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/kernel.h>
17 #include <linux/module.h>
18 #include <linux/scatterlist.h>
19
20 #include <asm/simd.h>
21
22 #include "aegis.h"
23
24 #define AEGIS128_NONCE_SIZE 16
25 #define AEGIS128_STATE_BLOCKS 5
26 #define AEGIS128_KEY_SIZE 16
27 #define AEGIS128_MIN_AUTH_SIZE 8
28 #define AEGIS128_MAX_AUTH_SIZE 16
29
30 struct aegis_state {
31 union aegis_block blocks[AEGIS128_STATE_BLOCKS];
32 };
33
34 struct aegis_ctx {
35 union aegis_block key;
36 };
37
38 struct aegis128_ops {
39 int (*skcipher_walk_init)(struct skcipher_walk *walk,
40 struct aead_request *req, bool atomic);
41
42 void (*crypt_chunk)(struct aegis_state *state, u8 *dst,
43 const u8 *src, unsigned int size);
44 };
45
46 static bool have_simd;
47
48 static const union aegis_block crypto_aegis_const[2] = {
49 { .words64 = {
50 cpu_to_le64(U64_C(0x0d08050302010100)),
51 cpu_to_le64(U64_C(0x6279e99059372215)),
52 } },
53 { .words64 = {
54 cpu_to_le64(U64_C(0xf12fc26d55183ddb)),
55 cpu_to_le64(U64_C(0xdd28b57342311120)),
56 } },
57 };
58
aegis128_do_simd(void)59 static bool aegis128_do_simd(void)
60 {
61 #ifdef CONFIG_CRYPTO_AEGIS128_SIMD
62 if (have_simd)
63 return crypto_simd_usable();
64 #endif
65 return false;
66 }
67
68 bool crypto_aegis128_have_simd(void);
69 void crypto_aegis128_update_simd(struct aegis_state *state, const void *msg);
70 void crypto_aegis128_encrypt_chunk_simd(struct aegis_state *state, u8 *dst,
71 const u8 *src, unsigned int size);
72 void crypto_aegis128_decrypt_chunk_simd(struct aegis_state *state, u8 *dst,
73 const u8 *src, unsigned int size);
74
crypto_aegis128_update(struct aegis_state * state)75 static void crypto_aegis128_update(struct aegis_state *state)
76 {
77 union aegis_block tmp;
78 unsigned int i;
79
80 tmp = state->blocks[AEGIS128_STATE_BLOCKS - 1];
81 for (i = AEGIS128_STATE_BLOCKS - 1; i > 0; i--)
82 crypto_aegis_aesenc(&state->blocks[i], &state->blocks[i - 1],
83 &state->blocks[i]);
84 crypto_aegis_aesenc(&state->blocks[0], &tmp, &state->blocks[0]);
85 }
86
crypto_aegis128_update_a(struct aegis_state * state,const union aegis_block * msg)87 static void crypto_aegis128_update_a(struct aegis_state *state,
88 const union aegis_block *msg)
89 {
90 if (aegis128_do_simd()) {
91 crypto_aegis128_update_simd(state, msg);
92 return;
93 }
94
95 crypto_aegis128_update(state);
96 crypto_aegis_block_xor(&state->blocks[0], msg);
97 }
98
crypto_aegis128_update_u(struct aegis_state * state,const void * msg)99 static void crypto_aegis128_update_u(struct aegis_state *state, const void *msg)
100 {
101 if (aegis128_do_simd()) {
102 crypto_aegis128_update_simd(state, msg);
103 return;
104 }
105
106 crypto_aegis128_update(state);
107 crypto_xor(state->blocks[0].bytes, msg, AEGIS_BLOCK_SIZE);
108 }
109
crypto_aegis128_init(struct aegis_state * state,const union aegis_block * key,const u8 * iv)110 static void crypto_aegis128_init(struct aegis_state *state,
111 const union aegis_block *key,
112 const u8 *iv)
113 {
114 union aegis_block key_iv;
115 unsigned int i;
116
117 key_iv = *key;
118 crypto_xor(key_iv.bytes, iv, AEGIS_BLOCK_SIZE);
119
120 state->blocks[0] = key_iv;
121 state->blocks[1] = crypto_aegis_const[1];
122 state->blocks[2] = crypto_aegis_const[0];
123 state->blocks[3] = *key;
124 state->blocks[4] = *key;
125
126 crypto_aegis_block_xor(&state->blocks[3], &crypto_aegis_const[0]);
127 crypto_aegis_block_xor(&state->blocks[4], &crypto_aegis_const[1]);
128
129 for (i = 0; i < 5; i++) {
130 crypto_aegis128_update_a(state, key);
131 crypto_aegis128_update_a(state, &key_iv);
132 }
133 }
134
crypto_aegis128_ad(struct aegis_state * state,const u8 * src,unsigned int size)135 static void crypto_aegis128_ad(struct aegis_state *state,
136 const u8 *src, unsigned int size)
137 {
138 if (AEGIS_ALIGNED(src)) {
