1 /*
2 * GCM: Galois/Counter Mode.
3 *
4 * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published
8 * by the Free Software Foundation.
9 */
10
11 #include <crypto/gf128mul.h>
12 #include <crypto/internal/aead.h>
13 #include <crypto/internal/skcipher.h>
14 #include <crypto/scatterwalk.h>
15 #include <linux/completion.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 };
25
26 struct crypto_gcm_ctx {
27 struct crypto_ablkcipher *ctr;
28 struct gf128mul_4k *gf128;
29 };
30
31 struct crypto_rfc4106_ctx {
32 struct crypto_aead *child;
33 u8 nonce[4];
34 };
35
36 struct crypto_gcm_ghash_ctx {
37 u32 bytes;
38 u32 flags;
39 struct gf128mul_4k *gf128;
40 u8 buffer[16];
41 };
42
43 struct crypto_gcm_req_priv_ctx {
44 u8 auth_tag[16];
45 u8 iauth_tag[16];
46 struct scatterlist src[2];
47 struct scatterlist dst[2];
48 struct crypto_gcm_ghash_ctx ghash;
49 struct ablkcipher_request abreq;
50 };
51
52 struct crypto_gcm_setkey_result {
53 int err;
54 struct completion completion;
55 };
56
crypto_gcm_reqctx(struct aead_request * req)57 static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
58 struct aead_request *req)
59 {
60 unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
61
62 return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
63 }
64
crypto_gcm_ghash_init(struct crypto_gcm_ghash_ctx * ctx,u32 flags,struct gf128mul_4k * gf128)65 static void crypto_gcm_ghash_init(struct crypto_gcm_ghash_ctx *ctx, u32 flags,
66 struct gf128mul_4k *gf128)
67 {
68 ctx->bytes = 0;
69 ctx->flags = flags;
70 ctx->gf128 = gf128;
71 memset(ctx->buffer, 0, 16);
72 }
73
crypto_gcm_ghash_update(struct crypto_gcm_ghash_ctx * ctx,const u8 * src,unsigned int srclen)74 static void crypto_gcm_ghash_update(struct crypto_gcm_ghash_ctx *ctx,
75 const u8 *src, unsigned int srclen)
76 {
77 u8 *dst = ctx->buffer;
78
79 if (ctx->bytes) {
80 int n = min(srclen, ctx->bytes);
81 u8 *pos = dst + (16 - ctx->bytes);
82
83 ctx->bytes -= n;
84 srclen -= n;
85
86 while (n--)
87 *pos++ ^= *src++;
88
89 if (!ctx->bytes)
90 gf128mul_4k_lle((be128 *)dst, ctx->gf128);
91 }
92
93 while (srclen >= 16) {
94 crypto_xor(dst, src, 16);
95 gf128mul_4k_lle((be128 *)dst, ctx->gf128);
96 src += 16;
97 srclen -= 16;
98 }
99
100 if (srclen) {
101 ctx->bytes = 16 - srclen;
102 while (srclen--)
103 *dst++ ^= *src++;
104 }
105 }
106
crypto_gcm_ghash_update_sg(struct crypto_gcm_ghash_ctx * ctx,struct scatterlist * sg,int len)107 static void crypto_gcm_ghash_update_sg(struct crypto_gcm_ghash_ctx *ctx,
108 struct scatterlist *sg, int len)
109 {
110 struct scatter_walk walk;
111 u8 *src;
112 int n;
113
114 if (!len)
115 return;
116
117 scatterwalk_start(&walk, sg);
118
119 while (len) {
120 n = scatterwalk_clamp(&walk, len);
121
122 if (!n) {
123 scatterwalk_start(&walk, scatterwalk_sg_next(walk.sg));
124 n = scatterwalk_clamp(&walk, len);
125 }
126
127 src = scatterwalk_map(&walk, 0);
128
129 crypto_gcm_ghash_update(ctx, src, n);
130 len -= n;
131
132 scatterwalk_unmap(src, 0);
133 scatterwalk_advance(&walk, n);
134 scatterwalk_done(&walk, 0, len);
135 if (len)
136 crypto_yield(ctx->flags);
137 }
138 }
139
crypto_gcm_ghash_flush(struct crypto_gcm_ghash_ctx * ctx)140 static void crypto_gcm_ghash_flush(struct crypto_gcm_ghash_ctx *ctx)
141 {
142 u8 *dst = ctx->buffer;
143
144 if (ctx->bytes) {
145 u8 *tmp = dst + (16 - ctx->bytes);
146
147 while (ctx->bytes--)
148 *tmp++ ^= 0;
149
150 gf128mul_4k_lle((be128 *)dst, ctx->gf128);
