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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 <[email protected]>
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/err.h>
19#include <linux/kernel.h>
20#include <linux/mm.h>
21#include <linux/module.h>
22#include <linux/seq_file.h>
23#include <linux/slab.h>
24#include <linux/string.h>
25#include <linux/string_choices.h>
26#include <net/netlink.h>
27#include "skcipher.h"
28
29#define CRYPTO_ALG_TYPE_SKCIPHER_MASK 0x0000000e
30
31enum {
32 SKCIPHER_WALK_SLOW = 1 << 0,
33 SKCIPHER_WALK_COPY = 1 << 1,
34 SKCIPHER_WALK_DIFF = 1 << 2,
35 SKCIPHER_WALK_SLEEP = 1 << 3,
36};
37
38static const struct crypto_type crypto_skcipher_type;
39
40static int skcipher_walk_next(struct skcipher_walk *walk);
41
42static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk)
43{
44 return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
45}
46
47static inline struct skcipher_alg *__crypto_skcipher_alg(
48 struct crypto_alg *alg)
49{
50 return container_of(alg, struct skcipher_alg, base);
51}
52
53/**
54 * skcipher_walk_done() - finish one step of a skcipher_walk
55 * @walk: the skcipher_walk
56 * @res: number of bytes *not* processed (>= 0) from walk->nbytes,
57 * or a -errno value to terminate the walk due to an error
58 *
59 * This function cleans up after one step of walking through the source and
60 * destination scatterlists, and advances to the next step if applicable.
61 * walk->nbytes is set to the number of bytes available in the next step,
62 * walk->total is set to the new total number of bytes remaining, and
63 * walk->{src,dst}.virt.addr is set to the next pair of data pointers. If there
64 * is no more data, or if an error occurred (i.e. -errno return), then
65 * walk->nbytes and walk->total are set to 0 and all resources owned by the
66 * skcipher_walk are freed.
67 *
68 * Return: 0 or a -errno value. If @res was a -errno value then it will be
69 * returned, but other errors may occur too.
70 */
71int skcipher_walk_done(struct skcipher_walk *walk, int res)
72{
73 unsigned int n = walk->nbytes; /* num bytes processed this step */
74 unsigned int total = 0; /* new total remaining */
75
76 if (!n)
77 goto finish;
78
79 if (likely(res >= 0)) {
80 n -= res; /* subtract num bytes *not* processed */
81 total = walk->total - n;
82 }
83
84 if (likely(!(walk->flags & (SKCIPHER_WALK_SLOW |
85 SKCIPHER_WALK_COPY |
86 SKCIPHER_WALK_DIFF)))) {
87 scatterwalk_advance(&walk->in, n);
88 } else if (walk->flags & SKCIPHER_WALK_DIFF) {
89 scatterwalk_done_src(&walk->in, n);
90 } else if (walk->flags & SKCIPHER_WALK_COPY) {
91 scatterwalk_advance(&walk->in, n);
92 scatterwalk_map(&walk->out);
93 memcpy(walk->out.addr, walk->page, n);
94 } else { /* SKCIPHER_WALK_SLOW */
95 if (res > 0) {
96 /*
97 * Didn't process all bytes. Either the algorithm is
98 * broken, or this was the last step and it turned out
99 * the message wasn't evenly divisible into blocks but
100 * the algorithm requires it.
