[linux-2.6-block.git] / crypto / aegis128.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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.
 */

#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;

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

	while (walk.nbytes) {
		unsigned int nbytes = walk.nbytes;

		if (nbytes < walk.total)
			nbytes = round_down(nbytes, walk.stride);

		ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr,
				 nbytes);

		skcipher_walk_done(&walk, walk.nbytes - nbytes);
	}
}

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);
}

subsys_initcall(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");
Commit	Line	Data
bb4ce825	1	// SPDX-License-Identifier: GPL-2.0-or-later
f606a88e OM	2	/*
	3	* The AEGIS-128 Authenticated-Encryption Algorithm
	4	*
	5	* Copyright (c) 2017-2018 Ondrej Mosnacek <omosnacek@gmail.com>
	6	* Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
f606a88e OM	7	*/
	8
	9	#include <crypto/algapi.h>
	10	#include <crypto/internal/aead.h>
	11	#include <crypto/internal/skcipher.h>
	12	#include <crypto/scatterwalk.h>
	13	#include <linux/err.h>
	14	#include <linux/init.h>
	15	#include <linux/kernel.h>
	16	#include <linux/module.h>
	17	#include <linux/scatterlist.h>
	18
	19	#include "aegis.h"
	20
	21	#define AEGIS128_NONCE_SIZE 16
	22	#define AEGIS128_STATE_BLOCKS 5
	23	#define AEGIS128_KEY_SIZE 16
	24	#define AEGIS128_MIN_AUTH_SIZE 8
	25	#define AEGIS128_MAX_AUTH_SIZE 16
	26
	27	struct aegis_state {
	28	union aegis_block blocks[AEGIS128_STATE_BLOCKS];
	29	};
	30
	31	struct aegis_ctx {
	32	union aegis_block key;
	33	};
	34
	35	struct aegis128_ops {
	36	int (skcipher_walk_init)(struct skcipher_walk walk,
	37	struct aead_request *req, bool atomic);
	38
	39	void (crypt_chunk)(struct aegis_state state, u8 *dst,
	40	const u8 *src, unsigned int size);
	41	};
	42
	43	static void crypto_aegis128_update(struct aegis_state *state)
	44	{
	45	union aegis_block tmp;
	46	unsigned int i;
	47
	48	tmp = state->blocks[AEGIS128_STATE_BLOCKS - 1];
	49	for (i = AEGIS128_STATE_BLOCKS - 1; i > 0; i--)
	50	crypto_aegis_aesenc(&state->blocks[i], &state->blocks[i - 1],
	51	&state->blocks[i]);
	52	crypto_aegis_aesenc(&state->blocks[0], &tmp, &state->blocks[0]);
	53	}
	54
	55	static void crypto_aegis128_update_a(struct aegis_state *state,
	56	const union aegis_block *msg)
	57	{
	58	crypto_aegis128_update(state);
	59	crypto_aegis_block_xor(&state->blocks[0], msg);
	60	}
	61
	62	static void crypto_aegis128_update_u(struct aegis_state state, const void msg)
	63	{
	64	crypto_aegis128_update(state);
	65	crypto_xor(state->blocks[0].bytes, msg, AEGIS_BLOCK_SIZE);
	66	}
	67
	68	static void crypto_aegis128_init(struct aegis_state *state,
	69	const union aegis_block *key,
	70	const u8 *iv)
71	{
72	union aegis_block key_iv;
73	unsigned int i;
74
75	key_iv = *key;
76	crypto_xor(key_iv.bytes, iv, AEGIS_BLOCK_SIZE);
77
78	state->blocks[0] = key_iv;
79	state->blocks[1] = crypto_aegis_const[1];
80	state->blocks[2] = crypto_aegis_const[0];
81	state->blocks[3] = *key;
82	state->blocks[4] = *key;
83
84	crypto_aegis_block_xor(&state->blocks[3], &crypto_aegis_const[0]);
85	crypto_aegis_block_xor(&state->blocks[4], &crypto_aegis_const[1]);
86
87	for (i = 0; i < 5; i++) {
88	crypto_aegis128_update_a(state, key);
89	crypto_aegis128_update_a(state, &key_iv);
90	}
91	}
92
93	static void crypto_aegis128_ad(struct aegis_state *state,
94	const u8 *src, unsigned int size)
95	{
96	if (AEGIS_ALIGNED(src)) {
