1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Symmetric key cipher operations.
4 *
5 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
6 * multiple page boundaries by using temporary blocks. In user context,
7 * the kernel is given a chance to schedule us once per page.
8 *
9 * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
10 */
11
12 #include <crypto/internal/aead.h>
13 #include <crypto/internal/cipher.h>
14 #include <crypto/internal/skcipher.h>
15 #include <crypto/scatterwalk.h>
16 #include <linux/bug.h>
17 #include <linux/cryptouser.h>
18 #include <linux/compiler.h>
19 #include <linux/list.h>
20 #include <linux/module.h>
21 #include <linux/rtnetlink.h>
22 #include <linux/seq_file.h>
23 #include <net/netlink.h>
24
25 #include "internal.h"
26
27 enum {
28 SKCIPHER_WALK_PHYS = 1 << 0,
29 SKCIPHER_WALK_SLOW = 1 << 1,
30 SKCIPHER_WALK_COPY = 1 << 2,
31 SKCIPHER_WALK_DIFF = 1 << 3,
32 SKCIPHER_WALK_SLEEP = 1 << 4,
33 };
34
35 struct skcipher_walk_buffer {
36 struct list_head entry;
37 struct scatter_walk dst;
38 unsigned int len;
39 u8 *data;
40 u8 buffer[];
41 };
42
43 static int skcipher_walk_next(struct skcipher_walk *walk);
44
skcipher_unmap(struct scatter_walk * walk,void * vaddr)45 static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr)
46 {
47 if (PageHighMem(scatterwalk_page(walk)))
48 kunmap_atomic(vaddr);
49 }
50
skcipher_map(struct scatter_walk * walk)51 static inline void *skcipher_map(struct scatter_walk *walk)
52 {
53 struct page *page = scatterwalk_page(walk);
54
55 return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) +
56 offset_in_page(walk->offset);
57 }
58
skcipher_map_src(struct skcipher_walk * walk)59 static inline void skcipher_map_src(struct skcipher_walk *walk)
60 {
61 walk->src.virt.addr = skcipher_map(&walk->in);
62 }
63
skcipher_map_dst(struct skcipher_walk * walk)64 static inline void skcipher_map_dst(struct skcipher_walk *walk)
65 {
66 walk->dst.virt.addr = skcipher_map(&walk->out);
67 }
68
skcipher_unmap_src(struct skcipher_walk * walk)69 static inline void skcipher_unmap_src(struct skcipher_walk *walk)
70 {
71 skcipher_unmap(&walk->in, walk->src.virt.addr);
72 }
73
skcipher_unmap_dst(struct skcipher_walk * walk)74 static inline void skcipher_unmap_dst(struct skcipher_walk *walk)
75 {
76 skcipher_unmap(&walk->out, walk->dst.virt.addr);
77 }
78
skcipher_walk_gfp(struct skcipher_walk * walk)79 static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk)
80 {
81 return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
82 }
83
84 /* Get a spot of the specified length that does not straddle a page.
85 * The caller needs to ensure that there is enough space for this operation.
86 */
skcipher_get_spot(u8 * start,unsigned int len)87 static inline u8 *skcipher_get_spot(u8 *start, unsigned int len)
88 {
89 u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
90
91 return max(start, end_page);
92 }
93
skcipher_done_slow(struct skcipher_walk * walk,unsigned int bsize)94 static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
95 {
96 u8 *addr;
97
98 addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
99 addr = skcipher_get_spot(addr, bsize);
100 scatterwalk_copychunks(addr, &walk->out, bsize,
101 (walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1);
102 return 0;
103 }
104
skcipher_walk_done(struct skcipher_walk * walk,int err)105 int skcipher_walk_done(struct skcipher_walk *walk, int err)
106 {
107 unsigned int n = walk->nbytes;
108 unsigned int nbytes = 0;
109
110 if (!n)
111 goto finish;
112
113 if (likely(err >= 0)) {
114 n -= err;
115 nbytes = walk->total - n;
116 }
117
118 if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
119 SKCIPHER_WALK_SLOW |
120 SKCIPHER_WALK_COPY |
121 SKCIPHER_WALK_DIFF)))) {
122 unmap_src:
123 skcipher_unmap_src(walk);
124 } else if (walk->flags & SKCIPHER_WALK_DIFF) {
125 skcipher_unmap_dst(walk);
126 goto unmap_src;
127 } else if (walk->flags & SKCIPHER_WALK_COPY) {
128 skcipher_map_dst(walk);
129 memcpy(walk->dst.virt.addr, walk->page, n);
130 skcipher_unmap_dst(walk);
131 } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
132 if (err > 0) {
133 /*
134 * Didn't process all bytes. Either the algorithm is
135 * broken, or this was the last step and it turned out
136 * the message wasn't evenly divisible into blocks but
137 * the algorithm requires it.
