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1// SPDX-License-Identifier: GPL-2.0-or-later
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.
7 */
8
9#include <crypto/algapi.h>
10#include <crypto/internal/aead.h>
11#include <crypto/internal/simd.h>
12#include <crypto/internal/skcipher.h>
13#include <crypto/scatterwalk.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <linux/jump_label.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/scatterlist.h>
20
21#include <asm/simd.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
31struct aegis_state {
32 union aegis_block blocks[AEGIS128_STATE_BLOCKS];
33};
34
35struct aegis_ctx {
36 union aegis_block key;
37};
38
39static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_simd);
40
41static const union aegis_block crypto_aegis_const[2] = {
42 { .words64 = {
43 cpu_to_le64(U64_C(0x0d08050302010100)),
44 cpu_to_le64(U64_C(0x6279e99059372215)),
45 } },
46 { .words64 = {
47 cpu_to_le64(U64_C(0xf12fc26d55183ddb)),
48 cpu_to_le64(U64_C(0xdd28b57342311120)),
49 } },
50};
51
52static bool aegis128_do_simd(void)
53{
54#ifdef CONFIG_CRYPTO_AEGIS128_SIMD
55 if (static_branch_likely(&have_simd))
56 return crypto_simd_usable();
57#endif
58 return false;
59}
60
61static void crypto_aegis128_update(struct aegis_state *state)
62{
63 union aegis_block tmp;
64 unsigned int i;
65
66 tmp = state->blocks[AEGIS128_STATE_BLOCKS - 1];
67 for (i = AEGIS128_STATE_BLOCKS - 1; i > 0; i--)
68 crypto_aegis_aesenc(&state->blocks[i], &state->blocks[i - 1],
69 &state->blocks[i]);
70 crypto_aegis_aesenc(&state->blocks[0], &tmp, &state->blocks[0]);
71}
72
73static void crypto_aegis128_update_a(struct aegis_state *state,
74 const union aegis_block *msg,
75 bool do_simd)
76{
77 if (IS_ENABLED(CONFIG_CRYPTO_AEGIS128_SIMD) && do_simd) {
78 crypto_aegis128_update_simd(state, msg);
79 return;
80 }
81
82 crypto_aegis128_update(state);
83 crypto_aegis_block_xor(&state->blocks[0], msg);
84}
85
86static void crypto_aegis128_update_u(struct aegis_state *state, const void *msg,
87 bool do_simd)
88{
89 if (IS_ENABLED(CONFIG_CRYPTO_AEGIS128_SIMD) && do_simd) {
90 crypto_aegis128_update_simd(state, msg);
91 return;
92 }
93
94 crypto_aegis128_update(state);
95 crypto_xor(state->blocks[0].bytes, msg, AEGIS_BLOCK_SIZE);
96}
97
98static void crypto_aegis128_init(struct aegis_state *state,
99 const union aegis_block *key,
100 const u8 *iv)
101{
102 union aegis_block key_iv;
103 unsigned int i;
104
105 key_iv = *key;
106 crypto_xor(key_iv.bytes, iv, AEGIS_BLOCK_SIZE);
107
108 state->blocks[0] = key_iv;
109 state->blocks[1] = crypto_aegis_const[1];
110 state->blocks[2] = crypto_aegis_const[0];
111 state->blocks[3] = *key;
112 state->blocks[4] = *key;
113
114 crypto_aegis_block_xor(&state->blocks[3], &crypto_aegis_const[0]);
115 crypto_aegis_block_xor(&state->blocks[4], &crypto_aegis_const[1]);
116
117 for (i = 0; i < 5; i++) {
118 crypto_aegis128_update_a(state, key, false);
119 crypto_aegis128_update_a(state, &key_iv, false);
120 }
121}
122
123static void crypto_aegis128_ad(struct aegis_state *state,
124 const u8 *src, unsigned int size,
125 bool do_simd)
126{
127 if (AEGIS_ALIGNED(src)) {
128 const union aegis_block *src_blk =
129 (const union aegis_block *)src;
130
131 while (size >= AEGIS_BLOCK_SIZE) {
132 crypto_aegis128_update_a(state, src_blk, do_simd);
133
134 size -= AEGIS_BLOCK_SIZE;
135 src_blk++;
136 }