151 }
152
153 ctx->bytes = 0;
154 }
155
crypto_gcm_ghash_final_xor(struct crypto_gcm_ghash_ctx * ctx,unsigned int authlen,unsigned int cryptlen,u8 * dst)156 static void crypto_gcm_ghash_final_xor(struct crypto_gcm_ghash_ctx *ctx,
157 unsigned int authlen,
158 unsigned int cryptlen, u8 *dst)
159 {
160 u8 *buf = ctx->buffer;
161 u128 lengths;
162
163 lengths.a = cpu_to_be64(authlen * 8);
164 lengths.b = cpu_to_be64(cryptlen * 8);
165
166 crypto_gcm_ghash_flush(ctx);
167 crypto_xor(buf, (u8 *)&lengths, 16);
168 gf128mul_4k_lle((be128 *)buf, ctx->gf128);
169 crypto_xor(dst, buf, 16);
170 }
171
crypto_gcm_setkey_done(struct crypto_async_request * req,int err)172 static void crypto_gcm_setkey_done(struct crypto_async_request *req, int err)
173 {
174 struct crypto_gcm_setkey_result *result = req->data;
175
176 if (err == -EINPROGRESS)
177 return;
178
179 result->err = err;
180 complete(&result->completion);
181 }
182
crypto_gcm_setkey(struct crypto_aead * aead,const u8 * key,unsigned int keylen)183 static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
184 unsigned int keylen)
185 {
186 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
187 struct crypto_ablkcipher *ctr = ctx->ctr;
188 struct {
189 be128 hash;
190 u8 iv[8];
191
192 struct crypto_gcm_setkey_result result;
193
194 struct scatterlist sg[1];
195 struct ablkcipher_request req;
196 } *data;
197 int err;
198
199 crypto_ablkcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
200 crypto_ablkcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
201 CRYPTO_TFM_REQ_MASK);
202
203 err = crypto_ablkcipher_setkey(ctr, key, keylen);
204 if (err)
205 return err;
206
207 crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctr) &
208 CRYPTO_TFM_RES_MASK);
209
210 data = kzalloc(sizeof(*data) + crypto_ablkcipher_reqsize(ctr),
211 GFP_KERNEL);
212 if (!data)
213 return -ENOMEM;
214
215 init_completion(&data->result.completion);
216 sg_init_one(data->sg, &data->hash, sizeof(data->hash));
217 ablkcipher_request_set_tfm(&data->req, ctr);
218 ablkcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
219 CRYPTO_TFM_REQ_MAY_BACKLOG,
220 crypto_gcm_setkey_done,
221 &data->result);
222 ablkcipher_request_set_crypt(&data->req, data->sg, data->sg,
223 sizeof(data->hash), data->iv);
224
225 err = crypto_ablkcipher_encrypt(&data->req);
226 if (err == -EINPROGRESS || err == -EBUSY) {
227 err = wait_for_completion_interruptible(
228 &data->result.completion);
229 if (!err)
230 err = data->result.err;
231 }
232
233 if (err)
234 goto out;
235
236 if (ctx->gf128 != NULL)
237 gf128mul_free_4k(ctx->gf128);
238
239 ctx->gf128 = gf128mul_init_4k_lle(&data->hash);
240
241 if (ctx->gf128 == NULL)
242 err = -ENOMEM;
243
244 out:
245 kfree(data);
246 return err;
247 }
248
crypto_gcm_setauthsize(struct crypto_aead * tfm,unsigned int authsize)249 static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
250 unsigned int authsize)
251 {
252 switch (authsize) {
253 case 4:
254 case 8:
255 case 12:
256 case 13:
257 case 14:
258 case 15:
259 case 16:
260 break;
261 default:
262 return -EINVAL;
263 }
264
265 return 0;
266 }
267
crypto_gcm_init_crypt(struct ablkcipher_request * ablk_req,struct aead_request * req,unsigned int cryptlen)268 static void crypto_gcm_init_crypt(struct ablkcipher_request *ablk_req,
269 struct aead_request *req,
270 unsigned int cryptlen)
271 {
272 struct crypto_aead *aead = crypto_aead_reqtfm(req);
