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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 <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/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: &walk->in, nbytes: n);
88 } else if (walk->flags & SKCIPHER_WALK_DIFF) {
89 scatterwalk_done_src(walk: &walk->in, nbytes: n);
90 } else if (walk->flags & SKCIPHER_WALK_COPY) {
91 scatterwalk_advance(walk: &walk->in, nbytes: n);
92 scatterwalk_map(walk: &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: &walk->out, buf: walk->out.addr, nbytes: n);
106 goto dst_done;
107 }
108
109 scatterwalk_done_dst(walk: &walk->out, nbytes: 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(objp: 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(buf: buffer, walk: &walk->in, nbytes: 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: &walk->in);
178 memcpy(tmp, walk->in.addr, walk->nbytes);
179 scatterwalk_unmap(walk: &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(sg: walk->in.sg) + (walk->in.offset >> PAGE_SHIFT)) -
197 (u8 *)(sg_page(sg: walk->out.sg) + (walk->out.offset >> PAGE_SHIFT));
198
199 scatterwalk_map(walk: &walk->out);
200 walk->in.__addr = walk->out.__addr;
201
202 if (diff) {
203 walk->flags |= SKCIPHER_WALK_DIFF;
204 scatterwalk_map(walk: &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: &walk->in, nbytes: n);
218 n = scatterwalk_clamp(walk: &walk->out, nbytes: 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: &walk->in, sg: req->src);
306 scatterwalk_start(walk: &walk->out, sg: 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: &walk->in, sg: req->src, pos: req->assoclen);
339 scatterwalk_start_at_pos(walk: &walk->out, sg: req->dst, pos: 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(objp: 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(tfm: *ctx, CRYPTO_TFM_REQ_MASK);
409 crypto_lskcipher_set_flags(tfm: *ctx,
410 flags: crypto_skcipher_get_flags(tfm) &
411 CRYPTO_TFM_REQ_MASK);
412 err = crypto_lskcipher_setkey(tfm: *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(tfm: 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(tfm: skcipher);
531
532 skcipher_set_needkey(tfm: skcipher);
533
534 if (tfm->__crt_alg->cra_type != &crypto_skcipher_type) {
535 unsigned am = crypto_skcipher_alignmask(tfm: skcipher);
536 unsigned reqsize;
537
538 reqsize = am & ~(crypto_tfm_ctx_alignment() - 1);
539 reqsize += crypto_skcipher_ivsize(tfm: skcipher);
540 reqsize += crypto_skcipher_statesize(tfm: 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, reqsize: 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 crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
574 __maybe_unused;
575static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
576{
577 struct skcipher_alg *skcipher = __crypto_skcipher_alg(alg);
578
579 seq_printf(m, fmt: "type : skcipher\n");
580 seq_printf(m, fmt: "async : %s\n",
581 str_yes_no(v: alg->cra_flags & CRYPTO_ALG_ASYNC));
582 seq_printf(m, fmt: "blocksize : %u\n", alg->cra_blocksize);
583 seq_printf(m, fmt: "min keysize : %u\n", skcipher->min_keysize);
584 seq_printf(m, fmt: "max keysize : %u\n", skcipher->max_keysize);
585 seq_printf(m, fmt: "ivsize : %u\n", skcipher->ivsize);
586 seq_printf(m, fmt: "chunksize : %u\n", skcipher->chunksize);
587 seq_printf(m, fmt: "walksize : %u\n", skcipher->walksize);
588 seq_printf(m, fmt: "statesize : %u\n", skcipher->statesize);
589}
590
591static int __maybe_unused crypto_skcipher_report(
592 struct sk_buff *skb, struct crypto_alg *alg)
593{
594 struct skcipher_alg *skcipher = __crypto_skcipher_alg(alg);
595 struct crypto_report_blkcipher rblkcipher;
596
597 memset(&rblkcipher, 0, sizeof(rblkcipher));
598
599 strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
600 strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
601
602 rblkcipher.blocksize = alg->cra_blocksize;
603 rblkcipher.min_keysize = skcipher->min_keysize;
604 rblkcipher.max_keysize = skcipher->max_keysize;
605 rblkcipher.ivsize = skcipher->ivsize;
606
607 return nla_put(skb, attrtype: CRYPTOCFGA_REPORT_BLKCIPHER,
608 attrlen: sizeof(rblkcipher), data: &rblkcipher);
609}
610
611static const struct crypto_type crypto_skcipher_type = {
612 .extsize = crypto_skcipher_extsize,
613 .init_tfm = crypto_skcipher_init_tfm,