137 } else {
138 while (size >= AEGIS_BLOCK_SIZE) {
139 crypto_aegis128_update_u(state, src, do_simd);
140
141 size -= AEGIS_BLOCK_SIZE;
142 src += AEGIS_BLOCK_SIZE;
143 }
144 }
145}
146
147static void crypto_aegis128_wipe_chunk(struct aegis_state *state, u8 *dst,
148 const u8 *src, unsigned int size)
149{
150 memzero_explicit(dst, size);
151}
152
153static void crypto_aegis128_encrypt_chunk(struct aegis_state *state, u8 *dst,
154 const u8 *src, unsigned int size)
155{
156 union aegis_block tmp;
157
158 if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
159 while (size >= AEGIS_BLOCK_SIZE) {
160 union aegis_block *dst_blk =
161 (union aegis_block *)dst;
162 const union aegis_block *src_blk =
163 (const union aegis_block *)src;
164
165 tmp = state->blocks[2];
166 crypto_aegis_block_and(&tmp, &state->blocks[3]);
167 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
168 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
169 crypto_aegis_block_xor(&tmp, src_blk);
170
171 crypto_aegis128_update_a(state, src_blk, false);
172
173 *dst_blk = tmp;
174
175 size -= AEGIS_BLOCK_SIZE;
176 src += AEGIS_BLOCK_SIZE;
177 dst += AEGIS_BLOCK_SIZE;
178 }
179 } else {
180 while (size >= AEGIS_BLOCK_SIZE) {
181 tmp = state->blocks[2];
182 crypto_aegis_block_and(&tmp, &state->blocks[3]);
183 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
184 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
185 crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
186
187 crypto_aegis128_update_u(state, src, false);
188
189 memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
190
191 size -= AEGIS_BLOCK_SIZE;
192 src += AEGIS_BLOCK_SIZE;
193 dst += AEGIS_BLOCK_SIZE;
194 }
195 }
196
197 if (size > 0) {
198 union aegis_block msg = {};
199 memcpy(msg.bytes, src, size);
200
201 tmp = state->blocks[2];
202 crypto_aegis_block_and(&tmp, &state->blocks[3]);
203 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
204 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
205
206 crypto_aegis128_update_a(state, &msg, false);
207
208 crypto_aegis_block_xor(&msg, &tmp);
209
210 memcpy(dst, msg.bytes, size);
211 }
212}
213
214static void crypto_aegis128_decrypt_chunk(struct aegis_state *state, u8 *dst,
215 const u8 *src, unsigned int size)
216{
217 union aegis_block tmp;
218
219 if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
220 while (size >= AEGIS_BLOCK_SIZE) {
221 union aegis_block *dst_blk =
222 (union aegis_block *)dst;
223 const union aegis_block *src_blk =
224 (const union aegis_block *)src;
225
226 tmp = state->blocks[2];
227 crypto_aegis_block_and(&tmp, &state->blocks[3]);
228 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
229 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
230 crypto_aegis_block_xor(&tmp, src_blk);
231
232 crypto_aegis128_update_a(state, &tmp, false);
233
234 *dst_blk = tmp;
235
236 size -= AEGIS_BLOCK_SIZE;
237 src += AEGIS_BLOCK_SIZE;
238 dst += AEGIS_BLOCK_SIZE;
239 }
240 } else {
241 while (size >= AEGIS_BLOCK_SIZE) {
242 tmp = state->blocks[2];
243 crypto_aegis_block_and(&tmp, &state->blocks[3]);
244 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
245 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
246 crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
247
248 crypto_aegis128_update_a(state, &tmp, false);
249
250 memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
251
252 size -= AEGIS_BLOCK_SIZE;