101 */
102 res = -EINVAL;
103 total = 0;
104 } else
105 memcpy_to_scatterwalk(&walk->out, walk->out.addr, n);
106 goto dst_done;
107 }
108
109 scatterwalk_done_dst(&walk->out, n);
110dst_done:
111
112 if (res > 0)
113 res = 0;
114
115 walk->total = total;
116 walk->nbytes = 0;
117
118 if (total) {
119 if (walk->flags & SKCIPHER_WALK_SLEEP)
120 cond_resched();
121 walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY |
122 SKCIPHER_WALK_DIFF);
123 return skcipher_walk_next(walk);
124 }
125
126finish:
127 /* Short-circuit for the common/fast path. */
128 if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
129 goto out;
130
131 if (walk->iv != walk->oiv)
132 memcpy(walk->oiv, walk->iv, walk->ivsize);
133 if (walk->buffer != walk->page)
134 kfree(walk->buffer);
135 if (walk->page)
136 free_page((unsigned long)walk->page);
137
138out:
139 return res;
140}
141EXPORT_SYMBOL_GPL(skcipher_walk_done);
142
143static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize)
144{
145 unsigned alignmask = walk->alignmask;
146 unsigned n;
147 void *buffer;
148
149 if (!walk->buffer)
150 walk->buffer = walk->page;
151 buffer = walk->buffer;
152 if (!buffer) {
153 /* Min size for a buffer of bsize bytes aligned to alignmask */
154 n = bsize + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
155
156 buffer = kzalloc(n, skcipher_walk_gfp(walk));
157 if (!buffer)
158 return skcipher_walk_done(walk, -ENOMEM);
159 walk->buffer = buffer;
160 }
161
162 buffer = PTR_ALIGN(buffer, alignmask + 1);
163 memcpy_from_scatterwalk(buffer, &walk->in, bsize);
164 walk->out.__addr = buffer;
165 walk->in.__addr = walk->out.addr;
166
167 walk->nbytes = bsize;
168 walk->flags |= SKCIPHER_WALK_SLOW;
169
170 return 0;
171}
172
173static int skcipher_next_copy(struct skcipher_walk *walk)
174{
175 void *tmp = walk->page;
176
177 scatterwalk_map(&walk->in);
178 memcpy(tmp, walk->in.addr, walk->nbytes);
179 scatterwalk_unmap(&walk->in);
180 /*
181 * walk->in is advanced later when the number of bytes actually
182 * processed (which might be less than walk->nbytes) is known.
183 */
184
185 walk->in.__addr = tmp;
186 walk->out.__addr = tmp;
187 return 0;
188}
189
190static int skcipher_next_fast(struct skcipher_walk *walk)
191{
192 unsigned long diff;
193
194 diff = offset_in_page(walk->in.offset) -
195 offset_in_page(walk->out.offset);
196 diff |= (u8 *)(sg_page(walk->in.sg) + (walk->in.offset >> PAGE_SHIFT)) -
197 (u8 *)(sg_page(walk->out.sg) + (walk->out.offset >> PAGE_SHIFT));
198
199 scatterwalk_map(&walk->out);
200 walk->in.__addr = walk->out.__addr;
201
202 if (diff) {
203 walk->flags |= SKCIPHER_WALK_DIFF;
204 scatterwalk_map(&walk->in);
205 }
206
207 return 0;
208}
209
210static int skcipher_walk_next(struct skcipher_walk *walk)
211{
212 unsigned int bsize;
213 unsigned int n;
214
215 n = walk->total;
216 bsize = min(walk->stride, max(n, walk->blocksize));
217 n = scatterwalk_clamp(&walk->in, n);
218 n = scatterwalk_clamp(&walk->out, n);
219
220 if (unlikely(n < bsize)) {
221 if (unlikely(walk->total < walk->blocksize))
222 return skcipher_walk_done(walk, -EINVAL);
223
224slow_path:
225 return skcipher_next_slow(walk, bsize);
226 }
227 walk->nbytes = n;
228
229 if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) {
230 if (!walk->page) {
231 gfp_t gfp = skcipher_walk_gfp(walk);
232
233 walk->page = (void *)__get_free_page(gfp);
234 if (!walk->page)
235 goto slow_path;
236 }
237 walk->flags |= SKCIPHER_WALK_COPY;
238 return skcipher_next_copy(walk);
239 }
240
241 return skcipher_next_fast(walk);
242}
243
244static int skcipher_copy_iv(struct skcipher_walk *walk)
245{
246 unsigned alignmask = walk->alignmask;
247 unsigned ivsize = walk->ivsize;
248 unsigned aligned_stride = ALIGN(walk->stride, alignmask + 1);
249 unsigned size;
250 u8 *iv;
251
252 /* Min size for a buffer of stride + ivsize, aligned to alignmask */
