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/list.h>
21 #include <linux/mm.h>
22 #include <linux/module.h>
23 #include <linux/seq_file.h>
24 #include <linux/slab.h>
25 #include <linux/string.h>
26 #include <net/netlink.h>
27 
28 #include "internal.h"
29 
30 enum {
31 	SKCIPHER_WALK_PHYS = 1 << 0,
32 	SKCIPHER_WALK_SLOW = 1 << 1,
33 	SKCIPHER_WALK_COPY = 1 << 2,
34 	SKCIPHER_WALK_DIFF = 1 << 3,
35 	SKCIPHER_WALK_SLEEP = 1 << 4,
36 };
37 
38 struct skcipher_walk_buffer {
39 	struct list_head entry;
40 	struct scatter_walk dst;
41 	unsigned int len;
42 	u8 *data;
43 	u8 buffer[];
44 };
45 
46 static int skcipher_walk_next(struct skcipher_walk *walk);
47 
skcipher_map_src(struct skcipher_walk * walk)48 static inline void skcipher_map_src(struct skcipher_walk *walk)
49 {
50 	walk->src.virt.addr = scatterwalk_map(&walk->in);
51 }
52 
skcipher_map_dst(struct skcipher_walk * walk)53 static inline void skcipher_map_dst(struct skcipher_walk *walk)
54 {
55 	walk->dst.virt.addr = scatterwalk_map(&walk->out);
56 }
57 
skcipher_unmap_src(struct skcipher_walk * walk)58 static inline void skcipher_unmap_src(struct skcipher_walk *walk)
59 {
60 	scatterwalk_unmap(walk->src.virt.addr);
61 }
62 
skcipher_unmap_dst(struct skcipher_walk * walk)63 static inline void skcipher_unmap_dst(struct skcipher_walk *walk)
64 {
65 	scatterwalk_unmap(walk->dst.virt.addr);
66 }
67 
skcipher_walk_gfp(struct skcipher_walk * walk)68 static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk)
69 {
70 	return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
71 }
72 
73 /* Get a spot of the specified length that does not straddle a page.
74  * The caller needs to ensure that there is enough space for this operation.
75  */
skcipher_get_spot(u8 * start,unsigned int len)76 static inline u8 *skcipher_get_spot(u8 *start, unsigned int len)
77 {
78 	u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
79 
80 	return max(start, end_page);
81 }
82 
__crypto_skcipher_alg(struct crypto_alg * alg)83 static inline struct skcipher_alg *__crypto_skcipher_alg(
84 	struct crypto_alg *alg)
85 {
86 	return container_of(alg, struct skcipher_alg, base);
87 }
88 
skcipher_get_stat(struct skcipher_alg * alg)89 static inline struct crypto_istat_cipher *skcipher_get_stat(
90 	struct skcipher_alg *alg)
91 {
92 #ifdef CONFIG_CRYPTO_STATS
93 	return &alg->stat;
94 #else
95 	return NULL;
96 #endif
97 }
98 
crypto_skcipher_errstat(struct skcipher_alg * alg,int err)99 static inline int crypto_skcipher_errstat(struct skcipher_alg *alg, int err)
100 {
101 	struct crypto_istat_cipher *istat = skcipher_get_stat(alg);
102 
103 	if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
104 		return err;
105 
106 	if (err && err != -EINPROGRESS && err != -EBUSY)
107 		atomic64_inc(&istat->err_cnt);
108 
109 	return err;
110 }
111 
skcipher_done_slow(struct skcipher_walk * walk,unsigned int bsize)112 static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
113 {
114 	u8 *addr;
115 
116 	addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
117 	addr = skcipher_get_spot(addr, bsize);
118 	scatterwalk_copychunks(addr, &walk->out, bsize,
119 			       (walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1);
120 	return 0;
121 }
122 
skcipher_walk_done(struct skcipher_walk * walk,int err)123 int skcipher_walk_done(struct skcipher_walk *walk, int err)
124 {
125 	unsigned int n = walk->nbytes;
126 	unsigned int nbytes = 0;
127 
128 	if (!n)
129 		goto finish;
130 
131 	if (likely(err >= 0)) {
132 		n -= err;
133 		nbytes = walk->total - n;
134 	}
135 
136 	if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
137 				    SKCIPHER_WALK_SLOW |
138 				    SKCIPHER_WALK_COPY |
139 				    SKCIPHER_WALK_DIFF)))) {
140 unmap_src:
141 		skcipher_unmap_src(walk);
142 	} else if (walk->flags & SKCIPHER_WALK_DIFF) {
143 		skcipher_unmap_dst(walk);
144 		goto unmap_src;
145 	} else if (walk->flags & SKCIPHER_WALK_COPY) {
146 		skcipher_map_dst(walk);
147 		memcpy(walk->dst.virt.addr, walk->page, n);
148 		skcipher_unmap_dst(walk);
149 	} else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
150 		if (err > 0) {
151 			/*
152 			 * Didn't process all bytes.  Either the algorithm is
153 			 * broken, or this was the last step and it turned out
154 			 * the message wasn't evenly divisible into blocks but
155 			 * the algorithm requires it.