273 struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
274 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
275 u32 flags = req->base.tfm->crt_flags;
276 struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash;
277 struct scatterlist *dst;
278 __be32 counter = cpu_to_be32(1);
279
280 memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag));
281 memcpy(req->iv + 12, &counter, 4);
282
283 sg_init_table(pctx->src, 2);
284 sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag));
285 scatterwalk_sg_chain(pctx->src, 2, req->src);
286
287 dst = pctx->src;
288 if (req->src != req->dst) {
289 sg_init_table(pctx->dst, 2);
290 sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag));
291 scatterwalk_sg_chain(pctx->dst, 2, req->dst);
292 dst = pctx->dst;
293 }
294
295 ablkcipher_request_set_tfm(ablk_req, ctx->ctr);
296 ablkcipher_request_set_crypt(ablk_req, pctx->src, dst,
297 cryptlen + sizeof(pctx->auth_tag),
298 req->iv);
299
300 crypto_gcm_ghash_init(ghash, flags, ctx->gf128);
301
302 crypto_gcm_ghash_update_sg(ghash, req->assoc, req->assoclen);
303 crypto_gcm_ghash_flush(ghash);
304 }
305
crypto_gcm_hash(struct aead_request * req)306 static int crypto_gcm_hash(struct aead_request *req)
307 {
308 struct crypto_aead *aead = crypto_aead_reqtfm(req);
309 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
310 u8 *auth_tag = pctx->auth_tag;
311 struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash;
312
313 crypto_gcm_ghash_update_sg(ghash, req->dst, req->cryptlen);
314 crypto_gcm_ghash_final_xor(ghash, req->assoclen, req->cryptlen,
315 auth_tag);
316
317 scatterwalk_map_and_copy(auth_tag, req->dst, req->cryptlen,
318 crypto_aead_authsize(aead), 1);
319 return 0;
320 }
321
crypto_gcm_encrypt_done(struct crypto_async_request * areq,int err)322 static void crypto_gcm_encrypt_done(struct crypto_async_request *areq, int err)
323 {
324 struct aead_request *req = areq->data;
325
326 if (!err)
327 err = crypto_gcm_hash(req);
328
329 aead_request_complete(req, err);
330 }
331
crypto_gcm_encrypt(struct aead_request * req)332 static int crypto_gcm_encrypt(struct aead_request *req)
333 {
334 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
335 struct ablkcipher_request *abreq = &pctx->abreq;
336 int err;
337
338 crypto_gcm_init_crypt(abreq, req, req->cryptlen);
339 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
340 crypto_gcm_encrypt_done, req);
341
342 err = crypto_ablkcipher_encrypt(abreq);
343 if (err)
344 return err;
345
346 return crypto_gcm_hash(req);
347 }
348
crypto_gcm_verify(struct aead_request * req)349 static int crypto_gcm_verify(struct aead_request *req)
350 {
351 struct crypto_aead *aead = crypto_aead_reqtfm(req);
352 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
353 struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash;
354 u8 *auth_tag = pctx->auth_tag;
355 u8 *iauth_tag = pctx->iauth_tag;
356 unsigned int authsize = crypto_aead_authsize(aead);
357 unsigned int cryptlen = req->cryptlen - authsize;
358
359 crypto_gcm_ghash_final_xor(ghash, req->assoclen, cryptlen, auth_tag);
360
361 authsize = crypto_aead_authsize(aead);
362 scatterwalk_map_and_copy(iauth_tag, req->src, cryptlen, authsize, 0);
363 return memcmp(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0;
364 }
365
crypto_gcm_decrypt_done(struct crypto_async_request * areq,int err)366 static void crypto_gcm_decrypt_done(struct crypto_async_request *areq, int err)
