1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * GCM: Galois/Counter Mode.
4 *
5 * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
6 */
7
8 #include <crypto/gf128mul.h>
9 #include <crypto/internal/aead.h>
10 #include <crypto/internal/skcipher.h>
11 #include <crypto/internal/hash.h>
12 #include <crypto/null.h>
13 #include <crypto/scatterwalk.h>
14 #include <crypto/gcm.h>
15 #include <crypto/hash.h>
16 #include <linux/err.h>
17 #include <linux/init.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/slab.h>
21
22 struct gcm_instance_ctx {
23 struct crypto_skcipher_spawn ctr;
24 struct crypto_ahash_spawn ghash;
25 };
26
27 struct crypto_gcm_ctx {
28 struct crypto_skcipher *ctr;
29 struct crypto_ahash *ghash;
30 };
31
32 struct crypto_rfc4106_ctx {
33 struct crypto_aead *child;
34 u8 nonce[4];
35 };
36
37 struct crypto_rfc4106_req_ctx {
38 struct scatterlist src[3];
39 struct scatterlist dst[3];
40 struct aead_request subreq;
41 };
42
43 struct crypto_rfc4543_instance_ctx {
44 struct crypto_aead_spawn aead;
45 };
46
47 struct crypto_rfc4543_ctx {
48 struct crypto_aead *child;
49 struct crypto_sync_skcipher *null;
50 u8 nonce[4];
51 };
52
53 struct crypto_rfc4543_req_ctx {
54 struct aead_request subreq;
55 };
56
57 struct crypto_gcm_ghash_ctx {
58 unsigned int cryptlen;
59 struct scatterlist *src;
60 int (*complete)(struct aead_request *req, u32 flags);
61 };
62
63 struct crypto_gcm_req_priv_ctx {
64 u8 iv[16];
65 u8 auth_tag[16];
66 u8 iauth_tag[16];
67 struct scatterlist src[3];
68 struct scatterlist dst[3];
69 struct scatterlist sg;
70 struct crypto_gcm_ghash_ctx ghash_ctx;
71 union {
72 struct ahash_request ahreq;
73 struct skcipher_request skreq;
74 } u;
75 };
76
77 static struct {
78 u8 buf[16];
79 struct scatterlist sg;
80 } *gcm_zeroes;
81
82 static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc);
83
84 static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
85 struct aead_request *req)
86 {
87 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
88
89 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
90 }
91
92 static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
93 unsigned int keylen)
94 {
95 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
96 struct crypto_ahash *ghash = ctx->ghash;
97 struct crypto_skcipher *ctr = ctx->ctr;
98 struct {
99 be128 hash;
100 u8 iv[16];
101
102 struct crypto_wait wait;
103
104 struct scatterlist sg[1];
105 struct skcipher_request req;
106 } *data;
107 int err;
108
109 crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
110 crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
111 CRYPTO_TFM_REQ_MASK);
112 err = crypto_skcipher_setkey(ctr, key, keylen);
113 if (err)
114 return err;
115
116 data = kzalloc(sizeof(*data) + crypto_skcipher_reqsize(ctr),
117 GFP_KERNEL);
118 if (!data)
119 return -ENOMEM;
120
121 crypto_init_wait(&data->wait);
122 sg_init_one(data->sg, &data->hash, sizeof(data->hash));
123 skcipher_request_set_tfm(&data->req, ctr);
124 skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
125 CRYPTO_TFM_REQ_MAY_BACKLOG,
126 crypto_req_done,
127 &data->wait);
128 skcipher_request_set_crypt(&data->req, data->sg, data->sg,
129 sizeof(data->hash), data->iv);
130
131 err = crypto_wait_req(crypto_skcipher_encrypt(&data->req),
132 &data->wait);
133
134 if (err)
135 goto out;
136
137 crypto_ahash_clear_flags(ghash, CRYPTO_TFM_REQ_MASK);
138 crypto_ahash_set_flags(ghash, crypto_aead_get_flags(aead) &
139 CRYPTO_TFM_REQ_MASK);
140 err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128));
141 out:
142 kfree_sensitive(data);
143 return err;
144 }
145
146 static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
147 unsigned int authsize)
148 {
149 return crypto_gcm_check_authsize(authsize);
150 }
151
152 static void crypto_gcm_init_common(struct aead_request *req)
153 {
154 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
155 __be32 counter = cpu_to_be32(1);
156 struct scatterlist *sg;
157
158 memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag));
159 memcpy(pctx->iv, req->iv, GCM_AES_IV_SIZE);
160 memcpy(pctx->iv + GCM_AES_IV_SIZE, &counter, 4);
161