253 size = aligned_stride + ivsize +
254 (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
255
256 walk->buffer = kmalloc(size, skcipher_walk_gfp(walk));
257 if (!walk->buffer)
258 return -ENOMEM;
259
260 iv = PTR_ALIGN(walk->buffer, alignmask + 1) + aligned_stride;
261
262 walk->iv = memcpy(iv, walk->iv, walk->ivsize);
263 return 0;
264}
265
266static int skcipher_walk_first(struct skcipher_walk *walk)
267{
268 if (WARN_ON_ONCE(in_hardirq()))
269 return -EDEADLK;
270
271 walk->buffer = NULL;
272 if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
273 int err = skcipher_copy_iv(walk);
274 if (err)
275 return err;
276 }
277
278 walk->page = NULL;
279
280 return skcipher_walk_next(walk);
281}
282
283int skcipher_walk_virt(struct skcipher_walk *__restrict walk,
284 struct skcipher_request *__restrict req, bool atomic)
285{
286 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
287 struct skcipher_alg *alg;
288
289 might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
290
291 alg = crypto_skcipher_alg(tfm);
292
293 walk->total = req->cryptlen;
294 walk->nbytes = 0;
295 walk->iv = req->iv;
296 walk->oiv = req->iv;
297 if ((req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) && !atomic)
298 walk->flags = SKCIPHER_WALK_SLEEP;
299 else
300 walk->flags = 0;
301
302 if (unlikely(!walk->total))
303 return 0;
304
305 scatterwalk_start(&walk->in, req->src);
306 scatterwalk_start(&walk->out, req->dst);
307
308 walk->blocksize = crypto_skcipher_blocksize(tfm);
309 walk->ivsize = crypto_skcipher_ivsize(tfm);
310 walk->alignmask = crypto_skcipher_alignmask(tfm);
311
312 if (alg->co.base.cra_type != &crypto_skcipher_type)
313 walk->stride = alg->co.chunksize;
314 else
315 walk->stride = alg->walksize;
316
317 return skcipher_walk_first(walk);
318}
319EXPORT_SYMBOL_GPL(skcipher_walk_virt);
320
321static int skcipher_walk_aead_common(struct skcipher_walk *__restrict walk,
322 struct aead_request *__restrict req,
323 bool atomic)
324{
325 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
326
327 walk->nbytes = 0;
328 walk->iv = req->iv;
329 walk->oiv = req->iv;
330 if ((req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) && !atomic)
331 walk->flags = SKCIPHER_WALK_SLEEP;
332 else
333 walk->flags = 0;
334
335 if (unlikely(!walk->total))
336 return 0;
337
338 scatterwalk_start_at_pos(&walk->in, req->src, req->assoclen);
339 scatterwalk_start_at_pos(&walk->out, req->dst, req->assoclen);
340
341 walk->blocksize = crypto_aead_blocksize(tfm);
342 walk->stride = crypto_aead_chunksize(tfm);
343 walk->ivsize = crypto_aead_ivsize(tfm);
344 walk->alignmask = crypto_aead_alignmask(tfm);
345
346 return skcipher_walk_first(walk);
347}
348
349int skcipher_walk_aead_encrypt(struct skcipher_walk *__restrict walk,
350 struct aead_request *__restrict req,
351 bool atomic)
352{
353 walk->total = req->cryptlen;
354
355 return skcipher_walk_aead_common(walk, req, atomic);
356}
357EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);
358
359int skcipher_walk_aead_decrypt(struct skcipher_walk *__restrict walk,
360 struct aead_request *__restrict req,
361 bool atomic)
362{
363 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
364
365 walk->total = req->cryptlen - crypto_aead_authsize(tfm);
366
367 return skcipher_walk_aead_common(walk, req, atomic);
368}
369EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);
370
371static void skcipher_set_needkey(struct crypto_skcipher *tfm)
372{
373 if (crypto_skcipher_max_keysize(tfm) != 0)
374 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
375}
376
377static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
378 const u8 *key, unsigned int keylen)
379{
380 unsigned long alignmask = crypto_skcipher_alignmask(tfm);
381 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
382 u8 *buffer, *alignbuffer;