367 {
368 struct aead_request *req = areq->data;
369
370 if (!err)
371 err = crypto_gcm_verify(req);
372
373 aead_request_complete(req, err);
374 }
375
crypto_gcm_decrypt(struct aead_request * req)376 static int crypto_gcm_decrypt(struct aead_request *req)
377 {
378 struct crypto_aead *aead = crypto_aead_reqtfm(req);
379 struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
380 struct ablkcipher_request *abreq = &pctx->abreq;
381 struct crypto_gcm_ghash_ctx *ghash = &pctx->ghash;
382 unsigned int cryptlen = req->cryptlen;
383 unsigned int authsize = crypto_aead_authsize(aead);
384 int err;
385
386 if (cryptlen < authsize)
387 return -EINVAL;
388 cryptlen -= authsize;
389
390 crypto_gcm_init_crypt(abreq, req, cryptlen);
391 ablkcipher_request_set_callback(abreq, aead_request_flags(req),
392 crypto_gcm_decrypt_done, req);
393
394 crypto_gcm_ghash_update_sg(ghash, req->src, cryptlen);
395
396 err = crypto_ablkcipher_decrypt(abreq);
397 if (err)
398 return err;
399
400 return crypto_gcm_verify(req);
401 }
402
crypto_gcm_init_tfm(struct crypto_tfm * tfm)403 static int crypto_gcm_init_tfm(struct crypto_tfm *tfm)
404 {
405 struct crypto_instance *inst = (void *)tfm->__crt_alg;
406 struct gcm_instance_ctx *ictx = crypto_instance_ctx(inst);
407 struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(tfm);
408 struct crypto_ablkcipher *ctr;
409 unsigned long align;
410 int err;
411
412 ctr = crypto_spawn_skcipher(&ictx->ctr);
413 err = PTR_ERR(ctr);
414 if (IS_ERR(ctr))
415 return err;
416
417 ctx->ctr = ctr;
418 ctx->gf128 = NULL;
419
420 align = crypto_tfm_alg_alignmask(tfm);
421 align &= ~(crypto_tfm_ctx_alignment() - 1);
422 tfm->crt_aead.reqsize = align +
423 sizeof(struct crypto_gcm_req_priv_ctx) +
424 crypto_ablkcipher_reqsize(ctr);
425
426 return 0;
427 }
428
crypto_gcm_exit_tfm(struct crypto_tfm * tfm)429 static void crypto_gcm_exit_tfm(struct crypto_tfm *tfm)
430 {
431 struct crypto_gcm_ctx *ctx = crypto_tfm_ctx(tfm);
432
433 if (ctx->gf128 != NULL)
434 gf128mul_free_4k(ctx->gf128);
435
436 crypto_free_ablkcipher(ctx->ctr);
437 }
438
crypto_gcm_alloc_common(struct rtattr ** tb,const char * full_name,const char * ctr_name)439 static struct crypto_instance *crypto_gcm_alloc_common(struct rtattr **tb,
440 const char *full_name,
441 const char *ctr_name)
442 {
443 struct crypto_attr_type *algt;
444 struct crypto_instance *inst;
445 struct crypto_alg *ctr;
446 struct gcm_instance_ctx *ctx;
447 int err;
448
449 algt = crypto_get_attr_type(tb);
450 err = PTR_ERR(algt);
451 if (IS_ERR(algt))
452 return ERR_PTR(err);
453
454 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
455 return ERR_PTR(-EINVAL);
456
457 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
458 if (!inst)
459 return ERR_PTR(-ENOMEM);
460
461 ctx = crypto_instance_ctx(inst);
462 crypto_set_skcipher_spawn(&ctx->ctr, inst);
463 err = crypto_grab_skcipher(&ctx->ctr, ctr_name, 0,
464 crypto_requires_sync(algt->type,
465 algt->mask));
466 if (err)
467 goto err_free_inst;
468
469 ctr = crypto_skcipher_spawn_alg(&ctx->ctr);
470
471 /* We only support 16-byte blocks. */
472 if (ctr->cra_ablkcipher.ivsize != 16)
473 goto out_put_ctr;
474
475 /* Not a stream cipher? */
476 err = -EINVAL;
477 if (ctr->cra_blocksize != 1)
478 goto out_put_ctr;
479
480 err = -ENAMETOOLONG;
481 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
482 "gcm_base(%s)", ctr->cra_driver_name) >=
