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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) |
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 | ||
f606a88e OM |
406 | static struct aead_alg crypto_aegis128_alg = { |
407 | .setkey = crypto_aegis128_setkey, | |
408 | .setauthsize = crypto_aegis128_setauthsize, | |
409 | .encrypt = crypto_aegis128_encrypt, | |
410 | .decrypt = crypto_aegis128_decrypt, | |
f606a88e OM |
411 | |
412 | .ivsize = AEGIS128_NONCE_SIZE, | |
413 | .maxauthsize = AEGIS128_MAX_AUTH_SIZE, | |
414 | .chunksize = AEGIS_BLOCK_SIZE, | |
415 | ||
416 | .base = { | |
f606a88e OM |
417 | .cra_blocksize = 1, |
418 | .cra_ctxsize = sizeof(struct aegis_ctx), | |
419 | .cra_alignmask = 0, | |
420 | ||
421 | .cra_priority = 100, | |
422 | ||
423 | .cra_name = "aegis128", | |
424 | .cra_driver_name = "aegis128-generic", | |
425 | ||
426 | .cra_module = THIS_MODULE, | |
427 | } | |
428 | }; | |
429 | ||
430 | static int __init crypto_aegis128_module_init(void) | |
431 | { | |
432 | return crypto_register_aead(&crypto_aegis128_alg); | |
433 | } | |
434 | ||
435 | static void __exit crypto_aegis128_module_exit(void) | |
436 | { | |
437 | crypto_unregister_aead(&crypto_aegis128_alg); | |
438 | } | |
439 | ||
c4741b23 | 440 | subsys_initcall(crypto_aegis128_module_init); |
f606a88e OM |
441 | module_exit(crypto_aegis128_module_exit); |
442 | ||
443 | MODULE_LICENSE("GPL"); | |
444 | MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>"); | |
445 | MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm"); | |
446 | MODULE_ALIAS_CRYPTO("aegis128"); | |
447 | MODULE_ALIAS_CRYPTO("aegis128-generic"); |