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/skcipher.h>
14 #include <crypto/scatterwalk.h>
15 #include <linux/bug.h>
16 #include <linux/cryptouser.h>
17 #include <linux/compiler.h>
18 #include <linux/list.h>
19 #include <linux/module.h>
20 #include <linux/rtnetlink.h>
21 #include <linux/seq_file.h>
22 #include <net/netlink.h>
23
24 #include "internal.h"
25
26 enum {
27 SKCIPHER_WALK_PHYS = 1 << 0,
28 SKCIPHER_WALK_SLOW = 1 << 1,
29 SKCIPHER_WALK_COPY = 1 << 2,
30 SKCIPHER_WALK_DIFF = 1 << 3,
31 SKCIPHER_WALK_SLEEP = 1 << 4,
32 };
33
34 struct skcipher_walk_buffer {
35 struct list_head entry;
36 struct scatter_walk dst;
37 unsigned int len;
38 u8 *data;
39 u8 buffer[];
40 };
41
42 static int skcipher_walk_next(struct skcipher_walk *walk);
43
skcipher_unmap(struct scatter_walk * walk,void * vaddr)44 static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr)
45 {
46 if (PageHighMem(scatterwalk_page(walk)))
47 kunmap_atomic(vaddr);
48 }
49
skcipher_map(struct scatter_walk * walk)50 static inline void *skcipher_map(struct scatter_walk *walk)
51 {
52 struct page *page = scatterwalk_page(walk);
53
54 return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) +
55 offset_in_page(walk->offset);
56 }
57
skcipher_map_src(struct skcipher_walk * walk)58 static inline void skcipher_map_src(struct skcipher_walk *walk)
59 {
60 walk->src.virt.addr = skcipher_map(&walk->in);
61 }
62
skcipher_map_dst(struct skcipher_walk * walk)63 static inline void skcipher_map_dst(struct skcipher_walk *walk)
64 {
65 walk->dst.virt.addr = skcipher_map(&walk->out);
66 }
67
skcipher_unmap_src(struct skcipher_walk * walk)68 static inline void skcipher_unmap_src(struct skcipher_walk *walk)
69 {
70 skcipher_unmap(&walk->in, walk->src.virt.addr);
71 }
72
skcipher_unmap_dst(struct skcipher_walk * walk)73 static inline void skcipher_unmap_dst(struct skcipher_walk *walk)
74 {
75 skcipher_unmap(&walk->out, walk->dst.virt.addr);
76 }
77
skcipher_walk_gfp(struct skcipher_walk * walk)78 static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk)
79 {
80 return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
81 }
82
83 /* Get a spot of the specified length that does not straddle a page.
84 * The caller needs to ensure that there is enough space for this operation.
85 */
skcipher_get_spot(u8 * start,unsigned int len)86 static inline u8 *skcipher_get_spot(u8 *start, unsigned int len)
87 {
88 u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
89
90 return max(start, end_page);
91 }
92
skcipher_done_slow(struct skcipher_walk * walk,unsigned int bsize)93 static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
94 {
95 u8 *addr;
96
97 addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
98 addr = skcipher_get_spot(addr, bsize);
99 scatterwalk_copychunks(addr, &walk->out, bsize,
100 (walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1);
101 return 0;
102 }
103
skcipher_walk_done(struct skcipher_walk * walk,int err)104 int skcipher_walk_done(struct skcipher_walk *walk, int err)
105 {
106 unsigned int n = walk->nbytes;
107 unsigned int nbytes = 0;
108
109 if (!n)
110 goto finish;
111
112 if (likely(err >= 0)) {
113 n -= err;
114 nbytes = walk->total - n;
115 }
116
117 if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
118 SKCIPHER_WALK_SLOW |
119 SKCIPHER_WALK_COPY |
120 SKCIPHER_WALK_DIFF)))) {
121 unmap_src:
122 skcipher_unmap_src(walk);
123 } else if (walk->flags & SKCIPHER_WALK_DIFF) {
124 skcipher_unmap_dst(walk);
125 goto unmap_src;
126 } else if (walk->flags & SKCIPHER_WALK_COPY) {
127 skcipher_map_dst(walk);
128 memcpy(walk->dst.virt.addr, walk->page, n);
129 skcipher_unmap_dst(walk);
130 } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
131 if (err > 0) {
132 /*
133 * Didn't process all bytes. Either the algorithm is
134 * broken, or this was the last step and it turned out
135 * the message wasn't evenly divisible into blocks but
136 * the algorithm requires it.