138 */
139 err = -EINVAL;
140 nbytes = 0;
141 } else
142 n = skcipher_done_slow(walk, n);
143 }
144
145 if (err > 0)
146 err = 0;
147
148 walk->total = nbytes;
149 walk->nbytes = 0;
150
151 scatterwalk_advance(&walk->in, n);
152 scatterwalk_advance(&walk->out, n);
153 scatterwalk_done(&walk->in, 0, nbytes);
154 scatterwalk_done(&walk->out, 1, nbytes);
155
156 if (nbytes) {
157 crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
158 CRYPTO_TFM_REQ_MAY_SLEEP : 0);
159 return skcipher_walk_next(walk);
160 }
161
162 finish:
163 /* Short-circuit for the common/fast path. */
164 if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
165 goto out;
166
167 if (walk->flags & SKCIPHER_WALK_PHYS)
168 goto out;
169
170 if (walk->iv != walk->oiv)
171 memcpy(walk->oiv, walk->iv, walk->ivsize);
172 if (walk->buffer != walk->page)
173 kfree(walk->buffer);
174 if (walk->page)
175 free_page((unsigned long)walk->page);
176
177 out:
178 return err;
179 }
180 EXPORT_SYMBOL_GPL(skcipher_walk_done);
181
skcipher_walk_complete(struct skcipher_walk * walk,int err)182 void skcipher_walk_complete(struct skcipher_walk *walk, int err)
183 {
184 struct skcipher_walk_buffer *p, *tmp;
185
186 list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
187 u8 *data;
188
189 if (err)
190 goto done;
191
192 data = p->data;
193 if (!data) {
194 data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1);
195 data = skcipher_get_spot(data, walk->stride);
196 }
197
198 scatterwalk_copychunks(data, &p->dst, p->len, 1);
199
200 if (offset_in_page(p->data) + p->len + walk->stride >
201 PAGE_SIZE)
202 free_page((unsigned long)p->data);
203
204 done:
205 list_del(&p->entry);
206 kfree(p);
207 }
208
209 if (!err && walk->iv != walk->oiv)
210 memcpy(walk->oiv, walk->iv, walk->ivsize);
211 if (walk->buffer != walk->page)
212 kfree(walk->buffer);
213 if (walk->page)
214 free_page((unsigned long)walk->page);
215 }
216 EXPORT_SYMBOL_GPL(skcipher_walk_complete);
217
skcipher_queue_write(struct skcipher_walk * walk,struct skcipher_walk_buffer * p)218 static void skcipher_queue_write(struct skcipher_walk *walk,
219 struct skcipher_walk_buffer *p)
220 {
221 p->dst = walk->out;
222 list_add_tail(&p->entry, &walk->buffers);
223 }
224
skcipher_next_slow(struct skcipher_walk * walk,unsigned int bsize)225 static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize)
226 {
227 bool phys = walk->flags & SKCIPHER_WALK_PHYS;
228 unsigned alignmask = walk->alignmask;
229 struct skcipher_walk_buffer *p;
230 unsigned a;
231 unsigned n;
232 u8 *buffer;
233 void *v;
234
235 if (!phys) {
236 if (!walk->buffer)
237 walk->buffer = walk->page;
238 buffer = walk->buffer;
239 if (buffer)
240 goto ok;
241 }
242
243 /* Start with the minimum alignment of kmalloc. */
244 a = crypto_tfm_ctx_alignment() - 1;
245 n = bsize;
246
247 if (phys) {
248 /* Calculate the minimum alignment of p->buffer. */
249 a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1;
250 n += sizeof(*p);
251 }
252
253 /* Minimum size to align p->buffer by alignmask. */
254 n += alignmask & ~a;
255
256 /* Minimum size to ensure p->buffer does not straddle a page. */
257 n += (bsize - 1) & ~(alignmask | a);
258
259 v = kzalloc(n, skcipher_walk_gfp(walk));
260 if (!v)
261 return skcipher_walk_done(walk, -ENOMEM);
262
263 if (phys) {
264 p = v;
265 p->len = bsize;
266 skcipher_queue_write(walk, p);
267 buffer = p->buffer;
268 } else {
269 walk->buffer = v;
270 buffer = v;
271 }
272
273 ok:
274 walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1);
275 walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize);
276 walk->src.virt.addr = walk->dst.virt.addr;
277
278 scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
279
280 walk->nbytes = bsize;
281 walk->flags |= SKCIPHER_WALK_SLOW;
282
283 return 0;
284 }
285
skcipher_next_copy(struct skcipher_walk * walk)286 static int skcipher_next_copy(struct skcipher_walk *walk)