156 			 */
157 			err = -EINVAL;
158 			nbytes = 0;
159 		} else
160 			n = skcipher_done_slow(walk, n);
161 	}
162 
163 	if (err > 0)
164 		err = 0;
165 
166 	walk->total = nbytes;
167 	walk->nbytes = 0;
168 
169 	scatterwalk_advance(&walk->in, n);
170 	scatterwalk_advance(&walk->out, n);
171 	scatterwalk_done(&walk->in, 0, nbytes);
172 	scatterwalk_done(&walk->out, 1, nbytes);
173 
174 	if (nbytes) {
175 		crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
176 			     CRYPTO_TFM_REQ_MAY_SLEEP : 0);
177 		return skcipher_walk_next(walk);
178 	}
179 
180 finish:
181 	/* Short-circuit for the common/fast path. */
182 	if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
183 		goto out;
184 
185 	if (walk->flags & SKCIPHER_WALK_PHYS)
186 		goto out;
187 
188 	if (walk->iv != walk->oiv)
189 		memcpy(walk->oiv, walk->iv, walk->ivsize);
190 	if (walk->buffer != walk->page)
191 		kfree(walk->buffer);
192 	if (walk->page)
193 		free_page((unsigned long)walk->page);
194 
195 out:
196 	return err;
197 }
198 EXPORT_SYMBOL_GPL(skcipher_walk_done);
199 
skcipher_walk_complete(struct skcipher_walk * walk,int err)200 void skcipher_walk_complete(struct skcipher_walk *walk, int err)
201 {
202 	struct skcipher_walk_buffer *p, *tmp;
203 
204 	list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
205 		u8 *data;
206 
207 		if (err)
208 			goto done;
209 
210 		data = p->data;
211 		if (!data) {
212 			data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1);
213 			data = skcipher_get_spot(data, walk->stride);
214 		}
215 
216 		scatterwalk_copychunks(data, &p->dst, p->len, 1);
217 
218 		if (offset_in_page(p->data) + p->len + walk->stride >
219 		    PAGE_SIZE)
220 			free_page((unsigned long)p->data);
221 
222 done:
223 		list_del(&p->entry);
224 		kfree(p);
225 	}
226 
227 	if (!err && walk->iv != walk->oiv)
228 		memcpy(walk->oiv, walk->iv, walk->ivsize);
229 	if (walk->buffer != walk->page)
230 		kfree(walk->buffer);
231 	if (walk->page)
232 		free_page((unsigned long)walk->page);
233 }
234 EXPORT_SYMBOL_GPL(skcipher_walk_complete);
235 
skcipher_queue_write(struct skcipher_walk * walk,struct skcipher_walk_buffer * p)236 static void skcipher_queue_write(struct skcipher_walk *walk,
237 				 struct skcipher_walk_buffer *p)
238 {
239 	p->dst = walk->out;
240 	list_add_tail(&p->entry, &walk->buffers);
241 }
242 
skcipher_next_slow(struct skcipher_walk * walk,unsigned int bsize)243 static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize)
244 {
245 	bool phys = walk->flags & SKCIPHER_WALK_PHYS;
246 	unsigned alignmask = walk->alignmask;
247 	struct skcipher_walk_buffer *p;
248 	unsigned a;
249 	unsigned n;
250 	u8 *buffer;
251 	void *v;
252 
253 	if (!phys) {
254 		if (!walk->buffer)
255 			walk->buffer = walk->page;
256 		buffer = walk->buffer;
257 		if (buffer)
258 			goto ok;
259 	}
260 
261 	/* Start with the minimum alignment of kmalloc. */
262 	a = crypto_tfm_ctx_alignment() - 1;
263 	n = bsize;
264 
265 	if (phys) {
266 		/* Calculate the minimum alignment of p->buffer. */
267 		a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1;
268 		n += sizeof(*p);
269 	}
270 
271 	/* Minimum size to align p->buffer by alignmask. */
272 	n += alignmask & ~a;
273 
274 	/* Minimum size to ensure p->buffer does not straddle a page. */
275 	n += (bsize - 1) & ~(alignmask | a);
276 
277 	v = kzalloc(n, skcipher_walk_gfp(walk));
278 	if (!v)
279 		return skcipher_walk_done(walk, -ENOMEM);
280 
281 	if (phys) {
282 		p = v;
283 		p->len = bsize;
284 		skcipher_queue_write(walk, p);
285 		buffer = p->buffer;
286 	} else {
287 		walk->buffer = v;
288 		buffer = v;
289 	}
290 
291 ok:
292 	walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1);
293 	walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize);
294 	walk->src.virt.addr = walk->dst.virt.addr;
295 
296 	scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
297 
298 	walk->nbytes = bsize;
299 	walk->flags |= SKCIPHER_WALK_SLOW;
300 
301 	return 0;
302 }
303 
skcipher_next_copy(struct skcipher_walk * walk)304 static int skcipher_next_copy(struct skcipher_walk *walk)
305 {