383 unsigned long absize;
384 int ret;
385
386 absize = keylen + alignmask;
387 buffer = kmalloc(absize, GFP_ATOMIC);
388 if (!buffer)
389 return -ENOMEM;
390
391 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
392 memcpy(alignbuffer, key, keylen);
393 ret = cipher->setkey(tfm, alignbuffer, keylen);
394 kfree_sensitive(buffer);
395 return ret;
396}
397
398int crypto_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
399 unsigned int keylen)
400{
401 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
402 unsigned long alignmask = crypto_skcipher_alignmask(tfm);
403 int err;
404
405 if (cipher->co.base.cra_type != &crypto_skcipher_type) {
406 struct crypto_lskcipher **ctx = crypto_skcipher_ctx(tfm);
407
408 crypto_lskcipher_clear_flags(*ctx, CRYPTO_TFM_REQ_MASK);
409 crypto_lskcipher_set_flags(*ctx,
410 crypto_skcipher_get_flags(tfm) &
411 CRYPTO_TFM_REQ_MASK);
412 err = crypto_lskcipher_setkey(*ctx, key, keylen);
413 goto out;
414 }
415
416 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize)
417 return -EINVAL;
418
419 if ((unsigned long)key & alignmask)
420 err = skcipher_setkey_unaligned(tfm, key, keylen);
421 else
422 err = cipher->setkey(tfm, key, keylen);
423
424out:
425 if (unlikely(err)) {
426 skcipher_set_needkey(tfm);
427 return err;
428 }
429
430 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
431 return 0;
432}
433EXPORT_SYMBOL_GPL(crypto_skcipher_setkey);
434
435int crypto_skcipher_encrypt(struct skcipher_request *req)
436{
437 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
438 struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
439
440 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
441 return -ENOKEY;
442 if (alg->co.base.cra_type != &crypto_skcipher_type)
443 return crypto_lskcipher_encrypt_sg(req);
444 return alg->encrypt(req);
445}
446EXPORT_SYMBOL_GPL(crypto_skcipher_encrypt);
447
448int crypto_skcipher_decrypt(struct skcipher_request *req)
449{
450 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
451 struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
452
453 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
454 return -ENOKEY;
455 if (alg->co.base.cra_type != &crypto_skcipher_type)
456 return crypto_lskcipher_decrypt_sg(req);
457 return alg->decrypt(req);
458}
459EXPORT_SYMBOL_GPL(crypto_skcipher_decrypt);
460
461static int crypto_lskcipher_export(struct skcipher_request *req, void *out)
462{
463 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
464 u8 *ivs = skcipher_request_ctx(req);
465
466 ivs = PTR_ALIGN(ivs, crypto_skcipher_alignmask(tfm) + 1);
467
468 memcpy(out, ivs + crypto_skcipher_ivsize(tfm),
469 crypto_skcipher_statesize(tfm));
470
471 return 0;
472}
473
474static int crypto_lskcipher_import(struct skcipher_request *req, const void *in)
475{
476 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
477 u8 *ivs = skcipher_request_ctx(req);
478
479 ivs = PTR_ALIGN(ivs, crypto_skcipher_alignmask(tfm) + 1);
480
481 memcpy(ivs + crypto_skcipher_ivsize(tfm), in,
482 crypto_skcipher_statesize(tfm));
483
484 return 0;
485}
486
487static int skcipher_noexport(struct skcipher_request *req, void *out)
488{
489 return 0;
490}
491
492static int skcipher_noimport(struct skcipher_request *req, const void *in)
493{
494 return 0;
495}
496
497int crypto_skcipher_export(struct skcipher_request *req, void *out)
498{
499 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
500 struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
501
502 if (alg->co.base.cra_type != &crypto_skcipher_type)
503 return crypto_lskcipher_export(req, out);
504 return alg->export(req, out);
505}
506EXPORT_SYMBOL_GPL(crypto_skcipher_export);
507
508int crypto_skcipher_import(struct skcipher_request *req, const void *in)
509{
510 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
