skcipher.c 31 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
/*
 * Symmetric key cipher operations.
 *
 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
 * multiple page boundaries by using temporary blocks.  In user context,
 * the kernel is given a chance to schedule us once per page.
 *
 * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

17
#include <crypto/internal/aead.h>
18
#include <crypto/internal/skcipher.h>
19
#include <crypto/scatterwalk.h>
20
#include <linux/bug.h>
21
#include <linux/cryptouser.h>
22
#include <linux/compiler.h>
23
#include <linux/list.h>
24
#include <linux/module.h>
25 26 27
#include <linux/rtnetlink.h>
#include <linux/seq_file.h>
#include <net/netlink.h>
28 29 30

#include "internal.h"

31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
enum {
	SKCIPHER_WALK_PHYS = 1 << 0,
	SKCIPHER_WALK_SLOW = 1 << 1,
	SKCIPHER_WALK_COPY = 1 << 2,
	SKCIPHER_WALK_DIFF = 1 << 3,
	SKCIPHER_WALK_SLEEP = 1 << 4,
};

struct skcipher_walk_buffer {
	struct list_head entry;
	struct scatter_walk dst;
	unsigned int len;
	u8 *data;
	u8 buffer[];
};

static int skcipher_walk_next(struct skcipher_walk *walk);

static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr)
{
	if (PageHighMem(scatterwalk_page(walk)))
		kunmap_atomic(vaddr);
}

static inline void *skcipher_map(struct scatter_walk *walk)
{
	struct page *page = scatterwalk_page(walk);

	return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) +
	       offset_in_page(walk->offset);
}

static inline void skcipher_map_src(struct skcipher_walk *walk)
{
	walk->src.virt.addr = skcipher_map(&walk->in);
}

static inline void skcipher_map_dst(struct skcipher_walk *walk)
{
	walk->dst.virt.addr = skcipher_map(&walk->out);
}

static inline void skcipher_unmap_src(struct skcipher_walk *walk)
{
	skcipher_unmap(&walk->in, walk->src.virt.addr);
}

static inline void skcipher_unmap_dst(struct skcipher_walk *walk)
{
	skcipher_unmap(&walk->out, walk->dst.virt.addr);
}

static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk)
{
	return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
}

/* Get a spot of the specified length that does not straddle a page.
 * The caller needs to ensure that there is enough space for this operation.
 */
static inline u8 *skcipher_get_spot(u8 *start, unsigned int len)
{
	u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);

	return max(start, end_page);
}

98
static void skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
99 100 101 102 103 104 105 106 107 108 109
{
	u8 *addr;

	addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
	addr = skcipher_get_spot(addr, bsize);
	scatterwalk_copychunks(addr, &walk->out, bsize,
			       (walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1);
}

int skcipher_walk_done(struct skcipher_walk *walk, int err)
{
110 111 112 113 114 115 116 117 118 119 120 121 122 123
	unsigned int n; /* bytes processed */
	bool more;

	if (unlikely(err < 0))
		goto finish;

	n = walk->nbytes - err;
	walk->total -= n;
	more = (walk->total != 0);

	if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
				    SKCIPHER_WALK_SLOW |
				    SKCIPHER_WALK_COPY |
				    SKCIPHER_WALK_DIFF)))) {
124 125 126 127 128 129 130 131 132 133 134
unmap_src:
		skcipher_unmap_src(walk);
	} else if (walk->flags & SKCIPHER_WALK_DIFF) {
		skcipher_unmap_dst(walk);
		goto unmap_src;
	} else if (walk->flags & SKCIPHER_WALK_COPY) {
		skcipher_map_dst(walk);
		memcpy(walk->dst.virt.addr, walk->page, n);
		skcipher_unmap_dst(walk);
	} else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
		if (WARN_ON(err)) {
135
			/* unexpected case; didn't process all bytes */
136
			err = -EINVAL;
137 138 139 140
			goto finish;
		}
		skcipher_done_slow(walk, n);
		goto already_advanced;
141 142 143 144
	}

	scatterwalk_advance(&walk->in, n);
	scatterwalk_advance(&walk->out, n);
145 146 147
already_advanced:
	scatterwalk_done(&walk->in, 0, more);
	scatterwalk_done(&walk->out, 1, more);
148