253 src += AEGIS_BLOCK_SIZE;
254 dst += AEGIS_BLOCK_SIZE;
255 }
256 }
257
258 if (size > 0) {
259 union aegis_block msg = {};
260 memcpy(msg.bytes, src, size);
261
262 tmp = state->blocks[2];
263 crypto_aegis_block_and(&tmp, &state->blocks[3]);
264 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
265 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
266 crypto_aegis_block_xor(&msg, &tmp);
267
268 memset(msg.bytes + size, 0, AEGIS_BLOCK_SIZE - size);
269
270 crypto_aegis128_update_a(state, &msg, false);
271
272 memcpy(dst, msg.bytes, size);
273 }
274}
275
276static void crypto_aegis128_process_ad(struct aegis_state *state,
277 struct scatterlist *sg_src,
278 unsigned int assoclen,
279 bool do_simd)
280{
281 struct scatter_walk walk;
282 union aegis_block buf;
283 unsigned int pos = 0;
284
285 scatterwalk_start(&walk, sg_src);
286 while (assoclen != 0) {
287 unsigned int size = scatterwalk_clamp(&walk, assoclen);
288 unsigned int left = size;
289 void *mapped = scatterwalk_map(&walk);
290 const u8 *src = (const u8 *)mapped;
291
292 if (pos + size >= AEGIS_BLOCK_SIZE) {
293 if (pos > 0) {
294 unsigned int fill = AEGIS_BLOCK_SIZE - pos;
295 memcpy(buf.bytes + pos, src, fill);
296 crypto_aegis128_update_a(state, &buf, do_simd);
297 pos = 0;
298 left -= fill;
299 src += fill;
300 }
301
302 crypto_aegis128_ad(state, src, left, do_simd);
303 src += left & ~(AEGIS_BLOCK_SIZE - 1);
304 left &= AEGIS_BLOCK_SIZE - 1;
305 }
306
307 memcpy(buf.bytes + pos, src, left);
308
309 pos += left;
310 assoclen -= size;
311 scatterwalk_unmap(mapped);
312 scatterwalk_advance(&walk, size);
313 scatterwalk_done(&walk, 0, assoclen);
314 }
315
316 if (pos > 0) {
317 memset(buf.bytes + pos, 0, AEGIS_BLOCK_SIZE - pos);
318 crypto_aegis128_update_a(state, &buf, do_simd);
319 }
320}
321
322static __always_inline
323int crypto_aegis128_process_crypt(struct aegis_state *state,
324 struct skcipher_walk *walk,
325 void (*crypt)(struct aegis_state *state,
326 u8 *dst,
327 const u8 *src,
328 unsigned int size))
329{
330 int err = 0;
331
332 while (walk->nbytes) {
333 unsigned int nbytes = walk->nbytes;
334
335 if (nbytes < walk->total)
336 nbytes = round_down(nbytes, walk->stride);
337
338 crypt(state, walk->dst.virt.addr, walk->src.virt.addr, nbytes);
339
340 err = skcipher_walk_done(walk, walk->nbytes - nbytes);
341 }
342 return err;
343}
344
345static void crypto_aegis128_final(struct aegis_state *state,
346 union aegis_block *tag_xor,
347 u64 assoclen, u64 cryptlen)
348{
349 u64 assocbits = assoclen * 8;
350 u64 cryptbits = cryptlen * 8;
351
352 union aegis_block tmp;
353 unsigned int i;
354
355 tmp.words64[0] = cpu_to_le64(assocbits);
356 tmp.words64[1] = cpu_to_le64(cryptbits);
357
358 crypto_aegis_block_xor(&tmp, &state->blocks[3]);
359
360 for (i = 0; i < 7; i++)
361 crypto_aegis128_update_a(state, &tmp, false);
362
363 for (i = 0; i < AEGIS128_STATE_BLOCKS; i++)
364 crypto_aegis_block_xor(tag_xor, &state->blocks[i]);
365}
366
367static int crypto_aegis128_setkey(struct crypto_aead *aead, const u8 *key,
368 unsigned int keylen)
369{
370 struct aegis_ctx *ctx = crypto_aead_ctx(aead);
371
372 if (keylen != AEGIS128_KEY_SIZE)
373 return -EINVAL;
374
375 memcpy(ctx->key.bytes, key, AEGIS128_KEY_SIZE);
376 return 0;
377}
378
379static int crypto_aegis128_setauthsize(struct crypto_aead *tfm,
380 unsigned int authsize)
381{
382 if (authsize > AEGIS128_MAX_AUTH_SIZE)