137 */
138 err = -EINVAL;
139 nbytes = 0;
140 } else
141 n = skcipher_done_slow(walk, n);
142 }
143
144 if (err > 0)
145 err = 0;
146
147 walk->total = nbytes;
148 walk->nbytes = 0;
149
150 scatterwalk_advance(&walk->in, n);
151 scatterwalk_advance(&walk->out, n);
152 scatterwalk_done(&walk->in, 0, nbytes);
153 scatterwalk_done(&walk->out, 1, nbytes);
154
155 if (nbytes) {
156 crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
157 CRYPTO_TFM_REQ_MAY_SLEEP : 0);
158 return skcipher_walk_next(walk);
159 }
160
161 finish:
162 /* Short-circuit for the common/fast path. */
163 if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
164 goto out;
165
166 if (walk->flags & SKCIPHER_WALK_PHYS)
167 goto out;
168
169 if (walk->iv != walk->oiv)
170 memcpy(walk->oiv, walk->iv, walk->ivsize);
171 if (walk->buffer != walk->page)
172 kfree(walk->buffer);
173 if (walk->page)
174 free_page((unsigned long)walk->page);
175
176 out:
177 return err;
178 }
179 EXPORT_SYMBOL_GPL(skcipher_walk_done);
180
skcipher_walk_complete(struct skcipher_walk * walk,int err)181 void skcipher_walk_complete(struct skcipher_walk *walk, int err)
182 {
183 struct skcipher_walk_buffer *p, *tmp;
184
185 list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
186 u8 *data;
187
188 if (err)
189 goto done;
190
191 data = p->data;
192 if (!data) {
193 data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1);
194 data = skcipher_get_spot(data, walk->stride);
195 }
196
197 scatterwalk_copychunks(data, &p->dst, p->len, 1);
198
199 if (offset_in_page(p->data) + p->len + walk->stride >
200 PAGE_SIZE)
201 free_page((unsigned long)p->data);
202
203 done:
204 list_del(&p->entry);
205 kfree(p);
206 }
207
208 if (!err && walk->iv != walk->oiv)
209 memcpy(walk->oiv, walk->iv, walk->ivsize);
210 if (walk->buffer != walk->page)
211 kfree(walk->buffer);
212 if (walk->page)
213 free_page((unsigned long)walk->page);
214 }
215 EXPORT_SYMBOL_GPL(skcipher_walk_complete);
216
skcipher_queue_write(struct skcipher_walk * walk,struct skcipher_walk_buffer * p)217 static void skcipher_queue_write(struct skcipher_walk *walk,
218 struct skcipher_walk_buffer *p)
219 {
220 p->dst = walk->out;
221 list_add_tail(&p->entry, &walk->buffers);
222 }
223
skcipher_next_slow(struct skcipher_walk * walk,unsigned int bsize)224 static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize)
225 {
226 bool phys = walk->flags & SKCIPHER_WALK_PHYS;
227 unsigned alignmask = walk->alignmask;
228 struct skcipher_walk_buffer *p;
229 unsigned a;
230 unsigned n;
231 u8 *buffer;
232 void *v;
233
234 if (!phys) {
235 if (!walk->buffer)
236 walk->buffer = walk->page;
237 buffer = walk->buffer;
238 if (buffer)
239 goto ok;
240 }
241
242 /* Start with the minimum alignment of kmalloc. */
243 a = crypto_tfm_ctx_alignment() - 1;
244 n = bsize;
245
246 if (phys) {
247 /* Calculate the minimum alignment of p->buffer. */
248 a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1;
249 n += sizeof(*p);
250 }
251
252 /* Minimum size to align p->buffer by alignmask. */
253 n += alignmask & ~a;
254
255 /* Minimum size to ensure p->buffer does not straddle a page. */
256 n += (bsize - 1) & ~(alignmask | a);
257
258 v = kzalloc(n, skcipher_walk_gfp(walk));
259 if (!v)
260 return skcipher_walk_done(walk, -ENOMEM);
261
262 if (phys) {
263 p = v;
264 p->len = bsize;
265 skcipher_queue_write(walk, p);
266 buffer = p->buffer;
267 } else {
268 walk->buffer = v;
269 buffer = v;
270 }
271
272 ok:
273 walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1);
274 walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize);
275 walk->src.virt.addr = walk->dst.virt.addr;
276
277 scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
278
279 walk->nbytes = bsize;
280 walk->flags |= SKCIPHER_WALK_SLOW;
281
282 return 0;
283 }
284
