skcipher.c 26.5 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));
350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397
	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;
}
EXPORT_SYMBOL_GPL(skcipher_walk_next);

static int skcipher_copy_iv(struct skcipher_walk *walk)
{
	unsigned a = crypto_tfm_ctx_alignment() - 1;
	unsigned alignmask = walk->alignmask;
	unsigned ivsize = walk->ivsize;
398
	unsigned bs = walk->stride;
399 400 401 402
	unsigned aligned_bs;
	unsigned size;
	u8 *iv;

403
	aligned_bs = ALIGN(bs, alignmask + 1);
404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450

	/* 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;
	walk->nbytes = walk->total;

	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);

451 452
	walk->total = req->cryptlen;
	walk->nbytes = 0;
453 454
	walk->iv = req->iv;
	walk->oiv = req->iv;
455 456 457 458

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

459 460 461 462 463 464 465 466
	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);
467
	walk->stride = crypto_skcipher_walksize(tfm);
468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505
	walk->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;

	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 *);

582 583 584
	if (alg->cra_type == &crypto_ablkcipher_type ||
	    alg->cra_type == &crypto_givcipher_type)
		return sizeof(struct crypto_ablkcipher *);
585

586
	return crypto_alg_extsize(alg);
587 588 589 590 591 592 593 594 595 596 597 598 599 600 601
}

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);
602 603
	if (err)
		return err;
604

605 606
	crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
	return 0;
607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651
}

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);
}

652
static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678
{
	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);
679
	skcipher->keysize = calg->cra_blkcipher.max_keysize;
680

681 682 683
	if (skcipher->keysize)
		crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY);

684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701
	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);
702 703
	if (err)
		return err;
704

705 706
	crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
	return 0;
707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749
}

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);
}

750
static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777
{
	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);
778
	skcipher->keysize = calg->cra_ablkcipher.max_keysize;
779

780 781 782
	if (skcipher->keysize)
		crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY);

783 784 785
	return 0;
}

786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811
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);
812
	int err;
813 814 815 816 817 818 819

	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)
820 821 822 823 824 825
		err = skcipher_setkey_unaligned(tfm, key, keylen);
	else
		err = cipher->setkey(tfm, key, keylen);

	if (err)
		return err;
826

827 828
	crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
	return 0;
829 830
}

831 832 833 834 835 836 837 838
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);
}

839 840
static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
{
841 842 843
	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
	struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);

844 845 846
	if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type)
		return crypto_init_skcipher_ops_blkcipher(tfm);

847 848 849 850
	if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type ||
	    tfm->__crt_alg->cra_type == &crypto_givcipher_type)
		return crypto_init_skcipher_ops_ablkcipher(tfm);

851
	skcipher->setkey = skcipher_setkey;
852 853 854 855 856
	skcipher->encrypt = alg->encrypt;
	skcipher->decrypt = alg->decrypt;
	skcipher->ivsize = alg->ivsize;
	skcipher->keysize = alg->max_keysize;

857 858 859
	if (skcipher->keysize)
		crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY);

860 861
	if (alg->exit)
		skcipher->base.exit = crypto_skcipher_exit_tfm;
862

863 864 865 866 867 868 869 870 871 872 873 874 875 876 877
	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)
878
	__maybe_unused;
879 880 881 882 883 884 885 886 887 888 889 890 891
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);
892
	seq_printf(m, "walksize     : %u\n", skcipher->walksize);
893 894
}

895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924
#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);

	strncpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
	strncpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));

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

	if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
		    sizeof(struct crypto_report_blkcipher), &rblkcipher))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -EMSGSIZE;
}
#else
static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	return -ENOSYS;
}
#endif

925 926 927
static const struct crypto_type crypto_skcipher_type2 = {
	.extsize = crypto_skcipher_extsize,
	.init_tfm = crypto_skcipher_init_tfm,
928 929 930 931 932
	.free = crypto_skcipher_free_instance,
#ifdef CONFIG_PROC_FS
	.show = crypto_skcipher_show,
#endif
	.report = crypto_skcipher_report,
933 934
	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
	.maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK,
935
	.type = CRYPTO_ALG_TYPE_SKCIPHER,
936 937 938
	.tfmsize = offsetof(struct crypto_skcipher, base),
};

939
int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
940 941 942 943 944
			  const char *name, u32 type, u32 mask)
{
	spawn->base.frontend = &crypto_skcipher_type2;
	return crypto_grab_spawn(&spawn->base, name, type, mask);
}
945
EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
946

947 948 949 950 951 952 953
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);

954 955 956 957 958 959 960 961 962 963 964
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;

965 966
	if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
	    alg->walksize > PAGE_SIZE / 8)
967 968 969 970
		return -EINVAL;

	if (!alg->chunksize)
		alg->chunksize = base->cra_blocksize;
971 972
	if (!alg->walksize)
		alg->walksize = alg->chunksize;
973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 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

	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);

1042 1043
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Symmetric key cipher type");