287 {
288 struct skcipher_walk_buffer *p;
289 u8 *tmp = walk->page;
290
291 skcipher_map_src(walk);
292 memcpy(tmp, walk->src.virt.addr, walk->nbytes);
293 skcipher_unmap_src(walk);
294
295 walk->src.virt.addr = tmp;
296 walk->dst.virt.addr = tmp;
297
298 if (!(walk->flags & SKCIPHER_WALK_PHYS))
299 return 0;
300
301 p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk));
302 if (!p)
303 return -ENOMEM;
304
305 p->data = walk->page;
306 p->len = walk->nbytes;
307 skcipher_queue_write(walk, p);
308
309 if (offset_in_page(walk->page) + walk->nbytes + walk->stride >
310 PAGE_SIZE)
311 walk->page = NULL;
312 else
313 walk->page += walk->nbytes;
314
315 return 0;
316 }
317
skcipher_next_fast(struct skcipher_walk * walk)318 static int skcipher_next_fast(struct skcipher_walk *walk)
319 {
320 unsigned long diff;
321
322 walk->src.phys.page = scatterwalk_page(&walk->in);
323 walk->src.phys.offset = offset_in_page(walk->in.offset);
324 walk->dst.phys.page = scatterwalk_page(&walk->out);
325 walk->dst.phys.offset = offset_in_page(walk->out.offset);
326
327 if (walk->flags & SKCIPHER_WALK_PHYS)
328 return 0;
329
330 diff = walk->src.phys.offset - walk->dst.phys.offset;
331 diff |= walk->src.virt.page - walk->dst.virt.page;
332
333 skcipher_map_src(walk);
334 walk->dst.virt.addr = walk->src.virt.addr;
335
336 if (diff) {
337 walk->flags |= SKCIPHER_WALK_DIFF;
338 skcipher_map_dst(walk);
339 }
340
341 return 0;
342 }
343
skcipher_walk_next(struct skcipher_walk * walk)344 static int skcipher_walk_next(struct skcipher_walk *walk)
345 {
346 unsigned int bsize;
347 unsigned int n;
348 int err;
349
350 walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY |
351 SKCIPHER_WALK_DIFF);
352
353 n = walk->total;
354 bsize = min(walk->stride, max(n, walk->blocksize));
355 n = scatterwalk_clamp(&walk->in, n);
356 n = scatterwalk_clamp(&walk->out, n);
357
358 if (unlikely(n < bsize)) {
359 if (unlikely(walk->total < walk->blocksize))
360 return skcipher_walk_done(walk, -EINVAL);
361
362 slow_path:
363 err = skcipher_next_slow(walk, bsize);
364 goto set_phys_lowmem;
365 }
366
367 if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) {
368 if (!walk->page) {
369 gfp_t gfp = skcipher_walk_gfp(walk);
370
371 walk->page = (void *)__get_free_page(gfp);
372 if (!walk->page)
373 goto slow_path;
374 }
375
376 walk->nbytes = min_t(unsigned, n,
377 PAGE_SIZE - offset_in_page(walk->page));
378 walk->flags |= SKCIPHER_WALK_COPY;
379 err = skcipher_next_copy(walk);
380 goto set_phys_lowmem;
381 }
382
383 walk->nbytes = n;
384
385 return skcipher_next_fast(walk);
386
387 set_phys_lowmem:
388 if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) {
389 walk->src.phys.page = virt_to_page(walk->src.virt.addr);
390 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
391 walk->src.phys.offset &= PAGE_SIZE - 1;
392 walk->dst.phys.offset &= PAGE_SIZE - 1;
393 }
394 return err;
395 }
396
skcipher_copy_iv(struct skcipher_walk * walk)397 static int skcipher_copy_iv(struct skcipher_walk *walk)
398 {
399 unsigned a = crypto_tfm_ctx_alignment() - 1;
400 unsigned alignmask = walk->alignmask;
401 unsigned ivsize = walk->ivsize;
402 unsigned bs = walk->stride;
403 unsigned aligned_bs;
404 unsigned size;
405 u8 *iv;
406
407 aligned_bs = ALIGN(bs, alignmask + 1);
408
409 /* Minimum size to align buffer by alignmask. */
410 size = alignmask & ~a;
411
412 if (walk->flags & SKCIPHER_WALK_PHYS)
413 size += ivsize;
414 else {
415 size += aligned_bs + ivsize;
416
417 /* Minimum size to ensure buffer does not straddle a page. */
418 size += (bs - 1) & ~(alignmask | a);
419 }
420
421 walk->buffer = kmalloc(size, skcipher_walk_gfp(walk));
422 if (!walk->buffer)
423 return -ENOMEM;
424
425 iv = PTR_ALIGN(walk->buffer, alignmask + 1);
426 iv = skcipher_get_spot(iv, bs) + aligned_bs;
427
