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
crypto_gcm_reqctx(struct aead_request * req)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
crypto_gcm_setkey(struct crypto_aead * aead,const u8 * key,unsigned int keylen)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
crypto_gcm_setauthsize(struct crypto_aead * tfm,unsigned int authsize)146 static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
147 unsigned int authsize)
148 {
149 return crypto_gcm_check_authsize(authsize);
150 }
151
crypto_gcm_init_common(struct aead_request * req)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
crypto_gcm_init_crypt(struct aead_request * req,unsigned int cryptlen)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
gcm_remain(unsigned int len)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
gcm_hash_update(struct aead_request * req,crypto_completion_t compl,struct scatterlist * src,unsigned int len,u32 flags)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
gcm_hash_remain(struct aead_request * req,unsigned int remain,crypto_completion_t compl,u32 flags)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
gcm_hash_len(struct aead_request * req,u32 flags)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
gcm_hash_len_continue(struct aead_request * req,u32 flags)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
gcm_hash_len_done(void * data,int err)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
gcm_hash_crypt_remain_continue(struct aead_request * req,u32 flags)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
gcm_hash_crypt_remain_done(void * data,int err)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
gcm_hash_crypt_continue(struct aead_request * req,u32 flags)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
gcm_hash_crypt_done(void * data,int err)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
gcm_hash_assoc_remain_continue(struct aead_request * req,u32 flags)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
gcm_hash_assoc_remain_done(void * data,int err)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
gcm_hash_assoc_continue(struct aead_request * req,u32 flags)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
gcm_hash_assoc_done(void * data,int err)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
gcm_hash_init_continue(struct aead_request * req,u32 flags)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
gcm_hash_init_done(void * data,int err)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
gcm_hash(struct aead_request * req,u32 flags)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
gcm_enc_copy_hash(struct aead_request * req,u32 flags)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
gcm_encrypt_continue(struct aead_request * req,u32 flags)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
gcm_encrypt_done(void * data,int err)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
crypto_gcm_encrypt(struct aead_request * req)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
crypto_gcm_verify(struct aead_request * req)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
gcm_decrypt_done(void * data,int err)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
gcm_dec_hash_continue(struct aead_request * req,u32 flags)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
crypto_gcm_decrypt(struct aead_request * req)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
crypto_gcm_init_tfm(struct crypto_aead * tfm)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
crypto_gcm_exit_tfm(struct crypto_aead * tfm)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
crypto_gcm_free(struct aead_instance * inst)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
crypto_gcm_create_common(struct crypto_template * tmpl,struct rtattr ** tb,const char * ctr_name,const char * ghash_name)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 u32 mask;
580 struct aead_instance *inst;
581 struct gcm_instance_ctx *ctx;
582 struct skcipher_alg *ctr;
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(&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 crypto_skcipher_alg_ivsize(ctr) != 16 ||
616 ctr->base.cra_blocksize != 1)
617 goto err_free_inst;
618
619 err = -ENAMETOOLONG;
620 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