511 struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
512
513 if (alg->co.base.cra_type != &crypto_skcipher_type)
514 return crypto_lskcipher_import(req, in);
515 return alg->import(req, in);
516}
517EXPORT_SYMBOL_GPL(crypto_skcipher_import);
518
519static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
520{
521 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
522 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
523
524 alg->exit(skcipher);
525}
526
527static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
528{
529 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
530 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
531
532 skcipher_set_needkey(skcipher);
533
534 if (tfm->__crt_alg->cra_type != &crypto_skcipher_type) {
535 unsigned am = crypto_skcipher_alignmask(skcipher);
536 unsigned reqsize;
537
538 reqsize = am & ~(crypto_tfm_ctx_alignment() - 1);
539 reqsize += crypto_skcipher_ivsize(skcipher);
540 reqsize += crypto_skcipher_statesize(skcipher);
541 crypto_skcipher_set_reqsize(skcipher, reqsize);
542
543 return crypto_init_lskcipher_ops_sg(tfm);
544 }
545
546 crypto_skcipher_set_reqsize(skcipher, crypto_tfm_alg_reqsize(tfm));
547
548 if (alg->exit)
549 skcipher->base.exit = crypto_skcipher_exit_tfm;
550
551 if (alg->init)
552 return alg->init(skcipher);
553
554 return 0;
555}
556
557static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg)
558{
559 if (alg->cra_type != &crypto_skcipher_type)
560 return sizeof(struct crypto_lskcipher *);
561
562 return crypto_alg_extsize(alg);
563}
564
565static void crypto_skcipher_free_instance(struct crypto_instance *inst)
566{
567 struct skcipher_instance *skcipher =
568 container_of(inst, struct skcipher_instance, s.base);
569
570 skcipher->free(skcipher);
571}
572
573static void __maybe_unused crypto_skcipher_show(struct seq_file *m,
574 struct crypto_alg *alg)
575{
576 struct skcipher_alg *skcipher = __crypto_skcipher_alg(alg);
577
578 seq_printf(m, "type : skcipher\n");
579 seq_printf(m, "async : %s\n",
580 str_yes_no(alg->cra_flags & CRYPTO_ALG_ASYNC));
581 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
582 seq_printf(m, "min keysize : %u\n", skcipher->min_keysize);
583 seq_printf(m, "max keysize : %u\n", skcipher->max_keysize);
584 seq_printf(m, "ivsize : %u\n", skcipher->ivsize);
585 seq_printf(m, "chunksize : %u\n", skcipher->chunksize);
586 seq_printf(m, "walksize : %u\n", skcipher->walksize);
587 seq_printf(m, "statesize : %u\n", skcipher->statesize);
588}
589
590static int __maybe_unused crypto_skcipher_report(
591 struct sk_buff *skb, struct crypto_alg *alg)
592{
593 struct skcipher_alg *skcipher = __crypto_skcipher_alg(alg);
594 struct crypto_report_blkcipher rblkcipher = {
595 .type = "skcipher",
596 .geniv = "<none>",
597 };
598
599 rblkcipher.blocksize = alg->cra_blocksize;
600 rblkcipher.min_keysize = skcipher->min_keysize;
601 rblkcipher.max_keysize = skcipher->max_keysize;
602 rblkcipher.ivsize = skcipher->ivsize;
603
604 return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
605 sizeof(rblkcipher), &rblkcipher);
606}
607
608static const struct crypto_type crypto_skcipher_type = {
609 .extsize = crypto_skcipher_extsize,
610 .init_tfm = crypto_skcipher_init_tfm,
611 .free = crypto_skcipher_free_instance,
612#ifdef CONFIG_PROC_FS
613 .show = crypto_skcipher_show,
614#endif
615#if IS_ENABLED(CONFIG_CRYPTO_USER)
616 .report = crypto_skcipher_report,
617#endif
618 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
619 .maskset = CRYPTO_ALG_TYPE_SKCIPHER_MASK,
620 .type = CRYPTO_ALG_TYPE_SKCIPHER,
621 .tfmsize = offsetof(struct crypto_skcipher, base),
622 .algsize = offsetof(struct skcipher_alg, base),
623};
624
625int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
626 struct crypto_instance *inst,
627 const char *name, u32 type, u32 mask)
628{