162 sg_init_table(pctx->src, 3);
163 sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag));
164 sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
165 if (sg != pctx->src + 1)
166 sg_chain(pctx->src, 2, sg);
167
168 if (req->src != req->dst) {
169 sg_init_table(pctx->dst, 3);
170 sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag));
171 sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
172 if (sg != pctx->dst + 1)
173 sg_chain(pctx->dst, 2, sg);
174 }
175 }
176
177 static void crypto_gcm_init_crypt(struct aead_request *req,
178 unsigned int cryptlen)
179 {
180 struct crypto_aead *aead = crypto_aead_reqtfm(req);
181 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
182 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
183 struct skcipher_request *skreq = &pctx->u.skreq;
184 struct scatterlist *dst;
185
186 dst = req->src == req->dst ? pctx->src : pctx->dst;
187
188 skcipher_request_set_tfm(skreq, ctx->ctr);
189 skcipher_request_set_crypt(skreq, pctx->src, dst,
190 cryptlen + sizeof(pctx->auth_tag),
191 pctx->iv);
192 }
193
194 static inline unsigned int gcm_remain(unsigned int len)
195 {
196 len &= 0xfU;
197 return len ? 16 - len : 0;
198 }
199
200 static void gcm_hash_len_done(void *data, int err);
201
202 static int gcm_hash_update(struct aead_request *req,
203 crypto_completion_t compl,
204 struct scatterlist *src,
205 unsigned int len, u32 flags)
206 {
207 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
208 struct ahash_request *ahreq = &pctx->u.ahreq;
209
210 ahash_request_set_callback(ahreq, flags, compl, req);
211 ahash_request_set_crypt(ahreq, src, NULL, len);
212
213 return crypto_ahash_update(ahreq);
214 }
215
216 static int gcm_hash_remain(struct aead_request *req,
217 unsigned int remain,
218 crypto_completion_t compl, u32 flags)
219 {
220 return gcm_hash_update(req, compl, &gcm_zeroes->sg, remain, flags);
221 }
222
223 static int gcm_hash_len(struct aead_request *req, u32 flags)
224 {
225 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
226 struct ahash_request *ahreq = &pctx->u.ahreq;
227 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
228 be128 lengths;
229
230 lengths.a = cpu_to_be64(req->assoclen * 8);
231 lengths.b = cpu_to_be64(gctx->cryptlen * 8);
232 memcpy(pctx->iauth_tag, &lengths, 16);
233 sg_init_one(&pctx->sg, pctx->iauth_tag, 16);
234 ahash_request_set_callback(ahreq, flags, gcm_hash_len_done, req);
235 ahash_request_set_crypt(ahreq, &pctx->sg,
236 pctx->iauth_tag, sizeof(lengths));
237
238 return crypto_ahash_finup(ahreq);
239 }
240
241 static int gcm_hash_len_continue(struct aead_request *req, u32 flags)
242 {
243 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
244 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
245
246 return gctx->complete(req, flags);
247 }
248
249 static void gcm_hash_len_done(void *data, int err)
250 {
251 struct aead_request *req = data;
252
253 if (err)
254 goto out;
255
256 err = gcm_hash_len_continue(req, 0);
257 if (err == -EINPROGRESS)
258 return;
259
260 out:
261 aead_request_complete(req, err);
262 }
263
264 static int gcm_hash_crypt_remain_continue(struct aead_request *req, u32 flags)
265 {
266 return gcm_hash_len(req, flags) ?:
267 gcm_hash_len_continue(req, flags);
268 }
269
270 static void gcm_hash_crypt_remain_done(void *data, int err)
271 {
272 struct aead_request *req = data;
273
274 if (err)
275 goto out;
276
277 err = gcm_hash_crypt_remain_continue(req, 0);
278 if (err == -EINPROGRESS)
279 return;
280
281 out:
282 aead_request_complete(req, err);
283 }
284
285 static int gcm_hash_crypt_continue(struct aead_request *req, u32 flags)
286 {
287 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
288 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
289 unsigned int remain;
290
291 remain = gcm_remain(gctx->cryptlen);
292 if (remain)
293 return gcm_hash_remain(req, remain,
294 gcm_hash_crypt_remain_done, flags) ?:
295 gcm_hash_crypt_remain_continue(req, flags);
296
297 return gcm_hash_crypt_remain_continue(req, flags);
298 }
299
300 static void gcm_hash_crypt_done(void *data, int err)
301 {
302 struct aead_request *req = data;
303