skcipher_next_copy(struct skcipher_walk * walk)285 static int skcipher_next_copy(struct skcipher_walk *walk)
286 {
287 struct skcipher_walk_buffer *p;
288 u8 *tmp = walk->page;
289
290 skcipher_map_src(walk);
291 memcpy(tmp, walk->src.virt.addr, walk->nbytes);
292 skcipher_unmap_src(walk);
293
294 walk->src.virt.addr = tmp;
295 walk->dst.virt.addr = tmp;
296
297 if (!(walk->flags & SKCIPHER_WALK_PHYS))
298 return 0;
299
300 p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk));
301 if (!p)
302 return -ENOMEM;
303
304 p->data = walk->page;
305 p->len = walk->nbytes;
306 skcipher_queue_write(walk, p);
307
308 if (offset_in_page(walk->page) + walk->nbytes + walk->stride >
309 PAGE_SIZE)
310 walk->page = NULL;
311 else
312 walk->page += walk->nbytes;
313
314 return 0;
315 }
316
skcipher_next_fast(struct skcipher_walk * walk)317 static int skcipher_next_fast(struct skcipher_walk *walk)
318 {
319 unsigned long diff;
320
321 walk->src.phys.page = scatterwalk_page(&walk->in);
322 walk->src.phys.offset = offset_in_page(walk->in.offset);
323 walk->dst.phys.page = scatterwalk_page(&walk->out);
324 walk->dst.phys.offset = offset_in_page(walk->out.offset);
325
326 if (walk->flags & SKCIPHER_WALK_PHYS)
327 return 0;
328
329 diff = walk->src.phys.offset - walk->dst.phys.offset;
330 diff |= walk->src.virt.page - walk->dst.virt.page;
331
332 skcipher_map_src(walk);
333 walk->dst.virt.addr = walk->src.virt.addr;
334
335 if (diff) {
336 walk->flags |= SKCIPHER_WALK_DIFF;
337 skcipher_map_dst(walk);
338 }
339
340 return 0;
341 }
342
skcipher_walk_next(struct skcipher_walk * walk)343 static int skcipher_walk_next(struct skcipher_walk *walk)
344 {
345 unsigned int bsize;
346 unsigned int n;
347 int err;
348
349 walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY |
350 SKCIPHER_WALK_DIFF);
351
352 n = walk->total;
353 bsize = min(walk->stride, max(n, walk->blocksize));
354 n = scatterwalk_clamp(&walk->in, n);
355 n = scatterwalk_clamp(&walk->out, n);
356
357 if (unlikely(n < bsize)) {
358 if (unlikely(walk->total < walk->blocksize))
359 return skcipher_walk_done(walk, -EINVAL);
360
361 slow_path:
362 err = skcipher_next_slow(walk, bsize);
363 goto set_phys_lowmem;
364 }
365
366 if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) {
367 if (!walk->page) {
368 gfp_t gfp = skcipher_walk_gfp(walk);
369
370 walk->page = (void *)__get_free_page(gfp);
371 if (!walk->page)
372 goto slow_path;
373 }
374
375 walk->nbytes = min_t(unsigned, n,
376 PAGE_SIZE - offset_in_page(walk->page));
377 walk->flags |= SKCIPHER_WALK_COPY;
378 err = skcipher_next_copy(walk);
379 goto set_phys_lowmem;
380 }
381
382 walk->nbytes = n;
383
384 return skcipher_next_fast(walk);
385
386 set_phys_lowmem:
387 if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) {
388 walk->src.phys.page = virt_to_page(walk->src.virt.addr);
389 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
390 walk->src.phys.offset &= PAGE_SIZE - 1;
391 walk->dst.phys.offset &= PAGE_SIZE - 1;
392 }
393 return err;
394 }
395
skcipher_copy_iv(struct skcipher_walk * walk)396 static int skcipher_copy_iv(struct skcipher_walk *walk)
397 {
398 unsigned a = crypto_tfm_ctx_alignment() - 1;
399 unsigned alignmask = walk->alignmask;
400 unsigned ivsize = walk->ivsize;
401 unsigned bs = walk->stride;
402 unsigned aligned_bs;
403 unsigned size;
404 u8 *iv;
405
406 aligned_bs = ALIGN(bs, alignmask + 1);
407
408 /* Minimum size to align buffer by alignmask. */
409 size = alignmask & ~a;
410
411 if (walk->flags & SKCIPHER_WALK_PHYS)
412 size += ivsize;
413 else {
414 size += aligned_bs + ivsize;
415
416 /* Minimum size to ensure buffer does not straddle a page. */
417 size += (bs - 1) & ~(alignmask | a);
418 }
419
420 walk->buffer = kmalloc(size, skcipher_walk_gfp(walk));
421 if (!walk->buffer)