149
	if (more) {
150 151 152 153
		crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
			     CRYPTO_TFM_REQ_MAY_SLEEP : 0);
		return skcipher_walk_next(walk);
	}
154 155 156
	err = 0;
finish:
	walk->nbytes = 0;
157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189

	/* Short-circuit for the common/fast path. */
	if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
		goto out;

	if (walk->flags & SKCIPHER_WALK_PHYS)
		goto out;

	if (walk->iv != walk->oiv)
		memcpy(walk->oiv, walk->iv, walk->ivsize);
	if (walk->buffer != walk->page)
		kfree(walk->buffer);
	if (walk->page)
		free_page((unsigned long)walk->page);

out:
	return err;
}
EXPORT_SYMBOL_GPL(skcipher_walk_done);

void skcipher_walk_complete(struct skcipher_walk *walk, int err)
{
	struct skcipher_walk_buffer *p, *tmp;

	list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
		u8 *data;

		if (err)
			goto done;

		data = p->data;
		if (!data) {
			data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1);
190
			data = skcipher_get_spot(data, walk->stride);
191 192 193 194
		}

		scatterwalk_copychunks(data, &p->dst, p->len, 1);

195
		if (offset_in_page(p->data) + p->len + walk->stride >
196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230
		    PAGE_SIZE)
			free_page((unsigned long)p->data);

done:
		list_del(&p->entry);
		kfree(p);
	}

	if (!err && walk->iv != walk->oiv)
		memcpy(walk->oiv, walk->iv, walk->ivsize);
	if (walk->buffer != walk->page)
		kfree(walk->buffer);
	if (walk->page)
		free_page((unsigned long)walk->page);
}
EXPORT_SYMBOL_GPL(skcipher_walk_complete);

static void skcipher_queue_write(struct skcipher_walk *walk,
				 struct skcipher_walk_buffer *p)
{
	p->dst = walk->out;
	list_add_tail(&p->entry, &walk->buffers);
}

static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize)
{
	bool phys = walk->flags & SKCIPHER_WALK_PHYS;
	unsigned alignmask = walk->alignmask;
	struct skcipher_walk_buffer *p;
	unsigned a;
	unsigned n;
	u8 *buffer;
	void *v;

	if (!phys) {
231 232 233
		if (!walk->buffer)
			walk->buffer = walk->page;
		buffer = walk->buffer;
234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303
		if (buffer)
			goto ok;
	}

	/* Start with the minimum alignment of kmalloc. */
	a = crypto_tfm_ctx_alignment() - 1;
	n = bsize;

	if (phys) {
		/* Calculate the minimum alignment of p->buffer. */
		a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1;
		n += sizeof(*p);
	}

	/* Minimum size to align p->buffer by alignmask. */
	n += alignmask & ~a;

	/* Minimum size to ensure p->buffer does not straddle a page. */
	n += (bsize - 1) & ~(alignmask | a);

	v = kzalloc(n, skcipher_walk_gfp(walk));
	if (!v)
		return skcipher_walk_done(walk, -ENOMEM);

	if (phys) {
		p = v;
		p->len = bsize;
		skcipher_queue_write(walk, p);
		buffer = p->buffer;
	} else {
		walk->buffer = v;
		buffer = v;
	}

ok:
	walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1);
	walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize);
	walk->src.virt.addr = walk->dst.virt.addr;

	scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);

	walk->nbytes = bsize;
	walk->flags |= SKCIPHER_WALK_SLOW;

	return 0;
}

static int skcipher_next_copy(struct skcipher_walk *walk)
{
	struct skcipher_walk_buffer *p;
	u8 *tmp = walk->page;

	skcipher_map_src(walk);
	memcpy(tmp, walk->src.virt.addr, walk->nbytes);
	skcipher_unmap_src(walk);

	walk->src.virt.addr = tmp;
	walk->dst.virt.addr = tmp;

	if (!(walk->flags & SKCIPHER_WALK_PHYS))
		return 0;

	p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk));
	if (!p)
		return -ENOMEM;

	p->data = walk->page;
	p->len = walk->nbytes;
	skcipher_queue_write(walk, p);