629 spawn->base.frontend = &crypto_skcipher_type;
630 return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
631}
632EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
633
634struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
635 u32 type, u32 mask)
636{
637 return crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
638}
639EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
640
641struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(
642 const char *alg_name, u32 type, u32 mask)
643{
644 struct crypto_skcipher *tfm;
645
646 /* Only sync algorithms allowed. */
647 mask |= CRYPTO_ALG_ASYNC | CRYPTO_ALG_SKCIPHER_REQSIZE_LARGE;
648 type &= ~(CRYPTO_ALG_ASYNC | CRYPTO_ALG_SKCIPHER_REQSIZE_LARGE);
649
650 tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
651
652 /*
653 * Make sure we do not allocate something that might get used with
654 * an on-stack request: check the request size.
655 */
656 if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) >
657 MAX_SYNC_SKCIPHER_REQSIZE)) {
658 crypto_free_skcipher(tfm);
659 return ERR_PTR(-EINVAL);
660 }
661
662 return (struct crypto_sync_skcipher *)tfm;
663}
664EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher);
665
666int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask)
667{
668 return crypto_type_has_alg(alg_name, &crypto_skcipher_type, type, mask);
669}
670EXPORT_SYMBOL_GPL(crypto_has_skcipher);
671
672int skcipher_prepare_alg_common(struct skcipher_alg_common *alg)
673{
674 struct crypto_alg *base = &alg->base;
675
676 if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
677 alg->statesize > PAGE_SIZE / 2 ||
678 (alg->ivsize + alg->statesize) > PAGE_SIZE / 2)
679 return -EINVAL;
680
681 if (!alg->chunksize)
682 alg->chunksize = base->cra_blocksize;
683
684 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
685
686 return 0;
687}
688
689static int skcipher_prepare_alg(struct skcipher_alg *alg)
690{
691 struct crypto_alg *base = &alg->base;
692 int err;
693
694 err = skcipher_prepare_alg_common(&alg->co);
695 if (err)
696 return err;
697
698 if (alg->walksize > PAGE_SIZE / 8)
699 return -EINVAL;
700
701 if (!alg->walksize)
702 alg->walksize = alg->chunksize;
703
704 if (!alg->statesize) {
705 alg->import = skcipher_noimport;
706 alg->export = skcipher_noexport;
707 } else if (!(alg->import && alg->export))
708 return -EINVAL;
709
710 base->cra_type = &crypto_skcipher_type;
711 base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
712
713 return 0;
714}
715
716int crypto_register_skcipher(struct skcipher_alg *alg)
717{
718 struct crypto_alg *base = &alg->base;
719 int err;
720
721 err = skcipher_prepare_alg(alg);
722 if (err)
723 return err;
724
725 return crypto_register_alg(base);
726}
727EXPORT_SYMBOL_GPL(crypto_register_skcipher);
728
729void crypto_unregister_skcipher(struct skcipher_alg *alg)
730{
731 crypto_unregister_alg(&alg->base);
732}
733EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
734
735int crypto_register_skciphers(struct skcipher_alg *algs, int count)
736{
737 int i, ret;
738
739 for (i = 0; i < count; i++) {
740 ret = crypto_register_skcipher(&algs[i]);
741 if (ret) {
742 crypto_unregister_skciphers(algs, i);
743 return ret;
744 }
745 }
746
747 return 0;
748}
749EXPORT_SYMBOL_GPL(crypto_register_skciphers);
750
751void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
752{
753 int i;
754
755 for (i = count - 1; i >= 0; --i)
756 crypto_unregister_skcipher(&algs[i]);
757}
758EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
759
760int skcipher_register_instance(struct crypto_template *tmpl,
761 struct skcipher_instance *inst)
762{
763 int err;
764
765 if (WARN_ON(!inst->free))
766 return -EINVAL;
767
768 err = skcipher_prepare_alg(&inst->alg);
769 if (err)
770 return err;
771
772 return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
773}