614 .free = crypto_skcipher_free_instance,
615#ifdef CONFIG_PROC_FS
616 .show = crypto_skcipher_show,
617#endif
618#if IS_ENABLED(CONFIG_CRYPTO_USER)
619 .report = crypto_skcipher_report,
620#endif
621 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
622 .maskset = CRYPTO_ALG_TYPE_SKCIPHER_MASK,
623 .type = CRYPTO_ALG_TYPE_SKCIPHER,
624 .tfmsize = offsetof(struct crypto_skcipher, base),
625 .algsize = offsetof(struct skcipher_alg, base),
626};
627
628int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
629 struct crypto_instance *inst,
630 const char *name, u32 type, u32 mask)
631{
632 spawn->base.frontend = &crypto_skcipher_type;
633 return crypto_grab_spawn(spawn: &spawn->base, inst, name, type, mask);
634}
635EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
636
637struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
638 u32 type, u32 mask)
639{
640 return crypto_alloc_tfm(alg_name, frontend: &crypto_skcipher_type, type, mask);
641}
642EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
643
644struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(
645 const char *alg_name, u32 type, u32 mask)
646{
647 struct crypto_skcipher *tfm;
648
649 /* Only sync algorithms allowed. */
650 mask |= CRYPTO_ALG_ASYNC | CRYPTO_ALG_SKCIPHER_REQSIZE_LARGE;
651 type &= ~(CRYPTO_ALG_ASYNC | CRYPTO_ALG_SKCIPHER_REQSIZE_LARGE);
652
653 tfm = crypto_alloc_tfm(alg_name, frontend: &crypto_skcipher_type, type, mask);
654
655 /*
656 * Make sure we do not allocate something that might get used with
657 * an on-stack request: check the request size.
658 */
659 if (!IS_ERR(ptr: tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) >
660 MAX_SYNC_SKCIPHER_REQSIZE)) {
661 crypto_free_skcipher(tfm);
662 return ERR_PTR(error: -EINVAL);
663 }
664
665 return (struct crypto_sync_skcipher *)tfm;
666}
667EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher);
668
669int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask)
670{
671 return crypto_type_has_alg(name: alg_name, frontend: &crypto_skcipher_type, type, mask);
672}
673EXPORT_SYMBOL_GPL(crypto_has_skcipher);
674
675int skcipher_prepare_alg_common(struct skcipher_alg_common *alg)
676{
677 struct crypto_alg *base = &alg->base;
678
679 if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
680 alg->statesize > PAGE_SIZE / 2 ||
681 (alg->ivsize + alg->statesize) > PAGE_SIZE / 2)
682 return -EINVAL;
683
684 if (!alg->chunksize)
685 alg->chunksize = base->cra_blocksize;
686
687 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
688
689 return 0;
690}
691
692static int skcipher_prepare_alg(struct skcipher_alg *alg)
693{
694 struct crypto_alg *base = &alg->base;
695 int err;
696
697 err = skcipher_prepare_alg_common(alg: &alg->co);
698 if (err)
699 return err;
700
701 if (alg->walksize > PAGE_SIZE / 8)
702 return -EINVAL;
703
704 if (!alg->walksize)
705 alg->walksize = alg->chunksize;
706
707 if (!alg->statesize) {
708 alg->import = skcipher_noimport;
709 alg->export = skcipher_noexport;
710 } else if (!(alg->import && alg->export))
711 return -EINVAL;
712
713 base->cra_type = &crypto_skcipher_type;
714 base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
715
716 return 0;
717}
718
719int crypto_register_skcipher(struct skcipher_alg *alg)
720{
721 struct crypto_alg *base = &alg->base;
722 int err;
723
724 err = skcipher_prepare_alg(alg);
725 if (err)
726 return err;
727
728 return crypto_register_alg(alg: base);
729}
730EXPORT_SYMBOL_GPL(crypto_register_skcipher);
731
732void crypto_unregister_skcipher(struct skcipher_alg *alg)
733{
734 crypto_unregister_alg(alg: &alg->base);
735}
736EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
737
738int crypto_register_skciphers(struct skcipher_alg *algs, int count)
739{
740 int i, ret;
741
742 for (i = 0; i < count; i++) {
743 ret = crypto_register_skcipher(&algs[i]);
744 if (ret)
745 goto err;
746 }
747
748 return 0;
749
750err:
751 for (--i; i >= 0; --i)
752 crypto_unregister_skcipher(&algs[i]);
753
754 return ret;
755}
756EXPORT_SYMBOL_GPL(crypto_register_skciphers);
757
758void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
759{
760 int i;
761
762 for (i = count - 1; i >= 0; --i)
763 crypto_unregister_skcipher(&algs[i]);
764}
765EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
766
767int skcipher_register_instance(struct crypto_template *tmpl,