428 walk->iv = memcpy(iv, walk->iv, walk->ivsize);
429 return 0;
430 }
431
skcipher_walk_first(struct skcipher_walk * walk)432 static int skcipher_walk_first(struct skcipher_walk *walk)
433 {
434 if (WARN_ON_ONCE(in_hardirq()))
435 return -EDEADLK;
436
437 walk->buffer = NULL;
438 if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
439 int err = skcipher_copy_iv(walk);
440 if (err)
441 return err;
442 }
443
444 walk->page = NULL;
445
446 return skcipher_walk_next(walk);
447 }
448
skcipher_walk_skcipher(struct skcipher_walk * walk,struct skcipher_request * req)449 static int skcipher_walk_skcipher(struct skcipher_walk *walk,
450 struct skcipher_request *req)
451 {
452 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
453
454 walk->total = req->cryptlen;
455 walk->nbytes = 0;
456 walk->iv = req->iv;
457 walk->oiv = req->iv;
458
459 if (unlikely(!walk->total))
460 return 0;
461
462 scatterwalk_start(&walk->in, req->src);
463 scatterwalk_start(&walk->out, req->dst);
464
465 walk->flags &= ~SKCIPHER_WALK_SLEEP;
466 walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
467 SKCIPHER_WALK_SLEEP : 0;
468
469 walk->blocksize = crypto_skcipher_blocksize(tfm);
470 walk->stride = crypto_skcipher_walksize(tfm);
471 walk->ivsize = crypto_skcipher_ivsize(tfm);
472 walk->alignmask = crypto_skcipher_alignmask(tfm);
473
474 return skcipher_walk_first(walk);
475 }
476
skcipher_walk_virt(struct skcipher_walk * walk,struct skcipher_request * req,bool atomic)477 int skcipher_walk_virt(struct skcipher_walk *walk,
478 struct skcipher_request *req, bool atomic)
479 {
480 int err;
481
482 might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
483
484 walk->flags &= ~SKCIPHER_WALK_PHYS;
485
486 err = skcipher_walk_skcipher(walk, req);
487
488 walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0;
489
490 return err;
491 }
492 EXPORT_SYMBOL_GPL(skcipher_walk_virt);
493
skcipher_walk_async(struct skcipher_walk * walk,struct skcipher_request * req)494 int skcipher_walk_async(struct skcipher_walk *walk,
495 struct skcipher_request *req)
496 {
497 walk->flags |= SKCIPHER_WALK_PHYS;
498
499 INIT_LIST_HEAD(&walk->buffers);
500
501 return skcipher_walk_skcipher(walk, req);
502 }
503 EXPORT_SYMBOL_GPL(skcipher_walk_async);
504
skcipher_walk_aead_common(struct skcipher_walk * walk,struct aead_request * req,bool atomic)505 static int skcipher_walk_aead_common(struct skcipher_walk *walk,
506 struct aead_request *req, bool atomic)
507 {
508 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
509 int err;
510
511 walk->nbytes = 0;
512 walk->iv = req->iv;
513 walk->oiv = req->iv;
514
515 if (unlikely(!walk->total))
516 return 0;
517
518 walk->flags &= ~SKCIPHER_WALK_PHYS;
519
520 scatterwalk_start(&walk->in, req->src);
521 scatterwalk_start(&walk->out, req->dst);
522
523 scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
524 scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);
525
526 scatterwalk_done(&walk->in, 0, walk->total);
527 scatterwalk_done(&walk->out, 0, walk->total);
528
529 if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
530 walk->flags |= SKCIPHER_WALK_SLEEP;
531 else
532 walk->flags &= ~SKCIPHER_WALK_SLEEP;
533
534 walk->blocksize = crypto_aead_blocksize(tfm);
535 walk->stride = crypto_aead_chunksize(tfm);
536 walk->ivsize = crypto_aead_ivsize(tfm);
537 walk->alignmask = crypto_aead_alignmask(tfm);
538
539 err = skcipher_walk_first(walk);
540
541 if (atomic)
542 walk->flags &= ~SKCIPHER_WALK_SLEEP;
543
544 return err;
545 }
546
skcipher_walk_aead_encrypt(struct skcipher_walk * walk,struct aead_request * req,bool atomic)547 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
548 struct aead_request *req, bool atomic)
549 {
550 walk->total = req->cryptlen;
551
552 return skcipher_walk_aead_common(walk, req, atomic);
553 }
554 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);
555