306 	struct skcipher_walk_buffer *p;
307 	u8 *tmp = walk->page;
308 
309 	skcipher_map_src(walk);
310 	memcpy(tmp, walk->src.virt.addr, walk->nbytes);
311 	skcipher_unmap_src(walk);
312 
313 	walk->src.virt.addr = tmp;
314 	walk->dst.virt.addr = tmp;
315 
316 	if (!(walk->flags & SKCIPHER_WALK_PHYS))
317 		return 0;
318 
319 	p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk));
320 	if (!p)
321 		return -ENOMEM;
322 
323 	p->data = walk->page;
324 	p->len = walk->nbytes;
325 	skcipher_queue_write(walk, p);
326 
327 	if (offset_in_page(walk->page) + walk->nbytes + walk->stride >
328 	    PAGE_SIZE)
329 		walk->page = NULL;
330 	else
331 		walk->page += walk->nbytes;
332 
333 	return 0;
334 }
335 
skcipher_next_fast(struct skcipher_walk * walk)336 static int skcipher_next_fast(struct skcipher_walk *walk)
337 {
338 	unsigned long diff;
339 
340 	walk->src.phys.page = scatterwalk_page(&walk->in);
341 	walk->src.phys.offset = offset_in_page(walk->in.offset);
342 	walk->dst.phys.page = scatterwalk_page(&walk->out);
343 	walk->dst.phys.offset = offset_in_page(walk->out.offset);
344 
345 	if (walk->flags & SKCIPHER_WALK_PHYS)
346 		return 0;
347 
348 	diff = walk->src.phys.offset - walk->dst.phys.offset;
349 	diff |= walk->src.virt.page - walk->dst.virt.page;
350 
351 	skcipher_map_src(walk);
352 	walk->dst.virt.addr = walk->src.virt.addr;
353 
354 	if (diff) {
355 		walk->flags |= SKCIPHER_WALK_DIFF;
356 		skcipher_map_dst(walk);
357 	}
358 
359 	return 0;
360 }
361 
skcipher_walk_next(struct skcipher_walk * walk)362 static int skcipher_walk_next(struct skcipher_walk *walk)
363 {
364 	unsigned int bsize;
365 	unsigned int n;
366 	int err;
367 
368 	walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY |
369 			 SKCIPHER_WALK_DIFF);
370 
371 	n = walk->total;
372 	bsize = min(walk->stride, max(n, walk->blocksize));
373 	n = scatterwalk_clamp(&walk->in, n);
374 	n = scatterwalk_clamp(&walk->out, n);
375 
376 	if (unlikely(n < bsize)) {
377 		if (unlikely(walk->total < walk->blocksize))
378 			return skcipher_walk_done(walk, -EINVAL);
379 
380 slow_path:
381 		err = skcipher_next_slow(walk, bsize);
382 		goto set_phys_lowmem;
383 	}
384 
385 	if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) {
386 		if (!walk->page) {
387 			gfp_t gfp = skcipher_walk_gfp(walk);
388 
389 			walk->page = (void *)__get_free_page(gfp);
390 			if (!walk->page)
391 				goto slow_path;
392 		}
393 
394 		walk->nbytes = min_t(unsigned, n,
395 				     PAGE_SIZE - offset_in_page(walk->page));
396 		walk->flags |= SKCIPHER_WALK_COPY;
397 		err = skcipher_next_copy(walk);
398 		goto set_phys_lowmem;
399 	}
400 
401 	walk->nbytes = n;
402 
403 	return skcipher_next_fast(walk);
404 
405 set_phys_lowmem:
406 	if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) {
407 		walk->src.phys.page = virt_to_page(walk->src.virt.addr);
408 		walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
409 		walk->src.phys.offset &= PAGE_SIZE - 1;
410 		walk->dst.phys.offset &= PAGE_SIZE - 1;
411 	}
412 	return err;
413 }
414 
skcipher_copy_iv(struct skcipher_walk * walk)415 static int skcipher_copy_iv(struct skcipher_walk *walk)
416 {
417 	unsigned a = crypto_tfm_ctx_alignment() - 1;
418 	unsigned alignmask = walk->alignmask;
419 	unsigned ivsize = walk->ivsize;
420 	unsigned bs = walk->stride;
421 	unsigned aligned_bs;
422 	unsigned size;
423 	u8 *iv;
424 
425 	aligned_bs = ALIGN(bs, alignmask + 1);
426 
427 	/* Minimum size to align buffer by alignmask. */
428 	size = alignmask & ~a;
429 
430 	if (walk->flags & SKCIPHER_WALK_PHYS)
431 		size += ivsize;
432 	else {
433 		size += aligned_bs + ivsize;
434 
435 		/* Minimum size to ensure buffer does not straddle a page. */
436 		size += (bs - 1) & ~(alignmask | a);
437 	}
438 
439 	walk->buffer = kmalloc(size, skcipher_walk_gfp(walk));
440 	if (!walk->buffer)
441 		return -ENOMEM;
442 
443 	iv = PTR_ALIGN(walk->buffer, alignmask + 1);
444 	iv = skcipher_get_spot(iv, bs) + aligned_bs;
445 
446 	walk->iv = memcpy(iv, walk->iv, walk->ivsize);
447 	return 0;
448 }
449 
skcipher_walk_first(struct skcipher_walk * walk)450 static int skcipher_walk_first(struct skcipher_walk *walk)