139 const union aegis_block *src_blk =
140 (const union aegis_block *)src;
141
142 while (size >= AEGIS_BLOCK_SIZE) {
143 crypto_aegis128_update_a(state, src_blk);
144
145 size -= AEGIS_BLOCK_SIZE;
146 src_blk++;
147 }
148 } else {
149 while (size >= AEGIS_BLOCK_SIZE) {
150 crypto_aegis128_update_u(state, src);
151
152 size -= AEGIS_BLOCK_SIZE;
153 src += AEGIS_BLOCK_SIZE;
154 }
155 }
156 }
157
crypto_aegis128_encrypt_chunk(struct aegis_state * state,u8 * dst,const u8 * src,unsigned int size)158 static void crypto_aegis128_encrypt_chunk(struct aegis_state *state, u8 *dst,
159 const u8 *src, unsigned int size)
160 {
161 union aegis_block tmp;
162
163 if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
164 while (size >= AEGIS_BLOCK_SIZE) {
165 union aegis_block *dst_blk =
166 (union aegis_block *)dst;
167 const union aegis_block *src_blk =
168 (const union aegis_block *)src;
169
170 tmp = state->blocks[2];
171 crypto_aegis_block_and(&tmp, &state->blocks[3]);
172 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
173 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
174 crypto_aegis_block_xor(&tmp, src_blk);
175
176 crypto_aegis128_update_a(state, src_blk);
177
178 *dst_blk = tmp;
179
180 size -= AEGIS_BLOCK_SIZE;
181 src += AEGIS_BLOCK_SIZE;
182 dst += AEGIS_BLOCK_SIZE;
183 }
184 } else {
185 while (size >= AEGIS_BLOCK_SIZE) {
186 tmp = state->blocks[2];
187 crypto_aegis_block_and(&tmp, &state->blocks[3]);
188 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
189 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
190 crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
191
192 crypto_aegis128_update_u(state, src);
193
194 memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
195
196 size -= AEGIS_BLOCK_SIZE;
197 src += AEGIS_BLOCK_SIZE;
198 dst += AEGIS_BLOCK_SIZE;
199 }
200 }
201
202 if (size > 0) {
203 union aegis_block msg = {};
204 memcpy(msg.bytes, src, size);
205
206 tmp = state->blocks[2];
207 crypto_aegis_block_and(&tmp, &state->blocks[3]);
208 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
209 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
210
211 crypto_aegis128_update_a(state, &msg);
212
213 crypto_aegis_block_xor(&msg, &tmp);
214
215 memcpy(dst, msg.bytes, size);
216 }
217 }
218
crypto_aegis128_decrypt_chunk(struct aegis_state * state,u8 * dst,const u8 * src,unsigned int size)219 static void crypto_aegis128_decrypt_chunk(struct aegis_state *state, u8 *dst,
220 const u8 *src, unsigned int size)
221 {
222 union aegis_block tmp;
223
224 if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
225 while (size >= AEGIS_BLOCK_SIZE) {
226 union aegis_block *dst_blk =
227 (union aegis_block *)dst;
228 const union aegis_block *src_blk =
229 (const union aegis_block *)src;
230
231 tmp = state->blocks[2];
232 crypto_aegis_block_and(&tmp, &state->blocks[3]);
233 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
234 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
235 crypto_aegis_block_xor(&tmp, src_blk);
236
237 crypto_aegis128_update_a(state, &tmp);
238
239 *dst_blk = tmp;
240
241 size -= AEGIS_BLOCK_SIZE;
242 src += AEGIS_BLOCK_SIZE;
243 dst += AEGIS_BLOCK_SIZE;
244 }
245 } else {
246 while (size >= AEGIS_BLOCK_SIZE) {
247 tmp = state->blocks[2];
248 crypto_aegis_block_and(&tmp, &state->blocks[3]);
249 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
250 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
251 crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
252
253 crypto_aegis128_update_a(state, &tmp);
254
255 memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
256
257 size -= AEGIS_BLOCK_SIZE;
258 src += AEGIS_BLOCK_SIZE;
259 dst += AEGIS_BLOCK_SIZE;
260 }
261 }
262
263 if (size > 0) {
264 union aegis_block msg = {};
265 memcpy(msg.bytes, src, size);
266
267 tmp = state->blocks[2];