97	const union aegis_block *src_blk =
98	(const union aegis_block *)src;
99
100	while (size >= AEGIS_BLOCK_SIZE) {
101	crypto_aegis128_update_a(state, src_blk);
102
103	size -= AEGIS_BLOCK_SIZE;
104	src_blk++;
105	}
106	} else {
107	while (size >= AEGIS_BLOCK_SIZE) {
108	crypto_aegis128_update_u(state, src);
109
110	size -= AEGIS_BLOCK_SIZE;
111	src += AEGIS_BLOCK_SIZE;
112	}
113	}
114	}
115
116	static void crypto_aegis128_encrypt_chunk(struct aegis_state state, u8 dst,
117	const u8 *src, unsigned int size)
118	{
119	union aegis_block tmp;
120
121	if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
122	while (size >= AEGIS_BLOCK_SIZE) {
123	union aegis_block *dst_blk =
124	(union aegis_block *)dst;
125	const union aegis_block *src_blk =
126	(const union aegis_block *)src;
127
128	tmp = state->blocks[2];
129	crypto_aegis_block_and(&tmp, &state->blocks[3]);
130	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
131	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
132	crypto_aegis_block_xor(&tmp, src_blk);
133
134	crypto_aegis128_update_a(state, src_blk);
135
136	*dst_blk = tmp;
137
138	size -= AEGIS_BLOCK_SIZE;
139	src += AEGIS_BLOCK_SIZE;
140	dst += AEGIS_BLOCK_SIZE;
141	}
142	} else {
143	while (size >= AEGIS_BLOCK_SIZE) {
144	tmp = state->blocks[2];
145	crypto_aegis_block_and(&tmp, &state->blocks[3]);
146	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
147	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
148	crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
149
150	crypto_aegis128_update_u(state, src);
151
152	memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
153
154	size -= AEGIS_BLOCK_SIZE;
155	src += AEGIS_BLOCK_SIZE;
156	dst += AEGIS_BLOCK_SIZE;
157	}
158	}
159
160	if (size > 0) {
161	union aegis_block msg = {};
162	memcpy(msg.bytes, src, size);
163
164	tmp = state->blocks[2];
165	crypto_aegis_block_and(&tmp, &state->blocks[3]);
166	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
167	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
168
169	crypto_aegis128_update_a(state, &msg);
170
171	crypto_aegis_block_xor(&msg, &tmp);
172
173	memcpy(dst, msg.bytes, size);
174	}
175	}
176
177	static void crypto_aegis128_decrypt_chunk(struct aegis_state state, u8 dst,
178	const u8 *src, unsigned int size)
179	{
180	union aegis_block tmp;
181
182	if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
183	while (size >= AEGIS_BLOCK_SIZE) {
184	union aegis_block *dst_blk =
185	(union aegis_block *)dst;
186	const union aegis_block *src_blk =
187	(const union aegis_block *)src;
188
189	tmp = state->blocks[2];
190	crypto_aegis_block_and(&tmp, &state->blocks[3]);
191	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
192	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
193	crypto_aegis_block_xor(&tmp, src_blk);
194
195	crypto_aegis128_update_a(state, &tmp);
196
197	*dst_blk = tmp;
198
199	size -= AEGIS_BLOCK_SIZE;
200	src += AEGIS_BLOCK_SIZE;
201	dst += AEGIS_BLOCK_SIZE;
202	}
203	} else {
204	while (size >= AEGIS_BLOCK_SIZE) {
205	tmp = state->blocks[2];
206	crypto_aegis_block_and(&tmp, &state->blocks[3]);
207	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
208	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
209	crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
210
211	crypto_aegis128_update_a(state, &tmp);
212
213	memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
214
215	size -= AEGIS_BLOCK_SIZE;
216	src += AEGIS_BLOCK_SIZE;