451 {
452 	if (WARN_ON_ONCE(in_hardirq()))
453 		return -EDEADLK;
454 
455 	walk->buffer = NULL;
456 	if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
457 		int err = skcipher_copy_iv(walk);
458 		if (err)
459 			return err;
460 	}
461 
462 	walk->page = NULL;
463 
464 	return skcipher_walk_next(walk);
465 }
466 
skcipher_walk_skcipher(struct skcipher_walk * walk,struct skcipher_request * req)467 static int skcipher_walk_skcipher(struct skcipher_walk *walk,
468 				  struct skcipher_request *req)
469 {
470 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
471 
472 	walk->total = req->cryptlen;
473 	walk->nbytes = 0;
474 	walk->iv = req->iv;
475 	walk->oiv = req->iv;
476 
477 	if (unlikely(!walk->total))
478 		return 0;
479 
480 	scatterwalk_start(&walk->in, req->src);
481 	scatterwalk_start(&walk->out, req->dst);
482 
483 	walk->flags &= ~SKCIPHER_WALK_SLEEP;
484 	walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
485 		       SKCIPHER_WALK_SLEEP : 0;
486 
487 	walk->blocksize = crypto_skcipher_blocksize(tfm);
488 	walk->stride = crypto_skcipher_walksize(tfm);
489 	walk->ivsize = crypto_skcipher_ivsize(tfm);
490 	walk->alignmask = crypto_skcipher_alignmask(tfm);
491 
492 	return skcipher_walk_first(walk);
493 }
494 
skcipher_walk_virt(struct skcipher_walk * walk,struct skcipher_request * req,bool atomic)495 int skcipher_walk_virt(struct skcipher_walk *walk,
496 		       struct skcipher_request *req, bool atomic)
497 {
498 	int err;
499 
500 	might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
501 
502 	walk->flags &= ~SKCIPHER_WALK_PHYS;
503 
504 	err = skcipher_walk_skcipher(walk, req);
505 
506 	walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0;
507 
508 	return err;
509 }
510 EXPORT_SYMBOL_GPL(skcipher_walk_virt);
511 
skcipher_walk_async(struct skcipher_walk * walk,struct skcipher_request * req)512 int skcipher_walk_async(struct skcipher_walk *walk,
513 			struct skcipher_request *req)
514 {
515 	walk->flags |= SKCIPHER_WALK_PHYS;
516 
517 	INIT_LIST_HEAD(&walk->buffers);
518 
519 	return skcipher_walk_skcipher(walk, req);
520 }
521 EXPORT_SYMBOL_GPL(skcipher_walk_async);
522 
skcipher_walk_aead_common(struct skcipher_walk * walk,struct aead_request * req,bool atomic)523 static int skcipher_walk_aead_common(struct skcipher_walk *walk,
524 				     struct aead_request *req, bool atomic)
525 {
526 	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
527 	int err;
528 
529 	walk->nbytes = 0;
530 	walk->iv = req->iv;
531 	walk->oiv = req->iv;
532 
533 	if (unlikely(!walk->total))
534 		return 0;
535 
536 	walk->flags &= ~SKCIPHER_WALK_PHYS;
537 
538 	scatterwalk_start(&walk->in, req->src);
539 	scatterwalk_start(&walk->out, req->dst);
540 
541 	scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
542 	scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);
543 
544 	scatterwalk_done(&walk->in, 0, walk->total);
545 	scatterwalk_done(&walk->out, 0, walk->total);
546 
547 	if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
548 		walk->flags |= SKCIPHER_WALK_SLEEP;
549 	else
550 		walk->flags &= ~SKCIPHER_WALK_SLEEP;
551 
552 	walk->blocksize = crypto_aead_blocksize(tfm);
553 	walk->stride = crypto_aead_chunksize(tfm);
554 	walk->ivsize = crypto_aead_ivsize(tfm);
555 	walk->alignmask = crypto_aead_alignmask(tfm);
556 
557 	err = skcipher_walk_first(walk);
558 
559 	if (atomic)
560 		walk->flags &= ~SKCIPHER_WALK_SLEEP;
561 
562 	return err;
563 }
564 
skcipher_walk_aead_encrypt(struct skcipher_walk * walk,struct aead_request * req,bool atomic)565 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
566 			       struct aead_request *req, bool atomic)
567 {
568 	walk->total = req->cryptlen;
569 
570 	return skcipher_walk_aead_common(walk, req, atomic);
571 }
572 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);
573 
skcipher_walk_aead_decrypt(struct skcipher_walk * walk,struct aead_request * req,bool atomic)574 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
575 			       struct aead_request *req, bool atomic)
576 {
577 	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