304
	if (offset_in_page(walk->page) + walk->nbytes + walk->stride >
305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348
	    PAGE_SIZE)
		walk->page = NULL;
	else
		walk->page += walk->nbytes;

	return 0;
}

static int skcipher_next_fast(struct skcipher_walk *walk)
{
	unsigned long diff;

	walk->src.phys.page = scatterwalk_page(&walk->in);
	walk->src.phys.offset = offset_in_page(walk->in.offset);
	walk->dst.phys.page = scatterwalk_page(&walk->out);
	walk->dst.phys.offset = offset_in_page(walk->out.offset);

	if (walk->flags & SKCIPHER_WALK_PHYS)
		return 0;

	diff = walk->src.phys.offset - walk->dst.phys.offset;
	diff |= walk->src.virt.page - walk->dst.virt.page;

	skcipher_map_src(walk);
	walk->dst.virt.addr = walk->src.virt.addr;

	if (diff) {
		walk->flags |= SKCIPHER_WALK_DIFF;
		skcipher_map_dst(walk);
	}

	return 0;
}

static int skcipher_walk_next(struct skcipher_walk *walk)
{
	unsigned int bsize;
	unsigned int n;
	int err;

	walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY |
			 SKCIPHER_WALK_DIFF);

	n = walk->total;
349
	bsize = min(walk->stride, max(n, walk->blocksize));
350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396
	n = scatterwalk_clamp(&walk->in, n);
	n = scatterwalk_clamp(&walk->out, n);

	if (unlikely(n < bsize)) {
		if (unlikely(walk->total < walk->blocksize))
			return skcipher_walk_done(walk, -EINVAL);

slow_path:
		err = skcipher_next_slow(walk, bsize);
		goto set_phys_lowmem;
	}

	if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) {
		if (!walk->page) {
			gfp_t gfp = skcipher_walk_gfp(walk);

			walk->page = (void *)__get_free_page(gfp);
			if (!walk->page)
				goto slow_path;
		}

		walk->nbytes = min_t(unsigned, n,
				     PAGE_SIZE - offset_in_page(walk->page));
		walk->flags |= SKCIPHER_WALK_COPY;
		err = skcipher_next_copy(walk);
		goto set_phys_lowmem;
	}

	walk->nbytes = n;

	return skcipher_next_fast(walk);

set_phys_lowmem:
	if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) {
		walk->src.phys.page = virt_to_page(walk->src.virt.addr);
		walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
		walk->src.phys.offset &= PAGE_SIZE - 1;
		walk->dst.phys.offset &= PAGE_SIZE - 1;
	}
	return err;
}

static int skcipher_copy_iv(struct skcipher_walk *walk)
{
	unsigned a = crypto_tfm_ctx_alignment() - 1;
	unsigned alignmask = walk->alignmask;
	unsigned ivsize = walk->ivsize;
397
	unsigned bs = walk->stride;
398 399 400 401
	unsigned aligned_bs;
	unsigned size;
	u8 *iv;

402
	aligned_bs = ALIGN(bs, alignmask + 1);
403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448

	/* Minimum size to align buffer by alignmask. */
	size = alignmask & ~a;

	if (walk->flags & SKCIPHER_WALK_PHYS)
		size += ivsize;
	else {
		size += aligned_bs + ivsize;

		/* Minimum size to ensure buffer does not straddle a page. */
		size += (bs - 1) & ~(alignmask | a);
	}

	walk->buffer = kmalloc(size, skcipher_walk_gfp(walk));
	if (!walk->buffer)
		return -ENOMEM;

	iv = PTR_ALIGN(walk->buffer, alignmask + 1);
	iv = skcipher_get_spot(iv, bs) + aligned_bs;

	walk->iv = memcpy(iv, walk->iv, walk->ivsize);
	return 0;
}

static int skcipher_walk_first(struct skcipher_walk *walk)
{
	if (WARN_ON_ONCE(in_irq()))
		return -EDEADLK;

	walk->buffer = NULL;
	if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
		int err = skcipher_copy_iv(walk);
		if (err)
			return err;
	}

	walk->page = NULL;

	return skcipher_walk_next(walk);
}

static int skcipher_walk_skcipher(struct skcipher_walk *walk,
				  struct skcipher_request *req)
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

