skcipher.c

  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->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 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, "type         : skcipher\n");
580	seq_printf(m, "async        : %s\n",
581		   str_yes_no(alg->cra_flags & CRYPTO_ALG_ASYNC));
582	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
583	seq_printf(m, "min keysize  : %u\n", skcipher->min_keysize);
584	seq_printf(m, "max keysize  : %u\n", skcipher->max_keysize);
585	seq_printf(m, "ivsize       : %u\n", skcipher->ivsize);
586	seq_printf(m, "chunksize    : %u\n", skcipher->chunksize);
587	seq_printf(m, "walksize     : %u\n", skcipher->walksize);
588	seq_printf(m, "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, CRYPTOCFGA_REPORT_BLKCIPHER,
608		       sizeof(rblkcipher), &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->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, &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, &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(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) >
660				    MAX_SYNC_SKCIPHER_REQSIZE)) {
661		crypto_free_skcipher(tfm);
662		return ERR_PTR(-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(alg_name, &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->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(base);
729}
730EXPORT_SYMBOL_GPL(crypto_register_skcipher);
731
732void crypto_unregister_skcipher(struct skcipher_alg *alg)
733{
734	crypto_unregister_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(&inst->alg);
776	if (err)
777		return err;
778
779	return crypto_register_instance(tmpl, 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(cipher, CRYPTO_TFM_REQ_MASK);
789	crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) &
790				CRYPTO_TFM_REQ_MASK);
791	return crypto_cipher_setkey(cipher, key, keylen);
792}
793
794static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm)
795{
796	struct skcipher_instance *inst = skcipher_alg_instance(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(cipher))
803		return PTR_ERR(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(ctx->cipher);
814}
815
816static void skcipher_free_instance_simple(struct skcipher_instance *inst)
817{
818	crypto_drop_cipher(skcipher_instance_ctx(inst));
819	kfree(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);
848	if (err)
849		return ERR_PTR(err);
850
851	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
852	if (!inst)
853		return ERR_PTR(-ENOMEM);
854	spawn = skcipher_instance_ctx(inst);
855
856	err = crypto_grab_cipher(spawn, skcipher_crypto_instance(inst),
857				 crypto_attr_alg_name(tb[1]), 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(err);
888}
889EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple);
890
891MODULE_LICENSE("GPL");
892MODULE_DESCRIPTION("Symmetric key cipher type");
893MODULE_IMPORT_NS("CRYPTO_INTERNAL");