578 
579 	walk->total = req->cryptlen - crypto_aead_authsize(tfm);
580 
581 	return skcipher_walk_aead_common(walk, req, atomic);
582 }
583 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);
584 
skcipher_set_needkey(struct crypto_skcipher * tfm)585 static void skcipher_set_needkey(struct crypto_skcipher *tfm)
586 {
587 	if (crypto_skcipher_max_keysize(tfm) != 0)
588 		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
589 }
590 
skcipher_setkey_unaligned(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)591 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
592 				     const u8 *key, unsigned int keylen)
593 {
594 	unsigned long alignmask = crypto_skcipher_alignmask(tfm);
595 	struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
596 	u8 *buffer, *alignbuffer;
597 	unsigned long absize;
598 	int ret;
599 
600 	absize = keylen + alignmask;
601 	buffer = kmalloc(absize, GFP_ATOMIC);
602 	if (!buffer)
603 		return -ENOMEM;
604 
605 	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
606 	memcpy(alignbuffer, key, keylen);
607 	ret = cipher->setkey(tfm, alignbuffer, keylen);
608 	kfree_sensitive(buffer);
609 	return ret;
610 }
611 
crypto_skcipher_setkey(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)612 int crypto_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
613 			   unsigned int keylen)
614 {
615 	struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
616 	unsigned long alignmask = crypto_skcipher_alignmask(tfm);
617 	int err;
618 
619 	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize)
620 		return -EINVAL;
621 
622 	if ((unsigned long)key & alignmask)
623 		err = skcipher_setkey_unaligned(tfm, key, keylen);
624 	else
625 		err = cipher->setkey(tfm, key, keylen);
626 
627 	if (unlikely(err)) {
628 		skcipher_set_needkey(tfm);
629 		return err;
630 	}
631 
632 	crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
633 	return 0;
634 }
635 EXPORT_SYMBOL_GPL(crypto_skcipher_setkey);
636 
crypto_skcipher_encrypt(struct skcipher_request * req)637 int crypto_skcipher_encrypt(struct skcipher_request *req)
638 {
639 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
640 	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
641 	int ret;
642 
643 	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
644 		struct crypto_istat_cipher *istat = skcipher_get_stat(alg);
645 
646 		atomic64_inc(&istat->encrypt_cnt);
647 		atomic64_add(req->cryptlen, &istat->encrypt_tlen);
648 	}
649 
650 	if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
651 		ret = -ENOKEY;
652 	else
653 		ret = alg->encrypt(req);
654 
655 	return crypto_skcipher_errstat(alg, ret);
656 }
657 EXPORT_SYMBOL_GPL(crypto_skcipher_encrypt);
658 
crypto_skcipher_decrypt(struct skcipher_request * req)659 int crypto_skcipher_decrypt(struct skcipher_request *req)
660 {
661 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
662 	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
663 	int ret;
664 
665 	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
666 		struct crypto_istat_cipher *istat = skcipher_get_stat(alg);
667 
668 		atomic64_inc(&istat->decrypt_cnt);
669 		atomic64_add(req->cryptlen, &istat->decrypt_tlen);
670 	}
671 
672 	if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
673 		ret = -ENOKEY;
674 	else
675 		ret = alg->decrypt(req);
676 
677 	return crypto_skcipher_errstat(alg, ret);
678 }
679 EXPORT_SYMBOL_GPL(crypto_skcipher_decrypt);
680 
crypto_skcipher_exit_tfm(struct crypto_tfm * tfm)681 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
682 {
683 	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
684 	struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
685 
686 	alg->exit(skcipher);
687 }
688 
crypto_skcipher_init_tfm(struct crypto_tfm * tfm)689 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
690 {
691 	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
692 	struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
693 
694 	skcipher_set_needkey(skcipher);
695 
696 	if (alg->exit)
697 		skcipher->base.exit = crypto_skcipher_exit_tfm;
698 
699 	if (alg->init)