449 450
	walk->total = req->cryptlen;
	walk->nbytes = 0;
451 452
	walk->iv = req->iv;
	walk->oiv = req->iv;
453 454 455 456

	if (unlikely(!walk->total))
		return 0;

457 458 459 460 461 462 463 464
	scatterwalk_start(&walk->in, req->src);
	scatterwalk_start(&walk->out, req->dst);

	walk->flags &= ~SKCIPHER_WALK_SLEEP;
	walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
		       SKCIPHER_WALK_SLEEP : 0;

	walk->blocksize = crypto_skcipher_blocksize(tfm);
465
	walk->stride = crypto_skcipher_walksize(tfm);
466 467 468 469 470 471 472 473 474 475 476
	walk->ivsize = crypto_skcipher_ivsize(tfm);
	walk->alignmask = crypto_skcipher_alignmask(tfm);

	return skcipher_walk_first(walk);
}

int skcipher_walk_virt(struct skcipher_walk *walk,
		       struct skcipher_request *req, bool atomic)
{
	int err;

477 478
	might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);

479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505
	walk->flags &= ~SKCIPHER_WALK_PHYS;

	err = skcipher_walk_skcipher(walk, req);

	walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0;

	return err;
}
EXPORT_SYMBOL_GPL(skcipher_walk_virt);

void skcipher_walk_atomise(struct skcipher_walk *walk)
{
	walk->flags &= ~SKCIPHER_WALK_SLEEP;
}
EXPORT_SYMBOL_GPL(skcipher_walk_atomise);

int skcipher_walk_async(struct skcipher_walk *walk,
			struct skcipher_request *req)
{
	walk->flags |= SKCIPHER_WALK_PHYS;

	INIT_LIST_HEAD(&walk->buffers);

	return skcipher_walk_skcipher(walk, req);
}
EXPORT_SYMBOL_GPL(skcipher_walk_async);

506 507
static int skcipher_walk_aead_common(struct skcipher_walk *walk,
				     struct aead_request *req, bool atomic)
508 509 510 511
{
	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
	int err;

512
	walk->nbytes = 0;
513 514
	walk->iv = req->iv;
	walk->oiv = req->iv;
515 516 517 518

	if (unlikely(!walk->total))
		return 0;

519 520
	walk->flags &= ~SKCIPHER_WALK_PHYS;

521 522 523 524 525 526
	scatterwalk_start(&walk->in, req->src);
	scatterwalk_start(&walk->out, req->dst);

	scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
	scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);

527 528 529
	scatterwalk_done(&walk->in, 0, walk->total);
	scatterwalk_done(&walk->out, 0, walk->total);

530 531 532 533 534 535
	if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
		walk->flags |= SKCIPHER_WALK_SLEEP;
	else
		walk->flags &= ~SKCIPHER_WALK_SLEEP;

	walk->blocksize = crypto_aead_blocksize(tfm);
536
	walk->stride = crypto_aead_chunksize(tfm);
537 538 539 540 541 542 543 544 545 546
	walk->ivsize = crypto_aead_ivsize(tfm);
	walk->alignmask = crypto_aead_alignmask(tfm);

	err = skcipher_walk_first(walk);

	if (atomic)
		walk->flags &= ~SKCIPHER_WALK_SLEEP;

	return err;
}
547 548 549 550 551 552 553 554

int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req,
		       bool atomic)
{
	walk->total = req->cryptlen;

	return skcipher_walk_aead_common(walk, req, atomic);
}
555 556
EXPORT_SYMBOL_GPL(skcipher_walk_aead);

557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576
int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
			       struct aead_request *req, bool atomic)
{
	walk->total = req->cryptlen;

	return skcipher_walk_aead_common(walk, req, atomic);
}
EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);

int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
			       struct aead_request *req, bool atomic)
{
	struct crypto_aead *tfm = crypto_aead_reqtfm(req);

	walk->total = req->cryptlen - crypto_aead_authsize(tfm);

	return skcipher_walk_aead_common(walk, req, atomic);
}
EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);

577 578 579 580 581
static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg)
{
	if (alg->cra_type == &crypto_blkcipher_type)
		return sizeof(struct crypto_blkcipher *);