383 return -EINVAL;
384 if (authsize < AEGIS128_MIN_AUTH_SIZE)
385 return -EINVAL;
386 return 0;
387}
388
389static int crypto_aegis128_encrypt_generic(struct aead_request *req)
390{
391 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
392 union aegis_block tag = {};
393 unsigned int authsize = crypto_aead_authsize(tfm);
394 struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
395 unsigned int cryptlen = req->cryptlen;
396 struct skcipher_walk walk;
397 struct aegis_state state;
398
399 skcipher_walk_aead_encrypt(&walk, req, false);
400 crypto_aegis128_init(&state, &ctx->key, req->iv);
401 crypto_aegis128_process_ad(&state, req->src, req->assoclen, false);
402 crypto_aegis128_process_crypt(&state, &walk,
403 crypto_aegis128_encrypt_chunk);
404 crypto_aegis128_final(&state, &tag, req->assoclen, cryptlen);
405
406 scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen,
407 authsize, 1);
408 return 0;
409}
410
411static int crypto_aegis128_decrypt_generic(struct aead_request *req)
412{
413 static const u8 zeros[AEGIS128_MAX_AUTH_SIZE] = {};
414 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
415 union aegis_block tag;
416 unsigned int authsize = crypto_aead_authsize(tfm);
417 unsigned int cryptlen = req->cryptlen - authsize;
418 struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
419 struct skcipher_walk walk;
420 struct aegis_state state;
421
422 scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen,
423 authsize, 0);
424
425 skcipher_walk_aead_decrypt(&walk, req, false);
426 crypto_aegis128_init(&state, &ctx->key, req->iv);
427 crypto_aegis128_process_ad(&state, req->src, req->assoclen, false);
428 crypto_aegis128_process_crypt(&state, &walk,
429 crypto_aegis128_decrypt_chunk);
430 crypto_aegis128_final(&state, &tag, req->assoclen, cryptlen);
431
432 if (unlikely(crypto_memneq(tag.bytes, zeros, authsize))) {
433 /*
434 * From Chapter 4. 'Security Analysis' of the AEGIS spec [0]
435 *
436 * "3. If verification fails, the decrypted plaintext and the
437 * wrong authentication tag should not be given as output."
438 *
439 * [0] https://competitions.cr.yp.to/round3/aegisv11.pdf
440 */
441 skcipher_walk_aead_decrypt(&walk, req, false);
442 crypto_aegis128_process_crypt(NULL, &walk,
443 crypto_aegis128_wipe_chunk);
444 memzero_explicit(&tag, sizeof(tag));
445 return -EBADMSG;
446 }
447 return 0;
448}
449
450static int crypto_aegis128_encrypt_simd(struct aead_request *req)
451{
452 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
453 union aegis_block tag = {};
454 unsigned int authsize = crypto_aead_authsize(tfm);
455 struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
456 unsigned int cryptlen = req->cryptlen;
457 struct skcipher_walk walk;
458 struct aegis_state state;
459
460 if (!aegis128_do_simd())
461 return crypto_aegis128_encrypt_generic(req);
462
463 skcipher_walk_aead_encrypt(&walk, req, false);
464 crypto_aegis128_init_simd(&state, &ctx->key, req->iv);
465 crypto_aegis128_process_ad(&state, req->src, req->assoclen, true);
466 crypto_aegis128_process_crypt(&state, &walk,
467 crypto_aegis128_encrypt_chunk_simd);
468 crypto_aegis128_final_simd(&state, &tag, req->assoclen, cryptlen, 0);
469
470 scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen,
471 authsize, 1);
472 return 0;
473}
474
475static int crypto_aegis128_decrypt_simd(struct aead_request *req)
476{
