Merge tag 'media/v5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...
[platform/kernel/linux-starfive.git] / crypto / aegis256.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * The AEGIS-256 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/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 AEGIS256_NONCE_SIZE 32
22 #define AEGIS256_STATE_BLOCKS 6
23 #define AEGIS256_KEY_SIZE 32
24 #define AEGIS256_MIN_AUTH_SIZE 8
25 #define AEGIS256_MAX_AUTH_SIZE 16
26
27 struct aegis_state {
28         union aegis_block blocks[AEGIS256_STATE_BLOCKS];
29 };
30
31 struct aegis_ctx {
32         union aegis_block key[AEGIS256_KEY_SIZE / AEGIS_BLOCK_SIZE];
33 };
34
35 struct aegis256_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_aegis256_update(struct aegis_state *state)
44 {
45         union aegis_block tmp;
46         unsigned int i;
47
48         tmp = state->blocks[AEGIS256_STATE_BLOCKS - 1];
49         for (i = AEGIS256_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_aegis256_update_a(struct aegis_state *state,
56                                      const union aegis_block *msg)
57 {
58         crypto_aegis256_update(state);
59         crypto_aegis_block_xor(&state->blocks[0], msg);
60 }
61
62 static void crypto_aegis256_update_u(struct aegis_state *state, const void *msg)
63 {
64         crypto_aegis256_update(state);
65         crypto_xor(state->blocks[0].bytes, msg, AEGIS_BLOCK_SIZE);
66 }
67
68 static void crypto_aegis256_init(struct aegis_state *state,
69                                  const union aegis_block *key,
70                                  const u8 *iv)
71 {
72         union aegis_block key_iv[2];
73         unsigned int i;
74
75         key_iv[0] = key[0];
76         key_iv[1] = key[1];
77         crypto_xor(key_iv[0].bytes, iv + 0 * AEGIS_BLOCK_SIZE,
78                         AEGIS_BLOCK_SIZE);
79         crypto_xor(key_iv[1].bytes, iv + 1 * AEGIS_BLOCK_SIZE,
80                         AEGIS_BLOCK_SIZE);
81
82         state->blocks[0] = key_iv[0];
83         state->blocks[1] = key_iv[1];
84         state->blocks[2] = crypto_aegis_const[1];
85         state->blocks[3] = crypto_aegis_const[0];
86         state->blocks[4] = key[0];
87         state->blocks[5] = key[1];
88
89         crypto_aegis_block_xor(&state->blocks[4], &crypto_aegis_const[0]);
90         crypto_aegis_block_xor(&state->blocks[5], &crypto_aegis_const[1]);
91
92         for (i = 0; i < 4; i++) {
93                 crypto_aegis256_update_a(state, &key[0]);
94                 crypto_aegis256_update_a(state, &key[1]);
95                 crypto_aegis256_update_a(state, &key_iv[0]);
96                 crypto_aegis256_update_a(state, &key_iv[1]);
97         }
98 }
99
100 static void crypto_aegis256_ad(struct aegis_state *state,
101                                const u8 *src, unsigned int size)
102 {
103         if (AEGIS_ALIGNED(src)) {
104                 const union aegis_block *src_blk =
105                                 (const union aegis_block *)src;
106
107                 while (size >= AEGIS_BLOCK_SIZE) {
108                         crypto_aegis256_update_a(state, src_blk);
109
110                         size -= AEGIS_BLOCK_SIZE;
111                         src_blk++;
112                 }
113         } else {
114                 while (size >= AEGIS_BLOCK_SIZE) {
115                         crypto_aegis256_update_u(state, src);
116
117                         size -= AEGIS_BLOCK_SIZE;
118                         src += AEGIS_BLOCK_SIZE;
119                 }
120         }
121 }
122
123 static void crypto_aegis256_encrypt_chunk(struct aegis_state *state, u8 *dst,
124                                           const u8 *src, unsigned int size)
125 {
126         union aegis_block tmp;
127
128         if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
129                 while (size >= AEGIS_BLOCK_SIZE) {
130                         union aegis_block *dst_blk =
131                                         (union aegis_block *)dst;
132                         const union aegis_block *src_blk =
133                                         (const union aegis_block *)src;
134
135                         tmp = state->blocks[2];
136                         crypto_aegis_block_and(&tmp, &state->blocks[3]);
137                         crypto_aegis_block_xor(&tmp, &state->blocks[5]);
138                         crypto_aegis_block_xor(&tmp, &state->blocks[4]);