skcipher_walk_aead_decrypt(struct skcipher_walk * walk,struct aead_request * req,bool atomic)556 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
557 struct aead_request *req, bool atomic)
558 {
559 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
560
561 walk->total = req->cryptlen - crypto_aead_authsize(tfm);
562
563 return skcipher_walk_aead_common(walk, req, atomic);
564 }
565 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);
566
skcipher_set_needkey(struct crypto_skcipher * tfm)567 static void skcipher_set_needkey(struct crypto_skcipher *tfm)
568 {
569 if (crypto_skcipher_max_keysize(tfm) != 0)
570 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
571 }
572
skcipher_setkey_unaligned(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)573 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
574 const u8 *key, unsigned int keylen)
575 {
576 unsigned long alignmask = crypto_skcipher_alignmask(tfm);
577 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
578 u8 *buffer, *alignbuffer;
579 unsigned long absize;
580 int ret;
581
582 absize = keylen + alignmask;
583 buffer = kmalloc(absize, GFP_ATOMIC);
584 if (!buffer)
585 return -ENOMEM;
586
587 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
588 memcpy(alignbuffer, key, keylen);
589 ret = cipher->setkey(tfm, alignbuffer, keylen);
590 kfree_sensitive(buffer);
591 return ret;
592 }
593
crypto_skcipher_setkey(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)594 int crypto_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
595 unsigned int keylen)
596 {
597 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
598 unsigned long alignmask = crypto_skcipher_alignmask(tfm);
599 int err;
600
601 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize)
602 return -EINVAL;
603
604 if ((unsigned long)key & alignmask)
605 err = skcipher_setkey_unaligned(tfm, key, keylen);
606 else
607 err = cipher->setkey(tfm, key, keylen);
608
609 if (unlikely(err)) {
610 skcipher_set_needkey(tfm);
611 return err;
612 }
613
614 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
615 return 0;
616 }
617 EXPORT_SYMBOL_GPL(crypto_skcipher_setkey);
618
crypto_skcipher_encrypt(struct skcipher_request * req)619 int crypto_skcipher_encrypt(struct skcipher_request *req)
620 {
621 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
622 struct crypto_alg *alg = tfm->base.__crt_alg;
623 unsigned int cryptlen = req->cryptlen;
624 int ret;
625
626 crypto_stats_get(alg);
627 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
628 ret = -ENOKEY;
629 else
630 ret = crypto_skcipher_alg(tfm)->encrypt(req);
631 crypto_stats_skcipher_encrypt(cryptlen, ret, alg);
632 return ret;
633 }
634 EXPORT_SYMBOL_GPL(crypto_skcipher_encrypt);
635
crypto_skcipher_decrypt(struct skcipher_request * req)636 int crypto_skcipher_decrypt(struct skcipher_request *req)
637 {
638 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
639 struct crypto_alg *alg = tfm->base.__crt_alg;
640 unsigned int cryptlen = req->cryptlen;
641 int ret;
642
643 crypto_stats_get(alg);
644 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
645 ret = -ENOKEY;
646 else
647 ret = crypto_skcipher_alg(tfm)->decrypt(req);
648 crypto_stats_skcipher_decrypt(cryptlen, ret, alg);
649 return ret;
650 }
651 EXPORT_SYMBOL_GPL(crypto_skcipher_decrypt);
652
crypto_skcipher_exit_tfm(struct crypto_tfm * tfm)653 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
654 {
655 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
656 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
657
658 alg->exit(skcipher);
659 }
660
crypto_skcipher_init_tfm(struct crypto_tfm * tfm)661 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
662 {
663 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
664 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
665
666 skcipher_set_needkey(skcipher);
667
668 if (alg->exit)