304 if (err)
305 goto out;
306
307 err = gcm_hash_crypt_continue(req, 0);
308 if (err == -EINPROGRESS)
309 return;
310
311 out:
312 aead_request_complete(req, err);
313 }
314
315 static int gcm_hash_assoc_remain_continue(struct aead_request *req, u32 flags)
316 {
317 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
318 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
319
320 if (gctx->cryptlen)
321 return gcm_hash_update(req, gcm_hash_crypt_done,
322 gctx->src, gctx->cryptlen, flags) ?:
323 gcm_hash_crypt_continue(req, flags);
324
325 return gcm_hash_crypt_remain_continue(req, flags);
326 }
327
328 static void gcm_hash_assoc_remain_done(void *data, int err)
329 {
330 struct aead_request *req = data;
331
332 if (err)
333 goto out;
334
335 err = gcm_hash_assoc_remain_continue(req, 0);
336 if (err == -EINPROGRESS)
337 return;
338
339 out:
340 aead_request_complete(req, err);
341 }
342
343 static int gcm_hash_assoc_continue(struct aead_request *req, u32 flags)
344 {
345 unsigned int remain;
346
347 remain = gcm_remain(req->assoclen);
348 if (remain)
349 return gcm_hash_remain(req, remain,
350 gcm_hash_assoc_remain_done, flags) ?:
351 gcm_hash_assoc_remain_continue(req, flags);
352
353 return gcm_hash_assoc_remain_continue(req, flags);
354 }
355
356 static void gcm_hash_assoc_done(void *data, int err)
357 {
358 struct aead_request *req = data;
359
360 if (err)
361 goto out;
362
363 err = gcm_hash_assoc_continue(req, 0);
364 if (err == -EINPROGRESS)
365 return;
366
367 out:
368 aead_request_complete(req, err);
369 }
370
371 static int gcm_hash_init_continue(struct aead_request *req, u32 flags)
372 {
373 if (req->assoclen)
374 return gcm_hash_update(req, gcm_hash_assoc_done,
375 req->src, req->assoclen, flags) ?:
376 gcm_hash_assoc_continue(req, flags);
377
378 return gcm_hash_assoc_remain_continue(req, flags);
379 }
380
381 static void gcm_hash_init_done(void *data, int err)
382 {
383 struct aead_request *req = data;
384
385 if (err)
386 goto out;
387
388 err = gcm_hash_init_continue(req, 0);
389 if (err == -EINPROGRESS)
390 return;
391
392 out:
393 aead_request_complete(req, err);
394 }
395
396 static int gcm_hash(struct aead_request *req, u32 flags)
397 {
398 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
399 struct ahash_request *ahreq = &pctx->u.ahreq;
400 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
401
402 ahash_request_set_tfm(ahreq, ctx->ghash);
403
404 ahash_request_set_callback(ahreq, flags, gcm_hash_init_done, req);
405 return crypto_ahash_init(ahreq) ?:
406 gcm_hash_init_continue(req, flags);
407 }
408
409 static int gcm_enc_copy_hash(struct aead_request *req, u32 flags)
410 {
411 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
412 struct crypto_aead *aead = crypto_aead_reqtfm(req);
413 u8 *auth_tag = pctx->auth_tag;
414
415 crypto_xor(auth_tag, pctx->iauth_tag, 16);
416 scatterwalk_map_and_copy(auth_tag, req->dst,
417 req->assoclen + req->cryptlen,
418 crypto_aead_authsize(aead), 1);
419 return 0;
420 }
421
422 static int gcm_encrypt_continue(struct aead_request *req, u32 flags)
423 {
424 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
425 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
426
427 gctx->src = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
428 gctx->cryptlen = req->cryptlen;
429 gctx->complete = gcm_enc_copy_hash;
430
431 return gcm_hash(req, flags);
432 }
433
434 static void gcm_encrypt_done(void *data, int err)
435 {
436 struct aead_request *req = data;
437
438 if (err)
439 goto out;
440
441 err = gcm_encrypt_continue(req, 0);
442 if (err == -EINPROGRESS)
443 return;
444
445 out:
446 aead_request_complete(req, err);
447 }
448
449 static int crypto_gcm_encrypt(struct aead_request *req)
450 {
451 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
452 struct skcipher_request *skreq = &pctx->u.skreq;
453 u32 flags = aead_request_flags(req);
454
455 crypto_gcm_init_common(req);
456 crypto_gcm_init_crypt(req, req->cryptlen);
457 skcipher_request_set_callback(skreq, flags, gcm_encrypt_done, req);
458
459 return crypto_skcipher_encrypt(skreq) ?:
460 gcm_encrypt_continue(req, flags);
461 }
