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11#include <asm/neon.h>
12#include <asm/simd.h>
13#include <asm/unaligned.h>
14#include <crypto/aes.h>
15#include <crypto/algapi.h>
16#include <crypto/b128ops.h>
17#include <crypto/gf128mul.h>
18#include <crypto/internal/aead.h>
19#include <crypto/internal/hash.h>
20#include <crypto/internal/skcipher.h>
21#include <crypto/scatterwalk.h>
22#include <linux/cpufeature.h>
23#include <linux/crypto.h>
24#include <linux/module.h>
25
26MODULE_DESCRIPTION("GHASH and AES-GCM using ARMv8 Crypto Extensions");
27MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
28MODULE_LICENSE("GPL v2");
29MODULE_ALIAS_CRYPTO("ghash");
30
31#define GHASH_BLOCK_SIZE 16
32#define GHASH_DIGEST_SIZE 16
33#define GCM_IV_SIZE 12
34
35struct ghash_key {
36 u64 a;
37 u64 b;
38 be128 k;
39};
40
41struct ghash_desc_ctx {
42 u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
43 u8 buf[GHASH_BLOCK_SIZE];
44 u32 count;
45};
46
47struct gcm_aes_ctx {
48 struct crypto_aes_ctx aes_key;
49 struct ghash_key ghash_key;
50};
51
52asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src,
53 struct ghash_key const *k,
54 const char *head);
55
56asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src,
57 struct ghash_key const *k,
58 const char *head);
59
60static void (*pmull_ghash_update)(int blocks, u64 dg[], const char *src,
61 struct ghash_key const *k,
62 const char *head);
63
64asmlinkage void pmull_gcm_encrypt(int blocks, u64 dg[], u8 dst[],
65 const u8 src[], struct ghash_key const *k,
66 u8 ctr[], u32 const rk[], int rounds,
67 u8 ks[]);
68
69asmlinkage void pmull_gcm_decrypt(int blocks, u64 dg[], u8 dst[],
70 const u8 src[], struct ghash_key const *k,
71 u8 ctr[], u32 const rk[], int rounds);
72
73asmlinkage void pmull_gcm_encrypt_block(u8 dst[], u8 const src[],
74 u32 const rk[], int rounds);
75
76asmlinkage void __aes_arm64_encrypt(u32 *rk, u8 *out, const u8 *in, int rounds);
77
78static int ghash_init(struct shash_desc *desc)
79{
80 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
81
82 *ctx = (struct ghash_desc_ctx){};
83 return 0;
84}
85
86static void ghash_do_update(int blocks, u64 dg[], const char *src,
87 struct ghash_key *key, const char *head)
88{
89 if (likely(may_use_simd())) {
90 kernel_neon_begin();
91 pmull_ghash_update(blocks, dg, src, key, head);
92 kernel_neon_end();
93 } else {
94 be128 dst = { cpu_to_be64(dg[1]), cpu_to_be64(dg[0]) };
95
96 do {
97 const u8 *in = src;
98
99 if (head) {
100 in = head;
101 blocks++;
102 head = NULL;
103 } else {
104 src += GHASH_BLOCK_SIZE;
105 }
106
107 crypto_xor((u8 *)&dst, in, GHASH_BLOCK_SIZE);
108 gf128mul_lle(&dst, &key->k);
109 } while (--blocks);
110
111 dg[0] = be64_to_cpu(dst.b);
112 dg[1] = be64_to_cpu(dst.a);
113 }
114}
115
116static int ghash_update(struct shash_desc *desc, const u8 *src,
117 unsigned int len)
118{
119 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
120 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
121
122 ctx->count += len;
123
124 if ((partial + len) >= GHASH_BLOCK_SIZE) {
125 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