669 skcipher->base.exit = crypto_skcipher_exit_tfm;
670
671 if (alg->init)
672 return alg->init(skcipher);
673
674 return 0;
675 }
676
crypto_skcipher_free_instance(struct crypto_instance * inst)677 static void crypto_skcipher_free_instance(struct crypto_instance *inst)
678 {
679 struct skcipher_instance *skcipher =
680 container_of(inst, struct skcipher_instance, s.base);
681
682 skcipher->free(skcipher);
683 }
684
685 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
686 __maybe_unused;
crypto_skcipher_show(struct seq_file * m,struct crypto_alg * alg)687 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
688 {
689 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
690 base);
691
692 seq_printf(m, "type : skcipher\n");
693 seq_printf(m, "async : %s\n",
694 alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no");
695 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
696 seq_printf(m, "min keysize : %u\n", skcipher->min_keysize);
697 seq_printf(m, "max keysize : %u\n", skcipher->max_keysize);
698 seq_printf(m, "ivsize : %u\n", skcipher->ivsize);
699 seq_printf(m, "chunksize : %u\n", skcipher->chunksize);
700 seq_printf(m, "walksize : %u\n", skcipher->walksize);
701 }
702
703 #ifdef CONFIG_NET
crypto_skcipher_report(struct sk_buff * skb,struct crypto_alg * alg)704 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
705 {
706 struct crypto_report_blkcipher rblkcipher;
707 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
708 base);
709
710 memset(&rblkcipher, 0, sizeof(rblkcipher));
711
712 strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
713 strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
714
715 rblkcipher.blocksize = alg->cra_blocksize;
716 rblkcipher.min_keysize = skcipher->min_keysize;
717 rblkcipher.max_keysize = skcipher->max_keysize;
718 rblkcipher.ivsize = skcipher->ivsize;
719
720 return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
721 sizeof(rblkcipher), &rblkcipher);
722 }
723 #else
crypto_skcipher_report(struct sk_buff * skb,struct crypto_alg * alg)724 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
725 {
726 return -ENOSYS;
727 }
728 #endif
729
730 static const struct crypto_type crypto_skcipher_type = {
731 .extsize = crypto_alg_extsize,
732 .init_tfm = crypto_skcipher_init_tfm,
733 .free = crypto_skcipher_free_instance,
734 #ifdef CONFIG_PROC_FS
735 .show = crypto_skcipher_show,
736 #endif
737 .report = crypto_skcipher_report,
738 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
739 .maskset = CRYPTO_ALG_TYPE_MASK,
740 .type = CRYPTO_ALG_TYPE_SKCIPHER,
741 .tfmsize = offsetof(struct crypto_skcipher, base),
742 };
743
crypto_grab_skcipher(struct crypto_skcipher_spawn * spawn,struct crypto_instance * inst,const char * name,u32 type,u32 mask)744 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
745 struct crypto_instance *inst,
746 const char *name, u32 type, u32 mask)
747 {
748 spawn->base.frontend = &crypto_skcipher_type;
749 return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
750 }
751 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
752
crypto_alloc_skcipher(const char * alg_name,u32 type,u32 mask)753 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
754 u32 type, u32 mask)
755 {
756 return crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
757 }
758 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
759
crypto_alloc_sync_skcipher(const char * alg_name,u32 type,u32 mask)760 struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(
761 const char *alg_name, u32 type, u32 mask)
762 {
763 struct crypto_skcipher *tfm;
764
765 /* Only sync algorithms allowed. */
766 mask |= CRYPTO_ALG_ASYNC;
767
768 tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
769
770 /*
771 * Make sure we do not allocate something that might get used with
772 * an on-stack request: check the request size.