700 		return alg->init(skcipher);
701 
702 	return 0;
703 }
704 
crypto_skcipher_free_instance(struct crypto_instance * inst)705 static void crypto_skcipher_free_instance(struct crypto_instance *inst)
706 {
707 	struct skcipher_instance *skcipher =
708 		container_of(inst, struct skcipher_instance, s.base);
709 
710 	skcipher->free(skcipher);
711 }
712 
713 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
714 	__maybe_unused;
crypto_skcipher_show(struct seq_file * m,struct crypto_alg * alg)715 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
716 {
717 	struct skcipher_alg *skcipher = __crypto_skcipher_alg(alg);
718 
719 	seq_printf(m, "type         : skcipher\n");
720 	seq_printf(m, "async        : %s\n",
721 		   alg->cra_flags & CRYPTO_ALG_ASYNC ?  "yes" : "no");
722 	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
723 	seq_printf(m, "min keysize  : %u\n", skcipher->min_keysize);
724 	seq_printf(m, "max keysize  : %u\n", skcipher->max_keysize);
725 	seq_printf(m, "ivsize       : %u\n", skcipher->ivsize);
726 	seq_printf(m, "chunksize    : %u\n", skcipher->chunksize);
727 	seq_printf(m, "walksize     : %u\n", skcipher->walksize);
728 }
729 
crypto_skcipher_report(struct sk_buff * skb,struct crypto_alg * alg)730 static int __maybe_unused crypto_skcipher_report(
731 	struct sk_buff *skb, struct crypto_alg *alg)
732 {
733 	struct skcipher_alg *skcipher = __crypto_skcipher_alg(alg);
734 	struct crypto_report_blkcipher rblkcipher;
735 
736 	memset(&rblkcipher, 0, sizeof(rblkcipher));
737 
738 	strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
739 	strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
740 
741 	rblkcipher.blocksize = alg->cra_blocksize;
742 	rblkcipher.min_keysize = skcipher->min_keysize;
743 	rblkcipher.max_keysize = skcipher->max_keysize;
744 	rblkcipher.ivsize = skcipher->ivsize;
745 
746 	return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
747 		       sizeof(rblkcipher), &rblkcipher);
748 }
749 
crypto_skcipher_report_stat(struct sk_buff * skb,struct crypto_alg * alg)750 static int __maybe_unused crypto_skcipher_report_stat(
751 	struct sk_buff *skb, struct crypto_alg *alg)
752 {
753 	struct skcipher_alg *skcipher = __crypto_skcipher_alg(alg);
754 	struct crypto_istat_cipher *istat;
755 	struct crypto_stat_cipher rcipher;
756 
757 	istat = skcipher_get_stat(skcipher);
758 
759 	memset(&rcipher, 0, sizeof(rcipher));
760 
761 	strscpy(rcipher.type, "cipher", sizeof(rcipher.type));
762 
763 	rcipher.stat_encrypt_cnt = atomic64_read(&istat->encrypt_cnt);
764 	rcipher.stat_encrypt_tlen = atomic64_read(&istat->encrypt_tlen);
765 	rcipher.stat_decrypt_cnt =  atomic64_read(&istat->decrypt_cnt);
766 	rcipher.stat_decrypt_tlen = atomic64_read(&istat->decrypt_tlen);
767 	rcipher.stat_err_cnt =  atomic64_read(&istat->err_cnt);
768 
769 	return nla_put(skb, CRYPTOCFGA_STAT_CIPHER, sizeof(rcipher), &rcipher);
770 }
771 
772 static const struct crypto_type crypto_skcipher_type = {
773 	.extsize = crypto_alg_extsize,
774 	.init_tfm = crypto_skcipher_init_tfm,
775 	.free = crypto_skcipher_free_instance,
776 #ifdef CONFIG_PROC_FS
777 	.show = crypto_skcipher_show,
778 #endif
779 #if IS_ENABLED(CONFIG_CRYPTO_USER)
780 	.report = crypto_skcipher_report,
781 #endif
782 #ifdef CONFIG_CRYPTO_STATS
783 	.report_stat = crypto_skcipher_report_stat,
784 #endif
785 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
786 	.maskset = CRYPTO_ALG_TYPE_MASK,
787 	.type = CRYPTO_ALG_TYPE_SKCIPHER,
788 	.tfmsize = offsetof(struct crypto_skcipher, base),
789 };
790 
crypto_grab_skcipher(struct crypto_skcipher_spawn * spawn,struct crypto_instance * inst,const char * name,u32 type,u32 mask)791 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
792 			 struct crypto_instance *inst,
793 			 const char *name, u32 type, u32 mask)
794 {
795 	spawn->base.frontend = &crypto_skcipher_type;
796 	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
797 }
798 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
799 
crypto_alloc_skcipher(const char * alg_name,u32 type,u32 mask)800 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
