const u8 *src, unsigned int size)
183	{
184	union aegis_block tmp;
185
186	if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
187	while (size >= AEGIS_BLOCK_SIZE) {
188	union aegis_block *dst_blk =
189	(union aegis_block *)dst;
190	const union aegis_block *src_blk =
191	(const union aegis_block *)src;
192
193	tmp = state->blocks[2];
194	crypto_aegis_block_and(&tmp, &state->blocks[3]);
195	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
196	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
197	crypto_aegis_block_xor(&tmp, src_blk);
198
199	crypto_aegis128_update_a(state, &tmp);
200
201	*dst_blk = tmp;
202
203	size -= AEGIS_BLOCK_SIZE;
204	src += AEGIS_BLOCK_SIZE;
205	dst += AEGIS_BLOCK_SIZE;
206	}
207	} else {
208	while (size >= AEGIS_BLOCK_SIZE) {
209	tmp = state->blocks[2];
210	crypto_aegis_block_and(&tmp, &state->blocks[3]);
211	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
212	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
213	crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
214
215	crypto_aegis128_update_a(state, &tmp);
216
217	memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
218
219	size -= AEGIS_BLOCK_SIZE;
220	src += AEGIS_BLOCK_SIZE;
221	dst += AEGIS_BLOCK_SIZE;
222	}
223	}
224
225	if (size > 0) {
226	union aegis_block msg = {};
227	memcpy(msg.bytes, src, size);
228
229	tmp = state->blocks[2];
230	crypto_aegis_block_and(&tmp, &state->blocks[3]);
231	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
232	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
233	crypto_aegis_block_xor(&msg, &tmp);
234
235	memset(msg.bytes + size, 0, AEGIS_BLOCK_SIZE - size);
236
237	crypto_aegis128_update_a(state, &msg);
238
239	memcpy(dst, msg.bytes, size);
240	}
241	}
242
243	static void crypto_aegis128_process_ad(struct aegis_state *state,
244	struct scatterlist *sg_src,
245	unsigned int assoclen)
246	{
247	struct scatter_walk walk;
248	union aegis_block buf;
249	unsigned int pos = 0;
250
251	scatterwalk_start(&walk, sg_src);
252	while (assoclen != 0) {
253	unsigned int size = scatterwalk_clamp(&walk, assoclen);
254	unsigned int left = size;
255	void *mapped = scatterwalk_map(&walk);
256	const u8 src = (const u8 )mapped;
257
258	if (pos + size >= AEGIS_BLOCK_SIZE) {
259	if (pos > 0) {
260	unsigned int fill = AEGIS_BLOCK_SIZE - pos;
261	memcpy(buf.bytes + pos, src, fill);
262	crypto_aegis128_update_a(state, &buf);
263	pos = 0;
264	left -= fill;
265	src += fill;
266	}
267
268	crypto_aegis128_ad(state, src, left);
269	src += left & ~(AEGIS_BLOCK_SIZE - 1);
270	left &= AEGIS_BLOCK_SIZE - 1;
271	}
272
273	memcpy(buf.bytes + pos, src, left);
274
275	pos += left;
276	assoclen -= size;
277	scatterwalk_unmap(mapped);
278	scatterwalk_advance(&walk, size);
279	scatterwalk_done(&walk, 0, assoclen);
280	}
281
282	if (pos > 0) {
283	memset(buf.bytes + pos, 0, AEGIS_BLOCK_SIZE - pos);
284	crypto_aegis128_update_a(state, &buf);
285	}
286	}
287
288	static void crypto_aegis128_process_crypt(struct aegis_state *state,
289	struct aead_request *req,
290	const struct aegis128_ops *ops)
291	{
292	struct skcipher_walk walk;
293	u8 src, dst;
294	unsigned int chunksize;
295
296	ops->skcipher_walk_init(&walk, req, false);
297
298	while (walk.nbytes) {
299	src = walk.src.virt.addr;
300	dst = walk.dst.virt.addr;
301	chunksize = walk.nbytes;
302
303	ops->crypt_chunk(state, dst, src, chunksize);
304
305	skcipher_walk_done(&walk, 0);
306	}
307	}
308
309	static void crypto_aegis128_final(struct aegis_state *state,
310	union aegis_block *tag_xor,
311	u64 assoclen, u64 cryptlen)
312	{
313	u64 assocbits = assoclen * 8;
314	u64 cryptbits = cryptlen * 8;
315
316	union aegis_block tmp;
317	unsigned int i;
318
319	tmp.words64[0] = cpu_to_le64(assocbits);
320	tmp.words64[1] = cpu_to_le64(cryptbits);
321
322	crypto_aegis_block_xor(&tmp, &state->blocks[3]);
323
324	for (i = 0; i < 7; i++)
325	crypto_aegis128_update_a(state, &tmp);
326
327	for (i = 0; i < AEGIS128_STATE_BLOCKS; i++)
328	crypto_aegis_block_xor(tag_xor, &state->blocks[i]);