462
463 static int crypto_gcm_verify(struct aead_request *req)
464 {
465 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
466 struct crypto_aead *aead = crypto_aead_reqtfm(req);
467 u8 *auth_tag = pctx->auth_tag;
468 u8 *iauth_tag = pctx->iauth_tag;
469 unsigned int authsize = crypto_aead_authsize(aead);
470 unsigned int cryptlen = req->cryptlen - authsize;
471
472 crypto_xor(auth_tag, iauth_tag, 16);
473 scatterwalk_map_and_copy(iauth_tag, req->src,
474 req->assoclen + cryptlen, authsize, 0);
475 return crypto_memneq(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0;
476 }
477
478 static void gcm_decrypt_done(void *data, int err)
479 {
480 struct aead_request *req = data;
481
482 if (!err)
483 err = crypto_gcm_verify(req);
484
485 aead_request_complete(req, err);
486 }
487
488 static int gcm_dec_hash_continue(struct aead_request *req, u32 flags)
489 {
490 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
491 struct skcipher_request *skreq = &pctx->u.skreq;
492 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
493
494 crypto_gcm_init_crypt(req, gctx->cryptlen);
495 skcipher_request_set_callback(skreq, flags, gcm_decrypt_done, req);
496 return crypto_skcipher_decrypt(skreq) ?: crypto_gcm_verify(req);
497 }
498
499 static int crypto_gcm_decrypt(struct aead_request *req)
500 {
501 struct crypto_aead *aead = crypto_aead_reqtfm(req);
502 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
503 struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
504 unsigned int authsize = crypto_aead_authsize(aead);
505 unsigned int cryptlen = req->cryptlen;
506 u32 flags = aead_request_flags(req);
507
508 cryptlen -= authsize;
509
510 crypto_gcm_init_common(req);
511
512 gctx->src = sg_next(pctx->src);
513 gctx->cryptlen = cryptlen;
514 gctx->complete = gcm_dec_hash_continue;
515
516 return gcm_hash(req, flags);
517 }
518
519 static int crypto_gcm_init_tfm(struct crypto_aead *tfm)
520 {
521 struct aead_instance *inst = aead_alg_instance(tfm);
522 struct gcm_instance_ctx *ictx = aead_instance_ctx(inst);
523 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
524 struct crypto_skcipher *ctr;
525 struct crypto_ahash *ghash;
526 unsigned long align;
527 int err;
528
529 ghash = crypto_spawn_ahash(&ictx->ghash);
530 if (IS_ERR(ghash))
531 return PTR_ERR(ghash);
532
533 ctr = crypto_spawn_skcipher(&ictx->ctr);
534 err = PTR_ERR(ctr);
535 if (IS_ERR(ctr))
536 goto err_free_hash;
537
538 ctx->ctr = ctr;
539 ctx->ghash = ghash;
540
541 align = crypto_aead_alignmask(tfm);
542 align &= ~(crypto_tfm_ctx_alignment() - 1);
543 crypto_aead_set_reqsize(tfm,
544 align + offsetof(struct crypto_gcm_req_priv_ctx, u) +
545 max(sizeof(struct skcipher_request) +
546 crypto_skcipher_reqsize(ctr),
547 sizeof(struct ahash_request) +
548 crypto_ahash_reqsize(ghash)));
549
550 return 0;
551
552 err_free_hash:
553 crypto_free_ahash(ghash);
554 return err;
555 }
556
557 static void crypto_gcm_exit_tfm(struct crypto_aead *tfm)
558 {
559 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
560
561 crypto_free_ahash(ctx->ghash);
562 crypto_free_skcipher(ctx->ctr);
563 }
564
565 static void crypto_gcm_free(struct aead_instance *inst)
566 {
567 struct gcm_instance_ctx *ctx = aead_instance_ctx(inst);
568
569 crypto_drop_skcipher(&ctx->ctr);
570 crypto_drop_ahash(&ctx->ghash);
571 kfree(inst);
572 }
573
574 static int crypto_gcm_create_common(struct crypto_template *tmpl,
575 struct rtattr **tb,
576 const char *ctr_name,
577 const char *ghash_name)
578 {
579 struct skcipher_alg_common *ctr;
580 u32 mask;
581 struct aead_instance *inst;
582 struct gcm_instance_ctx *ctx;
583 struct hash_alg_common *ghash;
584 int err;
585
586 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
587 if (err)
588 return err;
589
590 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
591 if (!inst)
592 return -ENOMEM;
593 ctx = aead_instance_ctx(inst);
594
595 err = crypto_grab_ahash(&ctx->ghash, aead_crypto_instance(inst),
596 ghash_name, 0, mask);
597 if (err)
598 goto err_free_inst;
599 ghash = crypto_spawn_ahash_alg(&ctx->ghash);
600
601 err = -EINVAL;
602 if (strcmp(ghash->base.cra_name, "ghash") != 0 ||