422 return -ENOMEM;
423
424 iv = PTR_ALIGN(walk->buffer, alignmask + 1);
425 iv = skcipher_get_spot(iv, bs) + aligned_bs;
426
427 walk->iv = memcpy(iv, walk->iv, walk->ivsize);
428 return 0;
429 }
430
skcipher_walk_first(struct skcipher_walk * walk)431 static int skcipher_walk_first(struct skcipher_walk *walk)
432 {
433 if (WARN_ON_ONCE(in_irq()))
434 return -EDEADLK;
435
436 walk->buffer = NULL;
437 if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
438 int err = skcipher_copy_iv(walk);
439 if (err)
440 return err;
441 }
442
443 walk->page = NULL;
444
445 return skcipher_walk_next(walk);
446 }
447
skcipher_walk_skcipher(struct skcipher_walk * walk,struct skcipher_request * req)448 static int skcipher_walk_skcipher(struct skcipher_walk *walk,
449 struct skcipher_request *req)
450 {
451 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
452
453 walk->total = req->cryptlen;
454 walk->nbytes = 0;
455 walk->iv = req->iv;
456 walk->oiv = req->iv;
457
458 if (unlikely(!walk->total))
459 return 0;
460
461 scatterwalk_start(&walk->in, req->src);
462 scatterwalk_start(&walk->out, req->dst);
463
464 walk->flags &= ~SKCIPHER_WALK_SLEEP;
465 walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
466 SKCIPHER_WALK_SLEEP : 0;
467
468 walk->blocksize = crypto_skcipher_blocksize(tfm);
469 walk->stride = crypto_skcipher_walksize(tfm);
470 walk->ivsize = crypto_skcipher_ivsize(tfm);
471 walk->alignmask = crypto_skcipher_alignmask(tfm);
472
473 return skcipher_walk_first(walk);
474 }
475
skcipher_walk_virt(struct skcipher_walk * walk,struct skcipher_request * req,bool atomic)476 int skcipher_walk_virt(struct skcipher_walk *walk,
477 struct skcipher_request *req, bool atomic)
478 {
479 int err;
480
481 might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
482
483 walk->flags &= ~SKCIPHER_WALK_PHYS;
484
485 err = skcipher_walk_skcipher(walk, req);
486
487 walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0;
488
489 return err;
490 }
491 EXPORT_SYMBOL_GPL(skcipher_walk_virt);
492
skcipher_walk_atomise(struct skcipher_walk * walk)493 void skcipher_walk_atomise(struct skcipher_walk *walk)
494 {
495 walk->flags &= ~SKCIPHER_WALK_SLEEP;
496 }
497 EXPORT_SYMBOL_GPL(skcipher_walk_atomise);
498
skcipher_walk_async(struct skcipher_walk * walk,struct skcipher_request * req)499 int skcipher_walk_async(struct skcipher_walk *walk,
500 struct skcipher_request *req)
501 {
502 walk->flags |= SKCIPHER_WALK_PHYS;
503
504 INIT_LIST_HEAD(&walk->buffers);
505
506 return skcipher_walk_skcipher(walk, req);
507 }
508 EXPORT_SYMBOL_GPL(skcipher_walk_async);
509
skcipher_walk_aead_common(struct skcipher_walk * walk,struct aead_request * req,bool atomic)510 static int skcipher_walk_aead_common(struct skcipher_walk *walk,
511 struct aead_request *req, bool atomic)
512 {
513 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
514 int err;
515
516 walk->nbytes = 0;
517 walk->iv = req->iv;
518 walk->oiv = req->iv;
519
520 if (unlikely(!walk->total))
521 return 0;
522
523 walk->flags &= ~SKCIPHER_WALK_PHYS;
524
525 scatterwalk_start(&walk->in, req->src);
526 scatterwalk_start(&walk->out, req->dst);
527
528 scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
529 scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);
530
531 scatterwalk_done(&walk->in, 0, walk->total);
532 scatterwalk_done(&walk->out, 0, walk->total);
533
534 if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
535 walk->flags |= SKCIPHER_WALK_SLEEP;
536 else
537 walk->flags &= ~SKCIPHER_WALK_SLEEP;
538
539 walk->blocksize = crypto_aead_blocksize(tfm);
540 walk->stride = crypto_aead_chunksize(tfm);
541 walk->ivsize = crypto_aead_ivsize(tfm);
542 walk->alignmask = crypto_aead_alignmask(tfm);
543
544 err = skcipher_walk_first(walk);
545
546 if (atomic)
547 walk->flags &= ~SKCIPHER_WALK_SLEEP;