582
	if (alg->cra_type == &crypto_ablkcipher_type)
583
		return sizeof(struct crypto_ablkcipher *);
584

585
	return crypto_alg_extsize(alg);
586 587 588 589 590 591 592 593 594 595 596 597 598 599 600
}

static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm,
				     const u8 *key, unsigned int keylen)
{
	struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
	struct crypto_blkcipher *blkcipher = *ctx;
	int err;

	crypto_blkcipher_clear_flags(blkcipher, ~0);
	crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) &
					      CRYPTO_TFM_REQ_MASK);
	err = crypto_blkcipher_setkey(blkcipher, key, keylen);
	crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) &
				       CRYPTO_TFM_RES_MASK);
601 602
	if (err)
		return err;
603

604 605
	crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
	return 0;
606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650
}

static int skcipher_crypt_blkcipher(struct skcipher_request *req,
				    int (*crypt)(struct blkcipher_desc *,
						 struct scatterlist *,
						 struct scatterlist *,
						 unsigned int))
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
	struct blkcipher_desc desc = {
		.tfm = *ctx,
		.info = req->iv,
		.flags = req->base.flags,
	};


	return crypt(&desc, req->dst, req->src, req->cryptlen);
}

static int skcipher_encrypt_blkcipher(struct skcipher_request *req)
{
	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
	struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;

	return skcipher_crypt_blkcipher(req, alg->encrypt);
}

static int skcipher_decrypt_blkcipher(struct skcipher_request *req)
{
	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
	struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;

	return skcipher_crypt_blkcipher(req, alg->decrypt);
}

static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
{
	struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);

	crypto_free_blkcipher(*ctx);
}

651
static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677
{
	struct crypto_alg *calg = tfm->__crt_alg;
	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
	struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
	struct crypto_blkcipher *blkcipher;
	struct crypto_tfm *btfm;

	if (!crypto_mod_get(calg))
		return -EAGAIN;

	btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER,
					CRYPTO_ALG_TYPE_MASK);
	if (IS_ERR(btfm)) {
		crypto_mod_put(calg);
		return PTR_ERR(btfm);
	}

	blkcipher = __crypto_blkcipher_cast(btfm);
	*ctx = blkcipher;
	tfm->exit = crypto_exit_skcipher_ops_blkcipher;

	skcipher->setkey = skcipher_setkey_blkcipher;
	skcipher->encrypt = skcipher_encrypt_blkcipher;
	skcipher->decrypt = skcipher_decrypt_blkcipher;

	skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher);
678
	skcipher->keysize = calg->cra_blkcipher.max_keysize;
679

680 681 682
	if (skcipher->keysize)
		crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY);

683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700
	return 0;
}

static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm,
				      const u8 *key, unsigned int keylen)
{
	struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
	struct crypto_ablkcipher *ablkcipher = *ctx;
	int err;

	crypto_ablkcipher_clear_flags(ablkcipher, ~0);
	crypto_ablkcipher_set_flags(ablkcipher,
				    crypto_skcipher_get_flags(tfm) &
				    CRYPTO_TFM_REQ_MASK);
	err = crypto_ablkcipher_setkey(ablkcipher, key, keylen);
	crypto_skcipher_set_flags(tfm,
				  crypto_ablkcipher_get_flags(ablkcipher) &
				  CRYPTO_TFM_RES_MASK);
701 702
	if (err)
		return err;
703

704 705
	crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
	return 0;
706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748
}

static int skcipher_crypt_ablkcipher(struct skcipher_request *req,
				     int (*crypt)(struct ablkcipher_request *))
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
	struct ablkcipher_request *subreq = skcipher_request_ctx(req);

	ablkcipher_request_set_tfm(subreq, *ctx);
	ablkcipher_request_set_callback(subreq, skcipher_request_flags(req),
					req->base.complete, req->base.data);
	ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
				     req->iv);

	return crypt(subreq);
}

static int skcipher_encrypt_ablkcipher(struct skcipher_request *req)
{
	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
	struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;

	return skcipher_crypt_ablkcipher(req, alg->encrypt);
}

static int skcipher_decrypt_ablkcipher(struct skcipher_request *req)
{
	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
	struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;