774EXPORT_SYMBOL_GPL(skcipher_register_instance);
775
776static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key,
777 unsigned int keylen)
778{
779 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
780
781 crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
782 crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) &
783 CRYPTO_TFM_REQ_MASK);
784 return crypto_cipher_setkey(cipher, key, keylen);
785}
786
787static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm)
788{
789 struct skcipher_instance *inst = skcipher_alg_instance(tfm);
790 struct crypto_cipher_spawn *spawn = skcipher_instance_ctx(inst);
791 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
792 struct crypto_cipher *cipher;
793
794 cipher = crypto_spawn_cipher(spawn);
795 if (IS_ERR(cipher))
796 return PTR_ERR(cipher);
797
798 ctx->cipher = cipher;
799 return 0;
800}
801
802static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm)
803{
804 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
805
806 crypto_free_cipher(ctx->cipher);
807}
808
809static void skcipher_free_instance_simple(struct skcipher_instance *inst)
810{
811 crypto_drop_cipher(skcipher_instance_ctx(inst));
812 kfree(inst);
813}
814
815/**
816 * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode
817 *
818 * Allocate an skcipher_instance for a simple block cipher mode of operation,
819 * e.g. cbc or ecb. The instance context will have just a single crypto_spawn,
820 * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize,
821 * alignmask, and priority are set from the underlying cipher but can be
822 * overridden if needed. The tfm context defaults to skcipher_ctx_simple, and
823 * default ->setkey(), ->init(), and ->exit() methods are installed.
824 *
825 * @tmpl: the template being instantiated
826 * @tb: the template parameters
827 *
828 * Return: a pointer to the new instance, or an ERR_PTR(). The caller still
829 * needs to register the instance.
830 */
831struct skcipher_instance *skcipher_alloc_instance_simple(
832 struct crypto_template *tmpl, struct rtattr **tb)
833{
834 u32 mask;
835 struct skcipher_instance *inst;
836 struct crypto_cipher_spawn *spawn;
837 struct crypto_alg *cipher_alg;
838 int err;
839
840 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
841 if (err)
842 return ERR_PTR(err);
843
844 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
845 if (!inst)
846 return ERR_PTR(-ENOMEM);
847 spawn = skcipher_instance_ctx(inst);
848
849 err = crypto_grab_cipher(spawn, skcipher_crypto_instance(inst),
850 crypto_attr_alg_name(tb[1]), 0, mask);
851 if (err)
852 goto err_free_inst;
853 cipher_alg = crypto_spawn_cipher_alg(spawn);
854
855 err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name,
856 cipher_alg);
857 if (err)
858 goto err_free_inst;
859
860 inst->free = skcipher_free_instance_simple;
861
862 /* Default algorithm properties, can be overridden */
863 inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize;
864 inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask;
865 inst->alg.base.cra_priority = cipher_alg->cra_priority;
866 inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
867 inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
868 inst->alg.ivsize = cipher_alg->cra_blocksize;
869
870 /* Use skcipher_ctx_simple by default, can be overridden */
871 inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple);
872 inst->alg.setkey = skcipher_setkey_simple;
873 inst->alg.init = skcipher_init_tfm_simple;
874 inst->alg.exit = skcipher_exit_tfm_simple;
875
876 return inst;
877
878err_free_inst:
879 skcipher_free_instance_simple(inst);
880 return ERR_PTR(err);
881}
882EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple);
883
884MODULE_LICENSE("GPL");
885MODULE_DESCRIPTION("Symmetric key cipher type");
886MODULE_IMPORT_NS("CRYPTO_INTERNAL");