483 CRYPTO_MAX_ALG_NAME)
484 goto out_put_ctr;
485
486 memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
487
488 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
489 inst->alg.cra_flags |= ctr->cra_flags & CRYPTO_ALG_ASYNC;
490 inst->alg.cra_priority = ctr->cra_priority;
491 inst->alg.cra_blocksize = 1;
492 inst->alg.cra_alignmask = ctr->cra_alignmask | (__alignof__(u64) - 1);
493 inst->alg.cra_type = &crypto_aead_type;
494 inst->alg.cra_aead.ivsize = 16;
495 inst->alg.cra_aead.maxauthsize = 16;
496 inst->alg.cra_ctxsize = sizeof(struct crypto_gcm_ctx);
497 inst->alg.cra_init = crypto_gcm_init_tfm;
498 inst->alg.cra_exit = crypto_gcm_exit_tfm;
499 inst->alg.cra_aead.setkey = crypto_gcm_setkey;
500 inst->alg.cra_aead.setauthsize = crypto_gcm_setauthsize;
501 inst->alg.cra_aead.encrypt = crypto_gcm_encrypt;
502 inst->alg.cra_aead.decrypt = crypto_gcm_decrypt;
503
504 out:
505 return inst;
506
507 out_put_ctr:
508 crypto_drop_skcipher(&ctx->ctr);
509 err_free_inst:
510 kfree(inst);
511 inst = ERR_PTR(err);
512 goto out;
513 }
514
crypto_gcm_alloc(struct rtattr ** tb)515 static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
516 {
517 int err;
518 const char *cipher_name;
519 char ctr_name[CRYPTO_MAX_ALG_NAME];
520 char full_name[CRYPTO_MAX_ALG_NAME];
521
522 cipher_name = crypto_attr_alg_name(tb[1]);
523 err = PTR_ERR(cipher_name);
524 if (IS_ERR(cipher_name))
525 return ERR_PTR(err);
526
527 if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
528 CRYPTO_MAX_ALG_NAME)
529 return ERR_PTR(-ENAMETOOLONG);
530
531 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm(%s)", cipher_name) >=
532 CRYPTO_MAX_ALG_NAME)
533 return ERR_PTR(-ENAMETOOLONG);
534
535 return crypto_gcm_alloc_common(tb, full_name, ctr_name);
536 }
537
crypto_gcm_free(struct crypto_instance * inst)538 static void crypto_gcm_free(struct crypto_instance *inst)
539 {
540 struct gcm_instance_ctx *ctx = crypto_instance_ctx(inst);
541
542 crypto_drop_skcipher(&ctx->ctr);
543 kfree(inst);
544 }
545
546 static struct crypto_template crypto_gcm_tmpl = {
547 .name = "gcm",
548 .alloc = crypto_gcm_alloc,
549 .free = crypto_gcm_free,
550 .module = THIS_MODULE,
551 };
552
crypto_gcm_base_alloc(struct rtattr ** tb)553 static struct crypto_instance *crypto_gcm_base_alloc(struct rtattr **tb)
554 {
555 int err;
556 const char *ctr_name;
557 char full_name[CRYPTO_MAX_ALG_NAME];
558
559 ctr_name = crypto_attr_alg_name(tb[1]);
560 err = PTR_ERR(ctr_name);
561 if (IS_ERR(ctr_name))
562 return ERR_PTR(err);
563
564 if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s)",
565 ctr_name) >= CRYPTO_MAX_ALG_NAME)
566 return ERR_PTR(-ENAMETOOLONG);
567
568 return crypto_gcm_alloc_common(tb, full_name, ctr_name);
569 }
570
571 static struct crypto_template crypto_gcm_base_tmpl = {
572 .name = "gcm_base",
573 .alloc = crypto_gcm_base_alloc,
574 .free = crypto_gcm_free,
575 .module = THIS_MODULE,
576 };
577
crypto_rfc4106_setkey(struct crypto_aead * parent,const u8 * key,unsigned int keylen)578 static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key,
579 unsigned int keylen)
580 {
581 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
582 struct crypto_aead *child = ctx->child;
583 int err;
584
585 if (keylen < 4)
586 return -EINVAL;
587
588 keylen -= 4;
589 memcpy(ctx->nonce, key + keylen, 4);
590
591 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
592 crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