	return skcipher_crypt_ablkcipher(req, alg->decrypt);
}

static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
{
	struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);

	crypto_free_ablkcipher(*ctx);
}

749
static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776
{
	struct crypto_alg *calg = tfm->__crt_alg;
	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
	struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
	struct crypto_ablkcipher *ablkcipher;
	struct crypto_tfm *abtfm;

	if (!crypto_mod_get(calg))
		return -EAGAIN;

	abtfm = __crypto_alloc_tfm(calg, 0, 0);
	if (IS_ERR(abtfm)) {
		crypto_mod_put(calg);
		return PTR_ERR(abtfm);
	}

	ablkcipher = __crypto_ablkcipher_cast(abtfm);
	*ctx = ablkcipher;
	tfm->exit = crypto_exit_skcipher_ops_ablkcipher;

	skcipher->setkey = skcipher_setkey_ablkcipher;
	skcipher->encrypt = skcipher_encrypt_ablkcipher;
	skcipher->decrypt = skcipher_decrypt_ablkcipher;

	skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher);
	skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) +
			    sizeof(struct ablkcipher_request);
777
	skcipher->keysize = calg->cra_ablkcipher.max_keysize;
778

779 780 781
	if (skcipher->keysize)
		crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY);

782 783 784
	return 0;
}

785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810
static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
				     const u8 *key, unsigned int keylen)
{
	unsigned long alignmask = crypto_skcipher_alignmask(tfm);
	struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
	u8 *buffer, *alignbuffer;
	unsigned long absize;
	int ret;

	absize = keylen + alignmask;
	buffer = kmalloc(absize, GFP_ATOMIC);
	if (!buffer)
		return -ENOMEM;

	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
	memcpy(alignbuffer, key, keylen);
	ret = cipher->setkey(tfm, alignbuffer, keylen);
	kzfree(buffer);
	return ret;
}

static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
			   unsigned int keylen)
{
	struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
	unsigned long alignmask = crypto_skcipher_alignmask(tfm);
811
	int err;
812 813 814 815 816 817 818

	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
		return -EINVAL;
	}

	if ((unsigned long)key & alignmask)
819 820 821 822 823 824
		err = skcipher_setkey_unaligned(tfm, key, keylen);
	else
		err = cipher->setkey(tfm, key, keylen);

	if (err)
		return err;
825

826 827
	crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
	return 0;
828 829
}

830 831 832 833 834 835 836 837
static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
{
	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
	struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);

	alg->exit(skcipher);
}

838 839
static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
{
840 841 842
	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
	struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);

843 844 845
	if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type)
		return crypto_init_skcipher_ops_blkcipher(tfm);

846
	if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type)
847 848
		return crypto_init_skcipher_ops_ablkcipher(tfm);

849
	skcipher->setkey = skcipher_setkey;
850 851 852 853 854
	skcipher->encrypt = alg->encrypt;
	skcipher->decrypt = alg->decrypt;
	skcipher->ivsize = alg->ivsize;
	skcipher->keysize = alg->max_keysize;

855 856 857
	if (skcipher->keysize)
		crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY);

858 859
	if (alg->exit)
		skcipher->base.exit = crypto_skcipher_exit_tfm;
860

861 862 863 864 865 866 867 868 869 870 871 872 873 874 875
	if (alg->init)
		return alg->init(skcipher);

	return 0;
}

static void crypto_skcipher_free_instance(struct crypto_instance *inst)
{
	struct skcipher_instance *skcipher =
		container_of(inst, struct skcipher_instance, s.base);

	skcipher->free(skcipher);
}

static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
876
	__maybe_unused;
877 878 879 880 881 882 883 884 885 886 887 888 889
static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
	struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
						     base);

	seq_printf(m, "type         : skcipher\n");
	seq_printf(m, "async        : %s\n",
		   alg->cra_flags & CRYPTO_ALG_ASYNC ?  "yes" : "no");
	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
	seq_printf(m, "min keysize  : %u\n", skcipher->min_keysize);
	seq_printf(m, "max keysize  : %u\n", skcipher->max_keysize);
	seq_printf(m, "ivsize       : %u\n", skcipher->ivsize);
	seq_printf(m, "chunksize    : %u\n", skcipher->chunksize);
890
	seq_printf(m, "walksize     : %u\n", skcipher->walksize);
891 892
}