768 struct skcipher_instance *inst)
769{
770 int err;
771
772 if (WARN_ON(!inst->free))
773 return -EINVAL;
774
775 err = skcipher_prepare_alg(alg: &inst->alg);
776 if (err)
777 return err;
778
779 return crypto_register_instance(tmpl, inst: skcipher_crypto_instance(inst));
780}
781EXPORT_SYMBOL_GPL(skcipher_register_instance);
782
783static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key,
784 unsigned int keylen)
785{
786 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
787
788 crypto_cipher_clear_flags(tfm: cipher, CRYPTO_TFM_REQ_MASK);
789 crypto_cipher_set_flags(tfm: cipher, flags: crypto_skcipher_get_flags(tfm) &
790 CRYPTO_TFM_REQ_MASK);
791 return crypto_cipher_setkey(tfm: cipher, key, keylen);
792}
793
794static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm)
795{
796 struct skcipher_instance *inst = skcipher_alg_instance(skcipher: tfm);
797 struct crypto_cipher_spawn *spawn = skcipher_instance_ctx(inst);
798 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
799 struct crypto_cipher *cipher;
800
801 cipher = crypto_spawn_cipher(spawn);
802 if (IS_ERR(ptr: cipher))
803 return PTR_ERR(ptr: cipher);
804
805 ctx->cipher = cipher;
806 return 0;
807}
808
809static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm)
810{
811 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
812
813 crypto_free_cipher(tfm: ctx->cipher);
814}
815
816static void skcipher_free_instance_simple(struct skcipher_instance *inst)
817{
818 crypto_drop_cipher(spawn: skcipher_instance_ctx(inst));
819 kfree(objp: inst);
820}
821
822/**
823 * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode
824 *
825 * Allocate an skcipher_instance for a simple block cipher mode of operation,
826 * e.g. cbc or ecb. The instance context will have just a single crypto_spawn,
827 * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize,
828 * alignmask, and priority are set from the underlying cipher but can be
829 * overridden if needed. The tfm context defaults to skcipher_ctx_simple, and
830 * default ->setkey(), ->init(), and ->exit() methods are installed.
831 *
832 * @tmpl: the template being instantiated
833 * @tb: the template parameters
834 *
835 * Return: a pointer to the new instance, or an ERR_PTR(). The caller still
836 * needs to register the instance.
837 */
838struct skcipher_instance *skcipher_alloc_instance_simple(
839 struct crypto_template *tmpl, struct rtattr **tb)
840{
841 u32 mask;
842 struct skcipher_instance *inst;
843 struct crypto_cipher_spawn *spawn;
844 struct crypto_alg *cipher_alg;
845 int err;
846
847 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, mask_ret: &mask);
848 if (err)
849 return ERR_PTR(error: err);
850
851 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
852 if (!inst)
853 return ERR_PTR(error: -ENOMEM);
854 spawn = skcipher_instance_ctx(inst);
855
856 err = crypto_grab_cipher(spawn, inst: skcipher_crypto_instance(inst),
857 name: crypto_attr_alg_name(rta: tb[1]), type: 0, mask);
858 if (err)
859 goto err_free_inst;
860 cipher_alg = crypto_spawn_cipher_alg(spawn);
861
862 err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name,
863 cipher_alg);
864 if (err)
865 goto err_free_inst;
866
867 inst->free = skcipher_free_instance_simple;
868
869 /* Default algorithm properties, can be overridden */
870 inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize;
871 inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask;
872 inst->alg.base.cra_priority = cipher_alg->cra_priority;
873 inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
874 inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
875 inst->alg.ivsize = cipher_alg->cra_blocksize;
876
877 /* Use skcipher_ctx_simple by default, can be overridden */
878 inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple);
879 inst->alg.setkey = skcipher_setkey_simple;
880 inst->alg.init = skcipher_init_tfm_simple;
881 inst->alg.exit = skcipher_exit_tfm_simple;
882
883 return inst;
884
885err_free_inst:
886 skcipher_free_instance_simple(inst);
887 return ERR_PTR(error: err);
888}
889EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple);
890
891MODULE_LICENSE("GPL");
892MODULE_DESCRIPTION("Symmetric key cipher type");
893MODULE_IMPORT_NS("CRYPTO_INTERNAL");
894

source code of linux/crypto/skcipher.c