217	dst += AEGIS_BLOCK_SIZE;
218	}
219	}
220
221	if (size > 0) {
222	union aegis_block msg = {};
223	memcpy(msg.bytes, src, size);
224
225	tmp = state->blocks[2];
226	crypto_aegis_block_and(&tmp, &state->blocks[3]);
227	crypto_aegis_block_xor(&tmp, &state->blocks[4]);
228	crypto_aegis_block_xor(&tmp, &state->blocks[1]);
229	crypto_aegis_block_xor(&msg, &tmp);
230
231	memset(msg.bytes + size, 0, AEGIS_BLOCK_SIZE - size);
232
233	crypto_aegis128_update_a(state, &msg);
234
235	memcpy(dst, msg.bytes, size);
236	}
237	}
238
239	static void crypto_aegis128_process_ad(struct aegis_state *state,
240	struct scatterlist *sg_src,
241	unsigned int assoclen)
242	{
243	struct scatter_walk walk;
244	union aegis_block buf;
245	unsigned int pos = 0;
246
247	scatterwalk_start(&walk, sg_src);
248	while (assoclen != 0) {
249	unsigned int size = scatterwalk_clamp(&walk, assoclen);
250	unsigned int left = size;
251	void *mapped = scatterwalk_map(&walk);
252	const u8 src = (const u8 )mapped;
253
254	if (pos + size >= AEGIS_BLOCK_SIZE) {
255	if (pos > 0) {
256	unsigned int fill = AEGIS_BLOCK_SIZE - pos;
257	memcpy(buf.bytes + pos, src, fill);
258	crypto_aegis128_update_a(state, &buf);
259	pos = 0;
260	left -= fill;
261	src += fill;
262	}
263
264	crypto_aegis128_ad(state, src, left);
265	src += left & ~(AEGIS_BLOCK_SIZE - 1);
266	left &= AEGIS_BLOCK_SIZE - 1;
267	}
268
269	memcpy(buf.bytes + pos, src, left);
270
271	pos += left;
272	assoclen -= size;
273	scatterwalk_unmap(mapped);
274	scatterwalk_advance(&walk, size);
275	scatterwalk_done(&walk, 0, assoclen);
276	}
277
278	if (pos > 0) {
279	memset(buf.bytes + pos, 0, AEGIS_BLOCK_SIZE - pos);
280	crypto_aegis128_update_a(state, &buf);
281	}
282	}
283
284	static void crypto_aegis128_process_crypt(struct aegis_state *state,
285	struct aead_request *req,
286	const struct aegis128_ops *ops)
287	{
288	struct skcipher_walk walk;
f606a88e OM	289
	290	ops->skcipher_walk_init(&walk, req, false);
	291
	292	while (walk.nbytes) {
0f533e67	293	unsigned int nbytes = walk.nbytes;
f606a88e	294
0f533e67 EB	295	if (nbytes < walk.total)
0f533e67 EB	296	nbytes = round_down(nbytes, walk.stride);
f606a88e	297
0f533e67 EB	298	ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr,
	299	nbytes);
	300
	301	skcipher_walk_done(&walk, walk.nbytes - nbytes);
f606a88e OM	302	}
	303	}
	304
	305	static void crypto_aegis128_final(struct aegis_state *state,
	306	union aegis_block *tag_xor,
	307	u64 assoclen, u64 cryptlen)
	308	{
	309	u64 assocbits = assoclen * 8;
	310	u64 cryptbits = cryptlen * 8;
	311
	312	union aegis_block tmp;
	313	unsigned int i;
	314
	315	tmp.words64[0] = cpu_to_le64(assocbits);
	316	tmp.words64[1] = cpu_to_le64(cryptbits);
	317
	318	crypto_aegis_block_xor(&tmp, &state->blocks[3]);
	319
	320	for (i = 0; i < 7; i++)
	321	crypto_aegis128_update_a(state, &tmp);
	322
	323	for (i = 0; i < AEGIS128_STATE_BLOCKS; i++)
	324	crypto_aegis_block_xor(tag_xor, &state->blocks[i]);
	325	}
	326
	327	static int crypto_aegis128_setkey(struct crypto_aead aead, const u8 key,
	328	unsigned int keylen)
	329	{
	330	struct aegis_ctx *ctx = crypto_aead_ctx(aead);
	331
	332	if (keylen != AEGIS128_KEY_SIZE) {
	333	crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
	334	return -EINVAL;
	335	}
	336
	337	memcpy(ctx->key.bytes, key, AEGIS128_KEY_SIZE);
	338	return 0;
	339	}
	340
	341	static int crypto_aegis128_setauthsize(struct crypto_aead *tfm,
	342	unsigned int authsize)
	343	{
	344	if (authsize > AEGIS128_MAX_AUTH_SIZE)