801 					      u32 type, u32 mask)
802 {
803 	return crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
804 }
805 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
806 
crypto_alloc_sync_skcipher(const char * alg_name,u32 type,u32 mask)807 struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(
808 				const char *alg_name, u32 type, u32 mask)
809 {
810 	struct crypto_skcipher *tfm;
811 
812 	/* Only sync algorithms allowed. */
813 	mask |= CRYPTO_ALG_ASYNC | CRYPTO_ALG_SKCIPHER_REQSIZE_LARGE;
814 
815 	tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
816 
817 	/*
818 	 * Make sure we do not allocate something that might get used with
819 	 * an on-stack request: check the request size.
820 	 */
821 	if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) >
822 				    MAX_SYNC_SKCIPHER_REQSIZE)) {
823 		crypto_free_skcipher(tfm);
824 		return ERR_PTR(-EINVAL);
825 	}
826 
827 	return (struct crypto_sync_skcipher *)tfm;
828 }
829 EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher);
830 
crypto_has_skcipher(const char * alg_name,u32 type,u32 mask)831 int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask)
832 {
833 	return crypto_type_has_alg(alg_name, &crypto_skcipher_type, type, mask);
834 }
835 EXPORT_SYMBOL_GPL(crypto_has_skcipher);
836 
skcipher_prepare_alg(struct skcipher_alg * alg)837 static int skcipher_prepare_alg(struct skcipher_alg *alg)
838 {
839 	struct crypto_istat_cipher *istat = skcipher_get_stat(alg);
840 	struct crypto_alg *base = &alg->base;
841 
842 	if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
843 	    alg->walksize > PAGE_SIZE / 8)
844 		return -EINVAL;
845 
846 	if (!alg->chunksize)
847 		alg->chunksize = base->cra_blocksize;
848 	if (!alg->walksize)
849 		alg->walksize = alg->chunksize;
850 
851 	base->cra_type = &crypto_skcipher_type;
852 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
853 	base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
854 
855 	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
856 		memset(istat, 0, sizeof(*istat));
857 
858 	return 0;
859 }
860 
crypto_register_skcipher(struct skcipher_alg * alg)861 int crypto_register_skcipher(struct skcipher_alg *alg)
862 {
863 	struct crypto_alg *base = &alg->base;
864 	int err;
865 
866 	err = skcipher_prepare_alg(alg);
867 	if (err)
868 		return err;
869 
870 	return crypto_register_alg(base);
871 }
872 EXPORT_SYMBOL_GPL(crypto_register_skcipher);
873 
crypto_unregister_skcipher(struct skcipher_alg * alg)874 void crypto_unregister_skcipher(struct skcipher_alg *alg)
875 {
876 	crypto_unregister_alg(&alg->base);
877 }
878 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
879 
crypto_register_skciphers(struct skcipher_alg * algs,int count)880 int crypto_register_skciphers(struct skcipher_alg *algs, int count)
881 {
882 	int i, ret;
883 
884 	for (i = 0; i < count; i++) {
885 		ret = crypto_register_skcipher(&algs[i]);
886 		if (ret)
887 			goto err;
888 	}
889 
890 	return 0;
891 
892 err:
893 	for (--i; i >= 0; --i)
894 		crypto_unregister_skcipher(&algs[i]);
895 
896 	return ret;
897 }
898 EXPORT_SYMBOL_GPL(crypto_register_skciphers);
899 
crypto_unregister_skciphers(struct skcipher_alg * algs,int count)900 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
901 {
902 	int i;
903 
904 	for (i = count - 1; i >= 0; --i)
905 		crypto_unregister_skcipher(&algs[i]);
906 }
907 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
908 
skcipher_register_instance(struct crypto_template * tmpl,struct skcipher_instance * inst)909 int skcipher_register_instance(struct crypto_template *tmpl,
910 			   struct skcipher_instance *inst)
911 {
912 	int err;
913 
914 	if (WARN_ON(!inst->free))
915 		return -EINVAL;
916 
917 	err = skcipher_prepare_alg(&inst->alg);
918 	if (err)
919 		return err;
920 
921 	return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
922 }
923 EXPORT_SYMBOL_GPL(skcipher_register_instance);
924 
skcipher_setkey_simple(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)925 static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key,
926 				  unsigned int keylen)
927 {