139                         crypto_aegis_block_xor(&tmp, &state->blocks[1]);
140                         crypto_aegis_block_xor(&tmp, src_blk);
141
142                         crypto_aegis256_update_a(state, src_blk);
143
144                         *dst_blk = tmp;
145
146                         size -= AEGIS_BLOCK_SIZE;
147                         src += AEGIS_BLOCK_SIZE;
148                         dst += AEGIS_BLOCK_SIZE;
149                 }
150         } else {
151                 while (size >= AEGIS_BLOCK_SIZE) {
152                         tmp = state->blocks[2];
153                         crypto_aegis_block_and(&tmp, &state->blocks[3]);
154                         crypto_aegis_block_xor(&tmp, &state->blocks[5]);
155                         crypto_aegis_block_xor(&tmp, &state->blocks[4]);
156                         crypto_aegis_block_xor(&tmp, &state->blocks[1]);
157                         crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
158
159                         crypto_aegis256_update_u(state, src);
160
161                         memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
162
163                         size -= AEGIS_BLOCK_SIZE;
164                         src += AEGIS_BLOCK_SIZE;
165                         dst += AEGIS_BLOCK_SIZE;
166                 }
167         }
168
169         if (size > 0) {
170                 union aegis_block msg = {};
171                 memcpy(msg.bytes, src, size);
172
173                 tmp = state->blocks[2];
174                 crypto_aegis_block_and(&tmp, &state->blocks[3]);
175                 crypto_aegis_block_xor(&tmp, &state->blocks[5]);
176                 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
177                 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
178
179                 crypto_aegis256_update_a(state, &msg);
180
181                 crypto_aegis_block_xor(&msg, &tmp);
182
183                 memcpy(dst, msg.bytes, size);
184         }
185 }
186
187 static void crypto_aegis256_decrypt_chunk(struct aegis_state *state, u8 *dst,
188                                           const u8 *src, unsigned int size)
189 {
190         union aegis_block tmp;
191
192         if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
193                 while (size >= AEGIS_BLOCK_SIZE) {
194                         union aegis_block *dst_blk =
195                                         (union aegis_block *)dst;
196                         const union aegis_block *src_blk =
197                                         (const union aegis_block *)src;
198
199                         tmp = state->blocks[2];
200                         crypto_aegis_block_and(&tmp, &state->blocks[3]);
201                         crypto_aegis_block_xor(&tmp, &state->blocks[5]);
202                         crypto_aegis_block_xor(&tmp, &state->blocks[4]);
203                         crypto_aegis_block_xor(&tmp, &state->blocks[1]);
204                         crypto_aegis_block_xor(&tmp, src_blk);
205
206                         crypto_aegis256_update_a(state, &tmp);
207
208                         *dst_blk = tmp;
209
210                         size -= AEGIS_BLOCK_SIZE;
211                         src += AEGIS_BLOCK_SIZE;
212                         dst += AEGIS_BLOCK_SIZE;
213                 }
214         } else {
215                 while (size >= AEGIS_BLOCK_SIZE) {
216                         tmp = state->blocks[2];
217                         crypto_aegis_block_and(&tmp, &state->blocks[3]);
218                         crypto_aegis_block_xor(&tmp, &state->blocks[5]);
219                         crypto_aegis_block_xor(&tmp, &state->blocks[4]);
220                         crypto_aegis_block_xor(&tmp, &state->blocks[1]);
221                         crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
222
223                         crypto_aegis256_update_a(state, &tmp);
224
225                         memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
226
227                         size -= AEGIS_BLOCK_SIZE;
228                         src += AEGIS_BLOCK_SIZE;
229                         dst += AEGIS_BLOCK_SIZE;
230                 }
231         }
232
233         if (size > 0) {
234                 union aegis_block msg = {};
235                 memcpy(msg.bytes, src, size);
236
237                 tmp = state->blocks[2];