548
549 return err;
550 }
551
skcipher_walk_aead_encrypt(struct skcipher_walk * walk,struct aead_request * req,bool atomic)552 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
553 struct aead_request *req, bool atomic)
554 {
555 walk->total = req->cryptlen;
556
557 return skcipher_walk_aead_common(walk, req, atomic);
558 }
559 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);
560
skcipher_walk_aead_decrypt(struct skcipher_walk * walk,struct aead_request * req,bool atomic)561 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
562 struct aead_request *req, bool atomic)
563 {
564 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
565
566 walk->total = req->cryptlen - crypto_aead_authsize(tfm);
567
568 return skcipher_walk_aead_common(walk, req, atomic);
569 }
570 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);
571
skcipher_set_needkey(struct crypto_skcipher * tfm)572 static void skcipher_set_needkey(struct crypto_skcipher *tfm)
573 {
574 if (crypto_skcipher_max_keysize(tfm) != 0)
575 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
576 }
577
skcipher_setkey_unaligned(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)578 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
579 const u8 *key, unsigned int keylen)
580 {
581 unsigned long alignmask = crypto_skcipher_alignmask(tfm);
582 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
583 u8 *buffer, *alignbuffer;
584 unsigned long absize;
585 int ret;
586
587 absize = keylen + alignmask;
588 buffer = kmalloc(absize, GFP_ATOMIC);
589 if (!buffer)
590 return -ENOMEM;
591
592 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
593 memcpy(alignbuffer, key, keylen);
594 ret = cipher->setkey(tfm, alignbuffer, keylen);
595 kfree_sensitive(buffer);
596 return ret;
597 }
598
crypto_skcipher_setkey(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)599 int crypto_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
600 unsigned int keylen)
601 {
602 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
603 unsigned long alignmask = crypto_skcipher_alignmask(tfm);
604 int err;
605
606 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize)
607 return -EINVAL;
608
609 if ((unsigned long)key & alignmask)
610 err = skcipher_setkey_unaligned(tfm, key, keylen);
611 else
612 err = cipher->setkey(tfm, key, keylen);
613
614 if (unlikely(err)) {
615 skcipher_set_needkey(tfm);
616 return err;
617 }
618
619 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
620 return 0;
621 }
622 EXPORT_SYMBOL_GPL(crypto_skcipher_setkey);
623
crypto_skcipher_encrypt(struct skcipher_request * req)624 int crypto_skcipher_encrypt(struct skcipher_request *req)
625 {
626 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
627 struct crypto_alg *alg = tfm->base.__crt_alg;
628 unsigned int cryptlen = req->cryptlen;
629 int ret;
630
631 crypto_stats_get(alg);
632 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
633 ret = -ENOKEY;
634 else
635 ret = crypto_skcipher_alg(tfm)->encrypt(req);
636 crypto_stats_skcipher_encrypt(cryptlen, ret, alg);
637 return ret;
638 }
639 EXPORT_SYMBOL_GPL(crypto_skcipher_encrypt);
640
crypto_skcipher_decrypt(struct skcipher_request * req)641 int crypto_skcipher_decrypt(struct skcipher_request *req)
642 {
643 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
644 struct crypto_alg *alg = tfm->base.__crt_alg;
645 unsigned int cryptlen = req->cryptlen;
646 int ret;
647
648 crypto_stats_get(alg);
649 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
650 ret = -ENOKEY;
651 else
652 ret = crypto_skcipher_alg(tfm)->decrypt(req);
653 crypto_stats_skcipher_decrypt(cryptlen, ret, alg);
654 return ret;
655 }
656 EXPORT_SYMBOL_GPL(crypto_skcipher_decrypt);
657
crypto_skcipher_exit_tfm(struct crypto_tfm * tfm)658 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