773 */
774 if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) >
775 MAX_SYNC_SKCIPHER_REQSIZE)) {
776 crypto_free_skcipher(tfm);
777 return ERR_PTR(-EINVAL);
778 }
779
780 return (struct crypto_sync_skcipher *)tfm;
781 }
782 EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher);
783
crypto_has_skcipher(const char * alg_name,u32 type,u32 mask)784 int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask)
785 {
786 return crypto_type_has_alg(alg_name, &crypto_skcipher_type, type, mask);
787 }
788 EXPORT_SYMBOL_GPL(crypto_has_skcipher);
789
skcipher_prepare_alg(struct skcipher_alg * alg)790 static int skcipher_prepare_alg(struct skcipher_alg *alg)
791 {
792 struct crypto_alg *base = &alg->base;
793
794 if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
795 alg->walksize > PAGE_SIZE / 8)
796 return -EINVAL;
797
798 if (!alg->chunksize)
799 alg->chunksize = base->cra_blocksize;
800 if (!alg->walksize)
801 alg->walksize = alg->chunksize;
802
803 base->cra_type = &crypto_skcipher_type;
804 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
805 base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
806
807 return 0;
808 }
809
crypto_register_skcipher(struct skcipher_alg * alg)810 int crypto_register_skcipher(struct skcipher_alg *alg)
811 {
812 struct crypto_alg *base = &alg->base;
813 int err;
814
815 err = skcipher_prepare_alg(alg);
816 if (err)
817 return err;
818
819 return crypto_register_alg(base);
820 }
821 EXPORT_SYMBOL_GPL(crypto_register_skcipher);
822
crypto_unregister_skcipher(struct skcipher_alg * alg)823 void crypto_unregister_skcipher(struct skcipher_alg *alg)
824 {
825 crypto_unregister_alg(&alg->base);
826 }
827 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
828
crypto_register_skciphers(struct skcipher_alg * algs,int count)829 int crypto_register_skciphers(struct skcipher_alg *algs, int count)
830 {
831 int i, ret;
832
833 for (i = 0; i < count; i++) {
834 ret = crypto_register_skcipher(&algs[i]);
835 if (ret)
836 goto err;
837 }
838
839 return 0;
840
841 err:
842 for (--i; i >= 0; --i)
843 crypto_unregister_skcipher(&algs[i]);
844
845 return ret;
846 }
847 EXPORT_SYMBOL_GPL(crypto_register_skciphers);
848
crypto_unregister_skciphers(struct skcipher_alg * algs,int count)849 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
850 {
851 int i;
852
853 for (i = count - 1; i >= 0; --i)
854 crypto_unregister_skcipher(&algs[i]);
855 }
856 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
857
skcipher_register_instance(struct crypto_template * tmpl,struct skcipher_instance * inst)858 int skcipher_register_instance(struct crypto_template *tmpl,
859 struct skcipher_instance *inst)
860 {
861 int err;
862
863 if (WARN_ON(!inst->free))
864 return -EINVAL;
865
866 err = skcipher_prepare_alg(&inst->alg);
867 if (err)
868 return err;
869
870 return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
871 }
872 EXPORT_SYMBOL_GPL(skcipher_register_instance);
873
skcipher_setkey_simple(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)874 static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key,
875 unsigned int keylen)
876 {
877 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
878
879 crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
880 crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) &
881 CRYPTO_TFM_REQ_MASK);
882 return crypto_cipher_setkey(cipher, key, keylen);
883 }
884
skcipher_init_tfm_simple(struct crypto_skcipher * tfm)885 static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm)
886 {