603 ghash->digestsize != 16)
604 goto err_free_inst;
605
606 err = crypto_grab_skcipher(&ctx->ctr, aead_crypto_instance(inst),
607 ctr_name, 0, mask);
608 if (err)
609 goto err_free_inst;
610 ctr = crypto_spawn_skcipher_alg_common(&ctx->ctr);
611
612 /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
613 err = -EINVAL;
614 if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
615 ctr->ivsize != 16 || ctr->base.cra_blocksize != 1)
616 goto err_free_inst;
617
618 err = -ENAMETOOLONG;
619 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
620 "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
621 goto err_free_inst;
622
623 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
624 "gcm_base(%s,%s)", ctr->base.cra_driver_name,
625 ghash->base.cra_driver_name) >=
626 CRYPTO_MAX_ALG_NAME)
627 goto err_free_inst;
628
629 inst->alg.base.cra_priority = (ghash->base.cra_priority +
630 ctr->base.cra_priority) / 2;
631 inst->alg.base.cra_blocksize = 1;
632 inst->alg.base.cra_alignmask = ctr->base.cra_alignmask;
633 inst->alg.base.cra_ctxsize = sizeof(struct crypto_gcm_ctx);
634 inst->alg.ivsize = GCM_AES_IV_SIZE;
635 inst->alg.chunksize = ctr->chunksize;
636 inst->alg.maxauthsize = 16;
637 inst->alg.init = crypto_gcm_init_tfm;
638 inst->alg.exit = crypto_gcm_exit_tfm;
639 inst->alg.setkey = crypto_gcm_setkey;
640 inst->alg.setauthsize = crypto_gcm_setauthsize;
641 inst->alg.encrypt = crypto_gcm_encrypt;
642 inst->alg.decrypt = crypto_gcm_decrypt;
643
644 inst->free = crypto_gcm_free;
645
646 err = aead_register_instance(tmpl, inst);
647 if (err) {
648 err_free_inst:
649 crypto_gcm_free(inst);
650 }
651 return err;
652 }
653
654 static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb)
655 {
656 const char *cipher_name;
657 char ctr_name[CRYPTO_MAX_ALG_NAME];
658
659 cipher_name = crypto_attr_alg_name(tb[1]);
660 if (IS_ERR(cipher_name))
661 return PTR_ERR(cipher_name);
662
663 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
664 CRYPTO_MAX_ALG_NAME)
665 return -ENAMETOOLONG;
666
667 return crypto_gcm_create_common(tmpl, tb, ctr_name, "ghash");
668 }
669
670 static int crypto_gcm_base_create(struct crypto_template *tmpl,
671 struct rtattr **tb)
672 {
673 const char *ctr_name;
674 const char *ghash_name;
675
676 ctr_name = crypto_attr_alg_name(tb[1]);
677 if (IS_ERR(ctr_name))
678 return PTR_ERR(ctr_name);
679
680 ghash_name = crypto_attr_alg_name(tb[2]);
681 if (IS_ERR(ghash_name))
682 return PTR_ERR(ghash_name);
683
684 return crypto_gcm_create_common(tmpl, tb, ctr_name, ghash_name);
685 }
686
687 static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key,
688 unsigned int keylen)
689 {
690 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
691 struct crypto_aead *child = ctx->child;
692
693 if (keylen < 4)
694 return -EINVAL;
695
696 keylen -= 4;
697 memcpy(ctx->nonce, key + keylen, 4);
698
699 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
700 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
701 CRYPTO_TFM_REQ_MASK);
702 return crypto_aead_setkey(child, key, keylen);
703 }
704
705 static int crypto_rfc4106_setauthsize(struct crypto_aead *parent,
706 unsigned int authsize)
707 {
708 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
709 int err;
710
711 err = crypto_rfc4106_check_authsize(authsize);
712 if (err)
713 return err;
714
715 return crypto_aead_setauthsize(ctx->child, authsize);
716 }
717
718 static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req)
719 {
720 struct crypto_rfc4106_req_ctx *rctx = aead_request_ctx(req);
721 struct crypto_aead *aead = crypto_aead_reqtfm(req);
722 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead);
723 struct aead_request *subreq = &rctx->subreq;
724 struct crypto_aead *child = ctx->child;
725 struct scatterlist *sg;
726 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
727 crypto_aead_alignmask(child) + 1);
728
729 scatterwalk_map_and_copy(iv + GCM_AES_IV_SIZE, req->src, 0, req->assoclen - 8, 0);
730
731 memcpy(iv, ctx->nonce, 4);
732 memcpy(iv + 4, req->iv, 8);
733
734 sg_init_table(rctx->src, 3);
735 sg_set_buf(rctx->src, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