659 {
660 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
661 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
662
663 alg->exit(skcipher);
664 }
665
crypto_skcipher_init_tfm(struct crypto_tfm * tfm)666 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
667 {
668 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
669 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
670
671 skcipher_set_needkey(skcipher);
672
673 if (alg->exit)
674 skcipher->base.exit = crypto_skcipher_exit_tfm;
675
676 if (alg->init)
677 return alg->init(skcipher);
678
679 return 0;
680 }
681
crypto_skcipher_free_instance(struct crypto_instance * inst)682 static void crypto_skcipher_free_instance(struct crypto_instance *inst)
683 {
684 struct skcipher_instance *skcipher =
685 container_of(inst, struct skcipher_instance, s.base);
686
687 skcipher->free(skcipher);
688 }
689
690 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
691 __maybe_unused;
crypto_skcipher_show(struct seq_file * m,struct crypto_alg * alg)692 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
693 {
694 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
695 base);
696
697 seq_printf(m, "type : skcipher\n");
698 seq_printf(m, "async : %s\n",
699 alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no");
700 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
701 seq_printf(m, "min keysize : %u\n", skcipher->min_keysize);
702 seq_printf(m, "max keysize : %u\n", skcipher->max_keysize);
703 seq_printf(m, "ivsize : %u\n", skcipher->ivsize);
704 seq_printf(m, "chunksize : %u\n", skcipher->chunksize);
705 seq_printf(m, "walksize : %u\n", skcipher->walksize);
706 }
707
708 #ifdef CONFIG_NET
crypto_skcipher_report(struct sk_buff * skb,struct crypto_alg * alg)709 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
710 {
711 struct crypto_report_blkcipher rblkcipher;
712 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
713 base);
714
715 memset(&rblkcipher, 0, sizeof(rblkcipher));
716
717 strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
718 strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
719
720 rblkcipher.blocksize = alg->cra_blocksize;
721 rblkcipher.min_keysize = skcipher->min_keysize;
722 rblkcipher.max_keysize = skcipher->max_keysize;
723 rblkcipher.ivsize = skcipher->ivsize;
724
725 return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
726 sizeof(rblkcipher), &rblkcipher);
727 }
728 #else
crypto_skcipher_report(struct sk_buff * skb,struct crypto_alg * alg)729 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
730 {
731 return -ENOSYS;
732 }
733 #endif
734
735 static const struct crypto_type crypto_skcipher_type = {
736 .extsize = crypto_alg_extsize,
737 .init_tfm = crypto_skcipher_init_tfm,
738 .free = crypto_skcipher_free_instance,
739 #ifdef CONFIG_PROC_FS
740 .show = crypto_skcipher_show,
741 #endif
742 .report = crypto_skcipher_report,
743 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
744 .maskset = CRYPTO_ALG_TYPE_MASK,
745 .type = CRYPTO_ALG_TYPE_SKCIPHER,
746 .tfmsize = offsetof(struct crypto_skcipher, base),
747 };
748
crypto_grab_skcipher(struct crypto_skcipher_spawn * spawn,struct crypto_instance * inst,const char * name,u32 type,u32 mask)749 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
750 struct crypto_instance *inst,
751 const char *name, u32 type, u32 mask)
752 {
753 spawn->base.frontend = &crypto_skcipher_type;
754 return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
755 }
756 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
757
crypto_alloc_skcipher(const char * alg_name,u32 type,u32 mask)758 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
759 u32 type, u32 mask)
760 {
761 return crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
762 }