238                 crypto_aegis_block_and(&tmp, &state->blocks[3]);
239                 crypto_aegis_block_xor(&tmp, &state->blocks[5]);
240                 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
241                 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
242                 crypto_aegis_block_xor(&msg, &tmp);
243
244                 memset(msg.bytes + size, 0, AEGIS_BLOCK_SIZE - size);
245
246                 crypto_aegis256_update_a(state, &msg);
247
248                 memcpy(dst, msg.bytes, size);
249         }
250 }
251
252 static void crypto_aegis256_process_ad(struct aegis_state *state,
253                                        struct scatterlist *sg_src,
254                                        unsigned int assoclen)
255 {
256         struct scatter_walk walk;
257         union aegis_block buf;
258         unsigned int pos = 0;
259
260         scatterwalk_start(&walk, sg_src);
261         while (assoclen != 0) {
262                 unsigned int size = scatterwalk_clamp(&walk, assoclen);
263                 unsigned int left = size;
264                 void *mapped = scatterwalk_map(&walk);
265                 const u8 *src = (const u8 *)mapped;
266
267                 if (pos + size >= AEGIS_BLOCK_SIZE) {
268                         if (pos > 0) {
269                                 unsigned int fill = AEGIS_BLOCK_SIZE - pos;
270                                 memcpy(buf.bytes + pos, src, fill);
271                                 crypto_aegis256_update_a(state, &buf);
272                                 pos = 0;
273                                 left -= fill;
274                                 src += fill;
275                         }
276
277                         crypto_aegis256_ad(state, src, left);
278                         src += left & ~(AEGIS_BLOCK_SIZE - 1);
279                         left &= AEGIS_BLOCK_SIZE - 1;
280                 }
281
282                 memcpy(buf.bytes + pos, src, left);
283
284                 pos += left;
285                 assoclen -= size;
286                 scatterwalk_unmap(mapped);
287                 scatterwalk_advance(&walk, size);
288                 scatterwalk_done(&walk, 0, assoclen);
289         }
290
291         if (pos > 0) {
292                 memset(buf.bytes + pos, 0, AEGIS_BLOCK_SIZE - pos);
293                 crypto_aegis256_update_a(state, &buf);
294         }
295 }
296
297 static void crypto_aegis256_process_crypt(struct aegis_state *state,
298                                           struct aead_request *req,
299                                           const struct aegis256_ops *ops)
300 {
301         struct skcipher_walk walk;
302
303         ops->skcipher_walk_init(&walk, req, false);
304
305         while (walk.nbytes) {
306                 unsigned int nbytes = walk.nbytes;
307
308                 if (nbytes < walk.total)
309                         nbytes = round_down(nbytes, walk.stride);
310
311                 ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr,
312                                  nbytes);
313
314                 skcipher_walk_done(&walk, walk.nbytes - nbytes);
315         }
316 }
317
318 static void crypto_aegis256_final(struct aegis_state *state,
319                                   union aegis_block *tag_xor,
320                                   u64 assoclen, u64 cryptlen)
321 {
322         u64 assocbits = assoclen * 8;
323         u64 cryptbits = cryptlen * 8;
324
325         union aegis_block tmp;
326         unsigned int i;
327
328         tmp.words64[0] = cpu_to_le64(assocbits);
329         tmp.words64[1] = cpu_to_le64(cryptbits);
330
331         crypto_aegis_block_xor(&tmp, &state->blocks[3]);
332
333         for (i = 0; i < 7; i++)
334                 crypto_aegis256_update_a(state, &tmp);
335
336         for (i = 0; i < AEGIS256_STATE_BLOCKS; i++)
337                 crypto_aegis_block_xor(tag_xor, &state->blocks[i]);
338 }
339
340 static int crypto_aegis256_setkey(struct crypto_aead *aead, const u8 *key,
341                                   unsigned int keylen)
342 {
343         struct aegis_ctx *ctx = crypto_aead_ctx(aead);
344
345         if (keylen != AEGIS256_KEY_SIZE) {
346                 crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
347                 return -EINVAL;
348         }
349
350         memcpy(ctx->key[0].bytes, key, AEGIS_BLOCK_SIZE);