736 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
737 if (sg != rctx->src + 1)
738 sg_chain(rctx->src, 2, sg);
739
740 if (req->src != req->dst) {
741 sg_init_table(rctx->dst, 3);
742 sg_set_buf(rctx->dst, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
743 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
744 if (sg != rctx->dst + 1)
745 sg_chain(rctx->dst, 2, sg);
746 }
747
748 aead_request_set_tfm(subreq, child);
749 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
750 req->base.data);
751 aead_request_set_crypt(subreq, rctx->src,
752 req->src == req->dst ? rctx->src : rctx->dst,
753 req->cryptlen, iv);
754 aead_request_set_ad(subreq, req->assoclen - 8);
755
756 return subreq;
757 }
758
759 static int crypto_rfc4106_encrypt(struct aead_request *req)
760 {
761 int err;
762
763 err = crypto_ipsec_check_assoclen(req->assoclen);
764 if (err)
765 return err;
766
767 req = crypto_rfc4106_crypt(req);
768
769 return crypto_aead_encrypt(req);
770 }
771
772 static int crypto_rfc4106_decrypt(struct aead_request *req)
773 {
774 int err;
775
776 err = crypto_ipsec_check_assoclen(req->assoclen);
777 if (err)
778 return err;
779
780 req = crypto_rfc4106_crypt(req);
781
782 return crypto_aead_decrypt(req);
783 }
784
785 static int crypto_rfc4106_init_tfm(struct crypto_aead *tfm)
786 {
787 struct aead_instance *inst = aead_alg_instance(tfm);
788 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
789 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
790 struct crypto_aead *aead;
791 unsigned long align;
792
793 aead = crypto_spawn_aead(spawn);
794 if (IS_ERR(aead))
795 return PTR_ERR(aead);
796
797 ctx->child = aead;
798
799 align = crypto_aead_alignmask(aead);
800 align &= ~(crypto_tfm_ctx_alignment() - 1);
801 crypto_aead_set_reqsize(
802 tfm,
803 sizeof(struct crypto_rfc4106_req_ctx) +
804 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
805 align + 24);
806
807 return 0;
808 }
809
810 static void crypto_rfc4106_exit_tfm(struct crypto_aead *tfm)
811 {
812 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
813
814 crypto_free_aead(ctx->child);
815 }
816
817 static void crypto_rfc4106_free(struct aead_instance *inst)
818 {
819 crypto_drop_aead(aead_instance_ctx(inst));
820 kfree(inst);
821 }
822
823 static int crypto_rfc4106_create(struct crypto_template *tmpl,
824 struct rtattr **tb)
825 {
826 u32 mask;
827 struct aead_instance *inst;
828 struct crypto_aead_spawn *spawn;
829 struct aead_alg *alg;
830 int err;
831
832 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
833 if (err)
834 return err;
835
836 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
837 if (!inst)
838 return -ENOMEM;
839
840 spawn = aead_instance_ctx(inst);
841 err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
842 crypto_attr_alg_name(tb[1]), 0, mask);
843 if (err)
844 goto err_free_inst;
845
846 alg = crypto_spawn_aead_alg(spawn);
847
848 err = -EINVAL;
849
850 /* Underlying IV size must be 12. */
851 if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
852 goto err_free_inst;
853
854 /* Not a stream cipher? */
855 if (alg->base.cra_blocksize != 1)
856 goto err_free_inst;
857
858 err = -ENAMETOOLONG;
859 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
860 "rfc4106(%s)", alg->base.cra_name) >=
861 CRYPTO_MAX_ALG_NAME ||
862 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
863 "rfc4106(%s)", alg->base.cra_driver_name) >=
864 CRYPTO_MAX_ALG_NAME)
865 goto err_free_inst;
866
867 inst->alg.base.cra_priority = alg->base.cra_priority;
868 inst->alg.base.cra_blocksize = 1;
869 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
870
871 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx);
872
873 inst->alg.ivsize = GCM_RFC4106_IV_SIZE;
874 inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
875 inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
876
877 inst->alg.init = crypto_rfc4106_init_tfm;
878 inst->alg.exit = crypto_rfc4106_exit_tfm;
879
880 inst->alg.setkey = crypto_rfc4106_setkey;
881 inst->alg.setauthsize = crypto_rfc4106_setauthsize;
882 inst->alg.encrypt = crypto_rfc4106_encrypt;
