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