593 CRYPTO_TFM_REQ_MASK);
594 err = crypto_aead_setkey(child, key, keylen);
595 crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
596 CRYPTO_TFM_RES_MASK);
597
598 return err;
599 }
600
crypto_rfc4106_setauthsize(struct crypto_aead * parent,unsigned int authsize)601 static int crypto_rfc4106_setauthsize(struct crypto_aead *parent,
602 unsigned int authsize)
603 {
604 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
605
606 switch (authsize) {
607 case 8:
608 case 12:
609 case 16:
610 break;
611 default:
612 return -EINVAL;
613 }
614
615 return crypto_aead_setauthsize(ctx->child, authsize);
616 }
617
crypto_rfc4106_crypt(struct aead_request * req)618 static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req)
619 {
620 struct aead_request *subreq = aead_request_ctx(req);
621 struct crypto_aead *aead = crypto_aead_reqtfm(req);
622 struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead);
623 struct crypto_aead *child = ctx->child;
624 u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
625 crypto_aead_alignmask(child) + 1);
626
627 memcpy(iv, ctx->nonce, 4);
628 memcpy(iv + 4, req->iv, 8);
629
630 aead_request_set_tfm(subreq, child);
631 aead_request_set_callback(subreq, req->base.flags, req->base.complete,
632 req->base.data);
633 aead_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, iv);
634 aead_request_set_assoc(subreq, req->assoc, req->assoclen);
635
636 return subreq;
637 }
638
crypto_rfc4106_encrypt(struct aead_request * req)639 static int crypto_rfc4106_encrypt(struct aead_request *req)
640 {
641 req = crypto_rfc4106_crypt(req);
642
643 return crypto_aead_encrypt(req);
644 }
645
crypto_rfc4106_decrypt(struct aead_request * req)646 static int crypto_rfc4106_decrypt(struct aead_request *req)
647 {
648 req = crypto_rfc4106_crypt(req);
649
650 return crypto_aead_decrypt(req);
651 }
652
crypto_rfc4106_init_tfm(struct crypto_tfm * tfm)653 static int crypto_rfc4106_init_tfm(struct crypto_tfm *tfm)
654 {
655 struct crypto_instance *inst = (void *)tfm->__crt_alg;
656 struct crypto_aead_spawn *spawn = crypto_instance_ctx(inst);
657 struct crypto_rfc4106_ctx *ctx = crypto_tfm_ctx(tfm);
658 struct crypto_aead *aead;
659 unsigned long align;
660
661 aead = crypto_spawn_aead(spawn);
662 if (IS_ERR(aead))
663 return PTR_ERR(aead);
664
665 ctx->child = aead;
666
667 align = crypto_aead_alignmask(aead);
668 align &= ~(crypto_tfm_ctx_alignment() - 1);
669 tfm->crt_aead.reqsize = sizeof(struct aead_request) +
670 ALIGN(crypto_aead_reqsize(aead),
671 crypto_tfm_ctx_alignment()) +
672 align + 16;
673
674 return 0;
675 }
676
crypto_rfc4106_exit_tfm(struct crypto_tfm * tfm)677 static void crypto_rfc4106_exit_tfm(struct crypto_tfm *tfm)
678 {
679 struct crypto_rfc4106_ctx *ctx = crypto_tfm_ctx(tfm);
680
681 crypto_free_aead(ctx->child);
682 }
683
crypto_rfc4106_alloc(struct rtattr ** tb)684 static struct crypto_instance *crypto_rfc4106_alloc(struct rtattr **tb)
685 {
686 struct crypto_attr_type *algt;
687 struct crypto_instance *inst;
688 struct crypto_aead_spawn *spawn;
689 struct crypto_alg *alg;
690 const char *ccm_name;
691 int err;
692
693 algt = crypto_get_attr_type(tb);
694 err = PTR_ERR(algt);
695 if (IS_ERR(algt))
696 return ERR_PTR(err);
697
698 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
699 return ERR_PTR(-EINVAL);
700
701 ccm_name = crypto_attr_alg_name(tb[1]);
702 err = PTR_ERR(ccm_name);
703 if (IS_ERR(ccm_name))