329	}
330
331	static int crypto_aegis128_setkey(struct crypto_aead aead, const u8 key,
332	unsigned int keylen)
333	{
334	struct aegis_ctx *ctx = crypto_aead_ctx(aead);
335
336	if (keylen != AEGIS128_KEY_SIZE) {
337	crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
338	return -EINVAL;
339	}
340
341	memcpy(ctx->key.bytes, key, AEGIS128_KEY_SIZE);
342	return 0;
343	}
344
345	static int crypto_aegis128_setauthsize(struct crypto_aead *tfm,
346	unsigned int authsize)
347	{
348	if (authsize > AEGIS128_MAX_AUTH_SIZE)
349	return -EINVAL;
350	if (authsize < AEGIS128_MIN_AUTH_SIZE)
351	return -EINVAL;
352	return 0;
353	}
354
355	static void crypto_aegis128_crypt(struct aead_request *req,
356	union aegis_block *tag_xor,
357	unsigned int cryptlen,
358	const struct aegis128_ops *ops)
359	{
360	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
361	struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
362	struct aegis_state state;
363
364	crypto_aegis128_init(&state, &ctx->key, req->iv);
365	crypto_aegis128_process_ad(&state, req->src, req->assoclen);
366	crypto_aegis128_process_crypt(&state, req, ops);
367	crypto_aegis128_final(&state, tag_xor, req->assoclen, cryptlen);
368	}
369
370	static int crypto_aegis128_encrypt(struct aead_request *req)
371	{
372	static const struct aegis128_ops ops = {
373	.skcipher_walk_init = skcipher_walk_aead_encrypt,
374	.crypt_chunk = crypto_aegis128_encrypt_chunk,
375	};
376
377	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
378	union aegis_block tag = {};
379	unsigned int authsize = crypto_aead_authsize(tfm);
380	unsigned int cryptlen = req->cryptlen;
381
382	crypto_aegis128_crypt(req, &tag, cryptlen, &ops);
383
384	scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen,
385	authsize, 1);
386	return 0;
387	}
388
389	static int crypto_aegis128_decrypt(struct aead_request *req)
390	{
391	static const struct aegis128_ops ops = {
392	.skcipher_walk_init = skcipher_walk_aead_decrypt,
393	.crypt_chunk = crypto_aegis128_decrypt_chunk,
394	};
395	static const u8 zeros[AEGIS128_MAX_AUTH_SIZE] = {};
396
397	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
398	union aegis_block tag;
399	unsigned int authsize = crypto_aead_authsize(tfm);
400	unsigned int cryptlen = req->cryptlen - authsize;
401
402	scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen,
403	authsize, 0);
404
405	crypto_aegis128_crypt(req, &tag, cryptlen, &ops);
406
407	return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0;
408	}
409
410	static int crypto_aegis128_init_tfm(struct crypto_aead *tfm)
411	{
412	return 0;
413	}
414
415	static void crypto_aegis128_exit_tfm(struct crypto_aead *tfm)
416	{
417	}
418
419	static struct aead_alg crypto_aegis128_alg = {
420	.setkey = crypto_aegis128_setkey,
421	.setauthsize = crypto_aegis128_setauthsize,
422	.encrypt = crypto_aegis128_encrypt,
423	.decrypt = crypto_aegis128_decrypt,
424	.init = crypto_aegis128_init_tfm,
425	.exit = crypto_aegis128_exit_tfm,
426
427	.ivsize = AEGIS128_NONCE_SIZE,
428	.maxauthsize = AEGIS128_MAX_AUTH_SIZE,
429	.chunksize = AEGIS_BLOCK_SIZE,
430
431	.base = {
f606a88e OM	432	.cra_blocksize = 1,
	433	.cra_ctxsize = sizeof(struct aegis_ctx),
	434	.cra_alignmask = 0,
	435
	436	.cra_priority = 100,
	437
	438	.cra_name = "aegis128",
	439	.cra_driver_name = "aegis128-generic",
	440
	441	.cra_module = THIS_MODULE,
	442	}
	443	};
	444
	445	static int __init crypto_aegis128_module_init(void)
	446	{
	447	return crypto_register_aead(&crypto_aegis128_alg);
	448	}
	449
	450	static void __exit crypto_aegis128_module_exit(void)
	451	{
	452	crypto_unregister_aead(&crypto_aegis128_alg);
	453	}
	454
	455	module_init(crypto_aegis128_module_init);
	456	module_exit(crypto_aegis128_module_exit);
	457
	458	MODULE_LICENSE("GPL");
	459	MODULE_AUTHOR("Ondrej Mosnacek <[email protected]>");
	460	MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm");
	461	MODULE_ALIAS_CRYPTO("aegis128");
	462	MODULE_ALIAS_CRYPTO("aegis128-generic");