621 "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
622 goto err_free_inst;
623
624 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
625 "gcm_base(%s,%s)", ctr->base.cra_driver_name,
626 ghash->base.cra_driver_name) >=
627 CRYPTO_MAX_ALG_NAME)
628 goto err_free_inst;
629
630 inst->alg.base.cra_priority = (ghash->base.cra_priority +
631 ctr->base.cra_priority) / 2;
632 inst->alg.base.cra_blocksize = 1;
633 inst->alg.base.cra_alignmask = ghash->base.cra_alignmask |
634 ctr->base.cra_alignmask;
635 inst->alg.base.cra_ctxsize = sizeof(struct crypto_gcm_ctx);
636 inst->alg.ivsize = GCM_AES_IV_SIZE;
637 inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
638 inst->alg.maxauthsize = 16;
639 inst->alg.init = crypto_gcm_init_tfm;
640 inst->alg.exit = crypto_gcm_exit_tfm;
641 inst->alg.setkey = crypto_gcm_setkey;
642 inst->alg.setauthsize = crypto_gcm_setauthsize;
643 inst->alg.encrypt = crypto_gcm_encrypt;
644 inst->alg.decrypt = crypto_gcm_decrypt;
645
646 inst->free = crypto_gcm_free;
647
648 err = aead_register_instance(tmpl, inst);
649 if (err) {
650 err_free_inst:
651 crypto_gcm_free(inst);
652 }
653 return err;
654 }
655
crypto_gcm_create(struct crypto_template * tmpl,struct rtattr ** tb)656 static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb)
657 {
658 const char *cipher_name;
659 char ctr_name[CRYPTO_MAX_ALG_NAME];
660
661 cipher_name = crypto_attr_alg_name(tb[1]);
662 if (IS_ERR(cipher_name))
663 return PTR_ERR(cipher_name);
664
665 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
666 CRYPTO_MAX_ALG_NAME)
667 return -ENAMETOOLONG;
668
669 return crypto_gcm_create_common(tmpl, tb, ctr_name, "ghash");
670 }
671
crypto_gcm_base_create(struct crypto_template * tmpl,struct rtattr ** tb)672 static int crypto_gcm_base_create(struct crypto_template *tmpl,
673 struct rtattr **tb)
674 {
675 const char *ctr_name;
676 const char *ghash_name;
677
678 ctr_name = crypto_attr_alg_name(tb[1]);
679 if (IS_ERR(ctr_name))
680 return PTR_ERR(ctr_name);
681
682 ghash_name = crypto_attr_alg_name(tb[2]);
683 if (IS_ERR(ghash_name))
684 return PTR_ERR(ghash_name);
685
686 return crypto_gcm_create_common(tmpl, tb, ctr_name, ghash_name);
687 }
688
crypto_rfc4106_setkey(struct crypto_aead * parent,const u8 * key,unsigned int keylen)689 static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key,
690 unsigned int keylen)
691 {
692 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
693 struct crypto_aead *child = ctx->child;
694
695 if (keylen < 4)
696 return -EINVAL;
697
698 keylen -= 4;
699 memcpy(ctx->nonce, key + keylen, 4);
700
701 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
702 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
703 CRYPTO_TFM_REQ_MASK);
704 return crypto_aead_setkey(child, key, keylen);
705 }
706
crypto_rfc4106_setauthsize(struct crypto_aead * parent,unsigned int authsize)707 static int crypto_rfc4106_setauthsize(struct crypto_aead *parent,
708 unsigned int authsize)
709 {
710 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
711 int err;
712
713 err = crypto_rfc4106_check_authsize(authsize);
714 if (err)
715 return err;
716
717 return crypto_aead_setauthsize(ctx->child, authsize);
718 }
719
crypto_rfc4106_crypt(struct aead_request * req)720 static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req)
721 {
722 struct crypto_rfc4106_req_ctx *rctx = aead_request_ctx(req);
723 struct crypto_aead *aead = crypto_aead_reqtfm(req);
724 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead);
725 struct aead_request *subreq = &rctx->subreq;
726 struct crypto_aead *child = ctx->child;
727 struct scatterlist *sg;
728 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
729 crypto_aead_alignmask(child) + 1);
730
731 scatterwalk_map_and_copy(iv + GCM_AES_IV_SIZE, req->src, 0, req->assoclen - 8, 0);
732
733 memcpy(iv, ctx->nonce, 4);
734 memcpy(iv + 4, req->iv, 8);
735
736 sg_init_table(rctx->src, 3);
737 sg_set_buf(rctx->src, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
738 sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
739 if (sg != rctx->src + 1)
740 sg_chain(rctx->src, 2, sg);
741
742 if (req->src != req->dst) {
743 sg_init_table(rctx->dst, 3);
744 sg_set_buf(rctx->dst, iv + GCM_AES_IV_SIZE, req->assoclen - 8);
745 sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
746 if (sg != rctx->dst + 1)