887 struct skcipher_instance *inst = skcipher_alg_instance(tfm);
888 struct crypto_cipher_spawn *spawn = skcipher_instance_ctx(inst);
889 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
890 struct crypto_cipher *cipher;
891
892 cipher = crypto_spawn_cipher(spawn);
893 if (IS_ERR(cipher))
894 return PTR_ERR(cipher);
895
896 ctx->cipher = cipher;
897 return 0;
898 }
899
skcipher_exit_tfm_simple(struct crypto_skcipher * tfm)900 static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm)
901 {
902 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
903
904 crypto_free_cipher(ctx->cipher);
905 }
906
skcipher_free_instance_simple(struct skcipher_instance * inst)907 static void skcipher_free_instance_simple(struct skcipher_instance *inst)
908 {
909 crypto_drop_cipher(skcipher_instance_ctx(inst));
910 kfree(inst);
911 }
912
913 /**
914 * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode
915 *
916 * Allocate an skcipher_instance for a simple block cipher mode of operation,
917 * e.g. cbc or ecb. The instance context will have just a single crypto_spawn,
918 * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize,
919 * alignmask, and priority are set from the underlying cipher but can be
920 * overridden if needed. The tfm context defaults to skcipher_ctx_simple, and
921 * default ->setkey(), ->init(), and ->exit() methods are installed.
922 *
923 * @tmpl: the template being instantiated
924 * @tb: the template parameters
925 *
926 * Return: a pointer to the new instance, or an ERR_PTR(). The caller still
927 * needs to register the instance.
928 */
skcipher_alloc_instance_simple(struct crypto_template * tmpl,struct rtattr ** tb)929 struct skcipher_instance *skcipher_alloc_instance_simple(
930 struct crypto_template *tmpl, struct rtattr **tb)
931 {
932 u32 mask;
933 struct skcipher_instance *inst;
934 struct crypto_cipher_spawn *spawn;
935 struct crypto_alg *cipher_alg;
936 int err;
937
938 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
939 if (err)
940 return ERR_PTR(err);
941
942 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
943 if (!inst)
944 return ERR_PTR(-ENOMEM);
945 spawn = skcipher_instance_ctx(inst);
946
947 err = crypto_grab_cipher(spawn, skcipher_crypto_instance(inst),
948 crypto_attr_alg_name(tb[1]), 0, mask);
949 if (err)
950 goto err_free_inst;
951 cipher_alg = crypto_spawn_cipher_alg(spawn);
952
953 err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name,
954 cipher_alg);
955 if (err)
956 goto err_free_inst;
957
958 inst->free = skcipher_free_instance_simple;
959
960 /* Default algorithm properties, can be overridden */
961 inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize;
962 inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask;
963 inst->alg.base.cra_priority = cipher_alg->cra_priority;
964 inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
965 inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
966 inst->alg.ivsize = cipher_alg->cra_blocksize;
967
968 /* Use skcipher_ctx_simple by default, can be overridden */
969 inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple);
970 inst->alg.setkey = skcipher_setkey_simple;
971 inst->alg.init = skcipher_init_tfm_simple;
972 inst->alg.exit = skcipher_exit_tfm_simple;
973
974 return inst;
975
976 err_free_inst:
977 skcipher_free_instance_simple(inst);
978 return ERR_PTR(err);
979 }
980 EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple);
981
982 MODULE_LICENSE("GPL");
983 MODULE_DESCRIPTION("Symmetric key cipher type");
984 MODULE_IMPORT_NS(CRYPTO_INTERNAL);
985