126 int blocks;
127
128 if (partial) {
129 int p = GHASH_BLOCK_SIZE - partial;
130
131 memcpy(ctx->buf + partial, src, p);
132 src += p;
133 len -= p;
134 }
135
136 blocks = len / GHASH_BLOCK_SIZE;
137 len %= GHASH_BLOCK_SIZE;
138
139 ghash_do_update(blocks, ctx->digest, src, key,
140 partial ? ctx->buf : NULL);
141
142 src += blocks * GHASH_BLOCK_SIZE;
143 partial = 0;
144 }
145 if (len)
146 memcpy(ctx->buf + partial, src, len);
147 return 0;
148}
149
150static int ghash_final(struct shash_desc *desc, u8 *dst)
151{
152 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
153 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
154
155 if (partial) {
156 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
157
158 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
159
160 ghash_do_update(1, ctx->digest, ctx->buf, key, NULL);
161 }
162 put_unaligned_be64(ctx->digest[1], dst);
163 put_unaligned_be64(ctx->digest[0], dst + 8);
164
165 *ctx = (struct ghash_desc_ctx){};
166 return 0;
167}
168
169static int __ghash_setkey(struct ghash_key *key,
170 const u8 *inkey, unsigned int keylen)
171{
172 u64 a, b;
173
174
175 memcpy(&key->k, inkey, GHASH_BLOCK_SIZE);
176
177
178 b = get_unaligned_be64(inkey);
179 a = get_unaligned_be64(inkey + 8);
180
181 key->a = (a << 1) | (b >> 63);
182 key->b = (b << 1) | (a >> 63);
183
184 if (b >> 63)
185 key->b ^= 0xc200000000000000UL;
186
187 return 0;
188}
189
190static int ghash_setkey(struct crypto_shash *tfm,
191 const u8 *inkey, unsigned int keylen)
192{
193 struct ghash_key *key = crypto_shash_ctx(tfm);
194
195 if (keylen != GHASH_BLOCK_SIZE) {
196 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
197 return -EINVAL;
198 }
199
200 return __ghash_setkey(key, inkey, keylen);
201}
202
203static struct shash_alg ghash_alg = {
204 .base.cra_name = "ghash",
205 .base.cra_driver_name = "ghash-ce",
206 .base.cra_priority = 200,
207 .base.cra_flags = CRYPTO_ALG_TYPE_SHASH,
208 .base.cra_blocksize = GHASH_BLOCK_SIZE,
209 .base.cra_ctxsize = sizeof(struct ghash_key),
210 .base.cra_module = THIS_MODULE,
211
212 .digestsize = GHASH_DIGEST_SIZE,
213 .init = ghash_init,
214 .update = ghash_update,
215 .final = ghash_final,
216 .setkey = ghash_setkey,
217 .descsize = sizeof(struct ghash_desc_ctx),
218};
219
220static int num_rounds(struct crypto_aes_ctx *ctx)
221{
222
223
224
225
226
227
228
229 return 6 + ctx->key_length / 4;
230}
231
232static int gcm_setkey(struct crypto_aead *tfm, const u8 *inkey,
233 unsigned int keylen)
234{
235 struct gcm_aes_ctx *ctx = crypto_aead_ctx(tfm);
236 u8 key[GHASH_BLOCK_SIZE];
237 int ret;
238
239 ret = crypto_aes_expand_key(&ctx->aes_key, inkey, keylen);
240 if (ret) {
241 tfm->base.crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
242 return -EINVAL;
243 }
244
245 __aes_arm64_encrypt(ctx->aes_key.key_enc, key, (u8[AES_BLOCK_SIZE]){},
246 num_rounds(&ctx->aes_key));
247
248 return __ghash_setkey(&ctx->ghash_key, key, sizeof(key));
249}
250
251static int gcm_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
252{
253 switch (authsize) {
254 case 4:
255 case 8:
256 case 12 ... 16:
257 break;