747 sg_chain(rctx->dst, 2, sg);
748 }
749
750 aead_request_set_tfm(subreq, child);
751 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
752 req->base.data);
753 aead_request_set_crypt(subreq, rctx->src,
754 req->src == req->dst ? rctx->src : rctx->dst,
755 req->cryptlen, iv);
756 aead_request_set_ad(subreq, req->assoclen - 8);
757
758 return subreq;
759 }
760
crypto_rfc4106_encrypt(struct aead_request * req)761 static int crypto_rfc4106_encrypt(struct aead_request *req)
762 {
763 int err;
764
765 err = crypto_ipsec_check_assoclen(req->assoclen);
766 if (err)
767 return err;
768
769 req = crypto_rfc4106_crypt(req);
770
771 return crypto_aead_encrypt(req);
772 }
773
crypto_rfc4106_decrypt(struct aead_request * req)774 static int crypto_rfc4106_decrypt(struct aead_request *req)
775 {
776 int err;
777
778 err = crypto_ipsec_check_assoclen(req->assoclen);
779 if (err)
780 return err;
781
782 req = crypto_rfc4106_crypt(req);
783
784 return crypto_aead_decrypt(req);
785 }
786
crypto_rfc4106_init_tfm(struct crypto_aead * tfm)787 static int crypto_rfc4106_init_tfm(struct crypto_aead *tfm)
788 {
789 struct aead_instance *inst = aead_alg_instance(tfm);
790 struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
791 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
792 struct crypto_aead *aead;
793 unsigned long align;
794
795 aead = crypto_spawn_aead(spawn);
796 if (IS_ERR(aead))
797 return PTR_ERR(aead);
798
799 ctx->child = aead;
800
801 align = crypto_aead_alignmask(aead);
802 align &= ~(crypto_tfm_ctx_alignment() - 1);
803 crypto_aead_set_reqsize(
804 tfm,
805 sizeof(struct crypto_rfc4106_req_ctx) +
806 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
807 align + 24);
808
809 return 0;
810 }
811
crypto_rfc4106_exit_tfm(struct crypto_aead * tfm)812 static void crypto_rfc4106_exit_tfm(struct crypto_aead *tfm)
813 {
814 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
815
816 crypto_free_aead(ctx->child);
817 }
818
crypto_rfc4106_free(struct aead_instance * inst)819 static void crypto_rfc4106_free(struct aead_instance *inst)
820 {
821 crypto_drop_aead(aead_instance_ctx(inst));
822 kfree(inst);
823 }
824
crypto_rfc4106_create(struct crypto_template * tmpl,struct rtattr ** tb)825 static int crypto_rfc4106_create(struct crypto_template *tmpl,
826 struct rtattr **tb)
827 {
828 u32 mask;
829 struct aead_instance *inst;
830 struct crypto_aead_spawn *spawn;
831 struct aead_alg *alg;
832 int err;
833
834 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
835 if (err)
836 return err;
837
838 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
839 if (!inst)
840 return -ENOMEM;
841
842 spawn = aead_instance_ctx(inst);
843 err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
844 crypto_attr_alg_name(tb[1]), 0, mask);
845 if (err)
846 goto err_free_inst;
847
848 alg = crypto_spawn_aead_alg(spawn);
849
850 err = -EINVAL;
851
852 /* Underlying IV size must be 12. */
853 if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
854 goto err_free_inst;
855
856 /* Not a stream cipher? */
857 if (alg->base.cra_blocksize != 1)
858 goto err_free_inst;
859
860 err = -ENAMETOOLONG;
861 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
862 "rfc4106(%s)", alg->base.cra_name) >=
863 CRYPTO_MAX_ALG_NAME ||
864 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
865 "rfc4106(%s)", alg->base.cra_driver_name) >=
866 CRYPTO_MAX_ALG_NAME)
867 goto err_free_inst;
868
869 inst->alg.base.cra_priority = alg->base.cra_priority;
870 inst->alg.base.cra_blocksize = 1;
871 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
872
873 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx);
874
875 inst->alg.ivsize = GCM_RFC4106_IV_SIZE;
876 inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
877 inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
878
879 inst->alg.init = crypto_rfc4106_init_tfm;
880 inst->alg.exit = crypto_rfc4106_exit_tfm;
881
882 inst->alg.setkey = crypto_rfc4106_setkey;
883 inst->alg.setauthsize = crypto_rfc4106_setauthsize;
884 inst->alg.encrypt = crypto_rfc4106_encrypt;
885 inst->alg.decrypt = crypto_rfc4106_decrypt;
886
887 inst->free = crypto_rfc4106_free;
888
889 err = aead_register_instance(tmpl, inst);
890 if (err) {
891 err_free_inst:
892 crypto_rfc4106_free(inst);
893 }
894 return err;
895 }
896