268 crypto_aegis_block_and(&tmp, &state->blocks[3]);
269 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
270 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
271 crypto_aegis_block_xor(&msg, &tmp);
272
273 memset(msg.bytes + size, 0, AEGIS_BLOCK_SIZE - size);
274
275 crypto_aegis128_update_a(state, &msg);
276
277 memcpy(dst, msg.bytes, size);
278 }
279 }
280
crypto_aegis128_process_ad(struct aegis_state * state,struct scatterlist * sg_src,unsigned int assoclen)281 static void crypto_aegis128_process_ad(struct aegis_state *state,
282 struct scatterlist *sg_src,
283 unsigned int assoclen)
284 {
285 struct scatter_walk walk;
286 union aegis_block buf;
287 unsigned int pos = 0;
288
289 scatterwalk_start(&walk, sg_src);
290 while (assoclen != 0) {
291 unsigned int size = scatterwalk_clamp(&walk, assoclen);
292 unsigned int left = size;
293 void *mapped = scatterwalk_map(&walk);
294 const u8 *src = (const u8 *)mapped;
295
296 if (pos + size >= AEGIS_BLOCK_SIZE) {
297 if (pos > 0) {
298 unsigned int fill = AEGIS_BLOCK_SIZE - pos;
299 memcpy(buf.bytes + pos, src, fill);
300 crypto_aegis128_update_a(state, &buf);
301 pos = 0;
302 left -= fill;
303 src += fill;
304 }
305
306 crypto_aegis128_ad(state, src, left);
307 src += left & ~(AEGIS_BLOCK_SIZE - 1);
308 left &= AEGIS_BLOCK_SIZE - 1;
309 }
310
311 memcpy(buf.bytes + pos, src, left);
312
313 pos += left;
314 assoclen -= size;
315 scatterwalk_unmap(mapped);
316 scatterwalk_advance(&walk, size);
317 scatterwalk_done(&walk, 0, assoclen);
318 }
319
320 if (pos > 0) {
321 memset(buf.bytes + pos, 0, AEGIS_BLOCK_SIZE - pos);
322 crypto_aegis128_update_a(state, &buf);
323 }
324 }
325
crypto_aegis128_process_crypt(struct aegis_state * state,struct aead_request * req,const struct aegis128_ops * ops)326 static void crypto_aegis128_process_crypt(struct aegis_state *state,
327 struct aead_request *req,
328 const struct aegis128_ops *ops)
329 {
330 struct skcipher_walk walk;
331
332 ops->skcipher_walk_init(&walk, req, false);
333
334 while (walk.nbytes) {
335 unsigned int nbytes = walk.nbytes;
336
337 if (nbytes < walk.total)
338 nbytes = round_down(nbytes, walk.stride);
339
340 ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr,
341 nbytes);
342
343 skcipher_walk_done(&walk, walk.nbytes - nbytes);
344 }
345 }
346
crypto_aegis128_final(struct aegis_state * state,union aegis_block * tag_xor,u64 assoclen,u64 cryptlen)347 static void crypto_aegis128_final(struct aegis_state *state,
348 union aegis_block *tag_xor,
349 u64 assoclen, u64 cryptlen)
350 {
351 u64 assocbits = assoclen * 8;
352 u64 cryptbits = cryptlen * 8;
353
354 union aegis_block tmp;
355 unsigned int i;
356
357 tmp.words64[0] = cpu_to_le64(assocbits);
358 tmp.words64[1] = cpu_to_le64(cryptbits);
359
360 crypto_aegis_block_xor(&tmp, &state->blocks[3]);
361
362 for (i = 0; i < 7; i++)
363 crypto_aegis128_update_a(state, &tmp);
364
365 for (i = 0; i < AEGIS128_STATE_BLOCKS; i++)
366 crypto_aegis_block_xor(tag_xor, &state->blocks[i]);
367 }
368
crypto_aegis128_setkey(struct crypto_aead * aead,const u8 * key,unsigned int keylen)369 static int crypto_aegis128_setkey(struct crypto_aead *aead, const u8 *key,
370 unsigned int keylen)
371 {
372 struct aegis_ctx *ctx = crypto_aead_ctx(aead);
373
374 if (keylen != AEGIS128_KEY_SIZE) {
375 crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
376 return -EINVAL;
377 }
378
379 memcpy(ctx->key.bytes, key, AEGIS128_KEY_SIZE);
380 return 0;
381 }
382
crypto_aegis128_setauthsize(struct crypto_aead * tfm,unsigned int authsize)383 static int crypto_aegis128_setauthsize(struct crypto_aead *tfm,
384 unsigned int authsize)
385 {
386 if (authsize > AEGIS128_MAX_AUTH_SIZE)
387 return -EINVAL;
388 if (authsize < AEGIS128_MIN_AUTH_SIZE)
389 return -EINVAL;
390 return 0;
391 }
392