258 default:
259 return -EINVAL;
260 }
261 return 0;
262}
263
264static void gcm_update_mac(u64 dg[], const u8 *src, int count, u8 buf[],
265 int *buf_count, struct gcm_aes_ctx *ctx)
266{
267 if (*buf_count > 0) {
268 int buf_added = min(count, GHASH_BLOCK_SIZE - *buf_count);
269
270 memcpy(&buf[*buf_count], src, buf_added);
271
272 *buf_count += buf_added;
273 src += buf_added;
274 count -= buf_added;
275 }
276
277 if (count >= GHASH_BLOCK_SIZE || *buf_count == GHASH_BLOCK_SIZE) {
278 int blocks = count / GHASH_BLOCK_SIZE;
279
280 ghash_do_update(blocks, dg, src, &ctx->ghash_key,
281 *buf_count ? buf : NULL);
282
283 src += blocks * GHASH_BLOCK_SIZE;
284 count %= GHASH_BLOCK_SIZE;
285 *buf_count = 0;
286 }
287
288 if (count > 0) {
289 memcpy(buf, src, count);
290 *buf_count = count;
291 }
292}
293
294static void gcm_calculate_auth_mac(struct aead_request *req, u64 dg[])
295{
296 struct crypto_aead *aead = crypto_aead_reqtfm(req);
297 struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead);
298 u8 buf[GHASH_BLOCK_SIZE];
299 struct scatter_walk walk;
300 u32 len = req->assoclen;
301 int buf_count = 0;
302
303 scatterwalk_start(&walk, req->src);
304
305 do {
306 u32 n = scatterwalk_clamp(&walk, len);
307 u8 *p;
308
309 if (!n) {
310 scatterwalk_start(&walk, sg_next(walk.sg));
311 n = scatterwalk_clamp(&walk, len);
312 }
313 p = scatterwalk_map(&walk);
314
315 gcm_update_mac(dg, p, n, buf, &buf_count, ctx);
316 len -= n;
317
318 scatterwalk_unmap(p);
319 scatterwalk_advance(&walk, n);
320 scatterwalk_done(&walk, 0, len);
321 } while (len);
322
323 if (buf_count) {
324 memset(&buf[buf_count], 0, GHASH_BLOCK_SIZE - buf_count);
325 ghash_do_update(1, dg, buf, &ctx->ghash_key, NULL);
326 }
327}
328
329static void gcm_final(struct aead_request *req, struct gcm_aes_ctx *ctx,
330 u64 dg[], u8 tag[], int cryptlen)
331{
332 u8 mac[AES_BLOCK_SIZE];
333 u128 lengths;
334
335 lengths.a = cpu_to_be64(req->assoclen * 8);
336 lengths.b = cpu_to_be64(cryptlen * 8);
337
338 ghash_do_update(1, dg, (void *)&lengths, &ctx->ghash_key, NULL);
339
340 put_unaligned_be64(dg[1], mac);
341 put_unaligned_be64(dg[0], mac + 8);
342
343 crypto_xor(tag, mac, AES_BLOCK_SIZE);
344}
345
346static int gcm_encrypt(struct aead_request *req)
347{
348 struct crypto_aead *aead = crypto_aead_reqtfm(req);
349 struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead);
350 struct skcipher_walk walk;
351 u8 iv[AES_BLOCK_SIZE];
352 u8 ks[AES_BLOCK_SIZE];
353 u8 tag[AES_BLOCK_SIZE];
354 u64 dg[2] = {};
355 int err;
356
357 if (req->assoclen)
358 gcm_calculate_auth_mac(req, dg);
359
360 memcpy(iv, req->iv, GCM_IV_SIZE);
361 put_unaligned_be32(1, iv + GCM_IV_SIZE);
362
363 if (likely(may_use_simd())) {
364 kernel_neon_begin();
365
366 pmull_gcm_encrypt_block(tag, iv, ctx->aes_key.key_enc,
367 num_rounds(&ctx->aes_key));
368 put_unaligned_be32(2, iv + GCM_IV_SIZE);
369 pmull_gcm_encrypt_block(ks, iv, NULL,
370 num_rounds(&ctx->aes_key));
371 put_unaligned_be32(3, iv + GCM_IV_SIZE);
372 kernel_neon_end();
373
374 err = skcipher_walk_aead_encrypt(&walk, req, false);
375
376 while (walk.nbytes >= AES_BLOCK_SIZE) {