477 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
478 union aegis_block tag;
479 unsigned int authsize = crypto_aead_authsize(tfm);
480 unsigned int cryptlen = req->cryptlen - authsize;
481 struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
482 struct skcipher_walk walk;
483 struct aegis_state state;
484
485 if (!aegis128_do_simd())
486 return crypto_aegis128_decrypt_generic(req);
487
488 scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen,
489 authsize, 0);
490
491 skcipher_walk_aead_decrypt(&walk, req, false);
492 crypto_aegis128_init_simd(&state, &ctx->key, req->iv);
493 crypto_aegis128_process_ad(&state, req->src, req->assoclen, true);
494 crypto_aegis128_process_crypt(&state, &walk,
495 crypto_aegis128_decrypt_chunk_simd);
496
497 if (unlikely(crypto_aegis128_final_simd(&state, &tag, req->assoclen,
498 cryptlen, authsize))) {
499 skcipher_walk_aead_decrypt(&walk, req, false);
500 crypto_aegis128_process_crypt(NULL, &walk,
501 crypto_aegis128_wipe_chunk);
502 return -EBADMSG;
503 }
504 return 0;
505}
506
507static struct aead_alg crypto_aegis128_alg_generic = {
508 .setkey = crypto_aegis128_setkey,
509 .setauthsize = crypto_aegis128_setauthsize,
510 .encrypt = crypto_aegis128_encrypt_generic,
511 .decrypt = crypto_aegis128_decrypt_generic,
512
513 .ivsize = AEGIS128_NONCE_SIZE,
514 .maxauthsize = AEGIS128_MAX_AUTH_SIZE,
515 .chunksize = AEGIS_BLOCK_SIZE,
516
517 .base.cra_blocksize = 1,
518 .base.cra_ctxsize = sizeof(struct aegis_ctx),
519 .base.cra_alignmask = 0,
520 .base.cra_priority = 100,
521 .base.cra_name = "aegis128",
522 .base.cra_driver_name = "aegis128-generic",
523 .base.cra_module = THIS_MODULE,
524};
525
526static struct aead_alg crypto_aegis128_alg_simd = {
527 .setkey = crypto_aegis128_setkey,
528 .setauthsize = crypto_aegis128_setauthsize,
529 .encrypt = crypto_aegis128_encrypt_simd,
530 .decrypt = crypto_aegis128_decrypt_simd,
531
532 .ivsize = AEGIS128_NONCE_SIZE,
533 .maxauthsize = AEGIS128_MAX_AUTH_SIZE,
534 .chunksize = AEGIS_BLOCK_SIZE,
535
536 .base.cra_blocksize = 1,
537 .base.cra_ctxsize = sizeof(struct aegis_ctx),
538 .base.cra_alignmask = 0,
539 .base.cra_priority = 200,
540 .base.cra_name = "aegis128",
541 .base.cra_driver_name = "aegis128-simd",
542 .base.cra_module = THIS_MODULE,
543};
544
545static int __init crypto_aegis128_module_init(void)
546{
547 int ret;
548
549 ret = crypto_register_aead(&crypto_aegis128_alg_generic);
550 if (ret)
551 return ret;
552
553 if (IS_ENABLED(CONFIG_CRYPTO_AEGIS128_SIMD) &&
554 crypto_aegis128_have_simd()) {
555 ret = crypto_register_aead(&crypto_aegis128_alg_simd);
556 if (ret) {
557 crypto_unregister_aead(&crypto_aegis128_alg_generic);
558 return ret;
559 }
560 static_branch_enable(&have_simd);
561 }
562 return 0;
563}
564
565static void __exit crypto_aegis128_module_exit(void)
566{
567 if (IS_ENABLED(CONFIG_CRYPTO_AEGIS128_SIMD) &&
568 crypto_aegis128_have_simd())
569 crypto_unregister_aead(&crypto_aegis128_alg_simd);
570
571 crypto_unregister_aead(&crypto_aegis128_alg_generic);
572}
573
574subsys_initcall(crypto_aegis128_module_init);
575module_exit(crypto_aegis128_module_exit);
576
577MODULE_LICENSE("GPL");
578MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
579MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm");
580MODULE_ALIAS_CRYPTO("aegis128");
581MODULE_ALIAS_CRYPTO("aegis128-generic");
582MODULE_ALIAS_CRYPTO("aegis128-simd");