	345	return -EINVAL;
	346	if (authsize < AEGIS128_MIN_AUTH_SIZE)
	347	return -EINVAL;
	348	return 0;
	349	}
	350
	351	static void crypto_aegis128_crypt(struct aead_request *req,
	352	union aegis_block *tag_xor,
	353	unsigned int cryptlen,
	354	const struct aegis128_ops *ops)
	355	{
	356	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
	357	struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
	358	struct aegis_state state;
	359
	360	crypto_aegis128_init(&state, &ctx->key, req->iv);
	361	crypto_aegis128_process_ad(&state, req->src, req->assoclen);
	362	crypto_aegis128_process_crypt(&state, req, ops);
	363	crypto_aegis128_final(&state, tag_xor, req->assoclen, cryptlen);
	364	}
	365
366	static int crypto_aegis128_encrypt(struct aead_request *req)
367	{
368	static const struct aegis128_ops ops = {
369	.skcipher_walk_init = skcipher_walk_aead_encrypt,
370	.crypt_chunk = crypto_aegis128_encrypt_chunk,
371	};
372
373	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
374	union aegis_block tag = {};
375	unsigned int authsize = crypto_aead_authsize(tfm);
376	unsigned int cryptlen = req->cryptlen;
377
378	crypto_aegis128_crypt(req, &tag, cryptlen, &ops);
379
380	scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen,
381	authsize, 1);
382	return 0;
383	}
384
385	static int crypto_aegis128_decrypt(struct aead_request *req)
386	{
387	static const struct aegis128_ops ops = {
388	.skcipher_walk_init = skcipher_walk_aead_decrypt,
389	.crypt_chunk = crypto_aegis128_decrypt_chunk,
390	};
391	static const u8 zeros[AEGIS128_MAX_AUTH_SIZE] = {};
392
393	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
394	union aegis_block tag;
395	unsigned int authsize = crypto_aead_authsize(tfm);
396	unsigned int cryptlen = req->cryptlen - authsize;
397
398	scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen,
399	authsize, 0);
400
401	crypto_aegis128_crypt(req, &tag, cryptlen, &ops);
402
403	return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0;
404	}
405
406	static int crypto_aegis128_init_tfm(struct crypto_aead *tfm)
407	{
408	return 0;
409	}
410
411	static void crypto_aegis128_exit_tfm(struct crypto_aead *tfm)
412	{
413	}
414
415	static struct aead_alg crypto_aegis128_alg = {
416	.setkey = crypto_aegis128_setkey,
417	.setauthsize = crypto_aegis128_setauthsize,
418	.encrypt = crypto_aegis128_encrypt,
419	.decrypt = crypto_aegis128_decrypt,
420	.init = crypto_aegis128_init_tfm,
421	.exit = crypto_aegis128_exit_tfm,
422
423	.ivsize = AEGIS128_NONCE_SIZE,
424	.maxauthsize = AEGIS128_MAX_AUTH_SIZE,
425	.chunksize = AEGIS_BLOCK_SIZE,
426
427	.base = {
f606a88e OM	428	.cra_blocksize = 1,
	429	.cra_ctxsize = sizeof(struct aegis_ctx),
	430	.cra_alignmask = 0,
	431
	432	.cra_priority = 100,
	433
	434	.cra_name = "aegis128",
	435	.cra_driver_name = "aegis128-generic",
	436
	437	.cra_module = THIS_MODULE,
	438	}
	439	};
	440
	441	static int __init crypto_aegis128_module_init(void)
	442	{
	443	return crypto_register_aead(&crypto_aegis128_alg);
	444	}
	445
	446	static void __exit crypto_aegis128_module_exit(void)
	447	{
	448	crypto_unregister_aead(&crypto_aegis128_alg);
	449	}
	450
c4741b23	451	subsys_initcall(crypto_aegis128_module_init);
f606a88e OM	452	module_exit(crypto_aegis128_module_exit);
	453
	454	MODULE_LICENSE("GPL");
	455	MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
	456	MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm");
	457	MODULE_ALIAS_CRYPTO("aegis128");
	458	MODULE_ALIAS_CRYPTO("aegis128-generic");