351         memcpy(ctx->key[1].bytes, key + AEGIS_BLOCK_SIZE,
352                         AEGIS_BLOCK_SIZE);
353         return 0;
354 }
355
356 static int crypto_aegis256_setauthsize(struct crypto_aead *tfm,
357                                        unsigned int authsize)
358 {
359         if (authsize > AEGIS256_MAX_AUTH_SIZE)
360                 return -EINVAL;
361         if (authsize < AEGIS256_MIN_AUTH_SIZE)
362                 return -EINVAL;
363         return 0;
364 }
365
366 static void crypto_aegis256_crypt(struct aead_request *req,
367                                   union aegis_block *tag_xor,
368                                   unsigned int cryptlen,
369                                   const struct aegis256_ops *ops)
370 {
371         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
372         struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
373         struct aegis_state state;
374
375         crypto_aegis256_init(&state, ctx->key, req->iv);
376         crypto_aegis256_process_ad(&state, req->src, req->assoclen);
377         crypto_aegis256_process_crypt(&state, req, ops);
378         crypto_aegis256_final(&state, tag_xor, req->assoclen, cryptlen);
379 }
380
381 static int crypto_aegis256_encrypt(struct aead_request *req)
382 {
383         static const struct aegis256_ops ops = {
384                 .skcipher_walk_init = skcipher_walk_aead_encrypt,
385                 .crypt_chunk = crypto_aegis256_encrypt_chunk,
386         };
387
388         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
389         union aegis_block tag = {};
390         unsigned int authsize = crypto_aead_authsize(tfm);
391         unsigned int cryptlen = req->cryptlen;
392
393         crypto_aegis256_crypt(req, &tag, cryptlen, &ops);
394
395         scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen,
396                                  authsize, 1);
397         return 0;
398 }
399
400 static int crypto_aegis256_decrypt(struct aead_request *req)
401 {
402         static const struct aegis256_ops ops = {
403                 .skcipher_walk_init = skcipher_walk_aead_decrypt,
404                 .crypt_chunk = crypto_aegis256_decrypt_chunk,
405         };
406         static const u8 zeros[AEGIS256_MAX_AUTH_SIZE] = {};
407
408         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
409         union aegis_block tag;
410         unsigned int authsize = crypto_aead_authsize(tfm);
411         unsigned int cryptlen = req->cryptlen - authsize;
412
413         scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen,
414                                  authsize, 0);
415
416         crypto_aegis256_crypt(req, &tag, cryptlen, &ops);
417
418         return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0;
419 }
420
421 static int crypto_aegis256_init_tfm(struct crypto_aead *tfm)
422 {
423         return 0;
424 }
425
426 static void crypto_aegis256_exit_tfm(struct crypto_aead *tfm)
427 {
428 }
429
430 static struct aead_alg crypto_aegis256_alg = {
431         .setkey = crypto_aegis256_setkey,
432         .setauthsize = crypto_aegis256_setauthsize,
433         .encrypt = crypto_aegis256_encrypt,
434         .decrypt = crypto_aegis256_decrypt,
435         .init = crypto_aegis256_init_tfm,
436         .exit = crypto_aegis256_exit_tfm,
437
438         .ivsize = AEGIS256_NONCE_SIZE,
439         .maxauthsize = AEGIS256_MAX_AUTH_SIZE,
440         .chunksize = AEGIS_BLOCK_SIZE,
441
442         .base = {
443                 .cra_blocksize = 1,
444                 .cra_ctxsize = sizeof(struct aegis_ctx),
445                 .cra_alignmask = 0,
446
447                 .cra_priority = 100,
448
449                 .cra_name = "aegis256",
450                 .cra_driver_name = "aegis256-generic",
451
452                 .cra_module = THIS_MODULE,
453         }
454 };
455
456 static int __init crypto_aegis256_module_init(void)
457 {
458         return crypto_register_aead(&crypto_aegis256_alg);
459 }
460
461 static void __exit crypto_aegis256_module_exit(void)
462 {
463         crypto_unregister_aead(&crypto_aegis256_alg);
464 }
465
466 subsys_initcall(crypto_aegis256_module_init);
467 module_exit(crypto_aegis256_module_exit);
468
469 MODULE_LICENSE("GPL");
470 MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
471 MODULE_DESCRIPTION("AEGIS-256 AEAD algorithm");
472 MODULE_ALIAS_CRYPTO("aegis256");
473 MODULE_ALIAS_CRYPTO("aegis256-generic");