763 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
764
crypto_alloc_sync_skcipher(const char * alg_name,u32 type,u32 mask)765 struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(
766 const char *alg_name, u32 type, u32 mask)
767 {
768 struct crypto_skcipher *tfm;
769
770 /* Only sync algorithms allowed. */
771 mask |= CRYPTO_ALG_ASYNC;
772
773 tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
774
775 /*
776 * Make sure we do not allocate something that might get used with
777 * an on-stack request: check the request size.
778 */
779 if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) >
780 MAX_SYNC_SKCIPHER_REQSIZE)) {
781 crypto_free_skcipher(tfm);
782 return ERR_PTR(-EINVAL);
783 }
784
785 return (struct crypto_sync_skcipher *)tfm;
786 }
787 EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher);
788
crypto_has_skcipher(const char * alg_name,u32 type,u32 mask)789 int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask)
790 {
791 return crypto_type_has_alg(alg_name, &crypto_skcipher_type, type, mask);
792 }
793 EXPORT_SYMBOL_GPL(crypto_has_skcipher);
794
skcipher_prepare_alg(struct skcipher_alg * alg)795 static int skcipher_prepare_alg(struct skcipher_alg *alg)
796 {
797 struct crypto_alg *base = &alg->base;
798
799 if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
800 alg->walksize > PAGE_SIZE / 8)
801 return -EINVAL;
802
803 if (!alg->chunksize)
804 alg->chunksize = base->cra_blocksize;
805 if (!alg->walksize)
806 alg->walksize = alg->chunksize;
807
808 base->cra_type = &crypto_skcipher_type;
809 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
810 base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
811
812 return 0;
813 }
814
crypto_register_skcipher(struct skcipher_alg * alg)815 int crypto_register_skcipher(struct skcipher_alg *alg)
816 {
817 struct crypto_alg *base = &alg->base;
818 int err;
819
820 err = skcipher_prepare_alg(alg);
821 if (err)
822 return err;
823
824 return crypto_register_alg(base);
825 }
826 EXPORT_SYMBOL_GPL(crypto_register_skcipher);
827
crypto_unregister_skcipher(struct skcipher_alg * alg)828 void crypto_unregister_skcipher(struct skcipher_alg *alg)
829 {
830 crypto_unregister_alg(&alg->base);
831 }
832 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
833
crypto_register_skciphers(struct skcipher_alg * algs,int count)834 int crypto_register_skciphers(struct skcipher_alg *algs, int count)
835 {
836 int i, ret;
837
838 for (i = 0; i < count; i++) {
839 ret = crypto_register_skcipher(&algs[i]);
840 if (ret)
841 goto err;
842 }
843
844 return 0;
845
846 err:
847 for (--i; i >= 0; --i)
848 crypto_unregister_skcipher(&algs[i]);
849
850 return ret;
851 }
852 EXPORT_SYMBOL_GPL(crypto_register_skciphers);
853
crypto_unregister_skciphers(struct skcipher_alg * algs,int count)854 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
855 {
856 int i;
857
858 for (i = count - 1; i >= 0; --i)
859 crypto_unregister_skcipher(&algs[i]);
860 }
861 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
862
skcipher_register_instance(struct crypto_template * tmpl,struct skcipher_instance * inst)863 int skcipher_register_instance(struct crypto_template *tmpl,
864 struct skcipher_instance *inst)
865 {
866 int err;
867
868 if (WARN_ON(!inst->free))
869 return -EINVAL;
870
871 err = skcipher_prepare_alg(&inst->alg);
872 if (err)
873 return err;
874
875 return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
876 }
877 EXPORT_SYMBOL_GPL(skcipher_register_instance);
878
skcipher_setkey_simple(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)879 static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key,
880 unsigned int keylen)
881 {
882 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
883
884 crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