883 inst->alg.decrypt = crypto_rfc4106_decrypt;
884
885 inst->free = crypto_rfc4106_free;
886
887 err = aead_register_instance(tmpl, inst);
888 if (err) {
889 err_free_inst:
890 crypto_rfc4106_free(inst);
891 }
892 return err;
893 }
894
895 static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key,
896 unsigned int keylen)
897 {
898 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
899 struct crypto_aead *child = ctx->child;
900
901 if (keylen < 4)
902 return -EINVAL;
903
904 keylen -= 4;
905 memcpy(ctx->nonce, key + keylen, 4);
906
907 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
908 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
909 CRYPTO_TFM_REQ_MASK);
910 return crypto_aead_setkey(child, key, keylen);
911 }
912
913 static int crypto_rfc4543_setauthsize(struct crypto_aead *parent,
914 unsigned int authsize)
915 {
916 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
917
918 if (authsize != 16)
919 return -EINVAL;
920
921 return crypto_aead_setauthsize(ctx->child, authsize);
922 }
923
924 static int crypto_rfc4543_crypt(struct aead_request *req, bool enc)
925 {
926 struct crypto_aead *aead = crypto_aead_reqtfm(req);
927 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
928 struct crypto_rfc4543_req_ctx *rctx = aead_request_ctx(req);
929 struct aead_request *subreq = &rctx->subreq;
930 unsigned int authsize = crypto_aead_authsize(aead);
931 u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child),
932 crypto_aead_alignmask(ctx->child) + 1);
933 int err;
934
935 if (req->src != req->dst) {
936 err = crypto_rfc4543_copy_src_to_dst(req, enc);
937 if (err)
938 return err;
939 }
940
941 memcpy(iv, ctx->nonce, 4);
942 memcpy(iv + 4, req->iv, 8);
943
944 aead_request_set_tfm(subreq, ctx->child);
945 aead_request_set_callback(subreq, req->base.flags,
946 req->base.complete, req->base.data);
947 aead_request_set_crypt(subreq, req->src, req->dst,
948 enc ? 0 : authsize, iv);
949 aead_request_set_ad(subreq, req->assoclen + req->cryptlen -
950 subreq->cryptlen);
951
952 return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq);
953 }
954
955 static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc)
956 {
957 struct crypto_aead *aead = crypto_aead_reqtfm(req);
958 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
959 unsigned int authsize = crypto_aead_authsize(aead);
960 unsigned int nbytes = req->assoclen + req->cryptlen -
961 (enc ? 0 : authsize);
962 SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null);
963
964 skcipher_request_set_sync_tfm(nreq, ctx->null);
965 skcipher_request_set_callback(nreq, req->base.flags, NULL, NULL);
966 skcipher_request_set_crypt(nreq, req->src, req->dst, nbytes, NULL);
967
968 return crypto_skcipher_encrypt(nreq);
969 }
970
971 static int crypto_rfc4543_encrypt(struct aead_request *req)
972 {
973 return crypto_ipsec_check_assoclen(req->assoclen) ?:
974 crypto_rfc4543_crypt(req, true);
975 }
976
977 static int crypto_rfc4543_decrypt(struct aead_request *req)
978 {
979 return crypto_ipsec_check_assoclen(req->assoclen) ?:
980 crypto_rfc4543_crypt(req, false);
981 }
982
983 static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm)
984 {
985 struct aead_instance *inst = aead_alg_instance(tfm);
986 struct crypto_rfc4543_instance_ctx *ictx = aead_instance_ctx(inst);
987 struct crypto_aead_spawn *spawn = &ictx->aead;
988 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
989 struct crypto_aead *aead;
990 struct crypto_sync_skcipher *null;
991 unsigned long align;
992 int err = 0;
993
994 aead = crypto_spawn_aead(spawn);
995 if (IS_ERR(aead))
996 return PTR_ERR(aead);
997
998 null = crypto_get_default_null_skcipher();
999 err = PTR_ERR(null);
1000 if (IS_ERR(null))
1001 goto err_free_aead;
1002
1003 ctx->child = aead;
1004 ctx->null = null;
1005
1006 align = crypto_aead_alignmask(aead);
1007 align &= ~(crypto_tfm_ctx_alignment() - 1);
1008 crypto_aead_set_reqsize(
1009 tfm,
1010 sizeof(struct crypto_rfc4543_req_ctx) +
1011 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
1012 align + GCM_AES_IV_SIZE);
1013
1014 return 0;
1015
1016 err_free_aead:
1017 crypto_free_aead(aead);
1018 return err;