crypto_rfc4543_setkey(struct crypto_aead * parent,const u8 * key,unsigned int keylen)897 static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key,
898 unsigned int keylen)
899 {
900 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
901 struct crypto_aead *child = ctx->child;
902
903 if (keylen < 4)
904 return -EINVAL;
905
906 keylen -= 4;
907 memcpy(ctx->nonce, key + keylen, 4);
908
909 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
910 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
911 CRYPTO_TFM_REQ_MASK);
912 return crypto_aead_setkey(child, key, keylen);
913 }
914
crypto_rfc4543_setauthsize(struct crypto_aead * parent,unsigned int authsize)915 static int crypto_rfc4543_setauthsize(struct crypto_aead *parent,
916 unsigned int authsize)
917 {
918 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
919
920 if (authsize != 16)
921 return -EINVAL;
922
923 return crypto_aead_setauthsize(ctx->child, authsize);
924 }
925
crypto_rfc4543_crypt(struct aead_request * req,bool enc)926 static int crypto_rfc4543_crypt(struct aead_request *req, bool enc)
927 {
928 struct crypto_aead *aead = crypto_aead_reqtfm(req);
929 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
930 struct crypto_rfc4543_req_ctx *rctx = aead_request_ctx(req);
931 struct aead_request *subreq = &rctx->subreq;
932 unsigned int authsize = crypto_aead_authsize(aead);
933 u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child),
934 crypto_aead_alignmask(ctx->child) + 1);
935 int err;
936
937 if (req->src != req->dst) {
938 err = crypto_rfc4543_copy_src_to_dst(req, enc);
939 if (err)
940 return err;
941 }
942
943 memcpy(iv, ctx->nonce, 4);
944 memcpy(iv + 4, req->iv, 8);
945
946 aead_request_set_tfm(subreq, ctx->child);
947 aead_request_set_callback(subreq, req->base.flags,
948 req->base.complete, req->base.data);
949 aead_request_set_crypt(subreq, req->src, req->dst,
950 enc ? 0 : authsize, iv);
951 aead_request_set_ad(subreq, req->assoclen + req->cryptlen -
952 subreq->cryptlen);
953
954 return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq);
955 }
956
crypto_rfc4543_copy_src_to_dst(struct aead_request * req,bool enc)957 static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc)
958 {
959 struct crypto_aead *aead = crypto_aead_reqtfm(req);
960 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
961 unsigned int authsize = crypto_aead_authsize(aead);
962 unsigned int nbytes = req->assoclen + req->cryptlen -
963 (enc ? 0 : authsize);
964 SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null);
965
966 skcipher_request_set_sync_tfm(nreq, ctx->null);
967 skcipher_request_set_callback(nreq, req->base.flags, NULL, NULL);
968 skcipher_request_set_crypt(nreq, req->src, req->dst, nbytes, NULL);
969
970 return crypto_skcipher_encrypt(nreq);
971 }
972
crypto_rfc4543_encrypt(struct aead_request * req)973 static int crypto_rfc4543_encrypt(struct aead_request *req)
974 {
975 return crypto_ipsec_check_assoclen(req->assoclen) ?:
976 crypto_rfc4543_crypt(req, true);
977 }
978
crypto_rfc4543_decrypt(struct aead_request * req)979 static int crypto_rfc4543_decrypt(struct aead_request *req)
980 {
981 return crypto_ipsec_check_assoclen(req->assoclen) ?:
982 crypto_rfc4543_crypt(req, false);
983 }
984
crypto_rfc4543_init_tfm(struct crypto_aead * tfm)985 static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm)
986 {
987 struct aead_instance *inst = aead_alg_instance(tfm);
988 struct crypto_rfc4543_instance_ctx *ictx = aead_instance_ctx(inst);
989 struct crypto_aead_spawn *spawn = &ictx->aead;
990 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
991 struct crypto_aead *aead;
992 struct crypto_sync_skcipher *null;
993 unsigned long align;
994 int err = 0;
995
996 aead = crypto_spawn_aead(spawn);
997 if (IS_ERR(aead))
998 return PTR_ERR(aead);
999
1000 null = crypto_get_default_null_skcipher();
1001 err = PTR_ERR(null);
1002 if (IS_ERR(null))
1003 goto err_free_aead;
1004
1005 ctx->child = aead;
1006 ctx->null = null;
1007
1008 align = crypto_aead_alignmask(aead);
1009 align &= ~(crypto_tfm_ctx_alignment() - 1);
1010 crypto_aead_set_reqsize(
1011 tfm,
1012 sizeof(struct crypto_rfc4543_req_ctx) +
1013 ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
1014 align + GCM_AES_IV_SIZE);
1015
1016 return 0;
1017
1018 err_free_aead:
1019 crypto_free_aead(aead);
1020 return err;