885 crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) &
886 CRYPTO_TFM_REQ_MASK);
887 return crypto_cipher_setkey(cipher, key, keylen);
888 }
889
skcipher_init_tfm_simple(struct crypto_skcipher * tfm)890 static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm)
891 {
892 struct skcipher_instance *inst = skcipher_alg_instance(tfm);
893 struct crypto_cipher_spawn *spawn = skcipher_instance_ctx(inst);
894 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
895 struct crypto_cipher *cipher;
896
897 cipher = crypto_spawn_cipher(spawn);
898 if (IS_ERR(cipher))
899 return PTR_ERR(cipher);
900
901 ctx->cipher = cipher;
902 return 0;
903 }
904
skcipher_exit_tfm_simple(struct crypto_skcipher * tfm)905 static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm)
906 {
907 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
908
909 crypto_free_cipher(ctx->cipher);
910 }
911
skcipher_free_instance_simple(struct skcipher_instance * inst)912 static void skcipher_free_instance_simple(struct skcipher_instance *inst)
913 {
914 crypto_drop_cipher(skcipher_instance_ctx(inst));
915 kfree(inst);
916 }
917
918 /**
919 * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode
920 *
921 * Allocate an skcipher_instance for a simple block cipher mode of operation,
922 * e.g. cbc or ecb. The instance context will have just a single crypto_spawn,
923 * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize,
924 * alignmask, and priority are set from the underlying cipher but can be
925 * overridden if needed. The tfm context defaults to skcipher_ctx_simple, and
926 * default ->setkey(), ->init(), and ->exit() methods are installed.
927 *
928 * @tmpl: the template being instantiated
929 * @tb: the template parameters
930 *
931 * Return: a pointer to the new instance, or an ERR_PTR(). The caller still
932 * needs to register the instance.
933 */
skcipher_alloc_instance_simple(struct crypto_template * tmpl,struct rtattr ** tb)934 struct skcipher_instance *skcipher_alloc_instance_simple(
935 struct crypto_template *tmpl, struct rtattr **tb)
936 {
937 u32 mask;
938 struct skcipher_instance *inst;
939 struct crypto_cipher_spawn *spawn;
940 struct crypto_alg *cipher_alg;
941 int err;
942
943 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
944 if (err)
945 return ERR_PTR(err);
946
947 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
948 if (!inst)
949 return ERR_PTR(-ENOMEM);
950 spawn = skcipher_instance_ctx(inst);
951
952 err = crypto_grab_cipher(spawn, skcipher_crypto_instance(inst),
953 crypto_attr_alg_name(tb[1]), 0, mask);
954 if (err)
955 goto err_free_inst;
956 cipher_alg = crypto_spawn_cipher_alg(spawn);
957
958 err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name,
959 cipher_alg);
960 if (err)
961 goto err_free_inst;
962
963 inst->free = skcipher_free_instance_simple;
964
965 /* Default algorithm properties, can be overridden */
966 inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize;
967 inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask;
968 inst->alg.base.cra_priority = cipher_alg->cra_priority;
969 inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
970 inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
971 inst->alg.ivsize = cipher_alg->cra_blocksize;
972
973 /* Use skcipher_ctx_simple by default, can be overridden */
974 inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple);
975 inst->alg.setkey = skcipher_setkey_simple;
976 inst->alg.init = skcipher_init_tfm_simple;
977 inst->alg.exit = skcipher_exit_tfm_simple;
978
979 return inst;
980
981 err_free_inst:
982 skcipher_free_instance_simple(inst);
983 return ERR_PTR(err);
984 }
985 EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple);
986
987 MODULE_LICENSE("GPL");
988 MODULE_DESCRIPTION("Symmetric key cipher type");
989