893 894 895 896 897 898 899
#ifdef CONFIG_NET
static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	struct crypto_report_blkcipher rblkcipher;
	struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
						     base);

900 901 902 903
	memset(&rblkcipher, 0, sizeof(rblkcipher));

	strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
	strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
904 905 906 907 908 909

	rblkcipher.blocksize = alg->cra_blocksize;
	rblkcipher.min_keysize = skcipher->min_keysize;
	rblkcipher.max_keysize = skcipher->max_keysize;
	rblkcipher.ivsize = skcipher->ivsize;

910 911
	return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
		       sizeof(rblkcipher), &rblkcipher);
912 913 914 915 916 917 918 919
}
#else
static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	return -ENOSYS;
}
#endif

920 921 922
static const struct crypto_type crypto_skcipher_type2 = {
	.extsize = crypto_skcipher_extsize,
	.init_tfm = crypto_skcipher_init_tfm,
923 924 925 926 927
	.free = crypto_skcipher_free_instance,
#ifdef CONFIG_PROC_FS
	.show = crypto_skcipher_show,
#endif
	.report = crypto_skcipher_report,
928 929
	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
	.maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK,
930
	.type = CRYPTO_ALG_TYPE_SKCIPHER,
931 932 933
	.tfmsize = offsetof(struct crypto_skcipher, base),
};

934
int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
935 936 937 938 939
			  const char *name, u32 type, u32 mask)
{
	spawn->base.frontend = &crypto_skcipher_type2;
	return crypto_grab_spawn(&spawn->base, name, type, mask);
}
940
EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
941

942 943 944 945 946 947 948
struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
					      u32 type, u32 mask)
{
	return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);

949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972
struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(
				const char *alg_name, u32 type, u32 mask)
{
	struct crypto_skcipher *tfm;

	/* Only sync algorithms allowed. */
	mask |= CRYPTO_ALG_ASYNC;

	tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask);

	/*
	 * Make sure we do not allocate something that might get used with
	 * an on-stack request: check the request size.
	 */
	if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) >
				    MAX_SYNC_SKCIPHER_REQSIZE)) {
		crypto_free_skcipher(tfm);
		return ERR_PTR(-EINVAL);
	}

	return (struct crypto_sync_skcipher *)tfm;
}
EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher);

973 974 975 976 977 978 979 980 981 982 983
int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask)
{
	return crypto_type_has_alg(alg_name, &crypto_skcipher_type2,
				   type, mask);
}
EXPORT_SYMBOL_GPL(crypto_has_skcipher2);

static int skcipher_prepare_alg(struct skcipher_alg *alg)
{
	struct crypto_alg *base = &alg->base;

984 985
	if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
	    alg->walksize > PAGE_SIZE / 8)
986 987 988 989
		return -EINVAL;

	if (!alg->chunksize)
		alg->chunksize = base->cra_blocksize;
990 991
	if (!alg->walksize)
		alg->walksize = alg->chunksize;
992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060

	base->cra_type = &crypto_skcipher_type2;
	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
	base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;

	return 0;
}

int crypto_register_skcipher(struct skcipher_alg *alg)
{
	struct crypto_alg *base = &alg->base;
	int err;

	err = skcipher_prepare_alg(alg);
	if (err)
		return err;

	return crypto_register_alg(base);
}
EXPORT_SYMBOL_GPL(crypto_register_skcipher);

void crypto_unregister_skcipher(struct skcipher_alg *alg)
{
	crypto_unregister_alg(&alg->base);
}
EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);

int crypto_register_skciphers(struct skcipher_alg *algs, int count)
{
	int i, ret;

	for (i = 0; i < count; i++) {
		ret = crypto_register_skcipher(&algs[i]);
		if (ret)
			goto err;
	}

	return 0;

err:
	for (--i; i >= 0; --i)
		crypto_unregister_skcipher(&algs[i]);

	return ret;
}
EXPORT_SYMBOL_GPL(crypto_register_skciphers);

void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
{
	int i;

	for (i = count - 1; i >= 0; --i)
		crypto_unregister_skcipher(&algs[i]);
}
EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);

int skcipher_register_instance(struct crypto_template *tmpl,
			   struct skcipher_instance *inst)
{
	int err;

	err = skcipher_prepare_alg(&inst->alg);
	if (err)
		return err;

	return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
}
EXPORT_SYMBOL_GPL(skcipher_register_instance);