1021 }
1022
crypto_rfc4543_exit_tfm(struct crypto_aead * tfm)1023 static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm)
1024 {
1025 struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
1026
1027 crypto_free_aead(ctx->child);
1028 crypto_put_default_null_skcipher();
1029 }
1030
crypto_rfc4543_free(struct aead_instance * inst)1031 static void crypto_rfc4543_free(struct aead_instance *inst)
1032 {
1033 struct crypto_rfc4543_instance_ctx *ctx = aead_instance_ctx(inst);
1034
1035 crypto_drop_aead(&ctx->aead);
1036
1037 kfree(inst);
1038 }
1039
crypto_rfc4543_create(struct crypto_template * tmpl,struct rtattr ** tb)1040 static int crypto_rfc4543_create(struct crypto_template *tmpl,
1041 struct rtattr **tb)
1042 {
1043 u32 mask;
1044 struct aead_instance *inst;
1045 struct aead_alg *alg;
1046 struct crypto_rfc4543_instance_ctx *ctx;
1047 int err;
1048
1049 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
1050 if (err)
1051 return err;
1052
1053 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
1054 if (!inst)
1055 return -ENOMEM;
1056
1057 ctx = aead_instance_ctx(inst);
1058 err = crypto_grab_aead(&ctx->aead, aead_crypto_instance(inst),
1059 crypto_attr_alg_name(tb[1]), 0, mask);
1060 if (err)
1061 goto err_free_inst;
1062
1063 alg = crypto_spawn_aead_alg(&ctx->aead);
1064
1065 err = -EINVAL;
1066
1067 /* Underlying IV size must be 12. */
1068 if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
1069 goto err_free_inst;
1070
1071 /* Not a stream cipher? */
1072 if (alg->base.cra_blocksize != 1)
1073 goto err_free_inst;
1074
1075 err = -ENAMETOOLONG;
1076 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
1077 "rfc4543(%s)", alg->base.cra_name) >=
1078 CRYPTO_MAX_ALG_NAME ||
1079 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
1080 "rfc4543(%s)", alg->base.cra_driver_name) >=
1081 CRYPTO_MAX_ALG_NAME)
1082 goto err_free_inst;
1083
1084 inst->alg.base.cra_priority = alg->base.cra_priority;
1085 inst->alg.base.cra_blocksize = 1;
1086 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
1087
1088 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx);
1089
1090 inst->alg.ivsize = GCM_RFC4543_IV_SIZE;
1091 inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
1092 inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
1093
1094 inst->alg.init = crypto_rfc4543_init_tfm;
1095 inst->alg.exit = crypto_rfc4543_exit_tfm;
1096
1097 inst->alg.setkey = crypto_rfc4543_setkey;
1098 inst->alg.setauthsize = crypto_rfc4543_setauthsize;
1099 inst->alg.encrypt = crypto_rfc4543_encrypt;
1100 inst->alg.decrypt = crypto_rfc4543_decrypt;
1101
1102 inst->free = crypto_rfc4543_free;
1103
1104 err = aead_register_instance(tmpl, inst);
1105 if (err) {
1106 err_free_inst:
1107 crypto_rfc4543_free(inst);
1108 }
1109 return err;
1110 }
1111
1112 static struct crypto_template crypto_gcm_tmpls[] = {
1113 {
1114 .name = "gcm_base",
1115 .create = crypto_gcm_base_create,
1116 .module = THIS_MODULE,
1117 }, {
1118 .name = "gcm",
1119 .create = crypto_gcm_create,
1120 .module = THIS_MODULE,
1121 }, {
1122 .name = "rfc4106",
1123 .create = crypto_rfc4106_create,
1124 .module = THIS_MODULE,
1125 }, {
1126 .name = "rfc4543",
1127 .create = crypto_rfc4543_create,
1128 .module = THIS_MODULE,
1129 },
1130 };
1131
crypto_gcm_module_init(void)1132 static int __init crypto_gcm_module_init(void)
1133 {
1134 int err;
1135
1136 gcm_zeroes = kzalloc(sizeof(*gcm_zeroes), GFP_KERNEL);
1137 if (!gcm_zeroes)
1138 return -ENOMEM;
1139
1140 sg_init_one(&gcm_zeroes->sg, gcm_zeroes->buf, sizeof(gcm_zeroes->buf));
1141
1142 err = crypto_register_templates(crypto_gcm_tmpls,
1143 ARRAY_SIZE(crypto_gcm_tmpls));
1144 if (err)
1145 kfree(gcm_zeroes);
1146
1147 return err;
1148 }
1149
crypto_gcm_module_exit(void)1150 static void __exit crypto_gcm_module_exit(void)
1151 {
1152 kfree(gcm_zeroes);
1153 crypto_unregister_templates(crypto_gcm_tmpls,
1154 ARRAY_SIZE(crypto_gcm_tmpls));
1155 }
1156
1157 subsys_initcall(crypto_gcm_module_init);
1158 module_exit(crypto_gcm_module_exit);
1159
1160 MODULE_LICENSE("GPL");
1161 MODULE_DESCRIPTION("Galois/Counter Mode");
1162 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
1163 MODULE_ALIAS_CRYPTO("gcm_base");
1164 MODULE_ALIAS_CRYPTO("rfc4106");
1165 MODULE_ALIAS_CRYPTO("rfc4543");
1166 MODULE_ALIAS_CRYPTO("gcm");
1167