377 int blocks = walk.nbytes / AES_BLOCK_SIZE;
378
379 kernel_neon_begin();
380 pmull_gcm_encrypt(blocks, dg, walk.dst.virt.addr,
381 walk.src.virt.addr, &ctx->ghash_key,
382 iv, ctx->aes_key.key_enc,
383 num_rounds(&ctx->aes_key), ks);
384 kernel_neon_end();
385
386 err = skcipher_walk_done(&walk,
387 walk.nbytes % AES_BLOCK_SIZE);
388 }
389 } else {
390 __aes_arm64_encrypt(ctx->aes_key.key_enc, tag, iv,
391 num_rounds(&ctx->aes_key));
392 put_unaligned_be32(2, iv + GCM_IV_SIZE);
393
394 err = skcipher_walk_aead_encrypt(&walk, req, false);
395
396 while (walk.nbytes >= AES_BLOCK_SIZE) {
397 int blocks = walk.nbytes / AES_BLOCK_SIZE;
398 u8 *dst = walk.dst.virt.addr;
399 u8 *src = walk.src.virt.addr;
400
401 do {
402 __aes_arm64_encrypt(ctx->aes_key.key_enc,
403 ks, iv,
404 num_rounds(&ctx->aes_key));
405 crypto_xor_cpy(dst, src, ks, AES_BLOCK_SIZE);
406 crypto_inc(iv, AES_BLOCK_SIZE);
407
408 dst += AES_BLOCK_SIZE;
409 src += AES_BLOCK_SIZE;
410 } while (--blocks > 0);
411
412 ghash_do_update(walk.nbytes / AES_BLOCK_SIZE, dg,
413 walk.dst.virt.addr, &ctx->ghash_key,
414 NULL);
415
416 err = skcipher_walk_done(&walk,
417 walk.nbytes % AES_BLOCK_SIZE);
418 }
419 if (walk.nbytes)
420 __aes_arm64_encrypt(ctx->aes_key.key_enc, ks, iv,
421 num_rounds(&ctx->aes_key));
422 }
423
424
425 if (walk.nbytes) {
426 u8 buf[GHASH_BLOCK_SIZE];
427
428 crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, ks,
429 walk.nbytes);
430
431 memcpy(buf, walk.dst.virt.addr, walk.nbytes);
432 memset(buf + walk.nbytes, 0, GHASH_BLOCK_SIZE - walk.nbytes);
433 ghash_do_update(1, dg, buf, &ctx->ghash_key, NULL);
434
435 err = skcipher_walk_done(&walk, 0);
436 }
437
438 if (err)
439 return err;
440
441 gcm_final(req, ctx, dg, tag, req->cryptlen);
442
443
444 scatterwalk_map_and_copy(tag, req->dst, req->assoclen + req->cryptlen,
445 crypto_aead_authsize(aead), 1);
446
447 return 0;
448}
449
450static int gcm_decrypt(struct aead_request *req)
451{
452 struct crypto_aead *aead = crypto_aead_reqtfm(req);
453 struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead);
454 unsigned int authsize = crypto_aead_authsize(aead);
455 struct skcipher_walk walk;
456 u8 iv[AES_BLOCK_SIZE];
457 u8 tag[AES_BLOCK_SIZE];
458 u8 buf[GHASH_BLOCK_SIZE];
459 u64 dg[2] = {};
460 int err;
461
462 if (req->assoclen)
463 gcm_calculate_auth_mac(req, dg);
464
465 memcpy(iv, req->iv, GCM_IV_SIZE);
466 put_unaligned_be32(1, iv + GCM_IV_SIZE);
467
468 if (likely(may_use_simd())) {
469 kernel_neon_begin();
470
471 pmull_gcm_encrypt_block(tag, iv, ctx->aes_key.key_enc,
472 num_rounds(&ctx->aes_key));
473 put_unaligned_be32(2, iv + GCM_IV_SIZE);
474 kernel_neon_end();
475
476 err = skcipher_walk_aead_decrypt(&walk, req, false);
477
478 while (walk.nbytes >= AES_BLOCK_SIZE) {
479 int blocks = walk.nbytes / AES_BLOCK_SIZE;
480
481 kernel_neon_begin();
482 pmull_gcm_decrypt(blocks, dg, walk.dst.virt.addr,
483 walk.src.virt.addr, &ctx->ghash_key,
484 iv, ctx->aes_key.key_enc,
485 num_rounds(&ctx->aes_key));
486 kernel_neon_end();
487
488 err = skcipher_walk_done(&walk,
489 walk.nbytes % AES_BLOCK_SIZE);
490 }