1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191
static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key,
				  unsigned int keylen)
{
	struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
	int err;

	crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
	crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) &
				CRYPTO_TFM_REQ_MASK);
	err = crypto_cipher_setkey(cipher, key, keylen);
	crypto_skcipher_set_flags(tfm, crypto_cipher_get_flags(cipher) &
				  CRYPTO_TFM_RES_MASK);
	return err;
}

static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm)
{
	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
	struct crypto_spawn *spawn = skcipher_instance_ctx(inst);
	struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
	struct crypto_cipher *cipher;

	cipher = crypto_spawn_cipher(spawn);
	if (IS_ERR(cipher))
		return PTR_ERR(cipher);

	ctx->cipher = cipher;
	return 0;
}

static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm)
{
	struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);

	crypto_free_cipher(ctx->cipher);
}

static void skcipher_free_instance_simple(struct skcipher_instance *inst)
{
	crypto_drop_spawn(skcipher_instance_ctx(inst));
	kfree(inst);
}

/**
 * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode
 *
 * Allocate an skcipher_instance for a simple block cipher mode of operation,
 * e.g. cbc or ecb.  The instance context will have just a single crypto_spawn,
 * that for the underlying cipher.  The {min,max}_keysize, ivsize, blocksize,
 * alignmask, and priority are set from the underlying cipher but can be
 * overridden if needed.  The tfm context defaults to skcipher_ctx_simple, and
 * default ->setkey(), ->init(), and ->exit() methods are installed.
 *
 * @tmpl: the template being instantiated
 * @tb: the template parameters
 * @cipher_alg_ret: on success, a pointer to the underlying cipher algorithm is
 *		    returned here.  It must be dropped with crypto_mod_put().
 *
 * Return: a pointer to the new instance, or an ERR_PTR().  The caller still
 *	   needs to register the instance.
 */
struct skcipher_instance *
skcipher_alloc_instance_simple(struct crypto_template *tmpl, struct rtattr **tb,
			       struct crypto_alg **cipher_alg_ret)
{
	struct crypto_attr_type *algt;
	struct crypto_alg *cipher_alg;
	struct skcipher_instance *inst;
	struct crypto_spawn *spawn;
	u32 mask;
	int err;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return ERR_CAST(algt);

	if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
		return ERR_PTR(-EINVAL);

	mask = CRYPTO_ALG_TYPE_MASK |
		crypto_requires_off(algt->type, algt->mask,
				    CRYPTO_ALG_NEED_FALLBACK);

	cipher_alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, mask);
	if (IS_ERR(cipher_alg))
		return ERR_CAST(cipher_alg);

	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
	if (!inst) {
		err = -ENOMEM;
		goto err_put_cipher_alg;
	}
	spawn = skcipher_instance_ctx(inst);

	err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name,
				  cipher_alg);
	if (err)
		goto err_free_inst;

	err = crypto_init_spawn(spawn, cipher_alg,
				skcipher_crypto_instance(inst),
				CRYPTO_ALG_TYPE_MASK);
	if (err)
		goto err_free_inst;
	inst->free = skcipher_free_instance_simple;

	/* Default algorithm properties, can be overridden */
	inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize;
	inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask;
	inst->alg.base.cra_priority = cipher_alg->cra_priority;
	inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
	inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
	inst->alg.ivsize = cipher_alg->cra_blocksize;

	/* Use skcipher_ctx_simple by default, can be overridden */
	inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple);
	inst->alg.setkey = skcipher_setkey_simple;
	inst->alg.init = skcipher_init_tfm_simple;
	inst->alg.exit = skcipher_exit_tfm_simple;

	*cipher_alg_ret = cipher_alg;
	return inst;

err_free_inst:
	kfree(inst);
err_put_cipher_alg:
	crypto_mod_put(cipher_alg);
	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple);

1192 1193
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Symmetric key cipher type");