crypto_aegis128_crypt(struct aead_request * req,union aegis_block * tag_xor,unsigned int cryptlen,const struct aegis128_ops * ops)393 static void crypto_aegis128_crypt(struct aead_request *req,
394 union aegis_block *tag_xor,
395 unsigned int cryptlen,
396 const struct aegis128_ops *ops)
397 {
398 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
399 struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
400 struct aegis_state state;
401
402 crypto_aegis128_init(&state, &ctx->key, req->iv);
403 crypto_aegis128_process_ad(&state, req->src, req->assoclen);
404 crypto_aegis128_process_crypt(&state, req, ops);
405 crypto_aegis128_final(&state, tag_xor, req->assoclen, cryptlen);
406 }
407
crypto_aegis128_encrypt(struct aead_request * req)408 static int crypto_aegis128_encrypt(struct aead_request *req)
409 {
410 const struct aegis128_ops *ops = &(struct aegis128_ops){
411 .skcipher_walk_init = skcipher_walk_aead_encrypt,
412 .crypt_chunk = crypto_aegis128_encrypt_chunk,
413 };
414
415 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
416 union aegis_block tag = {};
417 unsigned int authsize = crypto_aead_authsize(tfm);
418 unsigned int cryptlen = req->cryptlen;
419
420 if (aegis128_do_simd())
421 ops = &(struct aegis128_ops){
422 .skcipher_walk_init = skcipher_walk_aead_encrypt,
423 .crypt_chunk = crypto_aegis128_encrypt_chunk_simd };
424
425 crypto_aegis128_crypt(req, &tag, cryptlen, ops);
426
427 scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen,
428 authsize, 1);
429 return 0;
430 }
431
crypto_aegis128_decrypt(struct aead_request * req)432 static int crypto_aegis128_decrypt(struct aead_request *req)
433 {
434 const struct aegis128_ops *ops = &(struct aegis128_ops){
435 .skcipher_walk_init = skcipher_walk_aead_decrypt,
436 .crypt_chunk = crypto_aegis128_decrypt_chunk,
437 };
438 static const u8 zeros[AEGIS128_MAX_AUTH_SIZE] = {};
439
440 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
441 union aegis_block tag;
442 unsigned int authsize = crypto_aead_authsize(tfm);
443 unsigned int cryptlen = req->cryptlen - authsize;
444
445 scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen,
446 authsize, 0);
447
448 if (aegis128_do_simd())
449 ops = &(struct aegis128_ops){
450 .skcipher_walk_init = skcipher_walk_aead_decrypt,
451 .crypt_chunk = crypto_aegis128_decrypt_chunk_simd };
452
453 crypto_aegis128_crypt(req, &tag, cryptlen, ops);
454
455 return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0;
456 }
457
458 static struct aead_alg crypto_aegis128_alg = {
459 .setkey = crypto_aegis128_setkey,
460 .setauthsize = crypto_aegis128_setauthsize,
461 .encrypt = crypto_aegis128_encrypt,
462 .decrypt = crypto_aegis128_decrypt,
463
464 .ivsize = AEGIS128_NONCE_SIZE,
465 .maxauthsize = AEGIS128_MAX_AUTH_SIZE,
466 .chunksize = AEGIS_BLOCK_SIZE,
467
468 .base = {
469 .cra_blocksize = 1,
470 .cra_ctxsize = sizeof(struct aegis_ctx),
471 .cra_alignmask = 0,
472
473 .cra_priority = 100,
474
475 .cra_name = "aegis128",
476 .cra_driver_name = "aegis128-generic",
477
478 .cra_module = THIS_MODULE,
479 }
480 };
481
crypto_aegis128_module_init(void)482 static int __init crypto_aegis128_module_init(void)
483 {
484 if (IS_ENABLED(CONFIG_CRYPTO_AEGIS128_SIMD))
485 have_simd = crypto_aegis128_have_simd();
486
487 return crypto_register_aead(&crypto_aegis128_alg);
488 }
489
crypto_aegis128_module_exit(void)490 static void __exit crypto_aegis128_module_exit(void)
491 {
492 crypto_unregister_aead(&crypto_aegis128_alg);
493 }
494
495 subsys_initcall(crypto_aegis128_module_init);
496 module_exit(crypto_aegis128_module_exit);
497
498 MODULE_LICENSE("GPL");
499 MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
500 MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm");
501 MODULE_ALIAS_CRYPTO("aegis128");
502 MODULE_ALIAS_CRYPTO("aegis128-generic");
503