491 if (walk.nbytes) {
492 kernel_neon_begin();
493 pmull_gcm_encrypt_block(iv, iv, ctx->aes_key.key_enc,
494 num_rounds(&ctx->aes_key));
495 kernel_neon_end();
496 }
497
498 } else {
499 __aes_arm64_encrypt(ctx->aes_key.key_enc, tag, iv,
500 num_rounds(&ctx->aes_key));
501 put_unaligned_be32(2, iv + GCM_IV_SIZE);
502
503 err = skcipher_walk_aead_decrypt(&walk, req, false);
504
505 while (walk.nbytes >= AES_BLOCK_SIZE) {
506 int blocks = walk.nbytes / AES_BLOCK_SIZE;
507 u8 *dst = walk.dst.virt.addr;
508 u8 *src = walk.src.virt.addr;
509
510 ghash_do_update(blocks, dg, walk.src.virt.addr,
511 &ctx->ghash_key, NULL);
512
513 do {
514 __aes_arm64_encrypt(ctx->aes_key.key_enc,
515 buf, iv,
516 num_rounds(&ctx->aes_key));
517 crypto_xor_cpy(dst, src, buf, AES_BLOCK_SIZE);
518 crypto_inc(iv, AES_BLOCK_SIZE);
519
520 dst += AES_BLOCK_SIZE;
521 src += AES_BLOCK_SIZE;
522 } while (--blocks > 0);
523
524 err = skcipher_walk_done(&walk,
525 walk.nbytes % AES_BLOCK_SIZE);
526 }
527 if (walk.nbytes)
528 __aes_arm64_encrypt(ctx->aes_key.key_enc, iv, iv,
529 num_rounds(&ctx->aes_key));
530 }
531
532
533 if (walk.nbytes) {
534 memcpy(buf, walk.src.virt.addr, walk.nbytes);
535 memset(buf + walk.nbytes, 0, GHASH_BLOCK_SIZE - walk.nbytes);
536 ghash_do_update(1, dg, buf, &ctx->ghash_key, NULL);
537
538 crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, iv,
539 walk.nbytes);
540
541 err = skcipher_walk_done(&walk, 0);
542 }
543
544 if (err)
545 return err;
546
547 gcm_final(req, ctx, dg, tag, req->cryptlen - authsize);
548
549
550 scatterwalk_map_and_copy(buf, req->src,
551 req->assoclen + req->cryptlen - authsize,
552 authsize, 0);
553
554 if (crypto_memneq(tag, buf, authsize))
555 return -EBADMSG;
556 return 0;
557}
558
559static struct aead_alg gcm_aes_alg = {
560 .ivsize = GCM_IV_SIZE,
561 .chunksize = AES_BLOCK_SIZE,
562 .maxauthsize = AES_BLOCK_SIZE,
563 .setkey = gcm_setkey,
564 .setauthsize = gcm_setauthsize,
565 .encrypt = gcm_encrypt,
566 .decrypt = gcm_decrypt,
567
568 .base.cra_name = "gcm(aes)",
569 .base.cra_driver_name = "gcm-aes-ce",
570 .base.cra_priority = 300,
571 .base.cra_blocksize = 1,
572 .base.cra_ctxsize = sizeof(struct gcm_aes_ctx),
573 .base.cra_module = THIS_MODULE,
574};
575
576static int __init ghash_ce_mod_init(void)
577{
578 int ret;
579
580 if (!(elf_hwcap & HWCAP_ASIMD))
581 return -ENODEV;
582
583 if (elf_hwcap & HWCAP_PMULL)
584 pmull_ghash_update = pmull_ghash_update_p64;
585
586 else
587 pmull_ghash_update = pmull_ghash_update_p8;
588
589 ret = crypto_register_shash(&ghash_alg);
590 if (ret)
591 return ret;
592
593 if (elf_hwcap & HWCAP_PMULL) {
594 ret = crypto_register_aead(&gcm_aes_alg);
595 if (ret)
596 crypto_unregister_shash(&ghash_alg);
597 }
598 return ret;
599}
600
601static void __exit ghash_ce_mod_exit(void)
602{
603 crypto_unregister_shash(&ghash_alg);
604 crypto_unregister_aead(&gcm_aes_alg);
605}
606
607static const struct cpu_feature ghash_cpu_feature[] = {
608 { cpu_feature(PMULL) }, { }
609};
610MODULE_DEVICE_TABLE(cpu, ghash_cpu_feature);
611
612module_init(ghash_ce_mod_init);
613module_exit(ghash_ce_mod_exit);
614