1019 }
1020
1021 static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm)
1022 {
1023 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
1024
1025 crypto_free_aead(ctx->child);
1026 crypto_put_default_null_skcipher();
1027 }
1028
1029 static void crypto_rfc4543_free(struct aead_instance *inst)
1030 {
1031 struct crypto_rfc4543_instance_ctx *ctx = aead_instance_ctx(inst);
1032
1033 crypto_drop_aead(&ctx->aead);
1034
1035 kfree(inst);
1036 }
1037
1038 static int crypto_rfc4543_create(struct crypto_template *tmpl,
1039 struct rtattr **tb)
1040 {
1041 u32 mask;
1042 struct aead_instance *inst;
1043 struct aead_alg *alg;
1044 struct crypto_rfc4543_instance_ctx *ctx;
1045 int err;
1046
1047 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
1048 if (err)
1049 return err;
1050
1051 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
1052 if (!inst)
1053 return -ENOMEM;
1054
1055 ctx = aead_instance_ctx(inst);
1056 err = crypto_grab_aead(&ctx->aead, aead_crypto_instance(inst),
1057 crypto_attr_alg_name(tb[1]), 0, mask);
1058 if (err)
1059 goto err_free_inst;
1060
1061 alg = crypto_spawn_aead_alg(&ctx->aead);
1062
1063 err = -EINVAL;
1064
1065 /* Underlying IV size must be 12. */
1066 if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
1067 goto err_free_inst;
1068
1069 /* Not a stream cipher? */
1070 if (alg->base.cra_blocksize != 1)
1071 goto err_free_inst;
1072
1073 err = -ENAMETOOLONG;
1074 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
1075 "rfc4543(%s)", alg->base.cra_name) >=
1076 CRYPTO_MAX_ALG_NAME ||
1077 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
1078 "rfc4543(%s)", alg->base.cra_driver_name) >=
1079 CRYPTO_MAX_ALG_NAME)
1080 goto err_free_inst;
1081
1082 inst->alg.base.cra_priority = alg->base.cra_priority;
1083 inst->alg.base.cra_blocksize = 1;
1084 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
1085
1086 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx);
1087
1088 inst->alg.ivsize = GCM_RFC4543_IV_SIZE;
1089 inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
1090 inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
1091
1092 inst->alg.init = crypto_rfc4543_init_tfm;
1093 inst->alg.exit = crypto_rfc4543_exit_tfm;
1094
1095 inst->alg.setkey = crypto_rfc4543_setkey;
1096 inst->alg.setauthsize = crypto_rfc4543_setauthsize;
1097 inst->alg.encrypt = crypto_rfc4543_encrypt;
1098 inst->alg.decrypt = crypto_rfc4543_decrypt;
1099
1100 inst->free = crypto_rfc4543_free;
1101
1102 err = aead_register_instance(tmpl, inst);
1103 if (err) {
1104 err_free_inst:
1105 crypto_rfc4543_free(inst);
1106 }
1107 return err;
1108 }
1109
1110 static struct crypto_template crypto_gcm_tmpls[] = {
1111 {
1112 .name = "gcm_base",
1113 .create = crypto_gcm_base_create,
1114 .module = THIS_MODULE,
1115 }, {
1116 .name = "gcm",
1117 .create = crypto_gcm_create,
1118 .module = THIS_MODULE,
1119 }, {
1120 .name = "rfc4106",
1121 .create = crypto_rfc4106_create,
1122 .module = THIS_MODULE,
1123 }, {
1124 .name = "rfc4543",
1125 .create = crypto_rfc4543_create,
1126 .module = THIS_MODULE,
1127 },
1128 };
1129
1130 static int __init crypto_gcm_module_init(void)
1131 {
1132 int err;
1133
1134 gcm_zeroes = kzalloc(sizeof(*gcm_zeroes), GFP_KERNEL);
1135 if (!gcm_zeroes)
1136 return -ENOMEM;
1137
1138 sg_init_one(&gcm_zeroes->sg, gcm_zeroes->buf, sizeof(gcm_zeroes->buf));
1139
1140 err = crypto_register_templates(crypto_gcm_tmpls,
1141 ARRAY_SIZE(crypto_gcm_tmpls));
1142 if (err)
1143 kfree(gcm_zeroes);
1144
1145 return err;
1146 }
1147
1148 static void __exit crypto_gcm_module_exit(void)
1149 {
1150 kfree(gcm_zeroes);
1151 crypto_unregister_templates(crypto_gcm_tmpls,
1152 ARRAY_SIZE(crypto_gcm_tmpls));
1153 }
1154
1155 subsys_initcall(crypto_gcm_module_init);
1156 module_exit(crypto_gcm_module_exit);
1157
1158 MODULE_LICENSE("GPL");
1159 MODULE_DESCRIPTION("Galois/Counter Mode");
1160 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
1161 MODULE_ALIAS_CRYPTO("gcm_base");
1162 MODULE_ALIAS_CRYPTO("rfc4106");
1163 MODULE_ALIAS_CRYPTO("rfc4543");
1164 MODULE_ALIAS_CRYPTO("gcm");
1165
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