928 	struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
929 
930 	crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
931 	crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) &
932 				CRYPTO_TFM_REQ_MASK);
933 	return crypto_cipher_setkey(cipher, key, keylen);
934 }
935 
skcipher_init_tfm_simple(struct crypto_skcipher * tfm)936 static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm)
937 {
938 	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
939 	struct crypto_cipher_spawn *spawn = skcipher_instance_ctx(inst);
940 	struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
941 	struct crypto_cipher *cipher;
942 
943 	cipher = crypto_spawn_cipher(spawn);
944 	if (IS_ERR(cipher))
945 		return PTR_ERR(cipher);
946 
947 	ctx->cipher = cipher;
948 	return 0;
949 }
950 
skcipher_exit_tfm_simple(struct crypto_skcipher * tfm)951 static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm)
952 {
953 	struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
954 
955 	crypto_free_cipher(ctx->cipher);
956 }
957 
skcipher_free_instance_simple(struct skcipher_instance * inst)958 static void skcipher_free_instance_simple(struct skcipher_instance *inst)
959 {
960 	crypto_drop_cipher(skcipher_instance_ctx(inst));
961 	kfree(inst);
962 }
963 
964 /**
965  * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode
966  *
967  * Allocate an skcipher_instance for a simple block cipher mode of operation,
968  * e.g. cbc or ecb.  The instance context will have just a single crypto_spawn,
969  * that for the underlying cipher.  The {min,max}_keysize, ivsize, blocksize,
970  * alignmask, and priority are set from the underlying cipher but can be
971  * overridden if needed.  The tfm context defaults to skcipher_ctx_simple, and
972  * default ->setkey(), ->init(), and ->exit() methods are installed.
973  *
974  * @tmpl: the template being instantiated
975  * @tb: the template parameters
976  *
977  * Return: a pointer to the new instance, or an ERR_PTR().  The caller still
978  *	   needs to register the instance.
979  */
skcipher_alloc_instance_simple(struct crypto_template * tmpl,struct rtattr ** tb)980 struct skcipher_instance *skcipher_alloc_instance_simple(
981 	struct crypto_template *tmpl, struct rtattr **tb)
982 {
983 	u32 mask;
984 	struct skcipher_instance *inst;
985 	struct crypto_cipher_spawn *spawn;
986 	struct crypto_alg *cipher_alg;
987 	int err;
988 
989 	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
990 	if (err)
991 		return ERR_PTR(err);
992 
993 	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
994 	if (!inst)
995 		return ERR_PTR(-ENOMEM);
996 	spawn = skcipher_instance_ctx(inst);
997 
998 	err = crypto_grab_cipher(spawn, skcipher_crypto_instance(inst),
999 				 crypto_attr_alg_name(tb[1]), 0, mask);
1000 	if (err)
1001 		goto err_free_inst;
1002 	cipher_alg = crypto_spawn_cipher_alg(spawn);
1003 
1004 	err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name,
1005 				  cipher_alg);
1006 	if (err)
1007 		goto err_free_inst;
1008 
1009 	inst->free = skcipher_free_instance_simple;
1010 
1011 	/* Default algorithm properties, can be overridden */
1012 	inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize;
1013 	inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask;
1014 	inst->alg.base.cra_priority = cipher_alg->cra_priority;
1015 	inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
1016 	inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
1017 	inst->alg.ivsize = cipher_alg->cra_blocksize;
1018 
1019 	/* Use skcipher_ctx_simple by default, can be overridden */
1020 	inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple);
1021 	inst->alg.setkey = skcipher_setkey_simple;
1022 	inst->alg.init = skcipher_init_tfm_simple;
1023 	inst->alg.exit = skcipher_exit_tfm_simple;
1024 
1025 	return inst;
1026 
1027 err_free_inst:
1028 	skcipher_free_instance_simple(inst);
1029 	return ERR_PTR(err);
1030 }
1031 EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple);
1032 
1033 MODULE_LICENSE("GPL");
1034 MODULE_DESCRIPTION("Symmetric key cipher type");
1035 MODULE_IMPORT_NS(CRYPTO_INTERNAL);
1036