704 return ERR_PTR(err);
705
706 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
707 if (!inst)
708 return ERR_PTR(-ENOMEM);
709
710 spawn = crypto_instance_ctx(inst);
711 crypto_set_aead_spawn(spawn, inst);
712 err = crypto_grab_aead(spawn, ccm_name, 0,
713 crypto_requires_sync(algt->type, algt->mask));
714 if (err)
715 goto out_free_inst;
716
717 alg = crypto_aead_spawn_alg(spawn);
718
719 err = -EINVAL;
720
721 /* We only support 16-byte blocks. */
722 if (alg->cra_aead.ivsize != 16)
723 goto out_drop_alg;
724
725 /* Not a stream cipher? */
726 if (alg->cra_blocksize != 1)
727 goto out_drop_alg;
728
729 err = -ENAMETOOLONG;
730 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
731 "rfc4106(%s)", alg->cra_name) >= CRYPTO_MAX_ALG_NAME ||
732 snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
733 "rfc4106(%s)", alg->cra_driver_name) >=
734 CRYPTO_MAX_ALG_NAME)
735 goto out_drop_alg;
736
737 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
738 inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
739 inst->alg.cra_priority = alg->cra_priority;
740 inst->alg.cra_blocksize = 1;
741 inst->alg.cra_alignmask = alg->cra_alignmask;
742 inst->alg.cra_type = &crypto_nivaead_type;
743
744 inst->alg.cra_aead.ivsize = 8;
745 inst->alg.cra_aead.maxauthsize = 16;
746
747 inst->alg.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx);
748
749 inst->alg.cra_init = crypto_rfc4106_init_tfm;
750 inst->alg.cra_exit = crypto_rfc4106_exit_tfm;
751
752 inst->alg.cra_aead.setkey = crypto_rfc4106_setkey;
753 inst->alg.cra_aead.setauthsize = crypto_rfc4106_setauthsize;
754 inst->alg.cra_aead.encrypt = crypto_rfc4106_encrypt;
755 inst->alg.cra_aead.decrypt = crypto_rfc4106_decrypt;
756
757 inst->alg.cra_aead.geniv = "seqiv";
758
759 out:
760 return inst;
761
762 out_drop_alg:
763 crypto_drop_aead(spawn);
764 out_free_inst:
765 kfree(inst);
766 inst = ERR_PTR(err);
767 goto out;
768 }
769
crypto_rfc4106_free(struct crypto_instance * inst)770 static void crypto_rfc4106_free(struct crypto_instance *inst)
771 {
772 crypto_drop_spawn(crypto_instance_ctx(inst));
773 kfree(inst);
774 }
775
776 static struct crypto_template crypto_rfc4106_tmpl = {
777 .name = "rfc4106",
778 .alloc = crypto_rfc4106_alloc,
779 .free = crypto_rfc4106_free,
780 .module = THIS_MODULE,
781 };
782
crypto_gcm_module_init(void)783 static int __init crypto_gcm_module_init(void)
784 {
785 int err;
786
787 err = crypto_register_template(&crypto_gcm_base_tmpl);
788 if (err)
789 goto out;
790
791 err = crypto_register_template(&crypto_gcm_tmpl);
792 if (err)
793 goto out_undo_base;
794
795 err = crypto_register_template(&crypto_rfc4106_tmpl);
796 if (err)
797 goto out_undo_gcm;
798
799 out:
800 return err;
801
802 out_undo_gcm:
803 crypto_unregister_template(&crypto_gcm_tmpl);
804 out_undo_base:
805 crypto_unregister_template(&crypto_gcm_base_tmpl);
806 goto out;
807 }
808
crypto_gcm_module_exit(void)809 static void __exit crypto_gcm_module_exit(void)
810 {
811 crypto_unregister_template(&crypto_rfc4106_tmpl);
812 crypto_unregister_template(&crypto_gcm_tmpl);
813 crypto_unregister_template(&crypto_gcm_base_tmpl);
814 }
815
816 module_init(crypto_gcm_module_init);
817 module_exit(crypto_gcm_module_exit);
818
819 MODULE_LICENSE("GPL");
820 MODULE_DESCRIPTION("Galois/Counter Mode");
821 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
822 MODULE_ALIAS("gcm_base");
823 MODULE_ALIAS("rfc4106");
824